1 00:00:04,710 --> 00:00:02,310 drawer barnatan is a professor of pure 2 00:00:06,869 --> 00:00:04,720 mathematics at the university of toronto 3 00:00:09,030 --> 00:00:06,879 previously specializing in not theory 4 00:00:11,430 --> 00:00:09,040 and more recently specializing in finite 5 00:00:13,030 --> 00:00:11,440 type invariants and kavanaugh homology 6 00:00:15,270 --> 00:00:13,040 we touch on quantum field theory's 7 00:00:17,510 --> 00:00:15,280 connection to not theory how to learn 8 00:00:19,990 --> 00:00:17,520 mathematics in general we also touch on 9 00:00:22,390 --> 00:00:20,000 ed witton as jorah barnatan's advisor 10 00:00:23,990 --> 00:00:22,400 for his phd was edwitten and drawer 11 00:00:26,790 --> 00:00:24,000 gives some anecdotes about eric 12 00:00:29,509 --> 00:00:26,800 weinstein as while eric was pursuing his 13 00:00:31,830 --> 00:00:29,519 phd drawer served as an informal advisor 14 00:00:33,750 --> 00:00:31,840 to eric at harvard professor barnatan 15 00:00:35,270 --> 00:00:33,760 taught a course in linear algebra that i 16 00:00:37,510 --> 00:00:35,280 took while i was at the university of 17 00:00:39,350 --> 00:00:37,520 toronto although i was a terrible 18 00:00:41,510 --> 00:00:39,360 student and i regret that i skipped the 19 00:00:43,910 --> 00:00:41,520 majority of his classes because he had 20 00:00:45,910 --> 00:00:43,920 an exceedingly intuitive approach for 21 00:00:47,990 --> 00:00:45,920 example there are vector space axioms 22 00:00:49,510 --> 00:00:48,000 can i i do and they seem extremely 23 00:00:51,110 --> 00:00:49,520 disconnected from any reason or 24 00:00:52,869 --> 00:00:51,120 motivation so what the professor would 25 00:00:54,549 --> 00:00:52,879 do would be before introducing a 26 00:00:56,709 --> 00:00:54,559 particular abstraction he would say 27 00:00:58,470 --> 00:00:56,719 imagine seven times a vector instead of 28 00:01:00,549 --> 00:00:58,480 imagine a times a vector and then 29 00:01:02,549 --> 00:01:00,559 generalize it which gave the abstraction 30 00:01:04,789 --> 00:01:02,559 some concreteness for those new to this 31 00:01:06,710 --> 00:01:04,799 channel my name is kurt jaimungal i'm a 32 00:01:09,109 --> 00:01:06,720 filmmaker with a background in math and 33 00:01:11,270 --> 00:01:09,119 physics dedicated to explicating what 34 00:01:13,190 --> 00:01:11,280 are called theories of everything from a 35 00:01:14,630 --> 00:01:13,200 mathematical physics perspective but 36 00:01:16,310 --> 00:01:14,640 also the possible connections 37 00:01:18,630 --> 00:01:16,320 consciousness has to the fundamental 38 00:01:20,550 --> 00:01:18,640 laws of nature provided these laws exist 39 00:01:22,630 --> 00:01:20,560 at all and are knowable to us this 40 00:01:24,310 --> 00:01:22,640 particular podcast isn't one to be 41 00:01:25,990 --> 00:01:24,320 listened to or at least you can but 42 00:01:27,590 --> 00:01:26,000 you're going to be frustrated as what's 43 00:01:29,429 --> 00:01:27,600 being referred to are one-dimensional 44 00:01:31,830 --> 00:01:29,439 objects embedded in a three-dimensional 45 00:01:33,510 --> 00:01:31,840 space in some configuration and the 46 00:01:35,590 --> 00:01:33,520 verbal description leaves much to be 47 00:01:37,830 --> 00:01:35,600 desired if you're listening to this on 48 00:01:39,270 --> 00:01:37,840 spotify or itunes i recommend you click 49 00:01:41,830 --> 00:01:39,280 the link in the description and follow 50 00:01:43,749 --> 00:01:41,840 along you can also download a pdf of the 51 00:01:45,670 --> 00:01:43,759 written notes from this podcast in the 52 00:01:48,069 --> 00:01:45,680 description as well there are a couple 53 00:01:50,310 --> 00:01:48,079 sponsors of today's podcast the first is 54 00:01:52,469 --> 00:01:50,320 algo which is an end-to-end supply chain 55 00:01:54,149 --> 00:01:52,479 optimization software company with 56 00:01:56,310 --> 00:01:54,159 software that helps business users 57 00:01:58,550 --> 00:01:56,320 optimize sales and operations planning 58 00:02:00,630 --> 00:01:58,560 to avoid stockouts reduce returns and 59 00:02:02,870 --> 00:02:00,640 inventory write downs while reducing 60 00:02:05,510 --> 00:02:02,880 inventory investment it's a supply chain 61 00:02:07,749 --> 00:02:05,520 ai that drives smart roi headed by a 62 00:02:09,109 --> 00:02:07,759 bright individual named amjad hussein 63 00:02:11,589 --> 00:02:09,119 who's been a huge supporter of the 64 00:02:13,270 --> 00:02:11,599 podcast from his early days the second 65 00:02:15,430 --> 00:02:13,280 sponsor is brilliant brilliant 66 00:02:17,110 --> 00:02:15,440 illuminates the soul of mathematics 67 00:02:18,630 --> 00:02:17,120 science and engineering through 68 00:02:20,869 --> 00:02:18,640 bite-sized interactive learning 69 00:02:22,790 --> 00:02:20,879 experiences brilliance courses explore 70 00:02:24,470 --> 00:02:22,800 the laws that shape our world elevating 71 00:02:26,390 --> 00:02:24,480 math 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like to hear more 86 00:02:57,350 --> 00:02:54,560 conversations like this then do consider 87 00:02:58,949 --> 00:02:57,360 going to patreon.com kurtjimungle 88 00:03:00,630 --> 00:02:58,959 there's also a crypto address and a 89 00:03:02,630 --> 00:03:00,640 paypal address if that's more up your 90 00:03:04,550 --> 00:03:02,640 alley i now do this full time and the 91 00:03:06,630 --> 00:03:04,560 patrons are what allow for me to put out 92 00:03:08,710 --> 00:03:06,640 this content on such a frequent basis 93 00:03:10,229 --> 00:03:08,720 every dollar helps certainly and 94 00:03:13,030 --> 00:03:10,239 regardless i'm grateful for your 95 00:03:15,550 --> 00:03:13,040 viewership again that's patreon.com 96 00:03:17,509 --> 00:03:15,560 kurtjmungle 97 00:03:20,470 --> 00:03:17,519 c-u-r-t-j-a-i-m-u-n-g-a-l thank you and 98 00:03:25,750 --> 00:03:20,480 enjoy i actually had you as a professor 99 00:03:29,589 --> 00:03:28,070 i hope you didn't suffer too much 100 00:03:31,270 --> 00:03:29,599 that my favorite aspect of the course 101 00:03:32,710 --> 00:03:31,280 was that you would use the word seven 102 00:03:35,750 --> 00:03:32,720 you give an example of a number so you'd 103 00:03:37,670 --> 00:03:35,760 say a certain field number times a 104 00:03:39,030 --> 00:03:37,680 vector well let's call it seven so seven 105 00:03:41,750 --> 00:03:39,040 times a vector would be so-and-so you 106 00:03:45,110 --> 00:03:41,760 know it can get to extremes right you 107 00:03:46,710 --> 00:03:45,120 may end up doing things like uh 108 00:03:51,270 --> 00:03:46,720 the limit 109 00:03:52,949 --> 00:03:51,280 of uh e to the minus seven uh seven goes 110 00:03:56,390 --> 00:03:52,959 to infinity 111 00:03:57,750 --> 00:03:56,400 uh is equal to whatever it is zero right 112 00:04:00,309 --> 00:03:57,760 anyway yes 113 00:04:02,949 --> 00:04:00,319 what's your field of research 114 00:04:04,309 --> 00:04:02,959 uh not theory 115 00:04:07,830 --> 00:04:04,319 and 116 00:04:09,350 --> 00:04:07,840 from a very algebraic perspective 117 00:04:11,270 --> 00:04:09,360 and 118 00:04:13,589 --> 00:04:11,280 related 119 00:04:15,270 --> 00:04:13,599 algebra things 120 00:04:16,069 --> 00:04:15,280 it used to be 121 00:04:18,469 --> 00:04:16,079 uh 122 00:04:22,710 --> 00:04:18,479 much more not theory and quantum field 123 00:04:25,110 --> 00:04:22,720 theory and it slowly slowly moved to to 124 00:04:27,110 --> 00:04:25,120 being much more algebraic and their 125 00:04:29,909 --> 00:04:27,120 relationship with quantum field theory 126 00:04:31,909 --> 00:04:29,919 became more and more remote 127 00:04:33,350 --> 00:04:31,919 okay what's the relationship let's 128 00:04:35,030 --> 00:04:33,360 forget about the remoteness what's the 129 00:04:38,710 --> 00:04:35,040 close relationship between not theory 130 00:04:43,749 --> 00:04:40,830 oh it's a bit hard to 131 00:04:46,950 --> 00:04:43,759 explain and somewhat surprising and 132 00:04:49,670 --> 00:04:46,960 that's why that's why it took a long 133 00:04:51,990 --> 00:04:49,680 time to discover 134 00:04:53,670 --> 00:04:52,000 let me give you 135 00:04:55,350 --> 00:04:53,680 two answers 136 00:04:59,110 --> 00:04:55,360 that are 137 00:05:01,270 --> 00:04:59,120 somewhat unrelated and 138 00:05:06,469 --> 00:05:01,280 one answer is that quantum field theory 139 00:05:11,430 --> 00:05:07,990 and 140 00:05:14,790 --> 00:05:11,440 note theory is surprisingly also about 141 00:05:15,749 --> 00:05:14,800 the motion of particles 142 00:05:18,790 --> 00:05:15,759 so 143 00:05:19,830 --> 00:05:18,800 uh you know let's draw a simple minded 144 00:05:20,950 --> 00:05:19,840 knot 145 00:05:23,510 --> 00:05:20,960 uh 146 00:05:26,710 --> 00:05:23,520 so by the way is this a visible 147 00:05:32,390 --> 00:05:26,720 skin yeah okay so here is a simple 148 00:05:38,790 --> 00:05:36,390 it's actually the so-called trefoil knot 149 00:05:40,469 --> 00:05:38,800 but uh 150 00:05:43,830 --> 00:05:40,479 well whatever it is 151 00:05:45,189 --> 00:05:43,840 uh now uh what you can do 152 00:05:49,189 --> 00:05:45,199 is you can 153 00:05:53,909 --> 00:05:49,199 uh so it's living in in r3 154 00:05:55,350 --> 00:05:53,919 and uh i could set up my coordinates 155 00:05:56,150 --> 00:05:55,360 so that 156 00:05:58,790 --> 00:05:56,160 uh 157 00:06:00,710 --> 00:05:58,800 this coordinate will be called t maybe 158 00:06:03,670 --> 00:06:00,720 you want to call it z 159 00:06:06,950 --> 00:06:03,680 but you know i like to call it t at uh 160 00:06:09,830 --> 00:06:06,960 right now and the two coordinates here 161 00:06:14,629 --> 00:06:09,840 are x and y 162 00:06:15,430 --> 00:06:14,639 and then i can slice this knot 163 00:06:18,150 --> 00:06:15,440 at 164 00:06:22,550 --> 00:06:18,160 uh equal time 165 00:06:24,790 --> 00:06:22,560 uh slices so basically i uh 166 00:06:28,710 --> 00:06:24,800 draw a plane 167 00:06:32,309 --> 00:06:28,720 which leaves at some fixed height 168 00:06:36,790 --> 00:06:32,319 so at an equal in an equal time plane 169 00:06:39,670 --> 00:06:36,800 and slice the knot and then the slice is 170 00:06:43,510 --> 00:06:39,680 four points 171 00:06:45,510 --> 00:06:43,520 and as i move these points 172 00:06:50,150 --> 00:06:45,520 in time 173 00:06:52,390 --> 00:06:50,160 points move 174 00:06:54,070 --> 00:06:52,400 and they actually do a little lovely 175 00:06:54,950 --> 00:06:54,080 dance 176 00:06:57,749 --> 00:06:54,960 and 177 00:06:59,909 --> 00:06:57,759 uh the dance is as follows so if we call 178 00:07:00,790 --> 00:06:59,919 these points uh 179 00:07:01,510 --> 00:07:00,800 a 180 00:07:03,189 --> 00:07:01,520 b 181 00:07:07,350 --> 00:07:03,199 c and d 182 00:07:08,870 --> 00:07:07,360 then they start at a certain position 183 00:07:11,430 --> 00:07:08,880 a b 184 00:07:12,309 --> 00:07:11,440 c and d 185 00:07:13,270 --> 00:07:12,319 right 186 00:07:15,909 --> 00:07:13,280 and then 187 00:07:17,029 --> 00:07:15,919 as i move 188 00:07:19,589 --> 00:07:17,039 uh 189 00:07:22,870 --> 00:07:19,599 well you can see that c and b trade 190 00:07:24,870 --> 00:07:22,880 places so they play a dance they somehow 191 00:07:26,230 --> 00:07:24,880 dance around each other 192 00:07:31,510 --> 00:07:26,240 uh 193 00:07:37,510 --> 00:07:31,520 goes 194 00:07:38,870 --> 00:07:37,520 after a little while they trade places 195 00:07:40,790 --> 00:07:38,880 so you have 196 00:07:42,070 --> 00:07:40,800 a c 197 00:07:43,189 --> 00:07:42,080 sorry a 198 00:07:44,710 --> 00:07:43,199 uh 199 00:07:45,510 --> 00:07:44,720 c b 200 00:07:51,270 --> 00:07:45,520 d 201 00:07:55,510 --> 00:07:51,280 so 202 00:07:59,110 --> 00:07:55,520 uh again you will have a a b 203 00:08:02,629 --> 00:07:59,120 a c d and if you move a little further 204 00:08:04,710 --> 00:08:02,639 again they trade places so you'll have a 205 00:08:07,990 --> 00:08:04,720 c b d 206 00:08:09,110 --> 00:08:08,000 and then something funny happens 207 00:08:11,350 --> 00:08:09,120 uh 208 00:08:12,390 --> 00:08:11,360 points 209 00:08:15,270 --> 00:08:12,400 uh 210 00:08:18,390 --> 00:08:15,280 well points well by this time this is 211 00:08:19,430 --> 00:08:18,400 point b is over here and point c is over 212 00:08:25,350 --> 00:08:19,440 here 213 00:08:27,990 --> 00:08:25,360 what happens is that point c moves 214 00:08:30,790 --> 00:08:28,000 towards point d 215 00:08:31,510 --> 00:08:30,800 and points a more moves to points point 216 00:08:34,870 --> 00:08:31,520 b 217 00:08:35,909 --> 00:08:34,880 and they coincide 218 00:08:38,310 --> 00:08:35,919 and 219 00:08:40,230 --> 00:08:38,320 when they coincide they annihilate each 220 00:08:42,310 --> 00:08:40,240 other because if you look at the plane 221 00:08:43,269 --> 00:08:42,320 which is above 222 00:08:48,150 --> 00:08:43,279 the 223 00:08:51,190 --> 00:08:49,190 uh 224 00:08:53,350 --> 00:08:51,200 you no longer see any point so what 225 00:08:55,350 --> 00:08:53,360 happens next is that these points move 226 00:08:57,990 --> 00:08:55,360 towards each other these points move to 227 00:09:00,470 --> 00:08:58,000 each other they meet and bang they 228 00:09:02,630 --> 00:09:00,480 annihilate and after that there is an 229 00:09:06,150 --> 00:09:02,640 empty set 230 00:09:08,710 --> 00:09:06,160 and in fact i started a tight 231 00:09:12,310 --> 00:09:08,720 uh at a certain height had i started 232 00:09:15,509 --> 00:09:12,320 below i start with the empty set 233 00:09:18,230 --> 00:09:15,519 and instead of annihilation of pairs 234 00:09:20,070 --> 00:09:18,240 you get a creation of pairs so a pair of 235 00:09:22,630 --> 00:09:20,080 points get created here and a pair of 236 00:09:24,949 --> 00:09:22,640 points get created here and then they 237 00:09:27,350 --> 00:09:24,959 perform this nice dance 238 00:09:30,070 --> 00:09:27,360 so this was this particular note but the 239 00:09:33,030 --> 00:09:30,080 same story is true for every note every 240 00:09:35,110 --> 00:09:33,040 note can be written as a certain dance 241 00:09:39,590 --> 00:09:35,120 of points 242 00:09:42,710 --> 00:09:39,600 in which uh sometimes pairs 243 00:09:45,110 --> 00:09:42,720 get created sometimes pair meet and 244 00:09:48,829 --> 00:09:45,120 annihilate each other and in between 245 00:09:51,110 --> 00:09:48,839 these times they all dance 246 00:09:53,670 --> 00:09:51,120 anyway uh 247 00:09:57,269 --> 00:09:53,680 physics in general is about the motion 248 00:09:59,829 --> 00:09:57,279 of particles and it's not too surprising 249 00:10:02,949 --> 00:09:59,839 that there is a relationship 250 00:10:05,829 --> 00:10:02,959 physics also sees things like creation 251 00:10:08,389 --> 00:10:05,839 and annihilation of pairs of particles 252 00:10:09,829 --> 00:10:08,399 and i mean so again it's not so 253 00:10:13,509 --> 00:10:09,839 surprising 254 00:10:15,910 --> 00:10:13,519 but this is very very very loose 255 00:10:21,190 --> 00:10:18,310 gee the other explanation i can give you 256 00:10:22,230 --> 00:10:21,200 is even more loose 257 00:10:24,870 --> 00:10:22,240 uh 258 00:10:26,389 --> 00:10:24,880 but even but but in some sense 259 00:10:27,590 --> 00:10:26,399 more 260 00:10:31,350 --> 00:10:27,600 um 261 00:10:37,509 --> 00:10:34,630 uh well okay maybe you've heard 262 00:10:39,910 --> 00:10:37,519 that quantum mechanics is related to 263 00:10:40,710 --> 00:10:39,920 path integrals 264 00:10:43,990 --> 00:10:40,720 so 265 00:10:44,949 --> 00:10:44,000 uh you know in classical mechanics 266 00:10:47,910 --> 00:10:44,959 uh 267 00:10:49,269 --> 00:10:47,920 you know if a path goes from point a to 268 00:10:51,750 --> 00:10:49,279 point b 269 00:10:52,870 --> 00:10:51,760 sorry if a particle goes from point a to 270 00:10:57,030 --> 00:10:52,880 point b 271 00:10:58,310 --> 00:10:57,040 it goes along a specific path 272 00:11:03,829 --> 00:10:58,320 um 273 00:11:06,150 --> 00:11:03,839 probability of going uh from a to b and 274 00:11:08,069 --> 00:11:06,160 you compute this probability 275 00:11:09,750 --> 00:11:08,079 by doing a certain 276 00:11:13,509 --> 00:11:09,760 integral 277 00:11:16,310 --> 00:11:13,519 over the space of all paths 278 00:11:19,110 --> 00:11:16,320 so the particle or 279 00:11:21,110 --> 00:11:19,120 i mean again even even my interpretation 280 00:11:22,790 --> 00:11:21,120 of quantum mechanics here is a bit loose 281 00:11:24,949 --> 00:11:22,800 because interpreting quantum mechanics 282 00:11:28,870 --> 00:11:24,959 is a very hard thing 283 00:11:31,430 --> 00:11:28,880 but with this loose interpretation you 284 00:11:35,110 --> 00:11:31,440 sum over all probabilities of going this 285 00:11:38,150 --> 00:11:35,120 way or that way or that way 286 00:11:40,829 --> 00:11:38,160 or that way and by adding up all these 287 00:11:43,670 --> 00:11:40,839 probabilities or more precisely 288 00:11:46,069 --> 00:11:43,680 integrating over the space of all of 289 00:11:48,470 --> 00:11:46,079 those probabilities or more precisely 290 00:11:51,190 --> 00:11:48,480 phase factors or 291 00:11:52,629 --> 00:11:51,200 amplitudes 292 00:11:55,030 --> 00:11:52,639 uh you 293 00:11:58,870 --> 00:11:55,040 you can compute the probability of going 294 00:11:59,990 --> 00:11:58,880 from a to b that's quantum mechanics 295 00:12:01,750 --> 00:12:00,000 now 296 00:12:06,230 --> 00:12:01,760 uh 297 00:12:07,910 --> 00:12:06,240 quantum field theory it's essentially 298 00:12:10,470 --> 00:12:07,920 the same except the integrals are more 299 00:12:13,829 --> 00:12:10,480 complicated but the point is that 300 00:12:18,389 --> 00:12:13,839 already these integrals 301 00:12:20,150 --> 00:12:18,399 are not like integrals over rn 302 00:12:24,629 --> 00:12:20,160 right rn 303 00:12:28,389 --> 00:12:24,639 is uh the collection of n tuples of 304 00:12:32,629 --> 00:12:28,399 points a1 up to a n 305 00:12:34,949 --> 00:12:32,639 so a point in rn is determined by n 306 00:12:37,750 --> 00:12:34,959 real numbers 307 00:12:40,470 --> 00:12:37,760 whereas a function the space we are 308 00:12:42,710 --> 00:12:40,480 integrating over now 309 00:12:43,829 --> 00:12:42,720 is the space of all functions and a 310 00:12:46,710 --> 00:12:43,839 function 311 00:12:49,190 --> 00:12:46,720 is determined by infinitely many real 312 00:12:50,949 --> 00:12:49,200 values you need to know the value of the 313 00:12:52,470 --> 00:12:50,959 function here the value of the function 314 00:12:54,389 --> 00:12:52,480 here the value of the function here the 315 00:12:56,470 --> 00:12:54,399 value of the function here so to 316 00:12:58,870 --> 00:12:56,480 determine a function you need to know 317 00:13:01,509 --> 00:12:58,880 infinite infinitely many 318 00:13:06,550 --> 00:13:01,519 uh real numbers 319 00:13:07,310 --> 00:13:06,560 so the integral that you end up doing is 320 00:13:11,350 --> 00:13:07,320 not 321 00:13:13,750 --> 00:13:11,360 157 style sorry now i'm using a 322 00:13:17,269 --> 00:13:13,760 toronto style language or it's not one 323 00:13:20,230 --> 00:13:17,279 variable calculus in integral which is 324 00:13:23,509 --> 00:13:20,240 again one variable 325 00:13:26,069 --> 00:13:23,519 uh integral it's not this 326 00:13:28,069 --> 00:13:26,079 it's not second year calculus when you 327 00:13:30,310 --> 00:13:28,079 do n variable 328 00:13:33,990 --> 00:13:30,320 uh integrals 329 00:13:37,350 --> 00:13:34,000 it's infinite dimensional so infinitely 330 00:13:39,189 --> 00:13:37,360 many variables integration this is what 331 00:13:40,629 --> 00:13:39,199 we need 332 00:13:41,829 --> 00:13:40,639 okay 333 00:13:42,790 --> 00:13:41,839 so 334 00:13:47,829 --> 00:13:42,800 uh 335 00:13:53,430 --> 00:13:50,310 ended up developing 336 00:13:56,790 --> 00:13:53,440 a bag of techniques for computing 337 00:13:58,870 --> 00:13:56,800 infinite dimensional integrals 338 00:14:00,389 --> 00:13:58,880 and what these techniques are is a whole 339 00:14:03,829 --> 00:14:00,399 different story 340 00:14:05,910 --> 00:14:03,839 but uh but quantum field theory ended up 341 00:14:07,030 --> 00:14:05,920 doing this 342 00:14:08,470 --> 00:14:07,040 and then 343 00:14:10,389 --> 00:14:08,480 uh 344 00:14:13,189 --> 00:14:10,399 it turns out 345 00:14:15,590 --> 00:14:13,199 that infinite dimensional integrals are 346 00:14:17,910 --> 00:14:15,600 useful to topology 347 00:14:20,069 --> 00:14:17,920 so so the the the 348 00:14:22,629 --> 00:14:20,079 the way that quantum field theory 349 00:14:25,030 --> 00:14:22,639 becomes useful in topology is indirect 350 00:14:26,710 --> 00:14:25,040 it's not that the quantum field theory 351 00:14:28,870 --> 00:14:26,720 itself 352 00:14:30,949 --> 00:14:28,880 is useful 353 00:14:33,110 --> 00:14:30,959 even this is a lie because sometimes the 354 00:14:35,509 --> 00:14:33,120 quantum field theory itself is useful 355 00:14:38,230 --> 00:14:35,519 but but the main path by which quantum 356 00:14:39,430 --> 00:14:38,240 filter becomes useful to topology 357 00:14:40,389 --> 00:14:39,440 is not 358 00:14:45,670 --> 00:14:40,399 uh 359 00:14:48,310 --> 00:14:45,680 field theory developed a bag of 360 00:14:51,829 --> 00:14:48,320 techniques and this bag of techniques 361 00:14:55,990 --> 00:14:54,550 anyway why are infinite dimensional 362 00:14:58,790 --> 00:14:56,000 integrals 363 00:15:00,069 --> 00:14:58,800 useful to topology 364 00:15:03,430 --> 00:15:00,079 um 365 00:15:04,949 --> 00:15:03,440 the answer is again a bit 366 00:15:06,389 --> 00:15:04,959 uh 367 00:15:08,949 --> 00:15:06,399 complicated 368 00:15:13,110 --> 00:15:08,959 but let me try to summarize it 369 00:15:15,110 --> 00:15:13,120 so let me bring a knot here's a knot 370 00:15:16,310 --> 00:15:15,120 okay great 371 00:15:21,590 --> 00:15:16,320 uh 372 00:15:25,350 --> 00:15:21,600 why not picking what i'm showing you is 373 00:15:28,150 --> 00:15:27,110 a note 374 00:15:30,470 --> 00:15:28,160 is 375 00:15:38,150 --> 00:15:35,269 an equivalence class of such curves so 376 00:15:40,470 --> 00:15:38,160 this is a curve if i deform it a bit 377 00:15:43,509 --> 00:15:40,480 it's still a curve but it's considered 378 00:15:45,749 --> 00:15:43,519 the same knot if i deform it some more 379 00:15:47,829 --> 00:15:45,759 it's still a curve but it con but but 380 00:15:50,310 --> 00:15:47,839 but but it's the same not 381 00:15:53,590 --> 00:15:50,320 so a knot is not a single curve but an 382 00:15:56,069 --> 00:15:53,600 equivalent class of curves 383 00:15:59,749 --> 00:15:56,079 now suppose you want 384 00:16:03,110 --> 00:15:59,759 quantities that are associated to notes 385 00:16:04,470 --> 00:16:03,120 you want to be able to tell notes apart 386 00:16:05,910 --> 00:16:04,480 so you need 387 00:16:08,470 --> 00:16:05,920 quantities 388 00:16:10,550 --> 00:16:08,480 uh that would be computable from the 389 00:16:12,150 --> 00:16:10,560 knot and that you would use them to tell 390 00:16:14,150 --> 00:16:12,160 the notes apart 391 00:16:17,389 --> 00:16:14,160 okay 392 00:16:19,030 --> 00:16:17,399 now it's very easy to compute 393 00:16:22,629 --> 00:16:19,040 quantities 394 00:16:25,189 --> 00:16:22,639 that are associated with curves 395 00:16:29,110 --> 00:16:25,199 so if you have a curve 396 00:16:32,790 --> 00:16:29,120 uh you can measure its how much it bends 397 00:16:35,509 --> 00:16:32,800 so the radius of of the bending 398 00:16:38,230 --> 00:16:35,519 okay again these things have technical 399 00:16:39,509 --> 00:16:38,240 names the curvature maybe the torsion 400 00:16:42,150 --> 00:16:39,519 there are various 401 00:16:43,590 --> 00:16:42,160 names for for various quantities you can 402 00:16:44,870 --> 00:16:43,600 associate with 403 00:16:47,430 --> 00:16:44,880 curves 404 00:16:51,030 --> 00:16:47,440 so you know i can look at the maximal 405 00:16:53,030 --> 00:16:51,040 curvature of this knot of this curve and 406 00:16:55,269 --> 00:16:53,040 the maximal curvature will be the place 407 00:16:57,910 --> 00:16:55,279 where it turns the most and that's 408 00:17:00,710 --> 00:16:57,920 probably around here for this particular 409 00:17:03,269 --> 00:17:00,720 curve around here okay 410 00:17:06,630 --> 00:17:03,279 now um 411 00:17:09,590 --> 00:17:06,640 uh but that quantity is a quantity which 412 00:17:12,630 --> 00:17:09,600 is associated with curves 413 00:17:14,710 --> 00:17:12,640 it's a useless as a quantity for not 414 00:17:16,710 --> 00:17:14,720 it's useless as a quantity for knots 415 00:17:19,350 --> 00:17:16,720 because if we're talking about not you 416 00:17:22,470 --> 00:17:19,360 know i could deform it and the maximal 417 00:17:25,590 --> 00:17:22,480 curvature could go somewhere else 418 00:17:26,789 --> 00:17:25,600 could change could grow could shrink 419 00:17:27,990 --> 00:17:26,799 could differ 420 00:17:31,430 --> 00:17:28,000 right 421 00:17:32,789 --> 00:17:31,440 so the way to get quantities that are 422 00:17:34,630 --> 00:17:32,799 associated 423 00:17:36,230 --> 00:17:34,640 with knots 424 00:17:37,590 --> 00:17:36,240 rather than with 425 00:17:41,669 --> 00:17:37,600 curves 426 00:17:44,310 --> 00:17:41,679 is to integrate over the space of all 427 00:17:47,270 --> 00:17:44,320 geometries 428 00:17:50,470 --> 00:17:47,280 so instead of picking the quantity for a 429 00:17:51,990 --> 00:17:50,480 specific geometric manifestation of the 430 00:17:54,390 --> 00:17:52,000 knot 431 00:17:57,909 --> 00:17:54,400 you integrate over the space of all 432 00:18:00,750 --> 00:17:57,919 geometries and then the result will be a 433 00:18:03,510 --> 00:18:00,760 a quantity associated with the note 434 00:18:04,789 --> 00:18:03,520 unfortunately the examples are very very 435 00:18:07,990 --> 00:18:04,799 hard 436 00:18:10,230 --> 00:18:08,000 so you know the the famous example the 437 00:18:13,430 --> 00:18:10,240 example that uh 438 00:18:15,510 --> 00:18:13,440 got written uh well one of the examples 439 00:18:18,789 --> 00:18:15,520 that got written very very famous in 440 00:18:22,390 --> 00:18:18,799 topology or among mathematicians is the 441 00:18:26,950 --> 00:18:22,400 so-called chern simon's theory 442 00:18:31,590 --> 00:18:26,960 uh or chen simon's quantity which is um 443 00:18:35,430 --> 00:18:31,600 uh so uh in itself some integral so you 444 00:18:38,470 --> 00:18:35,440 integrate over r3 445 00:18:40,710 --> 00:18:38,480 so the quantity itself is a finite 446 00:18:45,110 --> 00:18:40,720 dimensional integral 447 00:18:48,070 --> 00:18:45,120 right so you integrate over r3 something 448 00:18:50,789 --> 00:18:48,080 called the churn simon's form 449 00:18:52,470 --> 00:18:50,799 uh which is something called which is a 450 00:18:54,630 --> 00:18:52,480 wedge d a 451 00:18:55,590 --> 00:18:54,640 plus two thirds 452 00:18:58,470 --> 00:18:55,600 uh 453 00:19:00,710 --> 00:18:58,480 a wedge a wedge a 454 00:19:03,029 --> 00:19:00,720 whatever that is but this is you know 455 00:19:05,750 --> 00:19:03,039 related to stuff appearing in second 456 00:19:08,710 --> 00:19:05,760 year uh multivariable calculus in the 457 00:19:10,630 --> 00:19:08,720 most advanced versions okay so wedge 458 00:19:13,669 --> 00:19:10,640 products and differential forms and 459 00:19:16,950 --> 00:19:13,679 exterior derivatives and stuff like that 460 00:19:20,190 --> 00:19:16,960 then you take this quantity and you 461 00:19:22,230 --> 00:19:20,200 multiply it by i multiply by k 462 00:19:25,510 --> 00:19:22,240 exponentiate it 463 00:19:29,510 --> 00:19:25,520 multiply by another quantity the 464 00:19:32,150 --> 00:19:29,520 so-called holonomy along the note of a 465 00:19:34,390 --> 00:19:32,160 whatever that is so i'm throwing names 466 00:19:36,070 --> 00:19:34,400 because i really have no choice because 467 00:19:38,710 --> 00:19:36,080 giving the precise definition is a 468 00:19:41,430 --> 00:19:38,720 matter for a graduate class yeah okay 469 00:19:45,909 --> 00:19:41,440 and this is the quantity that you 470 00:19:49,270 --> 00:19:45,919 associate with a geometric note 471 00:19:51,830 --> 00:19:49,280 and then to get an invariant of notes or 472 00:19:53,510 --> 00:19:51,840 to get a quantity associated with the 473 00:19:55,990 --> 00:19:53,520 not itself 474 00:19:59,270 --> 00:19:56,000 you integrate it 475 00:20:01,350 --> 00:19:59,280 over the space of all such a's and i 476 00:20:03,110 --> 00:20:01,360 didn't really tell you what these a's 477 00:20:04,549 --> 00:20:03,120 are but it's an infinite dimensional 478 00:20:05,350 --> 00:20:04,559 space 479 00:20:08,149 --> 00:20:05,360 so 480 00:20:10,710 --> 00:20:08,159 uh i guess i haven't really answered 481 00:20:13,909 --> 00:20:10,720 your question by giving an example but i 482 00:20:16,549 --> 00:20:13,919 just told you the examples are hard 483 00:20:19,110 --> 00:20:16,559 okay anyway um 484 00:20:20,630 --> 00:20:19,120 well they're hard but they're exactly of 485 00:20:21,430 --> 00:20:20,640 the nature 486 00:20:24,149 --> 00:20:21,440 that 487 00:20:26,710 --> 00:20:24,159 physics knows how to study 488 00:20:27,909 --> 00:20:26,720 or that quantum field theory developed 489 00:20:31,510 --> 00:20:27,919 techniques 490 00:20:34,149 --> 00:20:31,520 to study and so one can study it using 491 00:20:37,590 --> 00:20:34,159 quantum field theory techniques and get 492 00:20:39,750 --> 00:20:37,600 all sorts of um 493 00:20:42,310 --> 00:20:39,760 well 494 00:20:45,270 --> 00:20:42,320 quantities relevance to not relevant to 495 00:20:46,950 --> 00:20:45,280 not the so-called jones polynomial is an 496 00:20:48,710 --> 00:20:46,960 example and then there are many other 497 00:20:50,950 --> 00:20:48,720 examples 498 00:20:53,510 --> 00:20:50,960 are there any relationships between not 499 00:20:55,029 --> 00:20:53,520 theory and gravity so general relativity 500 00:20:56,789 --> 00:20:55,039 let's say 501 00:21:00,870 --> 00:20:56,799 um 502 00:21:05,350 --> 00:21:02,549 i'm not an expert 503 00:21:06,390 --> 00:21:05,360 the answer is yes 504 00:21:11,830 --> 00:21:06,400 uh 505 00:21:13,590 --> 00:21:11,840 i told you i've actually moved away from 506 00:21:15,190 --> 00:21:13,600 that subject 507 00:21:17,270 --> 00:21:15,200 what got you interested in not theory 508 00:21:19,110 --> 00:21:17,280 originally 509 00:21:21,110 --> 00:21:19,120 this subject 510 00:21:24,710 --> 00:21:21,120 so mainly you were interested in physics 511 00:21:25,590 --> 00:21:24,720 well okay i was a math undergrad 512 00:21:28,390 --> 00:21:25,600 uh 513 00:21:33,270 --> 00:21:31,590 during my time as an undergrad and then 514 00:21:36,230 --> 00:21:33,280 a master's student in tel aviv 515 00:21:39,029 --> 00:21:36,240 university i never finished the masters 516 00:21:41,430 --> 00:21:39,039 i moved on to doing my phd in in 517 00:21:43,830 --> 00:21:41,440 princeton but during my time as a 518 00:21:46,070 --> 00:21:43,840 master's student in in 519 00:21:49,029 --> 00:21:46,080 in tel aviv i got more and more 520 00:21:49,909 --> 00:21:49,039 interested in in physics 521 00:21:52,390 --> 00:21:49,919 and 522 00:21:54,390 --> 00:21:52,400 uh there's just wonderful mathematics 523 00:21:56,310 --> 00:21:54,400 inside physics so i got interested in 524 00:21:57,669 --> 00:21:56,320 physics and the fundamental question of 525 00:21:59,990 --> 00:21:57,679 physics right 526 00:22:03,350 --> 00:22:00,000 what are the basic laws of the universe 527 00:22:05,590 --> 00:22:03,360 i mean you can't ask a better question 528 00:22:07,669 --> 00:22:05,600 so i got more and more interested in 529 00:22:10,310 --> 00:22:07,679 physics and decided to do my phd in 530 00:22:13,430 --> 00:22:10,320 mathematical physics 531 00:22:18,070 --> 00:22:13,440 and i ended up uh working with ed 532 00:22:20,230 --> 00:22:18,080 wheaton uh who who is a very famous 533 00:22:23,990 --> 00:22:20,240 physicist or mathematical physicist or 534 00:22:27,270 --> 00:22:24,000 mathematician depending whom you ask 535 00:22:30,950 --> 00:22:27,280 and um 536 00:22:32,310 --> 00:22:30,960 uh and originally my interest was in 537 00:22:33,590 --> 00:22:32,320 physics 538 00:22:36,070 --> 00:22:33,600 or you know 539 00:22:37,990 --> 00:22:36,080 my aim was to do things that was rather 540 00:22:40,070 --> 00:22:38,000 were relevant to physics 541 00:22:41,750 --> 00:22:40,080 somehow that's not what happened you 542 00:22:42,789 --> 00:22:41,760 know at the end you don't choose your 543 00:22:47,990 --> 00:22:42,799 career 544 00:22:48,789 --> 00:22:48,000 you know so uh 545 00:23:09,430 --> 00:22:48,799 i 546 00:23:12,549 --> 00:23:09,440 turned out that that was relevant to 547 00:23:14,870 --> 00:23:12,559 something called finite type invariants 548 00:23:16,950 --> 00:23:14,880 and i thought i had new things to say 549 00:23:20,070 --> 00:23:16,960 about finite typing variance and that's 550 00:23:20,830 --> 00:23:20,080 completely and not theoretic subject 551 00:23:22,070 --> 00:23:20,840 so 552 00:23:22,950 --> 00:23:22,080 i uh 553 00:23:34,870 --> 00:23:22,960 i 554 00:23:38,070 --> 00:23:34,880 about and that paper or two became 10 555 00:23:39,750 --> 00:23:38,080 years with several paper many papers and 556 00:23:41,430 --> 00:23:39,760 many results and 557 00:23:43,350 --> 00:23:41,440 and 558 00:23:45,430 --> 00:23:43,360 you know 559 00:23:47,510 --> 00:23:45,440 and then a chinese meeting led me to yet 560 00:23:49,830 --> 00:23:47,520 another subject and you know 561 00:23:51,269 --> 00:23:49,840 what was the other subject it led you to 562 00:23:53,590 --> 00:23:51,279 um 563 00:23:56,390 --> 00:23:53,600 well no the next subject after finite 564 00:23:58,549 --> 00:23:56,400 typing variance was juvano homology 565 00:24:02,549 --> 00:23:58,559 anyway you don't choose what you do you 566 00:24:03,669 --> 00:24:02,559 you know you you at most uh try to steer 567 00:24:04,470 --> 00:24:03,679 it 568 00:24:06,870 --> 00:24:04,480 but 569 00:24:07,990 --> 00:24:06,880 it steers you much more than you steer 570 00:24:09,909 --> 00:24:08,000 it 571 00:24:12,870 --> 00:24:09,919 like the subject do you have an 572 00:24:13,990 --> 00:24:12,880 intuitive explanation for people who 573 00:24:17,190 --> 00:24:14,000 let's say they're at the second year 574 00:24:23,350 --> 00:24:17,200 level what is a homology 575 00:24:27,750 --> 00:24:24,630 it's a tough 576 00:24:29,990 --> 00:24:27,760 a very tough uh 577 00:24:32,070 --> 00:24:30,000 question 578 00:24:35,350 --> 00:24:32,080 because 579 00:24:36,470 --> 00:24:35,360 it's many things or it's related to many 580 00:24:40,470 --> 00:24:36,480 things 581 00:24:41,830 --> 00:24:40,480 and i could answer it in in many levels 582 00:24:44,310 --> 00:24:41,840 um 583 00:24:46,630 --> 00:24:44,320 you know 584 00:24:49,430 --> 00:24:46,640 uh let me 585 00:24:50,549 --> 00:24:49,440 let me give you a summary answer 586 00:24:51,830 --> 00:24:50,559 sure okay 587 00:24:55,669 --> 00:24:51,840 so 588 00:25:05,029 --> 00:25:00,630 there are two ways to describe objects 589 00:25:09,990 --> 00:25:05,039 you can describe them implicitly 590 00:25:10,990 --> 00:25:10,000 by telling what equations they satisfy 591 00:25:12,710 --> 00:25:11,000 or 592 00:25:15,750 --> 00:25:12,720 explicitly 593 00:25:18,230 --> 00:25:15,760 by constructing all of them 594 00:25:19,110 --> 00:25:18,240 let me give you the simplest example 595 00:25:20,950 --> 00:25:19,120 so 596 00:25:22,950 --> 00:25:20,960 uh consider 597 00:25:25,830 --> 00:25:22,960 the unit circle 598 00:25:28,549 --> 00:25:25,840 sorry i kind of care about the points of 599 00:25:32,230 --> 00:25:28,559 the unit circle so here is the unit 600 00:25:34,870 --> 00:25:32,240 circle in the x y plane and here is a 601 00:25:38,470 --> 00:25:34,880 point x y 602 00:25:40,630 --> 00:25:38,480 the implicit description of the circle 603 00:25:41,430 --> 00:25:40,640 so the implicit 604 00:25:44,630 --> 00:25:41,440 is 605 00:25:46,710 --> 00:25:44,640 by writing an equation which the points 606 00:25:49,510 --> 00:25:46,720 have to satisfy and everybody knows what 607 00:25:53,269 --> 00:25:49,520 the equation is the equation is x 608 00:25:56,390 --> 00:25:53,279 squared minus sorry plus y squared minus 609 00:25:57,830 --> 00:25:56,400 1 is equal to 0. 610 00:25:58,710 --> 00:25:57,840 okay 611 00:26:00,870 --> 00:25:58,720 uh 612 00:26:02,630 --> 00:26:00,880 but there is also an explicit 613 00:26:05,590 --> 00:26:02,640 description 614 00:26:07,990 --> 00:26:05,600 and again i'm not sure which one is 615 00:26:11,430 --> 00:26:08,000 why the naming is such but it it doesn't 616 00:26:14,630 --> 00:26:11,440 really matter namely i can construct all 617 00:26:17,669 --> 00:26:14,640 the points of the paper of the circle 618 00:26:18,870 --> 00:26:17,679 and the construction is you set x is 619 00:26:25,909 --> 00:26:18,880 equal to 620 00:26:31,350 --> 00:26:27,110 okay 621 00:26:34,070 --> 00:26:31,360 now this is the general 622 00:26:36,549 --> 00:26:34,080 a general feature in mathematics that 623 00:26:39,269 --> 00:26:36,559 many things can be described either be 624 00:26:42,789 --> 00:26:39,279 constructed that's the explicit 625 00:26:43,669 --> 00:26:42,799 or be defined by an equation 626 00:26:45,830 --> 00:26:43,679 now 627 00:26:48,230 --> 00:26:45,840 if you uh 628 00:26:50,310 --> 00:26:48,240 restrict your attention to linear 629 00:26:53,669 --> 00:26:50,320 algebra 630 00:26:55,990 --> 00:26:53,679 if you you you do the same thing but in 631 00:26:56,950 --> 00:26:56,000 linear algebra 632 00:26:57,750 --> 00:26:56,960 then 633 00:26:59,909 --> 00:26:57,760 uh 634 00:27:01,990 --> 00:26:59,919 the situation is that you have some 635 00:27:02,950 --> 00:27:02,000 space in the middle maybe it's a vector 636 00:27:09,029 --> 00:27:02,960 space 637 00:27:10,870 --> 00:27:09,039 describe things 638 00:27:13,269 --> 00:27:10,880 actually i'm not sure why i'm drawing it 639 00:27:15,029 --> 00:27:13,279 curve because the curve because if it's 640 00:27:17,909 --> 00:27:15,039 linear algebra i should be drawing it 641 00:27:19,430 --> 00:27:17,919 straight but anyway you want to describe 642 00:27:23,029 --> 00:27:19,440 things 643 00:27:24,549 --> 00:27:23,039 and there are two ways to describe them 644 00:27:26,549 --> 00:27:24,559 one way 645 00:27:28,230 --> 00:27:26,559 is by saying 646 00:27:30,630 --> 00:27:28,240 these things 647 00:27:32,470 --> 00:27:30,640 well you construct a map into another 648 00:27:37,029 --> 00:27:32,480 space 649 00:27:39,190 --> 00:27:37,039 and you say these things are the things 650 00:27:41,830 --> 00:27:39,200 in the kernel 651 00:27:43,269 --> 00:27:41,840 of this map so i don't know what let's 652 00:27:44,710 --> 00:27:43,279 call this map 653 00:27:46,630 --> 00:27:44,720 fi 654 00:27:51,430 --> 00:27:46,640 and these things 655 00:27:57,029 --> 00:27:52,549 and then 656 00:28:03,750 --> 00:28:00,950 so this is the implicit description 657 00:28:06,630 --> 00:28:03,760 this is you describe the things by an 658 00:28:08,710 --> 00:28:06,640 equation and and then there is also the 659 00:28:11,669 --> 00:28:08,720 explicit description so you have yet 660 00:28:15,590 --> 00:28:11,679 another vector space and you have a map 661 00:28:18,789 --> 00:28:15,600 let's call it let's call it psi 662 00:28:20,070 --> 00:28:18,799 and you say the things here 663 00:28:22,389 --> 00:28:20,080 that are 664 00:28:23,830 --> 00:28:22,399 well the good things like the points of 665 00:28:27,029 --> 00:28:23,840 the circle 666 00:28:30,149 --> 00:28:27,039 are the image of psy 667 00:28:32,870 --> 00:28:30,159 so you say these are the things that are 668 00:28:34,789 --> 00:28:32,880 the image of psy 669 00:28:37,350 --> 00:28:34,799 okay and this corresponds to the 670 00:28:39,909 --> 00:28:37,360 explicit view 671 00:28:44,310 --> 00:28:39,919 you construct the things you present 672 00:28:47,190 --> 00:28:44,320 them as an image via some operation 673 00:28:52,630 --> 00:28:49,830 coming from some you know maybe 674 00:28:55,269 --> 00:28:52,640 some smaller dimensional space 675 00:28:58,549 --> 00:28:56,830 uh so 676 00:29:01,029 --> 00:28:58,559 okay 677 00:29:05,430 --> 00:29:01,039 here's a funny thing so 678 00:29:08,389 --> 00:29:05,440 if your construction is reasonable 679 00:29:11,990 --> 00:29:08,399 then everything you construct 680 00:29:14,549 --> 00:29:12,000 solves the equations 681 00:29:16,070 --> 00:29:14,559 in other words everything in the image 682 00:29:19,750 --> 00:29:16,080 of psy 683 00:29:20,870 --> 00:29:19,760 is contained in the kernel of phi 684 00:29:23,510 --> 00:29:20,880 so 685 00:29:25,430 --> 00:29:23,520 once you have a situation like this you 686 00:29:27,830 --> 00:29:25,440 know that you're going to have that the 687 00:29:33,510 --> 00:29:27,840 image of psy 688 00:29:39,190 --> 00:29:36,789 and in fact if you're constructing the 689 00:29:42,549 --> 00:29:39,200 exact same things 690 00:29:45,909 --> 00:29:42,559 then the image of i will be equal 691 00:29:48,470 --> 00:29:45,919 to the kernel of i not just contained 692 00:29:52,310 --> 00:29:48,480 okay and then you will be saying that 693 00:29:55,430 --> 00:29:52,320 the situation is exact 694 00:29:57,269 --> 00:29:55,440 things got exactly the things that 695 00:30:00,710 --> 00:29:57,279 you've constructed are the things that 696 00:30:03,110 --> 00:30:00,720 you described by the equations 697 00:30:06,789 --> 00:30:03,120 but that's not always the case 698 00:30:09,590 --> 00:30:06,799 sometimes you have equations defining 699 00:30:12,470 --> 00:30:09,600 something and you want to know did i 700 00:30:17,269 --> 00:30:12,480 construct all the solutions 701 00:30:20,149 --> 00:30:17,279 so sometimes this inclusion is strict 702 00:30:24,789 --> 00:30:20,159 and then you want to measure 703 00:30:27,510 --> 00:30:24,799 by how much or how much did you fail 704 00:30:29,510 --> 00:30:27,520 so how much did you not construct 705 00:30:31,830 --> 00:30:29,520 everything and that's exactly the 706 00:30:34,470 --> 00:30:31,840 difference between the kernel of phi and 707 00:30:37,350 --> 00:30:34,480 the image of psy and in linear algebra 708 00:30:39,029 --> 00:30:37,360 the difference is quotient so you take 709 00:30:42,149 --> 00:30:39,039 the quotient space 710 00:30:44,870 --> 00:30:42,159 and this is the so-called homology 711 00:30:48,830 --> 00:30:44,880 so somehow homology measures 712 00:30:52,630 --> 00:30:51,269 uh uh 713 00:30:54,470 --> 00:30:52,640 how 714 00:30:55,669 --> 00:30:54,480 good 715 00:30:57,029 --> 00:30:55,679 are 716 00:31:00,950 --> 00:30:57,039 your 717 00:31:06,149 --> 00:31:03,350 did you construct everything or did you 718 00:31:08,630 --> 00:31:06,159 leave some stuff out 719 00:31:10,710 --> 00:31:08,640 is the kernel the implicit the 720 00:31:13,110 --> 00:31:10,720 description this 721 00:31:14,789 --> 00:31:13,120 does it contain more things and then 722 00:31:17,669 --> 00:31:14,799 you've constructed 723 00:31:20,389 --> 00:31:17,679 so somehow homology measures how good 724 00:31:22,230 --> 00:31:20,399 are your constructions and this is true 725 00:31:24,070 --> 00:31:22,240 in general 726 00:31:26,870 --> 00:31:24,080 uh 727 00:31:30,830 --> 00:31:26,880 and and and then there are lots and lots 728 00:31:32,870 --> 00:31:30,840 and lots and lots of specific examples 729 00:31:33,990 --> 00:31:32,880 uh and 730 00:31:36,549 --> 00:31:34,000 uh 731 00:31:38,789 --> 00:31:36,559 to some extent it's a bit of magic i'm 732 00:31:40,389 --> 00:31:38,799 not sure i i can give you a really good 733 00:31:43,909 --> 00:31:40,399 explanation 734 00:31:48,710 --> 00:31:43,919 why there are so many examples and why 735 00:31:51,430 --> 00:31:48,720 so much of mathematics uh end up 736 00:31:56,710 --> 00:31:54,149 having close relationships with with 737 00:31:59,110 --> 00:31:56,720 with uh with homology maybe this is a 738 00:32:01,269 --> 00:31:59,120 partial explanation so 739 00:32:02,950 --> 00:32:01,279 basically you always want to measure how 740 00:32:03,830 --> 00:32:02,960 good is what you've done 741 00:32:05,269 --> 00:32:03,840 so 742 00:32:07,350 --> 00:32:05,279 are you able to talk about what co 743 00:32:09,669 --> 00:32:07,360 homology is and then homology's 744 00:32:11,909 --> 00:32:09,679 relationship to co homology or is that a 745 00:32:13,990 --> 00:32:11,919 whole other can of worms it's another 746 00:32:17,509 --> 00:32:14,000 kind of forms but 747 00:32:19,990 --> 00:32:17,519 in some sense it's not interesting 748 00:32:21,190 --> 00:32:20,000 in in some philosophical sense it's not 749 00:32:27,990 --> 00:32:21,200 interesting 750 00:32:32,230 --> 00:32:30,789 it's essentially the same 751 00:32:34,230 --> 00:32:32,240 so 752 00:32:37,190 --> 00:32:34,240 the difference between a homology and 753 00:32:39,590 --> 00:32:37,200 co-homology more than anything else is a 754 00:32:41,590 --> 00:32:39,600 difference of conventions whether your 755 00:32:42,950 --> 00:32:41,600 map goes from left to right or from 756 00:32:46,549 --> 00:32:42,960 right to left 757 00:32:54,310 --> 00:32:49,590 from this 758 00:32:56,789 --> 00:32:54,320 very imprecise perspective there's 759 00:32:58,710 --> 00:32:56,799 really no difference 760 00:33:00,389 --> 00:32:58,720 professor what do your average days look 761 00:33:03,029 --> 00:33:00,399 like for example do you wake up at the 762 00:33:04,630 --> 00:33:03,039 same time do you drink the same type of 763 00:33:06,149 --> 00:33:04,640 do you drink coffee and it has to be 764 00:33:08,149 --> 00:33:06,159 this particular type of coffee do you 765 00:33:11,350 --> 00:33:08,159 eat a certain breakfast what does it 766 00:33:14,950 --> 00:33:11,360 look like paint the drawer picture 767 00:33:14,960 --> 00:33:18,870 well i'm a lazy bum 768 00:33:22,830 --> 00:33:19,909 and 769 00:33:26,070 --> 00:33:22,840 i'm a believer in the 770 00:33:29,350 --> 00:33:26,080 um you know there was at some point a 771 00:33:31,909 --> 00:33:29,360 revolution right before that uh people 772 00:33:34,470 --> 00:33:31,919 used to work seven days a week uh 12 773 00:33:36,789 --> 00:33:34,480 hours a day or maybe with a short break 774 00:33:38,870 --> 00:33:36,799 on sunday morning 775 00:33:39,990 --> 00:33:38,880 depending which culture you came from i 776 00:33:43,110 --> 00:33:40,000 suppose 777 00:33:45,190 --> 00:33:43,120 and then at some point there was this uh 778 00:33:46,070 --> 00:33:45,200 workers right uh 779 00:33:47,350 --> 00:33:46,080 uh 780 00:33:50,830 --> 00:33:47,360 revolution 781 00:33:54,870 --> 00:33:50,840 and somehow the working week shrunk to 782 00:33:56,630 --> 00:33:54,880 uh 40 hours a week or so like five days 783 00:33:58,149 --> 00:33:56,640 of eight hours 784 00:34:01,750 --> 00:33:58,159 hours a day right 785 00:34:04,870 --> 00:34:01,760 and i'm essentially a believer in that 786 00:34:08,310 --> 00:34:04,880 uh and furthermore i'm a lazy bum so 787 00:34:11,669 --> 00:34:08,320 during my eight hours of work a day 788 00:34:12,629 --> 00:34:11,679 five days a week i take coffee breaks i 789 00:34:15,909 --> 00:34:12,639 uh 790 00:34:16,869 --> 00:34:15,919 you know browse the web i cheat 791 00:34:18,069 --> 00:34:16,879 uh 792 00:34:21,430 --> 00:34:18,079 um 793 00:34:22,869 --> 00:34:21,440 but anyway you know i wake up at 6 30 i 794 00:34:29,990 --> 00:34:22,879 uh 795 00:34:32,869 --> 00:34:30,000 check my email do all sorts of 796 00:34:36,629 --> 00:34:32,879 unimportant things then uh 797 00:34:39,270 --> 00:34:36,639 around nine usually i start uh working 798 00:34:40,790 --> 00:34:39,280 i work until five or so i'm sorry i'm 799 00:34:44,389 --> 00:34:40,800 very dull 800 00:34:49,430 --> 00:34:47,030 and then i try to have fun for the rest 801 00:34:51,669 --> 00:34:49,440 of the day whatever that may be might be 802 00:34:53,030 --> 00:34:51,679 during the pandemic it was it is a bit 803 00:34:56,629 --> 00:34:53,040 harder 804 00:34:58,950 --> 00:34:56,639 and then on the weekends i try to go 805 00:35:01,510 --> 00:34:58,960 biking hiking 806 00:35:03,270 --> 00:35:01,520 puddling 807 00:35:05,430 --> 00:35:03,280 mostly things that don't have to do with 808 00:35:07,510 --> 00:35:05,440 work i'm lying a little bit because 809 00:35:09,510 --> 00:35:07,520 occasionally there is a reason to work 810 00:35:11,910 --> 00:35:09,520 on the weekend and occasionally i do 811 00:35:14,630 --> 00:35:11,920 have a meeting with somebody like i have 812 00:35:16,870 --> 00:35:14,640 an australian collaborator so often our 813 00:35:20,109 --> 00:35:16,880 meetings are in the evenings 814 00:35:23,030 --> 00:35:20,119 so i mean i'm i i've given you an 815 00:35:25,030 --> 00:35:23,040 idealized uh story the truth is a little 816 00:35:27,349 --> 00:35:25,040 different is you know 817 00:35:29,750 --> 00:35:27,359 varies when you're working from nine to 818 00:35:31,670 --> 00:35:29,760 five how much of that time is spent 819 00:35:34,150 --> 00:35:31,680 thinking versus reading someone else's 820 00:35:36,710 --> 00:35:34,160 paper versus answering departmental 821 00:35:39,190 --> 00:35:36,720 emails and requests like what is work 822 00:35:41,349 --> 00:35:39,200 because work obviously for a professor 823 00:35:42,630 --> 00:35:41,359 you have to teach you also have to do 824 00:35:45,349 --> 00:35:42,640 research there's 825 00:35:47,510 --> 00:35:45,359 perhaps 10. work is all of that and it 826 00:35:51,430 --> 00:35:47,520 depends on the season so 827 00:35:55,030 --> 00:35:51,440 basically when i teach two courses 828 00:36:00,710 --> 00:35:57,750 there's basically fall spring and summer 829 00:36:03,670 --> 00:36:00,720 you know fall semester spring semester 830 00:36:05,910 --> 00:36:03,680 and summer okay 831 00:36:07,990 --> 00:36:05,920 in the fall in the spring i teach either 832 00:36:10,550 --> 00:36:08,000 two or one course per semester in the 833 00:36:13,349 --> 00:36:10,560 summer i don't teach 834 00:36:14,470 --> 00:36:13,359 so when i teach two courses per semester 835 00:36:15,430 --> 00:36:14,480 that's 836 00:36:18,870 --> 00:36:15,440 almost 837 00:36:21,430 --> 00:36:18,880 have 838 00:36:22,390 --> 00:36:21,440 uh goes into that 839 00:36:25,109 --> 00:36:22,400 uh 840 00:36:27,670 --> 00:36:25,119 and the rest goes into the regular 841 00:36:30,230 --> 00:36:27,680 meetings that i have to keep 842 00:36:32,150 --> 00:36:30,240 so i have several graduate students that 843 00:36:34,390 --> 00:36:32,160 i work with several collaborators and 844 00:36:35,670 --> 00:36:34,400 i'm trying to keep weekly meetings with 845 00:36:37,750 --> 00:36:35,680 them 846 00:36:40,550 --> 00:36:37,760 so there is a certain amount of like 847 00:36:42,550 --> 00:36:40,560 weekly meetings that i have to keep 848 00:36:45,349 --> 00:36:42,560 when i teach one course 849 00:36:47,829 --> 00:36:45,359 uh i have some breathing room and when i 850 00:36:50,550 --> 00:36:47,839 teach nothing namely during the summer 851 00:36:52,390 --> 00:36:50,560 then a higher proportion goes into 852 00:36:54,630 --> 00:36:52,400 research 853 00:36:55,750 --> 00:36:54,640 even in the summer the proportion is not 854 00:36:57,990 --> 00:36:55,760 very high 855 00:37:00,150 --> 00:36:58,000 firstly is your ideal situation to 856 00:37:01,589 --> 00:37:00,160 simply be a research professor i know 857 00:37:03,589 --> 00:37:01,599 some professors 858 00:37:05,670 --> 00:37:03,599 don't they treat teaching as an aside 859 00:37:10,950 --> 00:37:05,680 they don't particularly like to do it 860 00:37:17,910 --> 00:37:12,950 well 861 00:37:25,270 --> 00:37:20,150 i mean 862 00:37:33,430 --> 00:37:27,510 um 863 00:37:39,430 --> 00:37:36,870 is to support teaching 864 00:37:42,790 --> 00:37:39,440 even the research is so that i will 865 00:37:43,589 --> 00:37:42,800 remain in shape 866 00:37:49,349 --> 00:37:43,599 and 867 00:37:51,349 --> 00:37:49,359 remain in shape so you know if if i do 868 00:37:52,230 --> 00:37:51,359 research i am able to 869 00:37:54,150 --> 00:37:52,240 uh 870 00:37:55,430 --> 00:37:54,160 teach graduate students how to do 871 00:37:57,910 --> 00:37:55,440 research 872 00:37:59,430 --> 00:37:57,920 and then they are 873 00:38:01,510 --> 00:37:59,440 become 874 00:38:05,589 --> 00:38:01,520 stronger mathematicians and can teach 875 00:38:09,030 --> 00:38:05,599 mathematics better so so so so so i even 876 00:38:12,150 --> 00:38:09,040 see researchers mostly uh supporting 877 00:38:16,230 --> 00:38:13,190 so 878 00:38:18,230 --> 00:38:16,240 i definitely wouldn't say that i see 879 00:38:19,750 --> 00:38:18,240 everything as research right i mean 880 00:38:23,109 --> 00:38:19,760 research 881 00:38:25,829 --> 00:38:23,119 again teaching is very significant 882 00:38:28,069 --> 00:38:25,839 well that's the theory 883 00:38:29,910 --> 00:38:28,079 in practice 884 00:38:32,230 --> 00:38:29,920 um 885 00:38:34,790 --> 00:38:32,240 you know waking up every morning and 886 00:38:36,870 --> 00:38:34,800 preparing your class and this marathon 887 00:38:38,230 --> 00:38:36,880 of teaching where you have to prepare 888 00:38:39,670 --> 00:38:38,240 your class 889 00:38:41,990 --> 00:38:39,680 uh you 890 00:38:44,310 --> 00:38:42,000 teach you feel 891 00:38:47,510 --> 00:38:44,320 terrible about the things you missed 892 00:38:49,670 --> 00:38:47,520 during class you don't even have time to 893 00:38:51,829 --> 00:38:49,680 digest it and you have to get ready for 894 00:38:54,150 --> 00:38:51,839 the next class already 895 00:38:55,190 --> 00:38:54,160 so uh 896 00:38:57,670 --> 00:38:55,200 you know 897 00:39:00,069 --> 00:38:57,680 it's very hard 898 00:39:02,950 --> 00:39:00,079 i mean people who haven't done that 899 00:39:06,950 --> 00:39:02,960 don't appreciate how it how hard it is 900 00:39:07,910 --> 00:39:06,960 but it's emotionally very very difficult 901 00:39:12,390 --> 00:39:07,920 and 902 00:39:16,870 --> 00:39:14,790 you have no idea how much i i'm i'm 903 00:39:21,589 --> 00:39:16,880 looking forward to the break so it's not 904 00:39:25,910 --> 00:39:22,950 you know i 905 00:39:27,990 --> 00:39:25,920 when i teach i want out 906 00:39:30,550 --> 00:39:28,000 do you find that to be true even if it's 907 00:39:33,190 --> 00:39:30,560 an undergraduate course the reason i ask 908 00:39:35,589 --> 00:39:33,200 this is that i imagine as a professor 909 00:39:37,270 --> 00:39:35,599 the undergraduate material you could 910 00:39:39,190 --> 00:39:37,280 teach with your pinky you don't have to 911 00:39:40,310 --> 00:39:39,200 think much about it because you first of 912 00:39:43,030 --> 00:39:40,320 all you've mastered it second you've 913 00:39:45,109 --> 00:39:43,040 taught it for years and years i do not 914 00:39:46,630 --> 00:39:45,119 teach the same class 915 00:39:47,589 --> 00:39:46,640 for years 916 00:39:49,829 --> 00:39:47,599 like 917 00:39:50,950 --> 00:39:49,839 i think the maximum i've ever repeated 918 00:39:54,230 --> 00:39:50,960 the class 919 00:39:56,390 --> 00:39:54,240 uh was like three years 920 00:39:57,430 --> 00:39:56,400 so it's not 921 00:40:02,630 --> 00:39:57,440 but 922 00:40:03,589 --> 00:40:02,640 uh you always have to prepare 923 00:40:06,150 --> 00:40:03,599 uh 924 00:40:08,550 --> 00:40:06,160 you always blunder i always blunder 925 00:40:13,349 --> 00:40:08,560 maybe perfect people don't 926 00:40:17,589 --> 00:40:15,190 here and there and then i have to figure 927 00:40:19,030 --> 00:40:17,599 out ways out 928 00:40:22,150 --> 00:40:19,040 i always 929 00:40:25,109 --> 00:40:22,160 find new things to do new ways to do 930 00:40:27,190 --> 00:40:25,119 things i always um 931 00:40:29,829 --> 00:40:27,200 even when i repeat but essentially but 932 00:40:32,710 --> 00:40:29,839 most of the time i don't repeat 933 00:40:36,710 --> 00:40:32,720 and the material is sometimes hard you 934 00:40:41,109 --> 00:40:39,750 and even when it's not hard 935 00:40:44,950 --> 00:40:41,119 so you know 936 00:40:47,349 --> 00:40:44,960 on day one of the class 937 00:40:52,550 --> 00:40:47,359 you teach of a linear algebra class you 938 00:40:59,910 --> 00:40:55,430 i obviously know these axions 939 00:41:02,390 --> 00:40:59,920 right i i obviously um 940 00:41:04,550 --> 00:41:02,400 when i see a vector space 941 00:41:07,430 --> 00:41:04,560 i know it 942 00:41:10,630 --> 00:41:07,440 when i when when you give me a vector 943 00:41:12,950 --> 00:41:10,640 space i know what to do with it 944 00:41:15,349 --> 00:41:12,960 but that's not the same thing 945 00:41:17,589 --> 00:41:15,359 as getting up in front of a class and 946 00:41:18,550 --> 00:41:17,599 listing the axioms 947 00:41:21,349 --> 00:41:18,560 and 948 00:41:24,150 --> 00:41:21,359 making sure that you haven't forgotten 949 00:41:26,790 --> 00:41:24,160 one small axiom somewhere 950 00:41:28,950 --> 00:41:26,800 or that you phrase them perfectly so 951 00:41:31,990 --> 00:41:28,960 that even people who have never seen 952 00:41:33,670 --> 00:41:32,000 these things before will understand 953 00:41:36,390 --> 00:41:33,680 um 954 00:41:39,829 --> 00:41:36,400 so i mean even day one of a very basic 955 00:41:41,270 --> 00:41:39,839 class uh requires preparation 956 00:41:42,710 --> 00:41:41,280 we're gonna talk about mathematical 957 00:41:45,190 --> 00:41:42,720 techniques 958 00:41:46,470 --> 00:41:45,200 in fact i believe when we emailed you 959 00:41:48,630 --> 00:41:46,480 said you don't like the emphasis on 960 00:41:50,790 --> 00:41:48,640 theorems and proofs you like 961 00:41:52,230 --> 00:41:50,800 well we can talk about that later 962 00:41:54,309 --> 00:41:52,240 as for 963 00:41:55,750 --> 00:41:54,319 teaching techniques i'm curious what 964 00:41:58,870 --> 00:41:55,760 have you gleaned what have you found to 965 00:42:01,349 --> 00:41:58,880 be productive and perhaps even some 966 00:42:03,670 --> 00:42:01,359 behaviors you find to be unproductive 967 00:42:07,270 --> 00:42:03,680 that you see other people other teachers 968 00:42:11,270 --> 00:42:09,750 i mean there is so much 969 00:42:13,270 --> 00:42:11,280 uh 970 00:42:14,390 --> 00:42:13,280 you know starting from 971 00:42:19,510 --> 00:42:14,400 com 972 00:42:22,069 --> 00:42:19,520 make sure that you're heard 973 00:42:25,109 --> 00:42:22,079 right if the classroom is large and you 974 00:42:27,270 --> 00:42:25,119 speak without a microphone 975 00:42:29,109 --> 00:42:27,280 uh people in the back are not going to 976 00:42:31,190 --> 00:42:29,119 hear you and then 977 00:42:33,910 --> 00:42:31,200 they're not going to follow 978 00:42:36,710 --> 00:42:33,920 uh make sure that you can be seen 979 00:42:39,510 --> 00:42:36,720 so if you write with a tiny you know if 980 00:42:40,870 --> 00:42:39,520 you write tiny letters with a faded 981 00:42:42,309 --> 00:42:40,880 chalk 982 00:42:46,950 --> 00:42:42,319 uh 983 00:42:48,710 --> 00:42:46,960 the class is a failure no matter what 984 00:42:50,870 --> 00:42:48,720 you say 985 00:42:52,150 --> 00:42:50,880 and then there are uh higher level 986 00:42:56,550 --> 00:42:52,160 things and 987 00:42:58,710 --> 00:42:56,560 basically everything should be motivated 988 00:43:01,349 --> 00:42:58,720 so you know i mentioned the first class 989 00:43:03,910 --> 00:43:01,359 of a linear the first class uh in a 990 00:43:07,510 --> 00:43:03,920 linear algebra course 991 00:43:09,510 --> 00:43:07,520 okay so you can give by uh you can give 992 00:43:12,710 --> 00:43:09,520 by this class 993 00:43:15,430 --> 00:43:12,720 by saying uh you can start this class by 994 00:43:18,990 --> 00:43:15,440 saying let f be 995 00:43:21,990 --> 00:43:20,870 essent 996 00:43:23,510 --> 00:43:22,000 v 997 00:43:24,950 --> 00:43:23,520 is 998 00:43:28,230 --> 00:43:24,960 called 999 00:43:30,710 --> 00:43:28,240 a vector space if 1000 00:43:33,430 --> 00:43:30,720 and then you can write property you know 1001 00:43:35,910 --> 00:43:33,440 operations and properties and you know 1002 00:43:37,190 --> 00:43:35,920 you write item number one to item number 1003 00:43:44,550 --> 00:43:37,200 15 1004 00:43:47,510 --> 00:43:44,560 like alpha times beta times a vector 1005 00:43:49,589 --> 00:43:47,520 you know whatever so one of the axioms 1006 00:43:53,990 --> 00:43:49,599 of a vector field 1007 00:43:55,349 --> 00:43:54,000 okay of a vector sorry a vector space 1008 00:43:58,390 --> 00:43:55,359 uh 1009 00:44:00,390 --> 00:43:58,400 and then the question arises why 1010 00:44:03,910 --> 00:44:00,400 and who cares 1011 00:44:05,829 --> 00:44:03,920 right right okay so if you start your 1012 00:44:08,710 --> 00:44:05,839 class this way 1013 00:44:09,829 --> 00:44:08,720 people aren't going to like it so before 1014 00:44:13,910 --> 00:44:09,839 this 1015 00:44:16,230 --> 00:44:13,920 there has to be a a little section 1016 00:44:18,069 --> 00:44:16,240 i don't know here 1017 00:44:21,190 --> 00:44:18,079 where you explain 1018 00:44:27,349 --> 00:44:24,630 well for such and such reasons we care 1019 00:44:31,270 --> 00:44:27,359 about vector spaces so there has to be 1020 00:44:34,470 --> 00:44:32,230 okay 1021 00:44:37,430 --> 00:44:34,480 and uh 1022 00:44:40,550 --> 00:44:37,440 and that's true 1023 00:44:42,230 --> 00:44:40,560 not only in the first class of the first 1024 00:44:43,910 --> 00:44:42,240 um 1025 00:44:47,270 --> 00:44:43,920 uh 1026 00:44:49,430 --> 00:44:47,280 of a linear algebra of course it's true 1027 00:44:51,990 --> 00:44:49,440 in every class whenever you say 1028 00:44:53,670 --> 00:44:52,000 something there has to be a reason 1029 00:44:55,990 --> 00:44:53,680 and the people who 1030 00:44:59,109 --> 00:44:56,000 um 1031 00:45:00,950 --> 00:44:59,119 who are listening to you uh 1032 00:45:04,309 --> 00:45:00,960 should know that you've thought about it 1033 00:45:06,150 --> 00:45:04,319 should know that you 1034 00:45:07,670 --> 00:45:06,160 that you're telling them these things 1035 00:45:08,870 --> 00:45:07,680 for a reason 1036 00:45:09,750 --> 00:45:08,880 okay 1037 00:45:12,710 --> 00:45:09,760 and 1038 00:45:13,910 --> 00:45:12,720 uh that's often omitted 1039 00:45:16,790 --> 00:45:13,920 it's often 1040 00:45:19,109 --> 00:45:16,800 too easy to just follow the definitions 1041 00:45:21,270 --> 00:45:19,119 in the theorems and never say what 1042 00:45:23,190 --> 00:45:21,280 they're good for 1043 00:45:25,030 --> 00:45:23,200 and um 1044 00:45:29,030 --> 00:45:25,040 and not only you should say these things 1045 00:45:29,040 --> 00:45:34,230 likewise when you write a proof uh 1046 00:45:38,950 --> 00:45:37,589 it's often easy to 1047 00:45:41,589 --> 00:45:38,960 well to 1048 00:45:43,030 --> 00:45:41,599 to so i mean often there is a picture 1049 00:45:47,589 --> 00:45:43,040 behind that proof 1050 00:45:49,750 --> 00:45:47,599 the proof is telling some story and you 1051 00:45:52,550 --> 00:45:49,760 and you want the picture of that story 1052 00:45:55,349 --> 00:45:52,560 in the minds of the students 1053 00:45:57,270 --> 00:45:55,359 but but but but it's often too easy to 1054 00:45:59,670 --> 00:45:57,280 reduce it to a 1055 00:46:02,470 --> 00:45:59,680 list of formulas 1056 00:46:03,990 --> 00:46:02,480 or a list of statements so a higher 1057 00:46:06,230 --> 00:46:04,000 level thing is to make sure that 1058 00:46:07,990 --> 00:46:06,240 everything is motivated 1059 00:46:10,710 --> 00:46:08,000 what else what's another higher level 1060 00:46:12,950 --> 00:46:10,720 aspect of teaching 1061 00:46:15,349 --> 00:46:12,960 that you find is a common mistake among 1062 00:46:18,150 --> 00:46:15,359 the teachers that you see 1063 00:46:23,190 --> 00:46:20,950 i think maybe this is the biggest 1064 00:46:25,510 --> 00:46:23,200 not showing the motivation clearly 1065 00:46:28,470 --> 00:46:25,520 enough 1066 00:46:30,790 --> 00:46:28,480 and by the way 1067 00:46:33,750 --> 00:46:30,800 uh 1068 00:46:37,349 --> 00:46:33,760 that's part of the reason why research 1069 00:46:39,109 --> 00:46:37,359 is a necessary part of teaching 1070 00:46:41,670 --> 00:46:39,119 because 1071 00:46:47,670 --> 00:46:45,430 you have to know the motivation 1072 00:46:51,270 --> 00:46:47,680 you know you can say 1073 00:46:53,670 --> 00:46:51,280 vector spaces are a great thing 1074 00:46:57,109 --> 00:46:53,680 unless you've actually worked with them 1075 00:46:59,589 --> 00:46:57,119 unless you've actually seen them used 1076 00:47:02,870 --> 00:46:59,599 so maybe vector spaces are good and are 1077 00:47:04,069 --> 00:47:02,880 easy enough so that you can um 1078 00:47:05,910 --> 00:47:04,079 uh 1079 00:47:07,990 --> 00:47:05,920 um 1080 00:47:10,069 --> 00:47:08,000 you know by third year you understand 1081 00:47:12,790 --> 00:47:10,079 why you why you learned about them in 1082 00:47:17,589 --> 00:47:15,190 but if you want to be able to say 1083 00:47:19,670 --> 00:47:17,599 something intelligent about homology you 1084 00:47:22,829 --> 00:47:19,680 have to have used it 1085 00:47:25,510 --> 00:47:22,839 the only way to use it is in research 1086 00:47:27,030 --> 00:47:25,520 so uh 1087 00:47:29,030 --> 00:47:27,040 uh 1088 00:47:33,670 --> 00:47:29,040 so that's what i meant by you have to be 1089 00:47:35,190 --> 00:47:33,680 in shape being in shape also means 1090 00:47:38,950 --> 00:47:35,200 remember what 1091 00:47:41,109 --> 00:47:38,960 what can be done with these things 1092 00:47:42,390 --> 00:47:41,119 do you find that you're more creative as 1093 00:47:44,790 --> 00:47:42,400 you get older 1094 00:47:50,790 --> 00:47:44,800 or that your creativity peaked at a 1095 00:47:55,190 --> 00:47:52,950 i you 1096 00:47:57,190 --> 00:47:55,200 you know i i wish i could answer the 1097 00:47:59,430 --> 00:47:57,200 truth is that 1098 00:48:04,069 --> 00:47:59,440 i don't really remember 1099 00:48:09,270 --> 00:48:06,790 it's very hard to remember myself at any 1100 00:48:11,270 --> 00:48:09,280 other age 1101 00:48:13,349 --> 00:48:11,280 so i mean certainly 1102 00:48:15,910 --> 00:48:13,359 um 1103 00:48:18,470 --> 00:48:15,920 i have matured 1104 00:48:21,829 --> 00:48:18,480 so the little i can remember from 20 or 1105 00:48:22,630 --> 00:48:21,839 30 years ago um 1106 00:48:30,309 --> 00:48:22,640 is 1107 00:48:38,069 --> 00:48:34,069 i'm more systematic perhaps 1108 00:48:45,109 --> 00:48:41,030 am i smarter am i more creative am i 1109 00:48:46,150 --> 00:48:45,119 stupider am i less creative i'm not sure 1110 00:48:47,750 --> 00:48:46,160 what do you mean when you say you're 1111 00:48:48,950 --> 00:48:47,760 more systematic now can you give an 1112 00:48:52,549 --> 00:48:48,960 example of how you would look at a 1113 00:49:01,190 --> 00:48:52,559 certain problem now or solve it versus 1114 00:49:06,230 --> 00:49:03,750 and also a sub question do you see being 1115 00:49:08,309 --> 00:49:06,240 systematic as a good thing or do you see 1116 00:49:10,790 --> 00:49:08,319 there being innovation in being 1117 00:49:12,309 --> 00:49:10,800 disorganized or creativity embedded 1118 00:49:16,790 --> 00:49:12,319 there 1119 00:49:25,349 --> 00:49:16,800 no systematic is generally better 1120 00:49:31,030 --> 00:49:26,549 much 1121 00:49:32,790 --> 00:49:31,040 more into the low hanging fruits 1122 00:49:36,790 --> 00:49:32,800 so 1123 00:49:39,910 --> 00:49:38,150 but 1124 00:49:45,510 --> 00:49:39,920 [Music] 1125 00:49:45,520 --> 00:49:50,470 i'd uh 1126 00:49:54,470 --> 00:49:52,950 like wait for opportunities and and then 1127 00:49:56,829 --> 00:49:54,480 use them 1128 00:50:02,470 --> 00:49:59,109 uh and 1129 00:50:07,270 --> 00:50:05,190 now it's much more i have a long-term 1130 00:50:08,150 --> 00:50:07,280 goal 1131 00:50:12,950 --> 00:50:08,160 uh 1132 00:50:16,470 --> 00:50:12,960 a theory of something 1133 00:50:18,870 --> 00:50:16,480 you know your your your uh 1134 00:50:21,750 --> 00:50:18,880 podcast is a theory of everything right 1135 00:50:24,390 --> 00:50:21,760 i just want a theory of something 1136 00:50:27,430 --> 00:50:24,400 so i want a theory of something because 1137 00:50:29,349 --> 00:50:27,440 i i feel for various reasons that it 1138 00:50:30,549 --> 00:50:29,359 ought to be there 1139 00:50:31,080 --> 00:50:30,559 and then i 1140 00:50:32,230 --> 00:50:31,090 um 1141 00:50:34,549 --> 00:50:32,240 [Music] 1142 00:50:35,589 --> 00:50:34,559 worked very hard 1143 00:50:38,069 --> 00:50:35,599 on 1144 00:50:40,950 --> 00:50:38,079 well very hard to my standards i already 1145 00:50:43,910 --> 00:50:40,960 admitted being a bomb so um 1146 00:50:44,870 --> 00:50:43,920 you know i i worked at least for a long 1147 00:50:49,030 --> 00:50:44,880 time 1148 00:50:52,150 --> 00:50:49,040 uh trying to find that theory 1149 00:50:54,630 --> 00:50:52,160 you know even assist even even at a very 1150 00:50:55,430 --> 00:50:54,640 at a much lower level 1151 00:50:56,309 --> 00:50:55,440 uh 1152 00:51:00,470 --> 00:50:56,319 so 1153 00:51:03,910 --> 00:51:01,349 uh 1154 00:51:05,750 --> 00:51:03,920 you know so you know math theorems and 1155 00:51:09,270 --> 00:51:05,760 proofs were 1156 00:51:11,349 --> 00:51:09,280 pressed into my brain was essentially an 1157 00:51:13,829 --> 00:51:11,359 external process right so i went to 1158 00:51:15,910 --> 00:51:13,839 classes and people pushed theorems into 1159 00:51:17,030 --> 00:51:15,920 my brain 1160 00:51:19,670 --> 00:51:17,040 and 1161 00:51:25,990 --> 00:51:20,829 some of 1162 00:51:28,790 --> 00:51:26,000 them seemed like complete formalities 1163 00:51:34,309 --> 00:51:31,990 a sequence of deductions 1164 00:51:36,870 --> 00:51:34,319 uh that i could have that i could 1165 00:51:39,430 --> 00:51:36,880 memorize and i could 1166 00:51:43,670 --> 00:51:39,440 verify 1167 00:51:46,790 --> 00:51:43,680 but were essentially created by aliens 1168 00:51:47,990 --> 00:51:46,800 you know i i had no idea how they came 1169 00:51:51,109 --> 00:51:48,000 to be 1170 00:51:52,230 --> 00:51:51,119 right in some theorems 1171 00:51:53,670 --> 00:51:52,240 uh 1172 00:51:54,790 --> 00:51:53,680 immediately 1173 00:51:57,270 --> 00:51:54,800 uh 1174 00:51:59,190 --> 00:51:57,280 became a picture i immediately 1175 00:52:01,030 --> 00:51:59,200 understood 1176 00:52:03,030 --> 00:52:01,040 uh 1177 00:52:08,230 --> 00:52:03,040 that 1178 00:52:11,109 --> 00:52:08,240 geometric reality 1179 00:52:13,349 --> 00:52:11,119 okay describe 1180 00:52:14,790 --> 00:52:13,359 i i i i could see the intuition behind 1181 00:52:16,390 --> 00:52:14,800 the proof 1182 00:52:17,990 --> 00:52:16,400 it's not always geometric though it's 1183 00:52:19,990 --> 00:52:18,000 just you see the internet necessarily 1184 00:52:22,470 --> 00:52:20,000 geometric i mean but i could see somehow 1185 00:52:24,870 --> 00:52:22,480 the motivation the the the i i could 1186 00:52:27,270 --> 00:52:24,880 imagine how the proof was discovered 1187 00:52:29,910 --> 00:52:27,280 i think i i i would get the feeling that 1188 00:52:31,910 --> 00:52:29,920 i understood the proof and there and and 1189 00:52:34,069 --> 00:52:31,920 that was essentially a dichotomy some 1190 00:52:37,270 --> 00:52:34,079 pictures some proofs 1191 00:52:39,190 --> 00:52:37,280 or some concept were of that type 1192 00:52:42,710 --> 00:52:39,200 made by aliens 1193 00:52:44,829 --> 00:52:42,720 and pushed into my brain by professors 1194 00:52:50,230 --> 00:52:44,839 and other 1195 00:52:53,349 --> 00:52:50,240 um uh concepts theorems proofs whatever 1196 00:52:56,390 --> 00:52:53,359 were clearly intuitive and made sense 1197 00:52:58,950 --> 00:52:56,400 and and i understood them 1198 00:53:01,270 --> 00:52:58,960 uh and that was it that was the world 1199 00:53:04,870 --> 00:53:01,280 there was this and there were those 1200 00:53:07,109 --> 00:53:04,880 and then sometime later in second year i 1201 00:53:09,750 --> 00:53:07,119 actually did my ba very very very 1202 00:53:12,069 --> 00:53:09,760 quickly so uh basically 1203 00:53:13,910 --> 00:53:12,079 i did it in essentially two years 1204 00:53:15,750 --> 00:53:13,920 so when i say second year you should 1205 00:53:18,470 --> 00:53:15,760 compare it maybe with year three and 1206 00:53:22,309 --> 00:53:18,480 four of um most students 1207 00:53:23,990 --> 00:53:22,319 so somewhere later in late in my studies 1208 00:53:27,589 --> 00:53:24,000 i realized 1209 00:53:30,630 --> 00:53:27,599 that if i think harder 1210 00:53:34,069 --> 00:53:30,640 about the theorems that 1211 00:53:35,349 --> 00:53:34,079 uh or the concepts that appear to be 1212 00:53:37,829 --> 00:53:35,359 alien 1213 00:53:40,870 --> 00:53:37,839 then sooner or later 1214 00:53:43,109 --> 00:53:40,880 i see the picture behind them sooner or 1215 00:53:43,910 --> 00:53:43,119 later i realize 1216 00:53:44,950 --> 00:53:43,920 uh 1217 00:53:46,790 --> 00:53:44,960 that 1218 00:53:47,750 --> 00:53:46,800 i i'm able to move them to the other 1219 00:53:53,109 --> 00:53:47,760 class 1220 00:53:56,950 --> 00:53:53,119 and and and um 1221 00:53:58,069 --> 00:53:56,960 and understand it and understood 1222 00:54:01,349 --> 00:53:58,079 and 1223 00:54:02,549 --> 00:54:01,359 it 1224 00:54:09,829 --> 00:54:02,559 so 1225 00:54:12,549 --> 00:54:09,839 i may learn it from a book that 1226 00:54:15,030 --> 00:54:12,559 describes it as a formula 1227 00:54:18,150 --> 00:54:15,040 okay and then i'll struggle to see the 1228 00:54:20,470 --> 00:54:18,160 intuition behind the formula 1229 00:54:23,510 --> 00:54:20,480 and so even at that level it's it's 1230 00:54:27,990 --> 00:54:23,520 something that took learning 1231 00:54:33,670 --> 00:54:31,109 again when i got to the university 1232 00:54:36,069 --> 00:54:33,680 you know when i when i was in first year 1233 00:54:38,950 --> 00:54:36,079 i took classes and i got good gr good 1234 00:54:42,150 --> 00:54:38,960 grades in in in all of them 1235 00:54:46,230 --> 00:54:43,670 and nevertheless 1236 00:54:51,190 --> 00:54:48,470 there was a point where 1237 00:54:53,270 --> 00:54:51,200 where things became better where where i 1238 00:54:55,990 --> 00:54:53,280 realize i can actually 1239 00:54:58,549 --> 00:54:56,000 understand everything 1240 00:55:00,069 --> 00:54:58,559 and not just repeat everything 1241 00:55:01,750 --> 00:55:00,079 and that came later 1242 00:55:03,829 --> 00:55:01,760 what does that process of finding the 1243 00:55:05,430 --> 00:55:03,839 intuition behind let's say a formula 1244 00:55:07,349 --> 00:55:05,440 that before you 1245 00:55:10,069 --> 00:55:07,359 previously simply had to memorize as 1246 00:55:12,150 --> 00:55:10,079 handed down from the gods or the aliens 1247 00:55:14,470 --> 00:55:12,160 what does that process look like the 1248 00:55:16,069 --> 00:55:14,480 process of finding the intuition does it 1249 00:55:17,750 --> 00:55:16,079 look like 1250 00:55:20,870 --> 00:55:17,760 i'm sure it's a variety of these but 1251 00:55:23,190 --> 00:55:20,880 does it majorly look like you copy it 1252 00:55:24,549 --> 00:55:23,200 down with the pen and paper precisely 1253 00:55:26,549 --> 00:55:24,559 and then you draw arrows and you say 1254 00:55:28,870 --> 00:55:26,559 okay so what's an example of this what's 1255 00:55:30,549 --> 00:55:28,880 a counter example of this or is it you 1256 00:55:32,710 --> 00:55:30,559 go on a bike ride and you keep thinking 1257 00:55:34,630 --> 00:55:32,720 about it what does that process look 1258 00:55:37,109 --> 00:55:34,640 like perhaps it would be edifying if you 1259 00:55:39,589 --> 00:55:37,119 took a specific example but if you can't 1260 00:55:42,309 --> 00:55:39,599 then just give the broad strokes 1261 00:55:45,910 --> 00:55:44,069 you know what it what does it look like 1262 00:55:48,390 --> 00:55:45,920 from the outside from the outside it 1263 00:55:51,270 --> 00:55:48,400 looks like i'm sitting on my chair and 1264 00:55:52,710 --> 00:55:51,280 staring into the into infinity 1265 00:55:54,710 --> 00:55:52,720 right or 1266 00:55:57,750 --> 00:55:54,720 sitting on my balcony and looking at the 1267 00:55:57,760 --> 00:56:16,230 what does it look like inside 1268 00:56:16,240 --> 00:56:32,549 it's very hard to answer without 1269 00:56:38,470 --> 00:56:35,109 without going through specific examples 1270 00:56:40,870 --> 00:56:38,480 and the specific examples are 1271 00:56:43,030 --> 00:56:40,880 far too complex or i i don't know if 1272 00:56:45,270 --> 00:56:43,040 they are far too complex but they fit in 1273 00:56:48,470 --> 00:56:45,280 a math class 1274 00:56:50,630 --> 00:56:48,480 and the other thing is um 1275 00:56:52,630 --> 00:56:50,640 you will never see these examples in my 1276 00:56:55,190 --> 00:56:52,640 classes because when i teach something i 1277 00:56:56,470 --> 00:56:55,200 try to motivate it 1278 00:56:59,349 --> 00:56:56,480 okay 1279 00:57:01,510 --> 00:56:59,359 so you will not see the alternative 1280 00:57:04,630 --> 00:57:01,520 okay you will see the motivated way of 1281 00:57:08,150 --> 00:57:04,640 explaining uh uh the 1282 00:57:12,789 --> 00:57:08,160 implicit function theorem or the uh 1283 00:57:15,589 --> 00:57:12,799 change of variables formula for multi 1284 00:57:21,270 --> 00:57:15,599 integrals right you'll see the motivated 1285 00:57:24,829 --> 00:57:23,030 i will not be showing you the 1286 00:57:27,430 --> 00:57:24,839 unmotivated 1287 00:57:29,349 --> 00:57:27,440 formulas for you much of the time when 1288 00:57:32,789 --> 00:57:29,359 it's difficult for you to understand a 1289 00:57:34,150 --> 00:57:32,799 proof or a theorem or concept is it 1290 00:57:42,710 --> 00:57:34,160 most of the time because it was 1291 00:57:47,030 --> 00:57:45,109 well the intuition is not explained 1292 00:57:50,390 --> 00:57:47,040 often 1293 00:57:54,549 --> 00:57:50,400 so in textbooks 1294 00:57:54,559 --> 00:58:06,829 often the intuition is not explained 1295 00:58:10,549 --> 00:58:08,549 now 1296 00:58:12,309 --> 00:58:10,559 some intuition is just getting used to 1297 00:58:15,270 --> 00:58:12,319 the concepts 1298 00:58:18,630 --> 00:58:15,280 so sometimes intuition is not is not 1299 00:58:22,390 --> 00:58:20,470 it's just playing around until you're 1300 00:58:23,829 --> 00:58:22,400 used to it 1301 00:58:24,870 --> 00:58:23,839 you know 1302 00:58:27,190 --> 00:58:24,880 uh 1303 00:58:30,470 --> 00:58:27,200 you've just landed in a foreign city 1304 00:58:31,589 --> 00:58:30,480 you've just landed in athens 1305 00:58:33,430 --> 00:58:31,599 uh 1306 00:58:37,109 --> 00:58:33,440 your hotel 1307 00:58:39,670 --> 00:58:37,119 is two kilometers from the acropolis 1308 00:58:40,950 --> 00:58:39,680 uh you got there at night you wake up in 1309 00:58:42,630 --> 00:58:40,960 the morning you want to go to the 1310 00:58:43,990 --> 00:58:42,640 acropolis 1311 00:58:47,030 --> 00:58:44,000 you 1312 00:58:49,990 --> 00:58:47,040 punch acropolis into google maps 1313 00:58:52,230 --> 00:58:50,000 and google maps tells you 1314 00:58:54,069 --> 00:58:52,240 you know go left go right go straight go 1315 00:58:56,390 --> 00:58:54,079 left go right and here's the cro 1316 00:58:58,950 --> 00:58:56,400 acropolis okay you follow the 1317 00:59:02,069 --> 00:58:58,960 instructions 1318 00:59:05,510 --> 00:59:02,079 you didn't learn atoms 1319 00:59:07,990 --> 00:59:05,520 you've learned the way to the acropolis 1320 00:59:10,230 --> 00:59:08,000 uh to learn athens 1321 00:59:12,870 --> 00:59:10,240 uh 1322 00:59:15,990 --> 00:59:12,880 in the afternoon after the acropolis you 1323 00:59:17,910 --> 00:59:16,000 have to wander around 1324 00:59:20,870 --> 00:59:17,920 uh and then you have to continue 1325 00:59:23,270 --> 00:59:20,880 wandering around for the next two weeks 1326 00:59:26,950 --> 00:59:23,280 and then maybe you're starting to have a 1327 00:59:29,670 --> 00:59:26,960 grasp of what athens is 1328 00:59:31,589 --> 00:59:29,680 so there is similar 1329 00:59:33,589 --> 00:59:31,599 there is something similar in in 1330 00:59:36,789 --> 00:59:33,599 mathematics 1331 00:59:38,950 --> 00:59:36,799 okay or in science or in fact in every 1332 00:59:42,470 --> 00:59:38,960 field of learning okay i mean but in 1333 00:59:44,870 --> 00:59:42,480 mathematics you know um 1334 00:59:46,630 --> 00:59:44,880 uh you don't 1335 00:59:48,309 --> 00:59:46,640 uh 1336 00:59:56,789 --> 00:59:48,319 learn 1337 00:59:58,390 --> 00:59:56,799 most interesting result result in a 1338 01:00:01,589 --> 00:59:58,400 certain field 1339 01:00:04,309 --> 01:00:01,599 you haven't learned the field 1340 01:00:07,109 --> 01:00:04,319 okay you've just learned and especially 1341 01:00:09,109 --> 01:00:07,119 if you if you follow the directions by 1342 01:00:10,870 --> 01:00:09,119 somebody else 1343 01:00:12,870 --> 01:00:10,880 okay 1344 01:00:14,390 --> 01:00:12,880 the learning happens if you wander 1345 01:00:16,230 --> 01:00:14,400 around later 1346 01:00:18,230 --> 01:00:16,240 and in a way you have to do it on your 1347 01:00:20,710 --> 01:00:18,240 own 1348 01:00:22,470 --> 01:00:20,720 right this this wandering around so 1349 01:00:25,430 --> 01:00:22,480 wandering around in mathematics means 1350 01:00:26,150 --> 01:00:25,440 you experiment you change the conditions 1351 01:00:34,069 --> 01:00:26,160 you 1352 01:00:40,950 --> 01:00:34,079 situations 1353 01:00:45,190 --> 01:00:43,030 well so i mean 1354 01:00:47,750 --> 01:00:45,200 like part of tourism you do with a tour 1355 01:00:49,990 --> 01:00:47,760 guide and part of an and a part you have 1356 01:00:56,470 --> 01:00:50,000 to do on your own on your own 1357 01:00:56,480 --> 01:01:02,069 uh so so so so some part of uh 1358 01:01:09,109 --> 01:01:04,549 being systematic if you wish is doing 1359 01:01:12,630 --> 01:01:09,119 this on my own thing in a systematic way 1360 01:01:15,190 --> 01:01:12,640 okay this realization that i can just 1361 01:01:18,309 --> 01:01:15,200 jump into a topic by 1362 01:01:19,589 --> 01:01:18,319 following somebody's guidance 1363 01:01:22,789 --> 01:01:19,599 i i 1364 01:01:26,630 --> 01:01:22,799 i must sit down and think and ask myself 1365 01:01:30,309 --> 01:01:26,640 many many many many more questions and 1366 01:01:34,230 --> 01:01:30,319 go on side tracks and until until it's 1367 01:01:38,470 --> 01:01:36,470 now in this example 1368 01:01:40,950 --> 01:01:38,480 let me let me see if i'm understanding 1369 01:01:42,390 --> 01:01:40,960 it correctly let's say athens athens the 1370 01:01:44,390 --> 01:01:42,400 city and then you have the acropolis 1371 01:01:45,589 --> 01:01:44,400 which is a landmark so that's almost 1372 01:01:47,430 --> 01:01:45,599 like a landmark theorem and then the 1373 01:01:48,549 --> 01:01:47,440 directions are the proof and the steps 1374 01:01:49,829 --> 01:01:48,559 to get there 1375 01:01:51,349 --> 01:01:49,839 would you say and you're saying the 1376 01:01:52,789 --> 01:01:51,359 learning comes from the wandering would 1377 01:01:55,510 --> 01:01:52,799 you say that when you first land in 1378 01:01:57,109 --> 01:01:55,520 athens you should wander or should you 1379 01:01:58,470 --> 01:01:57,119 learn the major landmarks and the 1380 01:02:00,549 --> 01:01:58,480 directions to get there perhaps 1381 01:02:02,230 --> 01:02:00,559 forgetting the directions you just get 1382 01:02:04,870 --> 01:02:02,240 yourself there so that you see what the 1383 01:02:06,630 --> 01:02:04,880 landmarks are like later you wonder the 1384 01:02:08,309 --> 01:02:06,640 analogy would be you learn the major 1385 01:02:09,670 --> 01:02:08,319 theorems and then later you try and get 1386 01:02:11,589 --> 01:02:09,680 the intuition by playing around with 1387 01:02:15,190 --> 01:02:11,599 them or do you play from the get-go i 1388 01:02:17,430 --> 01:02:15,200 mean there has to be a bit of both 1389 01:02:20,069 --> 01:02:17,440 uh basically you know if you land in 1390 01:02:23,270 --> 01:02:20,079 athens and start wondering randomly you 1391 01:02:26,470 --> 01:02:23,280 end up you may end up wandering randomly 1392 01:02:29,029 --> 01:02:26,480 in a completely uninteresting direction 1393 01:02:31,270 --> 01:02:29,039 plus there is a fear factor 1394 01:02:32,870 --> 01:02:31,280 and you know you may feared about 1395 01:02:35,270 --> 01:02:32,880 neighborhoods 1396 01:02:37,829 --> 01:02:35,280 interesting but but but but there 1397 01:02:39,670 --> 01:02:37,839 actually is an analog an analogy in 1398 01:02:40,950 --> 01:02:39,680 mathematics or 1399 01:02:45,910 --> 01:02:40,960 it 1400 01:02:48,870 --> 01:02:45,920 things and the guidance 1401 01:02:50,950 --> 01:02:48,880 can help you overcome the fear but maybe 1402 01:02:53,430 --> 01:02:50,960 fear is not the right way i mean think 1403 01:02:55,270 --> 01:02:53,440 that you have to explore atoms when when 1404 01:02:57,190 --> 01:02:55,280 it's dark 1405 01:02:59,589 --> 01:02:57,200 okay so you simply don't know which way 1406 01:03:01,589 --> 01:02:59,599 to go you just land 1407 01:03:03,750 --> 01:03:01,599 you know i tell you think about vector 1408 01:03:05,589 --> 01:03:03,760 spaces you have no idea what good 1409 01:03:08,789 --> 01:03:05,599 questions to ask are what are the good 1410 01:03:12,630 --> 01:03:09,750 and 1411 01:03:17,670 --> 01:03:14,150 [Music] 1412 01:03:19,670 --> 01:03:17,680 so you need guidance 1413 01:03:21,349 --> 01:03:19,680 or else you will be stuck in one 1414 01:03:23,430 --> 01:03:21,359 neighborhood and never realize that 1415 01:03:25,990 --> 01:03:23,440 there is more than that 1416 01:03:27,829 --> 01:03:26,000 but you know after the guidance took you 1417 01:03:31,829 --> 01:03:27,839 from here to there 1418 01:03:37,510 --> 01:03:34,870 go back and explore and explore more and 1419 01:03:40,630 --> 01:03:37,520 explore more and until you until it's a 1420 01:03:42,549 --> 01:03:40,640 solid and not just a single path 1421 01:03:44,950 --> 01:03:42,559 so you have to do your own finding path 1422 01:03:48,710 --> 01:03:44,960 integral over the space of mathematical 1423 01:03:50,069 --> 01:03:48,720 ideas there is a bit of that yes 1424 01:03:53,430 --> 01:03:50,079 what's your greatest strength as a 1425 01:03:56,549 --> 01:03:53,440 mathematician or some of your strengths 1426 01:04:00,069 --> 01:03:56,559 who says i have strengthens 1427 01:04:04,309 --> 01:04:02,390 i'm a lazy bum 1428 01:04:06,069 --> 01:04:04,319 are you being modest when you say that 1429 01:04:07,829 --> 01:04:06,079 because i imagine someone who has an 1430 01:04:09,750 --> 01:04:07,839 accelerated degree two-year degree that 1431 01:04:11,510 --> 01:04:09,760 should ordinarily take four years it's 1432 01:04:14,069 --> 01:04:11,520 not as if you spend the majority of your 1433 01:04:16,710 --> 01:04:14,079 time playing video games and 1434 01:04:20,069 --> 01:04:16,720 and being on industrious oh you'll be 1435 01:04:23,430 --> 01:04:21,589 uh 1436 01:04:29,349 --> 01:04:23,440 i mean of course i didn't play video 1437 01:04:35,349 --> 01:04:33,109 you know video video games came later 1438 01:04:36,470 --> 01:04:35,359 uh 1439 01:04:39,349 --> 01:04:36,480 but 1440 01:04:40,950 --> 01:04:39,359 i definitely killed a lot of time 1441 01:04:43,430 --> 01:04:40,960 so who are you comparing yourself to 1442 01:04:45,910 --> 01:04:43,440 when you say that you're slothful 1443 01:04:51,829 --> 01:04:45,920 gee i compare i compare myself to who i 1444 01:05:04,069 --> 01:04:53,109 anyway 1445 01:05:10,630 --> 01:05:07,109 i think i'm decently good at explaining 1446 01:05:10,640 --> 01:05:13,670 um 1447 01:05:18,069 --> 01:05:17,029 often that involves thinking about them 1448 01:05:20,630 --> 01:05:18,079 i mean 1449 01:05:24,710 --> 01:05:20,640 explaining is not just 1450 01:05:30,309 --> 01:05:26,789 reproducing what you've heard somewhere 1451 01:05:33,910 --> 01:05:30,319 else i mean it's it's first of all 1452 01:05:35,430 --> 01:05:33,920 being creative about these things 1453 01:05:37,029 --> 01:05:35,440 um 1454 01:05:41,190 --> 01:05:37,039 but you know 1455 01:05:44,789 --> 01:05:42,870 ask the students 1456 01:05:46,549 --> 01:05:44,799 ask the people who listen to me in 1457 01:05:48,829 --> 01:05:46,559 lectures 1458 01:05:53,589 --> 01:05:48,839 when i give research 1459 01:05:58,789 --> 01:05:55,430 it's very hard to 1460 01:06:03,430 --> 01:06:00,630 you know 1461 01:06:05,589 --> 01:06:03,440 there's a famous uh story about einstein 1462 01:06:08,390 --> 01:06:05,599 that 1463 01:06:10,789 --> 01:06:08,400 somebody complained to einstein about 1464 01:06:12,950 --> 01:06:10,799 his problems with math 1465 01:06:15,349 --> 01:06:12,960 and their reference was to high school 1466 01:06:16,630 --> 01:06:15,359 math like i never got high school math 1467 01:06:19,349 --> 01:06:16,640 and 1468 01:06:23,109 --> 01:06:19,359 einstein said let me assure you that my 1469 01:06:24,789 --> 01:06:23,990 uh 1470 01:06:25,990 --> 01:06:24,799 so 1471 01:06:28,309 --> 01:06:26,000 uh 1472 01:06:29,589 --> 01:06:28,319 sort of meaning what what did he mean by 1473 01:06:31,589 --> 01:06:29,599 that 1474 01:06:36,390 --> 01:06:31,599 you know i 1475 01:06:42,789 --> 01:06:39,589 all his life struggling with mathematics 1476 01:06:47,349 --> 01:06:42,799 not just high school time 1477 01:06:49,190 --> 01:06:47,359 okay so in a similar way uh gee i'm 1478 01:06:51,430 --> 01:06:49,200 sorry i mean now it might sound like i 1479 01:06:52,470 --> 01:06:51,440 need some analogy which i do i'm not 1480 01:06:55,589 --> 01:06:52,480 making 1481 01:06:57,029 --> 01:06:55,599 i understand trust me uh but but still 1482 01:07:01,109 --> 01:06:57,039 um 1483 01:07:03,510 --> 01:07:01,119 you know i like to implement 1484 01:07:06,069 --> 01:07:03,520 i like to compute things 1485 01:07:08,470 --> 01:07:06,079 implement them on the computer 1486 01:07:12,230 --> 01:07:08,480 which means that i spend a lot of time 1487 01:07:15,109 --> 01:07:12,240 programming the concepts i work on 1488 01:07:18,309 --> 01:07:15,119 turning them into running programs 1489 01:07:20,069 --> 01:07:18,319 you could say it's my strength but when 1490 01:07:22,230 --> 01:07:20,079 i look at it 1491 01:07:24,470 --> 01:07:22,240 all i see is that i'm struggling and 1492 01:07:26,710 --> 01:07:24,480 struggling and struggling and failing 1493 01:07:28,470 --> 01:07:26,720 and here and then here and there there 1494 01:07:30,549 --> 01:07:28,480 is a minor success 1495 01:07:32,549 --> 01:07:30,559 which gets superseded a little bit later 1496 01:07:33,349 --> 01:07:32,559 by somebody else 1497 01:07:34,710 --> 01:07:33,359 so 1498 01:07:37,349 --> 01:07:34,720 um 1499 01:07:40,069 --> 01:07:37,359 yeah maybe one of my strengths is the 1500 01:07:44,789 --> 01:07:40,079 ability to implement things 1501 01:07:49,510 --> 01:07:47,109 you know turn mathematical concepts into 1502 01:07:50,630 --> 01:07:49,520 running programs 1503 01:07:52,789 --> 01:07:50,640 uh 1504 01:07:56,309 --> 01:07:52,799 but it's also one of the things that 1505 01:07:58,630 --> 01:07:56,319 that keeps me depressed uh was so much 1506 01:08:00,309 --> 01:07:58,640 of my time 1507 01:08:02,950 --> 01:08:00,319 some people who are watching this they 1508 01:08:04,630 --> 01:08:02,960 may be discouraged because they were 1509 01:08:07,670 --> 01:08:04,640 they weren't particularly great at high 1510 01:08:09,270 --> 01:08:07,680 school mathematics or some people may 1511 01:08:11,510 --> 01:08:09,280 have struggled during their undergrad 1512 01:08:12,789 --> 01:08:11,520 what advice do you have for those people 1513 01:08:15,589 --> 01:08:12,799 if they want to continue to learn 1514 01:08:17,110 --> 01:08:15,599 mathematics or physics at a 1515 01:08:19,430 --> 01:08:17,120 graduate perhaps even larger than 1516 01:08:21,189 --> 01:08:19,440 graduate phd level 1517 01:08:23,430 --> 01:08:21,199 do they just continue 1518 01:08:25,669 --> 01:08:23,440 plugging away and not feel discouraged 1519 01:08:28,709 --> 01:08:25,679 because they feel like in imbecile on a 1520 01:08:35,110 --> 01:08:31,829 what advice do you have for them 1521 01:08:37,030 --> 01:08:35,120 there is chug along 1522 01:08:39,269 --> 01:08:37,040 and there is realize when it's not 1523 01:08:41,269 --> 01:08:39,279 working 1524 01:08:43,430 --> 01:08:41,279 and i hate to tell you that i don't know 1525 01:08:45,189 --> 01:08:43,440 i mean i can't give you a 1526 01:08:58,470 --> 01:08:45,199 a 1527 01:09:02,550 --> 01:08:58,480 struggle until 1528 01:09:04,470 --> 01:09:02,560 they succeed sometimes some people don't 1529 01:09:08,630 --> 01:09:04,480 uh or they struggle and struggle and 1530 01:09:08,640 --> 01:09:13,669 you get 1531 01:09:13,679 --> 01:09:18,870 feedback 1532 01:09:22,070 --> 01:09:19,829 i mean 1533 01:09:24,070 --> 01:09:22,080 some people depend on daily feedback 1534 01:09:26,789 --> 01:09:24,080 some people can leave with a feedback 1535 01:09:32,470 --> 01:09:26,799 with a bit of feedback once a year 1536 01:09:32,480 --> 01:09:36,550 a clear answer 1537 01:09:41,030 --> 01:09:38,789 what did you learn from ed whitton with 1538 01:09:42,630 --> 01:09:41,040 respect to mathematical techniques or 1539 01:09:43,749 --> 01:09:42,640 meta mathematical so how you should 1540 01:09:46,630 --> 01:09:43,759 think about 1541 01:09:46,640 --> 01:09:53,749 or physics 1542 01:09:57,030 --> 01:09:56,149 well i learned specific mathematics from 1543 01:09:59,510 --> 01:09:57,040 him 1544 01:10:02,630 --> 01:09:59,520 right so you know i learned like many 1545 01:10:04,630 --> 01:10:02,640 other people i learned this formula 1546 01:10:06,870 --> 01:10:04,640 from him 1547 01:10:09,910 --> 01:10:06,880 right and how to read it and how to use 1548 01:10:11,910 --> 01:10:09,920 use it interpret it work with it right 1549 01:10:15,030 --> 01:10:11,920 do things with it 1550 01:10:16,390 --> 01:10:15,040 but i learned many other specific things 1551 01:10:18,950 --> 01:10:16,400 with him 1552 01:10:26,550 --> 01:10:22,550 um 1553 01:10:31,110 --> 01:10:26,560 mean like 1554 01:10:36,390 --> 01:10:32,470 researcher 1555 01:10:39,590 --> 01:10:36,400 but he's also a great expositor 1556 01:10:39,600 --> 01:10:45,030 when you come to his lectures 1557 01:10:47,830 --> 01:10:46,870 he is 1558 01:10:50,229 --> 01:10:47,840 uh 1559 01:10:52,709 --> 01:10:50,239 able to make 1560 01:10:54,870 --> 01:10:52,719 even very complicated things appear 1561 01:10:56,550 --> 01:10:54,880 simple 1562 01:10:59,110 --> 01:10:56,560 uh 1563 01:11:01,990 --> 01:10:59,120 the problem is that often you will not 1564 01:11:05,350 --> 01:11:02,000 see that because he's turning the hyper 1565 01:11:08,310 --> 01:11:05,360 complicated into merely complicated 1566 01:11:10,390 --> 01:11:08,320 uh so so so so so you don't 1567 01:11:14,550 --> 01:11:10,400 automatically realize 1568 01:11:18,790 --> 01:11:14,560 uh what a great uh exposition 1569 01:11:23,270 --> 01:11:21,189 and i i 1570 01:11:25,590 --> 01:11:23,280 think i learned well i don't know if i 1571 01:11:29,910 --> 01:11:25,600 learned that from him 1572 01:11:32,229 --> 01:11:29,920 but i strive to learn that from him 1573 01:11:34,950 --> 01:11:32,239 um 1574 01:11:37,270 --> 01:11:34,960 and then in other ways i 1575 01:11:39,030 --> 01:11:37,280 there are senses in which i didn't learn 1576 01:11:41,990 --> 01:11:39,040 anything from him 1577 01:11:44,709 --> 01:11:42,000 namely uh he is 1578 01:11:46,870 --> 01:11:44,719 so much more talented 1579 01:11:49,110 --> 01:11:46,880 there's just no way of no other way of 1580 01:11:52,830 --> 01:11:49,120 saying it the guy is smart 1581 01:11:58,550 --> 01:11:52,840 the guy is extremely productive 1582 01:11:59,990 --> 01:11:58,560 uh if you try to imitate his 1583 01:12:01,350 --> 01:12:00,000 brilliance 1584 01:12:03,189 --> 01:12:01,360 you'll fail 1585 01:12:05,910 --> 01:12:03,199 at least i failed 1586 01:12:09,590 --> 01:12:05,920 uh if you try to imitate his 1587 01:12:10,470 --> 01:12:09,600 productivity you'll just be disappointed 1588 01:12:11,990 --> 01:12:10,480 so 1589 01:12:14,790 --> 01:12:12,000 um 1590 01:12:16,310 --> 01:12:14,800 in some ways i haven't learned there are 1591 01:12:19,430 --> 01:12:16,320 certain things i haven't learned from 1592 01:12:21,350 --> 01:12:19,440 him and i just simply couldn't 1593 01:12:23,270 --> 01:12:21,360 do you mind describing your relationship 1594 01:12:25,270 --> 01:12:23,280 with eric weinstein when i was speaking 1595 01:12:28,310 --> 01:12:25,280 to eric he said that you acted as a de 1596 01:12:31,590 --> 01:12:28,320 facto supervisor to him 1597 01:12:33,510 --> 01:12:31,600 because raul bot wasn't particularly 1598 01:12:36,630 --> 01:12:33,520 although it was officially his 1599 01:12:38,470 --> 01:12:36,640 supervisor he didn't act as the 1600 01:12:40,390 --> 01:12:38,480 supervisor for whatever reason it was a 1601 01:12:41,110 --> 01:12:40,400 strange relationship i don't understand 1602 01:12:42,870 --> 01:12:41,120 it 1603 01:12:44,630 --> 01:12:42,880 i'm curious what do you think he means 1604 01:12:46,550 --> 01:12:44,640 when he says that you acted as the 1605 01:12:48,950 --> 01:12:46,560 supervisor you gave him advice or i 1606 01:12:59,990 --> 01:12:48,960 don't think it's correct it's more like 1607 01:13:00,000 --> 01:13:03,430 so eric 1608 01:13:08,630 --> 01:13:06,390 eric was very unbalanced 1609 01:13:11,669 --> 01:13:08,640 and he still is unbalanced and i don't 1610 01:13:13,669 --> 01:13:11,679 mean emotionally unbalanced i mean 1611 01:13:16,550 --> 01:13:13,679 uh he has 1612 01:13:19,990 --> 01:13:16,560 great talents 1613 01:13:21,430 --> 01:13:20,000 in certain directions 1614 01:13:23,030 --> 01:13:21,440 and 1615 01:13:24,630 --> 01:13:23,040 fear 1616 01:13:26,470 --> 01:13:24,640 of others 1617 01:13:29,350 --> 01:13:26,480 and there are certain 1618 01:13:33,910 --> 01:13:29,360 things that one has to do certain type 1619 01:13:38,790 --> 01:13:33,920 of computation a certain type of writing 1620 01:13:40,550 --> 01:13:38,800 basically he has fear of turning his um 1621 01:13:44,229 --> 01:13:40,560 his 1622 01:13:48,070 --> 01:13:46,370 uh so um 1623 01:13:49,669 --> 01:13:48,080 [Music] 1624 01:13:52,070 --> 01:13:49,679 uh 1625 01:13:55,350 --> 01:13:52,080 and and that's 1626 01:13:56,470 --> 01:13:55,360 part of the reason why he had difficulty 1627 01:13:59,590 --> 01:13:56,480 uh 1628 01:14:01,350 --> 01:13:59,600 with raul balt and with um 1629 01:14:02,709 --> 01:14:01,360 basically with the normal system in 1630 01:14:07,669 --> 01:14:02,719 harvard 1631 01:14:15,750 --> 01:14:11,030 my role was to help him pick something 1632 01:14:19,350 --> 01:14:17,830 big theories 1633 01:14:25,270 --> 01:14:19,360 and 1634 01:14:31,189 --> 01:14:25,280 thesis 1635 01:14:35,669 --> 01:14:32,709 yeah i also helped him with some 1636 01:14:37,750 --> 01:14:35,679 computations you know i you know 1637 01:14:41,510 --> 01:14:37,760 at the end of the day there are some 1638 01:14:43,669 --> 01:14:41,520 like so so he's come he's 1639 01:14:45,750 --> 01:14:43,679 you know big theories 1640 01:14:47,990 --> 01:14:45,760 lead to something very concrete and 1641 01:14:50,470 --> 01:14:48,000 specific which was a tiny part of the 1642 01:14:53,350 --> 01:14:50,480 big theories but we extracted that tiny 1643 01:14:55,750 --> 01:14:53,360 part and made it uh more concrete and at 1644 01:14:58,870 --> 01:14:55,760 the end it became a question you know 1645 01:15:00,310 --> 01:14:58,880 some big matrix 500 by 500 or whatever 1646 01:15:03,510 --> 01:15:00,320 it was 1647 01:15:06,870 --> 01:15:03,520 is it positive definite or not 1648 01:15:09,030 --> 01:15:06,880 and i helped him uh i helped him 1649 01:15:11,430 --> 01:15:09,040 decide that 1650 01:15:13,189 --> 01:15:11,440 and that was decided by compute by a 1651 01:15:15,350 --> 01:15:13,199 computer like you ended up programming 1652 01:15:16,310 --> 01:15:15,360 it that one that one was decided by 1653 01:15:17,910 --> 01:15:16,320 computer 1654 01:15:19,990 --> 01:15:17,920 so we just 1655 01:15:21,030 --> 01:15:20,000 uh but 1656 01:15:26,709 --> 01:15:21,040 but 1657 01:15:29,110 --> 01:15:26,719 have never done on on his own 1658 01:15:30,790 --> 01:15:29,120 because 1659 01:15:32,390 --> 01:15:30,800 he has this 1660 01:15:34,070 --> 01:15:32,400 fear of 1661 01:15:35,910 --> 01:15:34,080 uh 1662 01:15:37,189 --> 01:15:35,920 in a way it's a fear of testing your 1663 01:15:39,510 --> 01:15:37,199 theories 1664 01:15:42,790 --> 01:15:39,520 because they might fail but in another 1665 01:15:45,590 --> 01:15:42,800 way it's just inability he never 1666 01:15:47,669 --> 01:15:45,600 learned how to do it he never got good 1667 01:15:52,310 --> 01:15:47,679 at um 1668 01:15:54,870 --> 01:15:52,320 turning the very abstract into concrete 1669 01:15:54,880 --> 01:15:58,950 so yes so that was my role 1670 01:16:04,070 --> 01:16:01,669 have you read his recent geometric unity 1671 01:16:06,390 --> 01:16:04,080 papers or heard about geometric unity at 1672 01:16:08,470 --> 01:16:06,400 all i've heard a tiny bit about it i 1673 01:16:09,910 --> 01:16:08,480 have not read it i'm not in the position 1674 01:16:12,310 --> 01:16:09,920 to comment 1675 01:16:14,149 --> 01:16:12,320 you talked about it's difficult to make 1676 01:16:16,550 --> 01:16:14,159 a concrete or take something concrete 1677 01:16:18,310 --> 01:16:16,560 from a theory at least in his case 1678 01:16:20,070 --> 01:16:18,320 do you mind giving an example of his 1679 01:16:30,630 --> 01:16:20,080 strengths or some or an example of a 1680 01:16:44,709 --> 01:16:31,830 he 1681 01:16:44,719 --> 01:16:48,070 uh 1682 01:16:52,390 --> 01:16:49,350 how they 1683 01:16:54,390 --> 01:16:52,400 interact with each other 1684 01:16:55,750 --> 01:16:54,400 uh so 1685 01:16:57,750 --> 01:16:55,760 uh 1686 01:16:59,030 --> 01:16:57,760 the small groups like the classical 1687 01:17:00,390 --> 01:16:59,040 groups or what do you mean when you say 1688 01:17:04,149 --> 01:17:00,400 the smoke 1689 01:17:05,189 --> 01:17:04,159 okay what i mean by the small is um 1690 01:17:06,390 --> 01:17:05,199 so you know 1691 01:17:09,430 --> 01:17:06,400 uh 1692 01:17:11,350 --> 01:17:09,440 there are several families of so-called 1693 01:17:14,149 --> 01:17:11,360 symmetry groups 1694 01:17:16,550 --> 01:17:14,159 okay so there are uh 1695 01:17:19,430 --> 01:17:16,560 uh s-u-n 1696 01:17:21,430 --> 01:17:19,440 and s-uh 1697 01:17:23,830 --> 01:17:21,440 and s-o-n 1698 01:17:26,149 --> 01:17:23,840 and s-p-n 1699 01:17:28,149 --> 01:17:26,159 and then there are a few sporadic ones 1700 01:17:31,830 --> 01:17:28,159 there is uh 1701 01:17:35,350 --> 01:17:31,840 uh g2 and f4 1702 01:17:39,830 --> 01:17:35,360 and e6 and e7 1703 01:17:42,390 --> 01:17:39,840 and e8 and it doesn't go beyond eight 1704 01:17:46,550 --> 01:17:42,400 uh and all of these so these are 1705 01:17:50,470 --> 01:17:48,950 they they have so-called representation 1706 01:17:51,430 --> 01:17:50,480 theory 1707 01:17:52,310 --> 01:17:51,440 so 1708 01:17:55,030 --> 01:17:52,320 uh 1709 01:17:58,709 --> 01:17:55,040 each one of them can be represented can 1710 01:18:00,950 --> 01:17:58,719 be written as a group of matrices can be 1711 01:18:03,430 --> 01:18:00,960 realized within the world of matrices 1712 01:18:05,189 --> 01:18:03,440 but in many ways 1713 01:18:07,189 --> 01:18:05,199 so eric 1714 01:18:09,270 --> 01:18:07,199 uh 1715 01:18:14,870 --> 01:18:09,280 intimately knows 1716 01:18:18,709 --> 01:18:16,390 these groups 1717 01:18:20,870 --> 01:18:18,719 and their representations and how they 1718 01:18:23,430 --> 01:18:20,880 sit inside each other 1719 01:18:25,510 --> 01:18:23,440 for small values of n 1720 01:18:27,590 --> 01:18:25,520 and well for all of those sporadic ones 1721 01:18:29,990 --> 01:18:27,600 which are all small 1722 01:18:32,630 --> 01:18:30,000 and their symmetries and their so-called 1723 01:18:33,990 --> 01:18:32,640 outer symmetries i mean he knows all 1724 01:18:34,870 --> 01:18:34,000 about 1725 01:18:37,189 --> 01:18:34,880 uh 1726 01:18:38,630 --> 01:18:37,199 these things 1727 01:18:41,270 --> 01:18:38,640 now 1728 01:18:42,470 --> 01:18:41,280 this is relevant to physics 1729 01:18:45,590 --> 01:18:42,480 because 1730 01:18:48,630 --> 01:18:45,600 uh you know electro weak theory is 1731 01:18:50,950 --> 01:18:48,640 somehow about su 2 1732 01:18:58,070 --> 01:18:53,990 the grand unified theory so a strong and 1733 01:18:59,270 --> 01:18:58,080 electroweak is somehow about su 3 1734 01:19:00,390 --> 01:18:59,280 or 1735 01:19:03,350 --> 01:19:00,400 so 1736 01:19:05,669 --> 01:19:03,360 uh no no no no no i have it wrong 1737 01:19:08,070 --> 01:19:05,679 sorry electromagnetism is 1738 01:19:10,310 --> 01:19:08,080 well electromagnetism 1739 01:19:11,350 --> 01:19:10,320 is you one and then 1740 01:19:12,390 --> 01:19:11,360 you know i 1741 01:19:17,350 --> 01:19:12,400 i i 1742 01:19:19,910 --> 01:19:17,360 these things for many many years 1743 01:19:22,229 --> 01:19:19,920 so i could be saying things wrong 1744 01:19:24,630 --> 01:19:22,239 but yeah but his strength is that he 1745 01:19:26,950 --> 01:19:24,640 knows these things really really really 1746 01:19:26,960 --> 01:19:29,430 uh 1747 01:19:33,990 --> 01:19:31,750 or one of his strengths is that he knows 1748 01:19:35,270 --> 01:19:34,000 these things really really really well 1749 01:19:37,510 --> 01:19:35,280 earlier when we were talking about 1750 01:19:39,189 --> 01:19:37,520 particle physics well not theory you 1751 01:19:41,590 --> 01:19:39,199 mentioned that for every knot there's a 1752 01:19:44,870 --> 01:19:41,600 corresponding physics story of particles 1753 01:19:46,390 --> 01:19:44,880 dancing and so on is the opposite true 1754 01:19:47,990 --> 01:19:46,400 so does the arrow go in the other 1755 01:19:49,830 --> 01:19:48,000 direction as well 1756 01:19:53,750 --> 01:19:49,840 for every particle interaction is there 1757 01:19:57,669 --> 01:19:55,990 for every particle interaction of a 1758 01:20:00,709 --> 01:19:57,679 specific type 1759 01:20:02,790 --> 01:20:00,719 in three-dimensional space 1760 01:20:05,189 --> 01:20:02,800 yes 1761 01:20:07,669 --> 01:20:05,199 but uh but you have to 1762 01:20:10,470 --> 01:20:07,679 be very specific you have to be you have 1763 01:20:11,910 --> 01:20:10,480 to specialize a great deal 1764 01:20:14,229 --> 01:20:11,920 physics mostly happens in 1765 01:20:15,990 --> 01:20:14,239 four-dimensional space 1766 01:20:18,470 --> 01:20:16,000 if this can be easily explained why is 1767 01:20:20,709 --> 01:20:18,480 it not simple to just extend the three 1768 01:20:21,830 --> 01:20:20,719 dimensions to four dimensions 1769 01:20:25,990 --> 01:20:21,840 and 1770 01:20:28,629 --> 01:20:26,000 vector in we're talking about vector 1771 01:20:31,669 --> 01:20:28,639 spaces it's trivial to go from r3 to r4 1772 01:20:33,270 --> 01:20:31,679 the same theorems apply okay so so the 1773 01:20:34,310 --> 01:20:33,280 answer is 1774 01:20:35,910 --> 01:20:34,320 um 1775 01:20:40,390 --> 01:20:35,920 or there's 1776 01:20:41,590 --> 01:20:40,400 first of all certain things do extend 1777 01:20:43,669 --> 01:20:41,600 so 1778 01:20:45,430 --> 01:20:43,679 um 1779 01:20:46,950 --> 01:20:45,440 you know if not 1780 01:20:50,229 --> 01:20:46,960 theory is 1781 01:20:53,590 --> 01:20:50,239 to some extent about dance the dancing 1782 01:20:55,030 --> 01:20:53,600 of points in two-dimensional space 1783 01:20:57,030 --> 01:20:55,040 so 1784 01:20:58,629 --> 01:20:57,040 you know he he 1785 01:21:01,990 --> 01:20:58,639 here is a 1786 01:21:03,510 --> 01:21:02,000 a very rough uh 1787 01:21:07,510 --> 01:21:03,520 uh 1788 01:21:11,669 --> 01:21:07,520 so 1789 01:21:17,510 --> 01:21:12,550 or 1790 01:21:18,390 --> 01:21:17,520 is roughly about 1791 01:21:20,149 --> 01:21:18,400 one 1792 01:21:22,070 --> 01:21:20,159 dimensional 1793 01:21:24,390 --> 01:21:22,080 things 1794 01:21:25,390 --> 01:21:24,400 or curves or whatever 1795 01:21:27,990 --> 01:21:25,400 in 1796 01:21:31,110 --> 01:21:28,000 three-dimensional space 1797 01:21:32,950 --> 01:21:31,120 and as i mentioned before 1798 01:21:34,870 --> 01:21:32,960 it can be 1799 01:21:36,870 --> 01:21:34,880 um 1800 01:21:37,830 --> 01:21:36,880 interpreted 1801 01:21:39,830 --> 01:21:37,840 as 1802 01:21:42,709 --> 01:21:39,840 points dancing 1803 01:21:46,229 --> 01:21:42,719 in two-dimensional place space 1804 01:21:47,110 --> 01:21:46,239 so points are zero dimensional 1805 01:21:48,870 --> 01:21:47,120 so 1806 01:21:49,990 --> 01:21:48,880 uh you can 1807 01:21:52,470 --> 01:21:50,000 uh 1808 01:21:54,629 --> 01:21:52,480 so you can interpret no theory as zero 1809 01:21:56,310 --> 01:21:54,639 dimensional things 1810 01:21:57,910 --> 01:21:56,320 right a single point is a zero 1811 01:22:03,350 --> 01:21:57,920 dimensional thing 1812 01:22:04,790 --> 01:22:03,360 dancing 1813 01:22:06,149 --> 01:22:04,800 in 1814 01:22:16,310 --> 01:22:06,159 a 1815 01:22:18,470 --> 01:22:16,320 one dimension up 1816 01:22:21,510 --> 01:22:18,480 so you can say 1817 01:22:25,430 --> 01:22:21,520 uh let's uh 1818 01:22:32,550 --> 01:22:28,790 zero dimensional things dancing in r2 1819 01:22:34,790 --> 01:22:32,560 you can think of one-dimensional 1820 01:22:37,750 --> 01:22:34,800 things 1821 01:22:37,760 --> 01:22:40,149 in 1822 01:22:42,550 --> 01:22:41,189 uh 1823 01:22:57,590 --> 01:22:42,560 r 1824 01:22:59,830 --> 01:22:57,600 sections 1825 01:23:00,750 --> 01:22:59,840 they somehow corresponds 1826 01:23:04,830 --> 01:23:00,760 to 1827 01:23:09,990 --> 01:23:04,840 two-dimensional notes so two-dimensional 1828 01:23:13,350 --> 01:23:11,510 in 1829 01:23:14,629 --> 01:23:13,360 r4 1830 01:23:16,550 --> 01:23:14,639 now you can ask 1831 01:23:19,110 --> 01:23:16,560 now what exactly are what is that 1832 01:23:22,550 --> 01:23:19,120 supposed to be r3 dancing sorry not r4 i 1833 01:23:25,590 --> 01:23:22,560 i wanted to add one this is in r2 adding 1834 01:23:28,149 --> 01:23:25,600 one you get r3 1835 01:23:29,590 --> 01:23:28,159 sorry so one dimensional thing dancing 1836 01:23:31,270 --> 01:23:29,600 in r3 1837 01:23:34,470 --> 01:23:31,280 now you can ask yourself what are one 1838 01:23:36,790 --> 01:23:34,480 dimensional things dancing in r3 and 1839 01:23:39,030 --> 01:23:36,800 fortunately i'm ready for that 1840 01:23:41,189 --> 01:23:39,040 so here are here is a one dimensional 1841 01:23:44,790 --> 01:23:41,199 thing 1842 01:23:48,149 --> 01:23:45,910 and 1843 01:23:50,149 --> 01:23:48,159 uh right this is a loop it's a 1844 01:23:52,229 --> 01:23:50,159 one-dimensional thing that's another one 1845 01:23:54,470 --> 01:23:52,239 it's a loop it's a one-dimensional thing 1846 01:23:56,790 --> 01:23:54,480 and they can dance around they can fly 1847 01:24:00,229 --> 01:23:56,800 in r3 and they can fly in interesting 1848 01:24:03,189 --> 01:24:00,239 ways that don't exist one dimension less 1849 01:24:04,310 --> 01:24:03,199 namely they can fly through each other 1850 01:24:05,189 --> 01:24:04,320 okay 1851 01:24:08,390 --> 01:24:05,199 so 1852 01:24:11,830 --> 01:24:08,400 yes there is a theory of one-dimensional 1853 01:24:14,830 --> 01:24:11,840 things dancing in r3 1854 01:24:18,229 --> 01:24:14,840 and it corresponds to a theory of 1855 01:24:20,149 --> 01:24:18,239 two-dimensional spaces noted inside 1856 01:24:22,629 --> 01:24:20,159 four-dimensional space 1857 01:24:25,030 --> 01:24:22,639 so to some extent 1858 01:24:28,070 --> 01:24:25,040 the answer to your question is yes there 1859 01:24:31,350 --> 01:24:28,080 is higher there are higher dimensional 1860 01:24:33,189 --> 01:24:31,360 analogs of not theory 1861 01:24:33,990 --> 01:24:33,199 it turns out 1862 01:24:34,950 --> 01:24:34,000 that 1863 01:24:38,149 --> 01:24:34,960 uh 1864 01:24:42,229 --> 01:24:38,159 some features are different 1865 01:24:45,430 --> 01:24:42,239 it turns out that in some ways uh 1866 01:24:48,310 --> 01:24:45,440 and they're actually qualitatively 1867 01:24:52,470 --> 01:24:48,320 sort of the theory of not in one them so 1868 01:24:54,950 --> 01:24:52,480 so you know unlike um vector spaces 1869 01:24:57,110 --> 01:24:54,960 so vector spaces you kind of once you 1870 01:24:59,510 --> 01:24:57,120 learn 1871 01:25:03,990 --> 01:24:59,520 r3 1872 01:25:04,950 --> 01:25:04,000 r4 you've learned r to the 50. 1873 01:25:07,990 --> 01:25:04,960 okay 1874 01:25:10,310 --> 01:25:08,000 but but but here there are qualitative 1875 01:25:11,350 --> 01:25:10,320 differences 1876 01:25:12,870 --> 01:25:11,360 so 1877 01:25:13,830 --> 01:25:12,880 uh 1878 01:25:19,510 --> 01:25:13,840 so 1879 01:25:22,310 --> 01:25:19,520 translate to things here and vice versa 1880 01:25:23,750 --> 01:25:22,320 but not everything 1881 01:25:26,229 --> 01:25:23,760 so 1882 01:25:30,149 --> 01:25:26,239 myself i've spent most of my time 1883 01:25:33,510 --> 01:25:31,590 okay 1884 01:25:35,430 --> 01:25:33,520 but then there is higher there is even 1885 01:25:38,550 --> 01:25:35,440 higher stuff 1886 01:25:42,790 --> 01:25:41,189 by the way so you know 1887 01:25:46,470 --> 01:25:42,800 um 1888 01:25:49,590 --> 01:25:48,149 uh 1889 01:25:52,390 --> 01:25:49,600 when you take 1890 01:25:55,270 --> 01:25:52,400 a first class in linear algebra and 1891 01:25:57,990 --> 01:25:55,280 maybe also a second class in linear 1892 01:25:59,590 --> 01:25:58,000 algebra you get this impression 1893 01:26:01,910 --> 01:25:59,600 that 1894 01:26:03,430 --> 01:26:01,920 uh everything is the same in all 1895 01:26:04,310 --> 01:26:03,440 dimensions 1896 01:26:06,550 --> 01:26:04,320 yep 1897 01:26:08,709 --> 01:26:06,560 but that's not true 1898 01:26:09,910 --> 01:26:08,719 even in linear algebra even in linear 1899 01:26:10,709 --> 01:26:09,920 algebra 1900 01:26:13,030 --> 01:26:10,719 so 1901 01:26:15,270 --> 01:26:13,040 well not quite linear algebra but in 1902 01:26:18,070 --> 01:26:15,280 algebra 1903 01:26:21,830 --> 01:26:18,080 okay so you know there is something 1904 01:26:23,189 --> 01:26:21,840 called uh the real numbers 1905 01:26:25,669 --> 01:26:23,199 then you can 1906 01:26:30,709 --> 01:26:25,679 add i 1907 01:26:31,910 --> 01:26:30,719 and you get the complex numbers 1908 01:26:33,750 --> 01:26:31,920 and then 1909 01:26:37,910 --> 01:26:33,760 uh you can say 1910 01:26:39,110 --> 01:26:37,920 let's add uh j and k as well 1911 01:26:43,669 --> 01:26:39,120 and you get 1912 01:26:45,990 --> 01:26:43,679 uh the so-called uh quaternions 1913 01:26:48,229 --> 01:26:46,000 but the quaternions are different than 1914 01:26:49,590 --> 01:26:48,239 the complex numbers in that this is a 1915 01:26:50,470 --> 01:26:49,600 commutative 1916 01:26:55,430 --> 01:26:50,480 ring 1917 01:26:57,910 --> 01:26:55,440 and then you can add g i forgot what's 1918 01:26:59,830 --> 01:26:57,920 the standard name for what you add so i 1919 01:27:00,709 --> 01:26:59,840 don't know add 1920 01:27:05,430 --> 01:27:00,719 in 1921 01:27:08,229 --> 01:27:05,440 i forgot the name and and you get 1922 01:27:11,669 --> 01:27:08,239 octaniums and the octaniums are no 1923 01:27:14,709 --> 01:27:11,679 longer even associative 1924 01:27:17,510 --> 01:27:14,719 so it's still sort of a ring 1925 01:27:19,830 --> 01:27:17,520 namely it has a multiplication but it's 1926 01:27:22,070 --> 01:27:19,840 not even associative and then the 1927 01:27:26,070 --> 01:27:22,080 process ends there is just nothing 1928 01:27:27,510 --> 01:27:26,080 beyond that you can't continue 1929 01:27:28,629 --> 01:27:27,520 uh so 1930 01:27:31,510 --> 01:27:28,639 uh 1931 01:27:33,510 --> 01:27:31,520 so even in linear algebra so that's not 1932 01:27:36,310 --> 01:27:33,520 quite well 1933 01:27:38,950 --> 01:27:36,320 i don't know even in basic algebra not 1934 01:27:41,270 --> 01:27:38,960 all dimensions are the same 1 is not the 1935 01:27:44,149 --> 01:27:41,280 same as 2 is not the same as 4 is not 1936 01:27:47,270 --> 01:27:44,159 the same as 8 and not the same as 16 1937 01:27:48,470 --> 01:27:47,280 where things no longer exist 1938 01:27:53,240 --> 01:27:48,480 so 1939 01:27:57,430 --> 01:27:54,629 [Music] 1940 01:27:59,110 --> 01:27:57,440 things are independent of the dimension 1941 01:28:01,270 --> 01:27:59,120 it's only they're only independent of 1942 01:28:01,990 --> 01:28:01,280 the dimension in the first two years of 1943 01:28:04,629 --> 01:28:02,000 uh 1944 01:28:07,189 --> 01:28:04,639 of of undergrad 1945 01:28:09,430 --> 01:28:07,199 now in this example we're going to 1946 01:28:11,750 --> 01:28:09,440 different spaces by adding one 1947 01:28:14,229 --> 01:28:11,760 or by adding whatever extra 1948 01:28:17,030 --> 01:28:14,239 variables there are there in the 1949 01:28:18,550 --> 01:28:17,040 previous example we're extending r 4 to 1950 01:28:22,310 --> 01:28:18,560 r 5 or 1951 01:28:25,189 --> 01:28:22,320 r n to n plus m 1952 01:28:27,350 --> 01:28:25,199 so we're in the same space in a sense 1953 01:28:30,149 --> 01:28:27,360 except adding an extra dimension so 1954 01:28:31,669 --> 01:28:30,159 what's an example that holds for r3 1955 01:28:33,189 --> 01:28:31,679 or actually sorry let's make this even 1956 01:28:36,870 --> 01:28:33,199 simpler what's an example that holds for 1957 01:28:39,510 --> 01:28:36,880 r2 but doesn't hold for r3 1958 01:28:41,590 --> 01:28:39,520 or you can say r3 to r4 like what's an 1959 01:28:43,830 --> 01:28:41,600 example of a quantity that drastically 1960 01:28:45,030 --> 01:28:43,840 changes as soon as you go to r4 1961 01:28:47,590 --> 01:28:45,040 and becomes 1962 01:28:49,750 --> 01:28:47,600 extremely complicated but in r3 it's 1963 01:28:52,790 --> 01:28:49,760 trivial 1964 01:28:56,229 --> 01:28:52,800 the motion of points 1965 01:28:56,950 --> 01:28:56,239 is fundamentally different 1966 01:29:01,110 --> 01:28:56,960 in 1967 01:29:03,030 --> 01:29:01,120 dimensions 1968 01:29:04,070 --> 01:29:03,040 so let me explain 1969 01:29:05,510 --> 01:29:04,080 so 1970 01:29:08,709 --> 01:29:05,520 uh 1971 01:29:09,669 --> 01:29:08,719 right suppose you have two points a and 1972 01:29:12,149 --> 01:29:09,679 b 1973 01:29:14,550 --> 01:29:12,159 in two dimensions 1974 01:29:17,110 --> 01:29:14,560 and you want them to trade places by 1975 01:29:22,070 --> 01:29:19,510 okay there are two basic ways they can 1976 01:29:23,110 --> 01:29:22,080 do it they can trade place 1977 01:29:27,669 --> 01:29:23,120 by 1978 01:29:28,550 --> 01:29:27,679 uh b going above a 1979 01:29:31,110 --> 01:29:28,560 or 1980 01:29:33,910 --> 01:29:31,120 they can trade places 1981 01:29:36,790 --> 01:29:33,920 uh in some sort sort of the opposite way 1982 01:29:39,430 --> 01:29:36,800 by a going above b so a will go to here 1983 01:29:40,310 --> 01:29:39,440 and b will go sorry a will go 1984 01:30:04,390 --> 01:29:40,320 a 1985 01:30:08,790 --> 01:30:04,400 continuously deform 1986 01:30:12,790 --> 01:30:08,800 this way of moving to that way of moving 1987 01:30:15,990 --> 01:30:12,800 but in r3 that's not 1988 01:30:19,270 --> 01:30:16,000 true anymore so in r3 1989 01:30:22,550 --> 01:30:19,280 points can trade places 1990 01:30:23,430 --> 01:30:22,560 in only one way 1991 01:30:27,669 --> 01:30:23,440 so 1992 01:30:28,470 --> 01:30:27,679 uh let me uh find two points for you 1993 01:30:31,910 --> 01:30:28,480 so 1994 01:30:32,870 --> 01:30:31,920 uh i suppose 1995 01:30:34,550 --> 01:30:32,880 uh 1996 01:30:39,669 --> 01:30:34,560 well they're not points but they're 1997 01:30:41,030 --> 01:30:39,679 close to points so here is uh red and 1998 01:30:44,790 --> 01:30:41,040 blue 1999 01:30:46,149 --> 01:30:44,800 so in r3 they can trade places going 2000 01:30:49,910 --> 01:30:46,159 this way 2001 01:30:52,790 --> 01:30:49,920 or they can trade places going that way 2002 01:30:54,950 --> 01:30:52,800 but there are many other ways they can 2003 01:30:57,350 --> 01:30:54,960 trade places they can trade places by 2004 01:30:59,590 --> 01:30:57,360 going that way or 2005 01:31:00,709 --> 01:30:59,600 that way 2006 01:31:02,870 --> 01:31:00,719 and 2007 01:31:05,270 --> 01:31:02,880 um 2008 01:31:08,070 --> 01:31:05,280 in a sense all of these 2009 01:31:10,629 --> 01:31:08,080 trading places ways 2010 01:31:12,070 --> 01:31:10,639 are equivalent to each other 2011 01:31:15,030 --> 01:31:12,080 because 2012 01:31:19,189 --> 01:31:15,040 if you trade places 2013 01:31:23,110 --> 01:31:19,199 wait if the two points trade places 2014 01:31:24,709 --> 01:31:23,120 they span a circle 2015 01:31:29,110 --> 01:31:24,719 right so 2016 01:31:31,189 --> 01:31:29,120 know they 2017 01:31:33,270 --> 01:31:31,199 spun a circle by 2018 01:31:36,310 --> 01:31:33,280 uh i wish i had a third hand maybe i 2019 01:31:39,830 --> 01:31:36,320 removed my sure sure sure okay they go 2020 01:31:43,430 --> 01:31:39,840 like that okay that spawns a circle and 2021 01:31:45,189 --> 01:31:43,440 the other way of spawning a circle is by 2022 01:31:47,830 --> 01:31:45,199 going the other way 2023 01:31:48,950 --> 01:31:47,840 around the same d around the same sorry 2024 01:31:56,550 --> 01:31:48,960 circle 2025 01:31:59,350 --> 01:31:56,560 and that homotops that deforms 2026 01:32:03,910 --> 01:31:59,360 one way of trading places to the other 2027 01:32:07,430 --> 01:32:03,920 way of trading places so in r3 2028 01:32:09,030 --> 01:32:07,440 so in r2 there are two 2029 01:32:10,709 --> 01:32:09,040 distinct 2030 01:32:14,149 --> 01:32:10,719 sorry this 2031 01:32:15,910 --> 01:32:14,159 can spell there are two 2032 01:32:18,709 --> 01:32:15,920 uh 2033 01:32:20,229 --> 01:32:18,719 distinct 2034 01:32:21,270 --> 01:32:20,239 ways 2035 01:32:22,310 --> 01:32:21,280 of 2036 01:32:24,149 --> 01:32:22,320 uh 2037 01:32:27,030 --> 01:32:24,159 trading 2038 01:32:29,189 --> 01:32:27,040 uh places 2039 01:32:31,270 --> 01:32:29,199 and in fact two are easy they're 2040 01:32:32,550 --> 01:32:31,280 actually a little bit more but anyway in 2041 01:32:33,950 --> 01:32:32,560 r3 2042 01:32:37,750 --> 01:32:33,960 so if you're talking about 2043 01:32:41,189 --> 01:32:39,350 and you have 2044 01:32:42,470 --> 01:32:41,199 two points in the three-dimensional 2045 01:32:43,830 --> 01:32:42,480 space there is 2046 01:32:45,030 --> 01:32:43,840 only 2047 01:32:46,229 --> 01:32:45,040 one 2048 01:32:51,430 --> 01:32:46,239 way 2049 01:32:55,270 --> 01:32:51,440 different let me say differently 2050 01:32:56,629 --> 01:32:55,280 uh all ways of trading places all 2051 01:32:57,910 --> 01:32:56,639 ways 2052 01:32:59,510 --> 01:32:57,920 of 2053 01:33:03,189 --> 01:32:59,520 trading 2054 01:33:07,430 --> 01:33:04,229 are 2055 01:33:09,830 --> 01:33:07,440 equivalent and again the basic the basic 2056 01:33:12,470 --> 01:33:09,840 point is that a way of trading places is 2057 01:33:14,790 --> 01:33:12,480 a circle right right one point goes 2058 01:33:18,310 --> 01:33:14,800 along one arc and the other point goes 2059 01:33:19,750 --> 01:33:18,320 about a guy over the other arc and you 2060 01:33:22,790 --> 01:33:19,760 can 2061 01:33:24,470 --> 01:33:22,800 switch from one place of trading place 2062 01:33:26,470 --> 01:33:24,480 one way of trading places to the other 2063 01:33:29,510 --> 01:33:26,480 by flipping the circle you can't do it 2064 01:33:31,030 --> 01:33:29,520 if you're only in the plane 2065 01:33:34,830 --> 01:33:31,040 um 2066 01:33:39,110 --> 01:33:34,840 since trading places is actually 2067 01:33:40,950 --> 01:33:39,120 fundamental it makes uh 2068 01:33:42,229 --> 01:33:40,960 but by the way it's also fundamental in 2069 01:33:44,470 --> 01:33:42,239 physics 2070 01:33:46,629 --> 01:33:44,480 so you know you you you know you you 2071 01:33:48,950 --> 01:33:46,639 might have heard of uh bosons and 2072 01:33:51,270 --> 01:33:48,960 fermions and how they behave 2073 01:33:53,830 --> 01:33:51,280 with respect to trading places and then 2074 01:33:56,390 --> 01:33:53,840 there are any ons that behave yet 2075 01:33:59,430 --> 01:33:56,400 differently uh with respect to trading 2076 01:34:01,669 --> 01:33:59,440 places so basically trading places or 2077 01:34:04,070 --> 01:34:01,679 how things behave under trading places 2078 01:34:05,110 --> 01:34:04,080 is a fundamental 2079 01:34:07,590 --> 01:34:05,120 thing 2080 01:34:10,070 --> 01:34:07,600 and it's different it's it's different 2081 01:34:11,990 --> 01:34:10,080 in two dimensions than in three 2082 01:34:13,830 --> 01:34:12,000 right likewise there are things that are 2083 01:34:14,870 --> 01:34:13,840 different between three dimensions and 2084 01:34:18,149 --> 01:34:14,880 four 2085 01:34:21,510 --> 01:34:18,159 and and so it's actually this kind of 2086 01:34:23,430 --> 01:34:21,520 myth or not myth but this um 2087 01:34:26,790 --> 01:34:23,440 the thing that you learn in first and 2088 01:34:30,070 --> 01:34:26,800 second year that uh rn is the same rn no 2089 01:34:31,669 --> 01:34:30,080 matter what n is is not actually true 2090 01:34:32,950 --> 01:34:31,679 have you heard of the hard problem of 2091 01:34:35,830 --> 01:34:32,960 consciousness 2092 01:34:38,070 --> 01:34:35,840 i have not heard it in this language 2093 01:34:39,990 --> 01:34:38,080 namely no no has nothing to do with 2094 01:34:41,590 --> 01:34:40,000 what was written on the board or maybe 2095 01:34:43,990 --> 01:34:41,600 it does but not as far as i see this is 2096 01:34:47,030 --> 01:34:44,000 sort of a clear philosophical problem 2097 01:34:49,830 --> 01:34:47,040 right but uh with the added prefix the 2098 01:34:52,709 --> 01:34:49,840 high and it's clearly hard 2099 01:34:54,229 --> 01:34:52,719 but but but as a phrase the hard problem 2100 01:34:57,350 --> 01:34:54,239 of consciousness i don't know what 2101 01:35:02,870 --> 01:34:59,270 there's only one consciousness that i 2102 01:35:05,430 --> 01:35:02,880 need to explain and it's my own 2103 01:35:07,990 --> 01:35:05,440 right from my perspective 2104 01:35:10,390 --> 01:35:08,000 you're not conscious 2105 01:35:13,590 --> 01:35:10,400 right you just react to 2106 01:35:15,430 --> 01:35:13,600 to to things that i do you know if i 2107 01:35:18,470 --> 01:35:15,440 you know if i tell you 2108 01:35:20,709 --> 01:35:18,480 uh you're stupid you get angry at me if 2109 01:35:22,149 --> 01:35:20,719 i give you a compliment you get happy 2110 01:35:24,790 --> 01:35:22,159 but these are all 2111 01:35:27,350 --> 01:35:24,800 i don't see consciousness here 2112 01:35:29,510 --> 01:35:27,360 okay i so there's only one consciousness 2113 01:35:31,109 --> 01:35:29,520 that i have to explain 2114 01:35:35,109 --> 01:35:31,119 and only one person that i have to 2115 01:35:46,950 --> 01:35:36,149 um 2116 01:35:46,960 --> 01:35:50,870 having said that 2117 01:35:50,880 --> 01:35:57,590 um 2118 01:35:57,600 --> 01:36:01,990 yeah i'll keep the rest private 2119 01:36:02,000 --> 01:36:10,790 what keeps you up at night 2120 01:36:10,800 --> 01:36:14,870 different things on different days 2121 01:36:19,030 --> 01:36:17,910 whether she loves me or not 2122 01:36:20,870 --> 01:36:19,040 uh 2123 01:36:22,950 --> 01:36:20,880 whether i can 2124 01:36:26,149 --> 01:36:22,960 complete the computer program or i'm 2125 01:36:29,030 --> 01:36:26,159 writing or not or why is it not written 2126 01:36:30,870 --> 01:36:29,040 my classes for tomorrow the theorem i 2127 01:36:33,590 --> 01:36:30,880 don't know how to 2128 01:36:34,950 --> 01:36:33,600 have no clue how to prove the state of 2129 01:36:37,270 --> 01:36:34,960 the world 2130 01:36:39,510 --> 01:36:37,280 covered i don't know different things at 2131 01:36:41,510 --> 01:36:39,520 different times 2132 01:36:44,070 --> 01:36:41,520 is there a through line so let's say one 2133 01:37:01,189 --> 01:36:44,080 that you've been thinking about for 15 2134 01:37:09,189 --> 01:37:04,470 you know i'm politically aware 2135 01:37:11,430 --> 01:37:09,199 and always been have always been so uh 2136 01:37:13,430 --> 01:37:11,440 uh 2137 01:37:15,109 --> 01:37:13,440 you know how to make the world a better 2138 01:37:18,470 --> 01:37:15,119 place 2139 01:37:21,030 --> 01:37:18,480 uh but but of course that's a subjective 2140 01:37:23,669 --> 01:37:21,040 thing what what is better 2141 01:37:25,590 --> 01:37:23,679 to me may or may not be the same as what 2142 01:37:27,590 --> 01:37:25,600 is better to you 2143 01:37:29,750 --> 01:37:27,600 so in a way when i'm saying 2144 01:37:31,669 --> 01:37:29,760 uh how to make a better pla the world a 2145 01:37:35,350 --> 01:37:31,679 better place it's more like how to make 2146 01:37:35,360 --> 01:37:44,709 i would how i would like it to be 2147 01:37:48,390 --> 01:37:46,629 yeah so i think about it a lot and 2148 01:37:50,709 --> 01:37:48,400 mostly my conclusion is that there's 2149 01:37:52,790 --> 01:37:50,719 nothing i can do or there is much i can 2150 01:37:57,109 --> 01:37:52,800 do 2151 01:38:05,510 --> 01:37:58,950 what direction would you like math 2152 01:38:12,310 --> 01:38:08,070 i think i mentioned 2153 01:38:12,320 --> 01:38:14,870 um 2154 01:38:14,880 --> 01:38:21,510 and i actually uh 2155 01:38:24,470 --> 01:38:23,350 so i mean it's not the only thing of 2156 01:38:26,709 --> 01:38:24,480 value 2157 01:38:33,750 --> 01:38:26,719 in mathematics 2158 01:38:38,070 --> 01:38:35,109 regardless of whether they are 2159 01:38:41,750 --> 01:38:38,080 computable or not 2160 01:38:47,669 --> 01:38:44,950 but those parts of mathematics that can 2161 01:38:52,070 --> 01:38:47,679 be computed 2162 01:38:56,830 --> 01:38:54,629 and often 2163 01:38:58,629 --> 01:38:56,840 people 2164 01:39:00,950 --> 01:38:58,639 uh 2165 01:39:02,070 --> 01:39:00,960 just don't care about computations they 2166 01:39:03,750 --> 01:39:02,080 pretend 2167 01:39:05,270 --> 01:39:03,760 that 2168 01:39:07,270 --> 01:39:05,280 well 2169 01:39:09,590 --> 01:39:07,280 they think of computation as something 2170 01:39:13,270 --> 01:39:09,600 as a technical thing to to to live for 2171 01:39:16,870 --> 01:39:13,280 their graduate students 2172 01:39:19,669 --> 01:39:16,880 and i see it as a much more integral 2173 01:39:20,790 --> 01:39:19,679 part of the work 2174 01:39:28,149 --> 01:39:20,800 so 2175 01:39:31,990 --> 01:39:30,629 i i i would make computation a bigger 2176 01:39:33,510 --> 01:39:32,000 part 2177 01:39:35,910 --> 01:39:33,520 computation in the sense of 2178 01:39:38,870 --> 01:39:35,920 implementation on the computer not in 2179 01:39:41,030 --> 01:39:38,880 the sense of writing by hand 2180 01:39:46,149 --> 01:39:41,040 i would make it a much bigger part and i 2181 01:39:51,990 --> 01:39:48,310 and that happens at many levels so when 2182 01:39:54,629 --> 01:39:52,000 you teach a class in linear algebra 2183 01:39:59,350 --> 01:39:54,639 you teach about uh 2184 01:40:01,750 --> 01:40:00,709 well 2185 01:40:03,750 --> 01:40:01,760 uh 2186 01:40:05,750 --> 01:40:03,760 along with it there should be a computer 2187 01:40:07,109 --> 01:40:05,760 program to compute compute the 2188 01:40:08,709 --> 01:40:07,119 determinant 2189 01:40:11,430 --> 01:40:08,719 and should and there should be a 2190 01:40:13,510 --> 01:40:11,440 realization that there are maybe two 2191 01:40:16,470 --> 01:40:13,520 formulas for the determinant and one of 2192 01:40:18,070 --> 01:40:16,480 them is way better than the other 2193 01:40:21,510 --> 01:40:18,080 uh 2194 01:40:23,350 --> 01:40:21,520 if you try to implement it 2195 01:40:25,189 --> 01:40:23,360 uh so 2196 01:40:26,310 --> 01:40:25,199 um 2197 01:40:32,310 --> 01:40:26,320 i would 2198 01:40:35,830 --> 01:40:33,270 um 2199 01:40:38,229 --> 01:40:35,840 yeah maybe that would be the main change 2200 01:40:41,990 --> 01:40:38,239 do you have a philosophy of math so for 2201 01:40:43,750 --> 01:40:42,000 example there's platonism and formalism 2202 01:40:46,390 --> 01:40:43,760 if anything i would be an ultra 2203 01:40:47,350 --> 01:40:46,400 finalitist 2204 01:40:49,990 --> 01:40:47,360 so 2205 01:40:53,669 --> 01:40:50,000 uh 2206 01:40:56,790 --> 01:40:53,679 it's much more graded than that 2207 01:40:57,910 --> 01:40:56,800 so you know there is a hierarchy 2208 01:41:00,310 --> 01:40:57,920 of 2209 01:41:02,350 --> 01:41:00,320 um 2210 01:41:06,709 --> 01:41:02,360 of 2211 01:41:09,189 --> 01:41:06,719 or sizes 2212 01:41:09,990 --> 01:41:09,199 of things in mathematics 2213 01:41:12,550 --> 01:41:10,000 so 2214 01:41:14,629 --> 01:41:12,560 you know people in set theory and logic 2215 01:41:19,990 --> 01:41:14,639 and you know talk about 2216 01:41:20,000 --> 01:41:22,950 and 2217 01:41:26,470 --> 01:41:24,550 then there are 2218 01:41:29,189 --> 01:41:26,480 parts of mathematics that have to do 2219 01:41:31,270 --> 01:41:29,199 with uncountable or 2220 01:41:33,910 --> 01:41:31,280 bigger than uncountable 2221 01:41:36,310 --> 01:41:33,920 and then there are infinite parts 2222 01:41:38,070 --> 01:41:36,320 and then there are just infinite without 2223 01:41:40,310 --> 01:41:38,080 being uncountable right and just 2224 01:41:44,950 --> 01:41:40,320 countable say and then there are parts 2225 01:41:50,870 --> 01:41:47,830 finite but huge 2226 01:41:51,750 --> 01:41:50,880 uh so you know ramsey theory 2227 01:41:57,510 --> 01:41:51,760 uh 2228 01:42:00,229 --> 01:41:57,520 you know you prove that if a graph is 2229 01:42:01,910 --> 01:42:00,239 large enough then it has properties 2230 01:42:04,629 --> 01:42:01,920 certain properties 2231 01:42:06,870 --> 01:42:04,639 but large enough means really really 2232 01:42:09,030 --> 01:42:06,880 really really really really really 2233 01:42:12,830 --> 01:42:09,040 really huge bigger than the number of 2234 01:42:12,840 --> 01:42:17,430 uh and then there are 2235 01:42:21,189 --> 01:42:18,709 uh 2236 01:42:21,990 --> 01:42:21,199 you know parts of mathematics 2237 01:42:32,310 --> 01:42:22,000 uh 2238 01:42:34,070 --> 01:42:32,320 and 10 to the 12 i don't know what a 2239 01:42:36,070 --> 01:42:34,080 computer can do in a fraction of a 2240 01:42:37,990 --> 01:42:36,080 second to what a computer can do in an 2241 01:42:40,470 --> 01:42:38,000 hour 2242 01:42:43,270 --> 01:42:40,480 okay and you know maybe you can go a 2243 01:42:45,430 --> 01:42:43,280 little bit beyond to 10 to the 16 i 2244 01:42:48,470 --> 01:42:45,440 don't know 10 to the 15. i don't know 2245 01:42:53,510 --> 01:42:52,070 so there is this whole grading 2246 01:42:57,510 --> 01:42:53,520 and to me 2247 01:43:01,109 --> 01:42:57,520 the bigger things are 2248 01:43:04,470 --> 01:43:02,709 uh 2249 01:43:07,270 --> 01:43:04,480 and 2250 01:43:09,270 --> 01:43:07,280 because they're farther away from our 2251 01:43:12,870 --> 01:43:09,280 everyday experience 2252 01:43:14,470 --> 01:43:12,880 so they may have philosophical value and 2253 01:43:16,629 --> 01:43:14,480 some of them do 2254 01:43:17,910 --> 01:43:16,639 so i don't want to 2255 01:43:19,030 --> 01:43:17,920 completely 2256 01:43:21,430 --> 01:43:19,040 say 2257 01:43:22,709 --> 01:43:21,440 anything about large cardinals is not 2258 01:43:25,590 --> 01:43:22,719 interesting 2259 01:43:28,550 --> 01:43:25,600 or anything about infinity 2260 01:43:30,790 --> 01:43:28,560 is not interesting 2261 01:43:34,149 --> 01:43:30,800 but the bar is higher 2262 01:43:35,430 --> 01:43:34,159 for something that genuinely use uses 2263 01:43:37,189 --> 01:43:35,440 infinity 2264 01:43:39,030 --> 01:43:37,199 to be interesting 2265 01:43:41,350 --> 01:43:39,040 the bar is higher 2266 01:43:42,390 --> 01:43:41,360 than if the thing is 2267 01:43:45,270 --> 01:43:42,400 uh 2268 01:43:48,790 --> 01:43:45,280 in this in the range of sizes 2269 01:43:50,550 --> 01:43:48,800 that we can actually hold in our hands 2270 01:43:52,709 --> 01:43:50,560 so that's what i mean by an ultra 2271 01:43:54,070 --> 01:43:52,719 finitist i mean 2272 01:43:56,550 --> 01:43:54,080 sort of the 2273 01:43:58,629 --> 01:43:56,560 or or so this is a form so an ultra 2274 01:44:00,870 --> 01:43:58,639 finalities would say the only numbers 2275 01:44:02,629 --> 01:44:00,880 that exist are the numbers i could count 2276 01:44:04,709 --> 01:44:02,639 to 2277 01:44:07,430 --> 01:44:04,719 and maybe by uh 2278 01:44:10,550 --> 01:44:07,440 extension that my computer could count 2279 01:44:13,990 --> 01:44:10,560 to so maybe my computer can count up to 2280 01:44:16,149 --> 01:44:14,000 this number but 10 to the 100 does not 2281 01:44:19,350 --> 01:44:16,159 exist in some sense because my computer 2282 01:44:22,870 --> 01:44:19,360 will never be able to count there 2283 01:44:23,830 --> 01:44:22,880 okay we'll never be able to get there 2284 01:44:29,830 --> 01:44:23,840 so 2285 01:44:31,910 --> 01:44:29,840 there is value to this one too 2286 01:44:34,390 --> 01:44:31,920 and sometimes there is even value to 2287 01:44:36,709 --> 01:44:34,400 infinity and sometimes there is even 2288 01:44:38,950 --> 01:44:36,719 value to the bigger form of infinity but 2289 01:44:42,550 --> 01:44:38,960 the bar has to be higher 2290 01:44:44,870 --> 01:44:42,560 uh the the the the philosophical value 2291 01:44:47,990 --> 01:44:44,880 bar has to be higher 2292 01:44:49,830 --> 01:44:48,000 the bigger the the size is 2293 01:44:51,590 --> 01:44:49,840 these things are always interesting 2294 01:44:55,030 --> 01:44:51,600 these things are interesting only on 2295 01:44:58,790 --> 01:44:56,790 now i'm not sure do you classify 2296 01:45:00,470 --> 01:44:58,800 yourself as a pure mathematician 2297 01:45:02,709 --> 01:45:00,480 definitely 2298 01:45:05,109 --> 01:45:02,719 okay so for a pure mathematician who 2299 01:45:06,390 --> 01:45:05,119 seemingly doesn't care about reality 2300 01:45:09,590 --> 01:45:06,400 it's supposed to be discontinued again 2301 01:45:13,109 --> 01:45:09,600 the valuable math is the math that i can 2302 01:45:14,790 --> 01:45:13,119 or the more valuable math 2303 01:45:20,870 --> 01:45:14,800 is the math that i can turn into a 2304 01:45:25,669 --> 01:45:23,109 it's still pure math in the sense that 2305 01:45:29,189 --> 01:45:25,679 i'm not looking for an immediate or a 2306 01:45:29,199 --> 01:45:32,629 uh but 2307 01:45:38,070 --> 01:45:35,270 both from the application perspective 2308 01:45:39,830 --> 01:45:38,080 and from the pedagogical perspective 2309 01:45:42,950 --> 01:45:39,840 i still prefer 2310 01:45:44,950 --> 01:45:42,960 the map that the math that can be 2311 01:45:46,870 --> 01:45:44,960 implemented because the math that can be 2312 01:45:49,109 --> 01:45:46,880 implemented even if i'm not looking for 2313 01:45:51,030 --> 01:45:49,119 an immediate application 2314 01:45:52,709 --> 01:45:51,040 is there is the math that has a higher 2315 01:45:55,510 --> 01:45:52,719 chance 2316 01:45:57,750 --> 01:45:55,520 of being applied 2317 01:45:59,109 --> 01:45:57,760 because in the application you'll end up 2318 01:46:00,310 --> 01:45:59,119 computing 2319 01:46:02,310 --> 01:46:00,320 and also 2320 01:46:07,430 --> 01:46:02,320 from the teaching perspective from the 2321 01:46:07,440 --> 01:46:11,270 there is more value 2322 01:46:16,070 --> 01:46:13,830 to the education you give 2323 01:46:17,990 --> 01:46:16,080 if it comes with implementation because 2324 01:46:22,390 --> 01:46:18,000 you want your students to be able to 2325 01:46:26,950 --> 01:46:24,790 yes sorry what were you asking oh i was 2326 01:46:28,629 --> 01:46:26,960 saying you ultimately care about the 2327 01:46:32,709 --> 01:46:28,639 practical aspect of math even though 2328 01:46:38,709 --> 01:46:36,070 ultimately yes though possibly very 2329 01:46:43,109 --> 01:46:38,719 indirectly 2330 01:46:44,709 --> 01:46:43,119 so maybe the way the math i'm doing 2331 01:46:47,510 --> 01:46:44,719 or maybe the 2332 01:46:49,350 --> 01:46:47,520 maybe the way i care is in that the pure 2333 01:46:52,310 --> 01:46:49,360 math i'm doing 2334 01:46:55,430 --> 01:46:52,320 uh enables me to teach graduate students 2335 01:47:00,470 --> 01:46:55,440 who will then become college instructors 2336 01:47:00,480 --> 01:47:02,790 uh 2337 01:47:06,470 --> 01:47:04,629 actually 2338 01:47:07,669 --> 01:47:06,480 implement the mathematics they're 2339 01:47:09,910 --> 01:47:07,679 learning 2340 01:47:11,830 --> 01:47:09,920 so i mean it it doesn't have to be 2341 01:47:13,990 --> 01:47:11,840 immediate and direct 2342 01:47:16,470 --> 01:47:14,000 but yes i do care about 2343 01:47:19,189 --> 01:47:16,480 how at the end it gets applied 2344 01:47:21,669 --> 01:47:19,199 or how i get the end it it becomes 2345 01:47:23,350 --> 01:47:21,679 applicable 2346 01:47:26,310 --> 01:47:23,360 great now we just have some audience 2347 01:47:27,669 --> 01:47:26,320 questions i asked people beforehand 2348 01:47:29,430 --> 01:47:27,679 what are some questions you have for 2349 01:47:31,910 --> 01:47:29,440 professor jor barnetten so the 2350 01:47:34,149 --> 01:47:31,920 scientific mystical philosopher that's 2351 01:47:36,149 --> 01:47:34,159 the username he wants to know he or she 2352 01:47:42,790 --> 01:47:36,159 wants to know why the unreasonable 2353 01:47:46,550 --> 01:47:44,229 sorry 2354 01:47:49,990 --> 01:47:46,560 why is mathematics unreasonably 2355 01:47:55,510 --> 01:47:51,350 gee i don't know 2356 01:47:59,350 --> 01:47:57,430 uh 2357 01:48:01,750 --> 01:47:59,360 she may or may not be able to give you 2358 01:48:08,390 --> 01:48:01,760 an answer 2359 01:48:15,109 --> 01:48:11,510 yeah it's weird we live in a predictable 2360 01:48:18,629 --> 01:48:16,470 uh 2361 01:48:21,270 --> 01:48:18,639 right when we throw something up in the 2362 01:48:23,109 --> 01:48:21,280 air it always uh 2363 01:48:25,189 --> 01:48:23,119 shows this you know goes through the 2364 01:48:27,189 --> 01:48:25,199 same trajectory 2365 01:48:30,149 --> 01:48:27,199 uh 2366 01:48:33,990 --> 01:48:30,159 nearly i don't know i mean 2367 01:48:38,870 --> 01:48:36,550 roman gekwad wants to know have you ever 2368 01:48:44,550 --> 01:48:38,880 had your iq scored 2369 01:48:51,109 --> 01:48:47,189 no clue 2370 01:48:59,189 --> 01:48:54,629 you know iq scores are very limited in 2371 01:48:59,199 --> 01:49:02,149 you know are 2372 01:49:07,910 --> 01:49:05,430 you know there is a fun story 2373 01:49:12,550 --> 01:49:09,350 uh that i 2374 01:49:13,669 --> 01:49:12,560 i've never verified it but i heard it 2375 01:49:14,390 --> 01:49:13,679 okay 2376 01:49:20,790 --> 01:49:14,400 that 2377 01:49:26,629 --> 01:49:24,390 when the people who introduced iq tests 2378 01:49:28,629 --> 01:49:26,639 first introduced them they run them on 2379 01:49:31,510 --> 01:49:28,639 test subjects 2380 01:49:39,350 --> 01:49:33,910 the women the females 2381 01:49:43,350 --> 01:49:41,589 that was back in the 50s or i don't know 2382 01:49:47,030 --> 01:49:43,360 exactly when but there was a long time 2383 01:49:49,750 --> 01:49:47,040 ago they figured hey that's impossible 2384 01:49:51,830 --> 01:49:49,760 uh and then they tweaked the tests again 2385 01:49:54,470 --> 01:49:51,840 a bit they changed the nature of the 2386 01:49:56,950 --> 01:49:54,480 questions they asked them differently 2387 01:50:02,709 --> 01:49:56,960 until they finally were able 2388 01:50:05,750 --> 01:50:02,719 to uh to make um uh men uh equal or 2389 01:50:08,229 --> 01:50:05,760 maybe better i don't know than women 2390 01:50:12,149 --> 01:50:08,239 and again this is true 2391 01:50:15,189 --> 01:50:12,159 to a certain system of education in a 2392 01:50:16,950 --> 01:50:15,199 certain time 2393 01:50:19,669 --> 01:50:16,960 right 2394 01:50:22,070 --> 01:50:19,679 men and women did not receive the same 2395 01:50:22,950 --> 01:50:22,080 education 2396 01:50:25,350 --> 01:50:22,960 uh 2397 01:50:27,589 --> 01:50:25,360 it would have been easy to do to 2398 01:50:28,550 --> 01:50:27,599 distinguish 2399 01:50:31,030 --> 01:50:28,560 because 2400 01:50:33,030 --> 01:50:31,040 they came as as their backgrounds were 2401 01:50:36,229 --> 01:50:33,040 different 2402 01:50:37,589 --> 01:50:36,239 uh so you could arrange 2403 01:50:39,510 --> 01:50:37,599 uh 2404 01:50:40,790 --> 01:50:39,520 such things 2405 01:50:42,550 --> 01:50:40,800 okay 2406 01:50:50,709 --> 01:50:42,560 uh 2407 01:50:54,709 --> 01:50:53,109 that's about the value of iq 2408 01:50:56,709 --> 01:50:54,719 of iq scores 2409 01:50:58,870 --> 01:50:56,719 okay they were 2410 01:51:02,070 --> 01:50:58,880 i mean 2411 01:51:03,910 --> 01:51:02,080 to some extent they measured something 2412 01:51:06,149 --> 01:51:03,920 to some extent they were cooked to 2413 01:51:10,550 --> 01:51:06,159 measure whatever people wanted them to 2414 01:51:13,990 --> 01:51:12,070 not much to learn from these 2415 01:51:15,669 --> 01:51:14,000 measurements 2416 01:51:18,550 --> 01:51:15,679 tori cole has 2417 01:51:21,589 --> 01:51:18,560 a question what do you think of biology 2418 01:51:23,510 --> 01:51:21,599 slash psychology slash philosophy 2419 01:51:25,669 --> 01:51:23,520 i think they're fun i think they're 2420 01:51:27,990 --> 01:51:25,679 foundational to understanding myself and 2421 01:51:29,990 --> 01:51:28,000 therefore my experience of the universe 2422 01:51:31,830 --> 01:51:30,000 do you think you would gain much of an 2423 01:51:34,310 --> 01:51:31,840 understanding 2424 01:51:37,750 --> 01:51:34,320 of an exploration from those fields to 2425 01:51:44,390 --> 01:51:39,830 again biology 2426 01:51:47,589 --> 01:51:45,189 i mean 2427 01:51:51,510 --> 01:51:47,599 they're all interesting fields i am not 2428 01:51:56,229 --> 01:51:54,709 what more to say you know 2429 01:51:57,910 --> 01:51:56,239 do you think there are insights there 2430 01:52:00,310 --> 01:51:57,920 that if you were to read a biology book 2431 01:52:01,430 --> 01:52:00,320 a psychology book perhaps a philosophy 2432 01:52:03,030 --> 01:52:01,440 book 2433 01:52:04,470 --> 01:52:03,040 do you think there are insights to be 2434 01:52:09,910 --> 01:52:04,480 gleaned from there that you can then 2435 01:52:09,920 --> 01:52:14,709 there are connections here and there 2436 01:52:14,719 --> 01:52:18,629 um 2437 01:52:23,830 --> 01:52:20,709 much of mathematics is independent of 2438 01:52:25,630 --> 01:52:25,270 uh 2439 01:52:28,870 --> 01:52:25,640 so 2440 01:52:33,430 --> 01:52:30,870 obviously 2441 01:52:36,149 --> 01:52:33,440 biology motivates parts of mathematics 2442 01:52:40,229 --> 01:52:36,159 so parts of mathematics 2443 01:52:46,070 --> 01:52:42,950 you know are about modeling biological 2444 01:52:49,510 --> 01:52:47,109 when we 2445 01:52:52,550 --> 01:52:49,520 compute the fibonacci numbers we give 2446 01:52:54,070 --> 01:52:52,560 examples of uh the reproduction rules of 2447 01:52:55,830 --> 01:52:54,080 rabbits 2448 01:52:57,589 --> 01:52:55,840 okay 2449 01:53:00,870 --> 01:52:57,599 and and then there is much more like 2450 01:53:04,629 --> 01:53:00,880 that and and then um 2451 01:53:07,669 --> 01:53:06,149 uh 2452 01:53:09,589 --> 01:53:07,679 but 2453 01:53:12,790 --> 01:53:09,599 and likewise and and and of course 2454 01:53:14,310 --> 01:53:12,800 philosophy so you know there are 2455 01:53:16,310 --> 01:53:14,320 bits of mathematics of great 2456 01:53:19,750 --> 01:53:16,320 philosophical values so 2457 01:53:20,629 --> 01:53:19,760 you know gideon's theorem says 2458 01:53:22,629 --> 01:53:20,639 uh 2459 01:53:25,510 --> 01:53:22,639 that there are all there will always be 2460 01:53:28,229 --> 01:53:25,520 things we do not we will not know 2461 01:53:31,510 --> 01:53:28,239 okay or said diff or or differently i 2462 01:53:34,070 --> 01:53:31,520 know there is no algorithm to decide 2463 01:53:41,270 --> 01:53:37,910 to find the proofs of theorems 2464 01:53:43,350 --> 01:53:41,280 uh these things have philosophical value 2465 01:53:44,790 --> 01:53:43,360 okay 2466 01:53:48,149 --> 01:53:44,800 uh 2467 01:53:49,030 --> 01:53:48,159 for most mathematicians it's not 2468 01:53:59,910 --> 01:53:49,040 a 2469 01:54:00,950 --> 01:53:59,920 benefits very little 2470 01:54:01,910 --> 01:54:00,960 if any 2471 01:54:04,229 --> 01:54:01,920 from the 2472 01:54:05,830 --> 01:54:04,239 from contact with biology 2473 01:54:11,750 --> 01:54:05,840 uh 2474 01:54:16,470 --> 01:54:13,910 okay phil thomas wants to know what led 2475 01:54:19,030 --> 01:54:16,480 him what led you professor to the field 2476 01:54:21,030 --> 01:54:19,040 of mathematics and is your field 2477 01:54:28,470 --> 01:54:21,040 something you think virtually anyone can 2478 01:54:28,480 --> 01:54:32,470 what led me there 2479 01:54:35,510 --> 01:54:33,430 you know 2480 01:54:37,830 --> 01:54:35,520 it's a question about my life story 2481 01:54:40,070 --> 01:54:37,840 right so what led me there is essentia 2482 01:54:48,310 --> 01:54:40,080 is is 2483 01:54:53,030 --> 01:54:50,750 a sequence of uh coincidences and 2484 01:54:54,870 --> 01:54:53,040 misunderstandings i don't know 2485 01:54:55,830 --> 01:54:54,880 a number of things but 2486 01:54:56,790 --> 01:54:55,840 so 2487 01:54:59,669 --> 01:54:56,800 um 2488 01:55:01,430 --> 01:54:59,679 to some extent to some extent i was good 2489 01:55:03,350 --> 01:55:01,440 at that 2490 01:55:11,990 --> 01:55:03,360 and that 2491 01:55:14,030 --> 01:55:12,000 many things right people tend to do what 2492 01:55:15,589 --> 01:55:14,040 they're good at 2493 01:55:18,149 --> 01:55:15,599 misunderstandings you said 2494 01:55:21,109 --> 01:55:18,159 misunderstandings as well yes to some 2495 01:55:23,270 --> 01:55:21,119 extent uh 2496 01:55:25,030 --> 01:55:23,280 i misunderstood math 2497 01:55:27,350 --> 01:55:25,040 so 2498 01:55:31,830 --> 01:55:27,360 you know there was a time that i really 2499 01:55:34,950 --> 01:55:31,840 liked uh computers and electronics 2500 01:55:36,790 --> 01:55:34,960 i uh at some point 2501 01:55:39,109 --> 01:55:36,800 realized that there is a lot of kind of 2502 01:55:40,390 --> 01:55:39,119 hard work in it 2503 01:55:43,189 --> 01:55:40,400 so 2504 01:55:47,910 --> 01:55:45,589 writing a computer program is very hard 2505 01:55:49,510 --> 01:55:47,920 you have to write hundreds of lines of 2506 01:55:51,669 --> 01:55:49,520 code and then 2507 01:55:54,310 --> 01:55:51,679 debug them and they whatever and 2508 01:55:56,550 --> 01:55:54,320 similarly for electronics right you have 2509 01:55:59,350 --> 01:55:56,560 to place those transistors on the board 2510 01:56:01,350 --> 01:55:59,360 and solder them together and 2511 01:56:03,109 --> 01:56:01,360 solder them together and 2512 01:56:05,270 --> 01:56:03,119 and you always get it wrong and you know 2513 01:56:07,510 --> 01:56:05,280 there is a lot of hard work where 2514 01:56:10,709 --> 01:56:07,520 mathematics is so much easier all you 2515 01:56:12,470 --> 01:56:10,719 have to do is to prove theorems 2516 01:56:16,070 --> 01:56:12,480 that was a complete misunderstanding i 2517 01:56:17,589 --> 01:56:16,080 mean i thought it was like much purer 2518 01:56:19,910 --> 01:56:17,599 uh i didn't 2519 01:56:23,189 --> 01:56:19,920 at the time i didn't realize how much 2520 01:56:24,950 --> 01:56:23,199 hard work is involved 2521 01:56:27,109 --> 01:56:24,960 so in some sense i got there i go to 2522 01:56:29,750 --> 01:56:27,119 mathematics by misunderstanding by being 2523 01:56:31,270 --> 01:56:29,760 lazy and not realizing that 2524 01:56:33,750 --> 01:56:31,280 i'm i'm 2525 01:56:35,750 --> 01:56:33,760 getting trapped into into a place where 2526 01:56:38,790 --> 01:56:35,760 laziness is is not 2527 01:56:41,270 --> 01:56:38,800 it is is not always enough 2528 01:56:44,470 --> 01:56:41,280 and also at the end i ended up liking 2529 01:56:48,149 --> 01:56:44,480 those parts that i first thought i was 2530 01:56:50,550 --> 01:56:48,159 going away from namely computation 2531 01:56:52,870 --> 01:56:50,560 so i ended up i mean computation to me 2532 01:56:54,870 --> 01:56:52,880 was like a childhood thing and a later 2533 01:56:56,709 --> 01:56:54,880 acquired taste 2534 01:56:58,550 --> 01:56:56,719 there was a period in between when in 2535 01:57:02,070 --> 01:56:58,560 between when i thought i was pure i 2536 01:57:02,080 --> 01:57:05,350 um 2537 01:57:09,109 --> 01:57:07,750 right what else did i answer or did i 2538 01:57:11,830 --> 01:57:09,119 mean there was a second part to the 2539 01:57:13,750 --> 01:57:11,840 question do you believe that your field 2540 01:57:15,189 --> 01:57:13,760 either the field of mathematics or your 2541 01:57:17,189 --> 01:57:15,199 subfield the one that you're working in 2542 01:57:19,270 --> 01:57:17,199 currently do you feel that your field is 2543 01:57:22,229 --> 01:57:19,280 something that virtually anyone can 2544 01:57:22,239 --> 01:57:25,589 no 2545 01:57:33,589 --> 01:57:26,390 uh 2546 01:57:42,950 --> 01:57:36,830 some 2547 01:57:47,510 --> 01:57:44,709 everybody can learn 2548 01:57:49,669 --> 01:57:47,520 and everybody should learn 2549 01:57:54,470 --> 01:57:49,679 and maybe it's more 2550 01:57:57,189 --> 01:57:54,480 than what is taught in uh 2551 01:58:00,390 --> 01:57:57,199 in our current educational system 2552 01:58:01,669 --> 01:58:00,400 education system okay 2553 01:58:03,350 --> 01:58:01,679 uh 2554 01:58:12,070 --> 01:58:03,360 but 2555 01:58:17,589 --> 01:58:13,189 you know i 2556 01:58:17,599 --> 01:58:21,189 okay 2557 01:58:29,510 --> 01:58:21,990 the 2558 01:58:32,310 --> 01:58:29,520 which he knows things 2559 01:58:35,910 --> 01:58:32,320 i'll never get there 2560 01:58:36,870 --> 01:58:35,920 it's not i'm not talented enough to get 2561 01:58:40,470 --> 01:58:36,880 there 2562 01:58:43,270 --> 01:58:40,480 it might be that in my 30 years in the 2563 01:58:45,750 --> 01:58:43,280 subject i've learned things that uh 2564 01:58:49,350 --> 01:58:45,760 most people 2565 01:58:56,149 --> 01:58:49,360 also wouldn't be able to catch up with 2566 01:58:59,990 --> 01:58:57,430 you know 2567 01:59:01,589 --> 01:59:00,000 there is the mushizuki proof of the abc 2568 01:59:03,750 --> 01:59:01,599 conjecture 2569 01:59:06,470 --> 01:59:03,760 disputed 2570 01:59:08,950 --> 01:59:06,480 okay moshizuki claims it's a proof other 2571 01:59:10,950 --> 01:59:08,960 people think it isn't 2572 01:59:13,669 --> 01:59:10,960 i will never be in the position to 2573 01:59:17,589 --> 01:59:13,679 understand that 2574 01:59:21,830 --> 01:59:20,149 possibly if i started early enough i'm 2575 01:59:24,070 --> 01:59:21,840 not even sure 2576 01:59:26,950 --> 01:59:24,080 i happen to know moshizuki i remember 2577 01:59:29,750 --> 01:59:26,960 him when he was young we we were friends 2578 01:59:31,109 --> 01:59:29,760 when like we went we're went to graduate 2579 01:59:32,550 --> 01:59:31,119 school together 2580 01:59:35,669 --> 01:59:32,560 so i uh 2581 01:59:38,470 --> 01:59:35,679 so i remember him when he was young 2582 01:59:40,550 --> 01:59:38,480 he was smarter and faster than me 2583 01:59:42,470 --> 01:59:40,560 it's conceivable that after 20 years 2584 01:59:45,030 --> 01:59:42,480 he's gone so far 2585 01:59:47,910 --> 01:59:45,040 that i will never be able to catch up 2586 01:59:49,430 --> 01:59:47,920 it's equally possible that 2587 01:59:52,229 --> 01:59:49,440 there are people who would never be able 2588 01:59:52,930 --> 01:59:52,239 to catch up with me 2589 01:59:55,109 --> 01:59:52,940 um 2590 01:59:57,990 --> 01:59:55,119 [Music] 2591 02:00:01,910 --> 01:59:58,000 they said 2592 02:00:01,920 --> 02:00:05,669 is useful to everybody 2593 02:00:10,629 --> 02:00:07,750 you know 2594 02:00:12,310 --> 02:00:10,639 we're we're now in the in the midst of a 2595 02:00:14,790 --> 02:00:12,320 pandemic 2596 02:00:16,790 --> 02:00:14,800 understanding what's the exponential 2597 02:00:21,750 --> 02:00:16,800 function 2598 02:00:25,350 --> 02:00:23,669 is basic knowledge is something that 2599 02:00:26,709 --> 02:00:25,360 every human should 2600 02:00:29,350 --> 02:00:26,719 should have 2601 02:00:31,189 --> 02:00:29,360 because it actually dictates if it tells 2602 02:00:33,189 --> 02:00:31,199 us something 2603 02:00:35,750 --> 02:00:33,199 about how to behave 2604 02:00:37,910 --> 02:00:35,760 uh at this time 2605 02:00:41,350 --> 02:00:37,920 uh 2606 02:00:43,030 --> 02:00:41,360 likewise making various probabilistic 2607 02:00:46,550 --> 02:00:43,040 estimates 2608 02:00:52,870 --> 02:00:49,510 if the chance of such and such type of 2609 02:00:55,750 --> 02:00:52,880 side effects is is one in a million what 2610 02:00:57,750 --> 02:00:55,760 does it mean 2611 02:01:00,149 --> 02:00:57,760 what does one in a million means in 2612 02:01:01,830 --> 02:01:00,159 practical term for me terms for me 2613 02:01:04,149 --> 02:01:01,840 should i fear it 2614 02:01:07,189 --> 02:01:04,159 or is it so remote that i have that i 2615 02:01:14,070 --> 02:01:11,109 so basic numeracy is is is is an 2616 02:01:15,189 --> 02:01:14,080 absolute necessary ingredient and for 2617 02:01:19,589 --> 02:01:15,199 everyone 2618 02:01:21,430 --> 02:01:19,599 when you mentioned that you'll never be 2619 02:01:22,629 --> 02:01:21,440 able to catch up to whitten and may 2620 02:01:25,030 --> 02:01:22,639 perhaps some people won't be able to 2621 02:01:27,189 --> 02:01:25,040 catch up to you and so on 2622 02:01:29,189 --> 02:01:27,199 what is that a function of biology you 2623 02:01:31,430 --> 02:01:29,199 mentioned the word talent so is it is 2624 02:01:33,589 --> 02:01:31,440 that just innate is 2625 02:01:36,390 --> 02:01:33,599 is what's innate called intelligence is 2626 02:01:37,910 --> 02:01:36,400 that associated with iq like what are 2627 02:01:40,070 --> 02:01:37,920 you referring to when you say you won't 2628 02:01:43,350 --> 02:01:40,080 be able to catch up 2629 02:01:45,589 --> 02:01:43,360 it's a number of things 2630 02:01:47,990 --> 02:01:45,599 you can call it talent 2631 02:01:50,870 --> 02:01:48,000 you can call it iq if you wish but of 2632 02:01:53,109 --> 02:01:50,880 course there is no numerical measurement 2633 02:02:01,350 --> 02:01:53,119 and it's a much much more complicated 2634 02:02:08,870 --> 02:02:03,750 you know so much of 2635 02:02:12,790 --> 02:02:10,790 depends on how much you concentrate on 2636 02:02:15,750 --> 02:02:12,800 mathematics 2637 02:02:20,149 --> 02:02:15,760 so you know uh 2638 02:02:25,109 --> 02:02:22,629 if at a certain part of your life you're 2639 02:02:28,870 --> 02:02:25,119 able to completely isolate yourself and 2640 02:02:31,510 --> 02:02:28,880 think on nothing but mathematics 2641 02:02:33,910 --> 02:02:31,520 you'll end up knowing more mathematics 2642 02:02:35,030 --> 02:02:33,920 than if you are also a human a human 2643 02:02:39,350 --> 02:02:35,040 along 2644 02:02:40,550 --> 02:02:39,360 okay uh 2645 02:02:53,470 --> 02:02:40,560 so 2646 02:02:57,910 --> 02:02:55,669 circumstance and 2647 02:02:59,669 --> 02:02:57,920 uh 2648 02:03:03,189 --> 02:02:59,679 and luck 2649 02:03:09,589 --> 02:03:06,870 in some sense being narrow-minded 2650 02:03:12,149 --> 02:03:09,599 so now being narrow-minded helps in 2651 02:03:15,430 --> 02:03:12,159 certain ways 2652 02:03:18,709 --> 02:03:17,669 speaking of eric weinstein you mentioned 2653 02:03:19,910 --> 02:03:18,719 him 2654 02:03:20,709 --> 02:03:19,920 okay so 2655 02:03:25,510 --> 02:03:20,719 so 2656 02:03:28,629 --> 02:03:25,520 talent for certain kind of things and 2657 02:03:30,149 --> 02:03:28,639 great fear of others 2658 02:03:32,310 --> 02:03:30,159 and 2659 02:03:35,270 --> 02:03:32,320 maybe he would have been a much more 2660 02:03:38,229 --> 02:03:35,280 famous mathematician physicist now 2661 02:03:40,830 --> 02:03:38,239 if if it wasn't for these 2662 02:03:44,550 --> 02:03:40,840 coincidences 2663 02:03:48,390 --> 02:03:45,669 i don't know 2664 02:03:54,950 --> 02:03:50,069 you could call it 2665 02:03:57,350 --> 02:03:54,960 uh learn you can call it many things but 2666 02:03:59,589 --> 02:03:57,360 it's a very complicated combination of 2667 02:04:01,830 --> 02:03:59,599 things 2668 02:04:03,830 --> 02:04:01,840 tyler goldstein has a question 2669 02:04:05,910 --> 02:04:03,840 do you think we need to make new 2670 02:04:07,990 --> 02:04:05,920 research institutions that aren't linked 2671 02:04:11,109 --> 02:04:08,000 to academia 2672 02:04:12,709 --> 02:04:11,119 and i imagine what he's referring to 2673 02:04:14,390 --> 02:04:12,719 is something that weinstein has brought 2674 02:04:16,709 --> 02:04:14,400 up in wolfram as well 2675 02:04:18,550 --> 02:04:16,719 they're not huge fans of the peer review 2676 02:04:20,390 --> 02:04:18,560 process or at least they're not huge 2677 02:04:21,830 --> 02:04:20,400 fans of only 2678 02:04:23,270 --> 02:04:21,840 thinking that work 2679 02:04:25,589 --> 02:04:23,280 is worth it if it's gone through the 2680 02:04:27,510 --> 02:04:25,599 peer review process 2681 02:04:29,589 --> 02:04:27,520 and 2682 02:04:31,669 --> 02:04:29,599 while that's associated with academia 2683 02:04:40,550 --> 02:04:31,679 i'm curious if you have any thoughts as 2684 02:04:44,149 --> 02:04:42,470 well there are things outside of 2685 02:04:46,709 --> 02:04:44,159 academia 2686 02:04:50,470 --> 02:04:48,950 arguably most research is done outside 2687 02:04:52,310 --> 02:04:50,480 of academia 2688 02:04:55,350 --> 02:04:52,320 i mean you know there are a lot of a lot 2689 02:04:56,950 --> 02:04:55,360 of research is done inside companies 2690 02:04:59,430 --> 02:04:56,960 inside 2691 02:05:03,189 --> 02:04:59,440 well a lot of research is done outside 2692 02:05:03,199 --> 02:05:08,149 um 2693 02:05:12,310 --> 02:05:10,470 but overall i think the system is 2694 02:05:14,390 --> 02:05:12,320 reasonable 2695 02:05:17,910 --> 02:05:14,400 sorry overall you think the system is i 2696 02:05:19,270 --> 02:05:17,920 think the system is reasonable 2697 02:05:23,589 --> 02:05:19,280 so 2698 02:05:26,069 --> 02:05:23,599 uh you know you can um 2699 02:05:27,669 --> 02:05:26,079 say bad things as much as you want about 2700 02:05:32,390 --> 02:05:27,679 peer review 2701 02:05:32,400 --> 02:05:36,870 it's better than having no review 2702 02:05:36,880 --> 02:05:41,030 um 2703 02:05:44,069 --> 02:05:42,870 you can say 2704 02:05:46,229 --> 02:05:44,079 uh 2705 02:05:47,990 --> 02:05:46,239 maybe mathematical should be more 2706 02:05:50,790 --> 02:05:48,000 hierarchical 2707 02:05:51,830 --> 02:05:50,800 okay there should be big bosses 2708 02:05:54,310 --> 02:05:51,840 who 2709 02:05:56,069 --> 02:05:54,320 determine which theorems we should be 2710 02:06:00,550 --> 02:05:56,079 proving 2711 02:06:04,069 --> 02:06:01,669 have their 2712 02:06:06,870 --> 02:06:04,079 smaller bosses who would be responsible 2713 02:06:09,109 --> 02:06:06,880 to specific theorems and they would be 2714 02:06:11,109 --> 02:06:09,119 the big bosses of other people who would 2715 02:06:12,870 --> 02:06:11,119 be proving dilemmas 2716 02:06:15,350 --> 02:06:12,880 you could say something like that it 2717 02:06:17,510 --> 02:06:15,360 sounds like it sounds ridiculous it 2718 02:06:18,950 --> 02:06:17,520 would work just as ridiculously as it 2719 02:06:21,750 --> 02:06:18,960 sounds 2720 02:06:23,350 --> 02:06:21,760 current system is 2721 02:06:25,030 --> 02:06:23,360 you know 2722 02:06:29,910 --> 02:06:25,040 given 2723 02:06:31,669 --> 02:06:29,920 reasonably good i believe there are some 2724 02:06:33,830 --> 02:06:31,679 arguments to say that 2725 02:06:36,229 --> 02:06:33,840 the what you just outlined is 2726 02:06:39,510 --> 02:06:36,239 somewhat like it happens given grant 2727 02:06:41,669 --> 02:06:39,520 agencies they have some field that they 2728 02:06:43,589 --> 02:06:41,679 fund and so then the research tends to 2729 02:06:46,390 --> 02:06:43,599 go toward there so you can view them as 2730 02:06:48,470 --> 02:06:46,400 the large boss and i believe lee smallin 2731 02:06:50,629 --> 02:06:48,480 makes some arguments saying that that's 2732 02:06:52,790 --> 02:06:50,639 why string theory is as large as as it 2733 02:06:54,390 --> 02:06:52,800 is even though it shouldn't be because 2734 02:06:56,629 --> 02:06:54,400 we haven't seen much success from it and 2735 02:06:58,709 --> 02:06:56,639 so on so do you see what you just 2736 02:07:00,790 --> 02:06:58,719 outlined as the ridiculous scenario do 2737 02:07:06,790 --> 02:07:00,800 you see that as having any bearing to 2738 02:07:06,800 --> 02:07:09,109 so 2739 02:07:09,119 --> 02:07:18,149 yes of course there is bias 2740 02:07:23,430 --> 02:07:21,189 generated by the granting agencies by 2741 02:07:25,990 --> 02:07:23,440 the powerful people 2742 02:07:29,030 --> 02:07:26,000 be them be them the writing granting 2743 02:07:31,189 --> 02:07:29,040 agencies or the editorial boards of 2744 02:07:33,750 --> 02:07:31,199 journals 2745 02:07:37,030 --> 02:07:33,760 so you know 2746 02:07:40,069 --> 02:07:37,040 if you publish if you have a result 2747 02:07:43,030 --> 02:07:40,079 uh that somebody on the editorial board 2748 02:07:44,310 --> 02:07:43,040 of an excellent journal uh 2749 02:07:46,310 --> 02:07:44,320 likes 2750 02:07:48,390 --> 02:07:46,320 you know that's close to the field of 2751 02:07:50,550 --> 02:07:48,400 somebody in the editorial board of an 2752 02:07:52,470 --> 02:07:50,560 excellent excellent journal then your 2753 02:07:56,550 --> 02:07:52,480 result is much more likely to get 2754 02:07:58,470 --> 02:07:56,560 published in this uh excellent journal 2755 02:08:01,830 --> 02:07:58,480 and then you're much more likely to get 2756 02:08:04,550 --> 02:08:01,840 tenure and then 2757 02:08:06,629 --> 02:08:04,560 more work will be produced in that field 2758 02:08:09,030 --> 02:08:06,639 and you'll advise students who will 2759 02:08:11,189 --> 02:08:09,040 produce even more more work on that 2760 02:08:16,470 --> 02:08:11,199 field 2761 02:08:16,480 --> 02:08:20,229 but 2762 02:08:25,270 --> 02:08:22,310 it's not clear that you can think of a 2763 02:08:27,589 --> 02:08:25,280 better alternative 2764 02:08:30,149 --> 02:08:27,599 and also 2765 02:08:33,750 --> 02:08:30,159 there is still some amount of academic 2766 02:08:37,510 --> 02:08:33,760 freedom so the granting agency 2767 02:08:41,270 --> 02:08:37,520 decides once every five years 2768 02:08:49,109 --> 02:08:46,069 in those five years some of my time i do 2769 02:08:51,430 --> 02:08:49,119 what is necessary to get my next grant 2770 02:08:54,470 --> 02:08:51,440 but some of the time i also do things 2771 02:08:55,990 --> 02:08:54,480 that i think are useful that i think are 2772 02:08:58,390 --> 02:08:56,000 useful 2773 02:08:59,350 --> 02:08:58,400 uh likewise 2774 02:09:02,709 --> 02:08:59,360 uh 2775 02:09:05,350 --> 02:09:02,719 you know some of my career 2776 02:09:09,589 --> 02:09:05,360 is is determined by which journal i 2777 02:09:12,470 --> 02:09:09,599 publish in but some is determined by 2778 02:09:14,069 --> 02:09:12,480 uh other factors 2779 02:09:16,390 --> 02:09:14,079 okay by the results that aren't 2780 02:09:19,750 --> 02:09:16,400 published by the lectures that i give in 2781 02:09:23,109 --> 02:09:19,760 conferences in china you know 2782 02:09:24,870 --> 02:09:23,119 it's much more multi-dimensional 2783 02:09:27,189 --> 02:09:24,880 than uh 2784 02:09:31,830 --> 02:09:27,199 than just having a boss and the boss is 2785 02:09:35,830 --> 02:09:33,910 even the fact that the editorial boards 2786 02:09:39,030 --> 02:09:35,840 are different than the review boards of 2787 02:09:40,950 --> 02:09:39,040 the granting agencies allows make some 2788 02:09:43,910 --> 02:09:40,960 variety 2789 02:09:47,350 --> 02:09:43,920 and again what is the alternative 2790 02:09:52,149 --> 02:09:50,069 one stupid alternative would be to say 2791 02:09:54,709 --> 02:09:52,159 to allow anyone to say 2792 02:09:57,910 --> 02:09:54,719 i am a mathematician 2793 02:10:01,350 --> 02:09:57,920 uh here is my proof that 2794 02:10:03,750 --> 02:10:01,360 pi is rational 2795 02:10:05,910 --> 02:10:03,760 or that you can 2796 02:10:08,709 --> 02:10:05,920 divide you know 2797 02:10:10,310 --> 02:10:08,719 here is my proof of the uh goldbach 2798 02:10:13,189 --> 02:10:10,320 conjecture 2799 02:10:15,350 --> 02:10:13,199 who's arguing with me i'm saying it's a 2800 02:10:20,390 --> 02:10:15,360 proof 2801 02:10:25,750 --> 02:10:23,189 it's much better not to lose control 2802 02:10:27,510 --> 02:10:25,760 completely 2803 02:10:29,669 --> 02:10:27,520 you just use the word mathematician and 2804 02:10:31,350 --> 02:10:29,679 i'm curious what do you see as a 2805 02:10:33,109 --> 02:10:31,360 mathematician is it someone who's a 2806 02:10:35,669 --> 02:10:33,119 professor of math is this someone who 2807 02:10:37,750 --> 02:10:35,679 gets their masters or phd do you have to 2808 02:10:39,510 --> 02:10:37,760 frequently publish research in order for 2809 02:10:40,790 --> 02:10:39,520 you to call yourself a mathematician 2810 02:10:43,830 --> 02:10:40,800 like what gives 2811 02:10:47,350 --> 02:10:43,840 obviously it's a nebulous term but it's 2812 02:10:49,589 --> 02:10:47,360 not extremely amorphous it's defined 2813 02:10:53,990 --> 02:10:49,599 so what do you define it as 2814 02:11:02,950 --> 02:10:55,030 you know 2815 02:11:09,430 --> 02:11:05,270 many definitions don't have sharp 2816 02:11:12,390 --> 02:11:09,440 boundaries in fact only in mathematics 2817 02:11:14,709 --> 02:11:12,400 uh there are sharp boundaries between 2818 02:11:17,270 --> 02:11:14,719 things like either 2819 02:11:20,229 --> 02:11:17,280 the series is convergent or it is not 2820 02:11:21,750 --> 02:11:20,239 convergent but only and there is a very 2821 02:11:24,310 --> 02:11:21,760 very specific 2822 02:11:26,790 --> 02:11:24,320 uh criteria to decide only in 2823 02:11:28,950 --> 02:11:26,800 mathematics there are 2824 02:11:30,709 --> 02:11:28,960 uh sharp boundaries and now you're 2825 02:11:32,310 --> 02:11:30,719 asking a meta-mathematical question 2826 02:11:33,830 --> 02:11:32,320 you're asking a question about 2827 02:11:36,390 --> 02:11:33,840 mathematics not a question in 2828 02:11:38,550 --> 02:11:36,400 mathematics so there aren't 2829 02:11:39,990 --> 02:11:38,560 sharp boundaries so basically all of the 2830 02:11:41,990 --> 02:11:40,000 above you know 2831 02:11:44,709 --> 02:11:42,000 if you teach mathematics if you think a 2832 02:11:47,510 --> 02:11:44,719 lot about mathematics if your way of 2833 02:11:50,830 --> 02:11:47,520 thought is abstraction 2834 02:11:50,840 --> 02:11:54,950 proof um 2835 02:12:00,709 --> 02:11:57,589 you know then that's mathematics but 2836 02:12:03,350 --> 02:12:00,719 but but you can always 2837 02:12:05,589 --> 02:12:03,360 you can always find the borderline 2838 02:12:07,830 --> 02:12:05,599 things that will be hard to decide 2839 02:12:09,270 --> 02:12:07,840 here's a reason why i'm asking because 2840 02:12:11,350 --> 02:12:09,280 not everyone can call themselves a 2841 02:12:13,589 --> 02:12:11,360 doctor i know that some people they get 2842 02:12:15,350 --> 02:12:13,599 their md and then they're no longer 2843 02:12:16,950 --> 02:12:15,360 practicing researchers they no longer 2844 02:12:18,870 --> 02:12:16,960 are connected with the field but then 2845 02:12:20,470 --> 02:12:18,880 they'll give health advice resting on 2846 02:12:21,910 --> 02:12:20,480 the laurel that they have an md and 2847 02:12:22,950 --> 02:12:21,920 they'll say well this comes from a 2848 02:12:25,350 --> 02:12:22,960 doctor 2849 02:12:27,270 --> 02:12:25,360 and i'm sure the same occurs in 2850 02:12:29,189 --> 02:12:27,280 mathematics though 2851 02:12:31,030 --> 02:12:29,199 to a much lesser degree same with 2852 02:12:33,109 --> 02:12:31,040 physics someone may say well i'm a 2853 02:12:36,149 --> 02:12:33,119 physicist because i 2854 02:12:37,990 --> 02:12:36,159 i have a degree from a university but 2855 02:12:40,229 --> 02:12:38,000 that in physics but that doesn't 2856 02:12:41,669 --> 02:12:40,239 necessarily make you a physicist doesn't 2857 02:12:43,669 --> 02:12:41,679 mean your physics works should be taken 2858 02:12:47,350 --> 02:12:43,679 more seriously because you have that 2859 02:12:52,470 --> 02:12:49,990 if you're so if you're looking for a 2860 02:12:54,550 --> 02:12:52,480 set of thumb rules 2861 02:12:57,510 --> 02:12:54,560 to decide uh 2862 02:12:59,510 --> 02:12:57,520 uh which experts are to be trusted and 2863 02:13:02,310 --> 02:12:59,520 which should not 2864 02:13:07,430 --> 02:13:02,320 be them experts in mathematics or 2865 02:13:13,910 --> 02:13:09,669 well the answer is these questions are 2866 02:13:13,920 --> 02:13:23,510 so you know in medicine uh 2867 02:13:28,470 --> 02:13:25,990 you probably have to look for the bigger 2868 02:13:30,870 --> 02:13:28,480 name doctors the more you know the more 2869 02:13:33,030 --> 02:13:30,880 established doctors because 2870 02:13:37,270 --> 02:13:33,040 the system actually does 2871 02:13:40,470 --> 02:13:37,280 on average promote the better people 2872 02:13:43,350 --> 02:13:40,480 even if not always 2873 02:13:46,149 --> 02:13:43,360 okay and you should look for 2874 02:13:47,910 --> 02:13:46,159 was it said by 2875 02:13:50,390 --> 02:13:47,920 most doctors 2876 02:13:52,709 --> 02:13:50,400 or by 2877 02:13:54,390 --> 02:13:52,719 one doctor who hasn't practiced for a 2878 02:13:57,830 --> 02:13:54,400 long time 2879 02:14:03,109 --> 02:13:59,589 and the same is in 2880 02:14:08,310 --> 02:14:05,270 uh 2881 02:14:11,270 --> 02:14:08,320 yes there are phd in mathematic people 2882 02:14:13,910 --> 02:14:11,280 with a phd in mathematics who who who 2883 02:14:16,229 --> 02:14:13,920 shouldn't have gotten their phd 2884 02:14:19,750 --> 02:14:16,239 yes there are people brilliant people 2885 02:14:22,229 --> 02:14:19,760 with bro who did real brilliant phd phds 2886 02:14:25,189 --> 02:14:22,239 in mathematics and 10 years later 2887 02:14:27,430 --> 02:14:25,199 uh lost their mind and are 2888 02:14:29,669 --> 02:14:27,440 speaking nonsense 2889 02:14:31,270 --> 02:14:29,679 i mean 2890 02:14:33,589 --> 02:14:31,280 it's 2891 02:14:37,030 --> 02:14:33,599 there is no look at this certificate and 2892 02:14:38,830 --> 02:14:37,040 if somebody has the certificate then 2893 02:14:41,750 --> 02:14:38,840 then they're 2894 02:14:43,510 --> 02:14:41,760 trustworthy ashley ship wants to know is 2895 02:14:45,589 --> 02:14:43,520 there a connection between not theory 2896 02:14:47,830 --> 02:14:45,599 and protein folding 2897 02:14:49,510 --> 02:14:47,840 and is it possible to use 2898 02:14:51,589 --> 02:14:49,520 well if so is it possible to use the 2899 02:14:53,830 --> 02:14:51,599 artificial intelligence research that 2900 02:14:57,990 --> 02:14:53,840 has been done on protein folding to 2901 02:15:03,510 --> 02:15:00,229 there is a connection between protein 2902 02:15:06,950 --> 02:15:03,520 folding and between dna and stuff like 2903 02:15:11,589 --> 02:15:09,589 in in not theory 2904 02:15:14,390 --> 02:15:11,599 uh people 2905 02:15:16,950 --> 02:15:14,400 it's not very strong 2906 02:15:20,629 --> 02:15:16,960 like in general 2907 02:15:20,639 --> 02:15:24,390 he 2908 02:15:29,510 --> 02:15:26,870 people like to say things about it but 2909 02:15:32,310 --> 02:15:29,520 the actual research at least my own 2910 02:15:35,990 --> 02:15:32,320 research is very different 2911 02:15:38,790 --> 02:15:36,000 from um 2912 02:15:43,510 --> 02:15:38,800 what you would end up doing with 2913 02:15:48,069 --> 02:15:46,790 of dnas or or proteins 2914 02:15:49,510 --> 02:15:48,079 by the way 2915 02:15:54,310 --> 02:15:49,520 uh 2916 02:15:57,109 --> 02:15:54,320 dna 2917 02:15:58,229 --> 02:15:57,119 the the study or 2918 02:16:00,229 --> 02:15:58,239 okay 2919 02:16:03,350 --> 02:16:00,239 so 2920 02:16:05,510 --> 02:16:03,360 dna molecules are really really really 2921 02:16:07,030 --> 02:16:05,520 really long strings 2922 02:16:09,189 --> 02:16:07,040 chromosomes 2923 02:16:11,350 --> 02:16:09,199 are really really really really really 2924 02:16:15,109 --> 02:16:11,360 long strings 2925 02:16:17,830 --> 02:16:15,119 namely they are of length billions 2926 02:16:21,189 --> 02:16:17,840 or the ratio of their length to their 2927 02:16:26,069 --> 02:16:21,199 width is billions 2928 02:16:33,509 --> 02:16:30,390 uh amino acids along them all right 2929 02:16:35,830 --> 02:16:33,519 and um 2930 02:16:37,270 --> 02:16:35,840 so so you know if you were to make it 2931 02:16:39,030 --> 02:16:37,280 out of probe 2932 02:16:41,830 --> 02:16:39,040 it would be 2933 02:16:43,349 --> 02:16:41,840 very very very thin rope which is very 2934 02:16:47,190 --> 02:16:43,359 very long 2935 02:16:53,349 --> 02:16:47,200 but yet this rope is compressed into a 2936 02:16:53,359 --> 02:16:57,110 so they get knotted 2937 02:17:01,429 --> 02:16:58,150 and 2938 02:17:04,389 --> 02:17:01,439 even your experience from a much smaller 2939 02:17:06,629 --> 02:17:04,399 knot so here's an electric cable if you 2940 02:17:09,190 --> 02:17:06,639 have a little bit of an experience with 2941 02:17:11,190 --> 02:17:09,200 letting loose of cables not tying them 2942 02:17:14,709 --> 02:17:11,200 nightly 2943 02:17:17,190 --> 02:17:14,719 nicely as i tied this yeah if you let it 2944 02:17:19,750 --> 02:17:17,200 loose it gets melted 2945 02:17:23,110 --> 02:17:19,760 and it it's it's very it's nearly 2946 02:17:25,830 --> 02:17:23,120 impossible to untie 2947 02:17:31,190 --> 02:17:28,389 chromosomes are much worse they're much 2948 02:17:34,469 --> 02:17:31,200 much much longer 2949 02:17:38,070 --> 02:17:34,479 in in relative terms and they get 2950 02:17:40,870 --> 02:17:38,080 cramped into tiny tiny tiny spaces so 2951 02:17:43,429 --> 02:17:40,880 how come they don't get knotted 2952 02:17:45,270 --> 02:17:43,439 and if they do get knotted 2953 02:17:46,230 --> 02:17:45,280 how come 2954 02:17:52,309 --> 02:17:46,240 uh 2955 02:17:55,270 --> 02:17:52,319 parts of the life of a cell so when when 2956 02:17:56,870 --> 02:17:55,280 when cells um 2957 02:17:59,509 --> 02:17:56,880 uh split 2958 02:18:02,389 --> 02:17:59,519 uh they split they somehow managed to 2959 02:18:04,629 --> 02:18:02,399 untie themselves and disconnect 2960 02:18:05,990 --> 02:18:04,639 so how how is it happening so there must 2961 02:18:09,030 --> 02:18:06,000 be some 2962 02:18:12,790 --> 02:18:09,040 huge brain inside every cell 2963 02:18:14,709 --> 02:18:12,800 uh that can untangle knots which are 2964 02:18:16,309 --> 02:18:14,719 much much much much much more 2965 02:18:20,230 --> 02:18:16,319 complicated 2966 02:18:23,110 --> 02:18:20,240 uh than the knots that uh 2967 02:18:24,709 --> 02:18:23,120 that you can untie 2968 02:18:27,429 --> 02:18:24,719 or you know the notes that you take 2969 02:18:28,469 --> 02:18:27,439 hours to untie with sometimes 2970 02:18:31,750 --> 02:18:28,479 okay 2971 02:18:34,309 --> 02:18:31,760 so there must be something there 2972 02:18:36,309 --> 02:18:34,319 and this and there is something there 2973 02:18:39,270 --> 02:18:36,319 and there are enzymes 2974 02:18:41,429 --> 02:18:39,280 that actually uh you know so 2975 02:18:42,790 --> 02:18:41,439 when when uh 2976 02:18:44,549 --> 02:18:42,800 uh 2977 02:18:49,270 --> 02:18:44,559 dna molecules 2978 02:18:52,389 --> 02:18:49,280 need to are not to untangle 2979 02:18:55,910 --> 02:18:52,399 there are enzymes that allow one 2980 02:18:59,190 --> 02:18:55,920 molecule to pass through the other so 2981 02:19:01,589 --> 02:18:59,200 basically you want to pass one string 2982 02:19:04,230 --> 02:19:01,599 through another so that they will come 2983 02:19:07,349 --> 02:19:04,240 to position there are enzymes that cut 2984 02:19:09,110 --> 02:19:07,359 this one temporarily it gets cut it 2985 02:19:11,429 --> 02:19:09,120 passes to the other side and it gets 2986 02:19:14,150 --> 02:19:11,439 reconnected 2987 02:19:16,709 --> 02:19:14,160 so in a sense 2988 02:19:20,709 --> 02:19:18,150 biology 2989 02:19:22,709 --> 02:19:20,719 invented anti-nautiorianza 2990 02:19:24,549 --> 02:19:22,719 enzymes 2991 02:19:27,589 --> 02:19:24,559 and and they are 2992 02:19:30,150 --> 02:19:27,599 necessary because of not theory 2993 02:19:33,270 --> 02:19:30,160 because if there were nots you wouldn't 2994 02:19:34,389 --> 02:19:33,280 be able to divide cells 2995 02:19:37,750 --> 02:19:34,399 uh 2996 02:19:40,870 --> 02:19:37,760 so so so so so biology invented some 2997 02:19:42,950 --> 02:19:40,880 some anti-node theory enzymes that allow 2998 02:19:45,509 --> 02:19:42,960 things to pass through each other that 2999 02:19:47,589 --> 02:19:45,519 nullify not theory so in some sense the 3000 02:19:52,630 --> 02:19:47,599 most interesting not theory that happens 3001 02:19:58,389 --> 02:19:56,309 that's a lovely story but in practice 3002 02:20:00,150 --> 02:19:58,399 there isn't much 3003 02:20:02,309 --> 02:20:00,160 jack desart wants to know is math a 3004 02:20:04,630 --> 02:20:02,319 human construct that we've devised to 3005 02:20:06,870 --> 02:20:04,640 better understand the universe or is 3006 02:20:09,429 --> 02:20:06,880 math a set of universal unchanging 3007 02:20:13,590 --> 02:20:09,439 principles i'm a human how would i know 3008 02:20:19,030 --> 02:20:16,469 you know how non-humans would say math 3009 02:20:21,190 --> 02:20:19,040 or how you know i 3010 02:20:22,469 --> 02:20:21,200 i don't know 3011 02:20:24,630 --> 02:20:22,479 but 3012 02:20:25,910 --> 02:20:24,640 this said 3013 02:20:27,750 --> 02:20:25,920 i mean i don't want to answer the 3014 02:20:30,550 --> 02:20:27,760 philosophical question but i want to 3015 02:20:32,550 --> 02:20:30,560 answer some there is some practical 3016 02:20:34,710 --> 02:20:32,560 things that comes out of it 3017 02:20:38,309 --> 02:20:34,720 every bit of math 3018 02:20:39,990 --> 02:20:38,319 so you know pick up a math book 3019 02:20:43,110 --> 02:20:40,000 here 3020 02:20:45,910 --> 02:20:43,120 every bit of math in this book 3021 02:20:48,710 --> 02:20:45,920 and not just this i mean every bit of 3022 02:20:52,630 --> 02:20:48,720 math in every book 3023 02:20:56,550 --> 02:20:54,070 ah 3024 02:20:59,429 --> 02:20:56,560 that's a good thing to remember it means 3025 02:21:01,990 --> 02:20:59,439 that there are no miracles 3026 02:21:05,270 --> 02:21:02,000 it means that 3027 02:21:05,280 --> 02:21:09,590 you know when you see a proof 3028 02:21:15,190 --> 02:21:10,830 and you have no 3029 02:21:17,510 --> 02:21:15,200 idea where could it come from 3030 02:21:23,110 --> 02:21:17,520 well you have no idea but somebody had 3031 02:21:23,120 --> 02:21:25,750 so 3032 02:21:32,870 --> 02:21:29,750 it's often extremely instructive 3033 02:21:34,870 --> 02:21:32,880 to try to reverse engineer somehow 3034 02:21:37,590 --> 02:21:34,880 not just understand the proof but 3035 02:21:40,070 --> 02:21:37,600 understand how 3036 02:21:44,230 --> 02:21:40,080 humans with all their failures could 3037 02:21:51,190 --> 02:21:45,830 so 3038 02:21:53,190 --> 02:21:51,200 math was entirely created by humans at 3039 02:21:55,190 --> 02:21:53,200 the end 3040 02:21:58,550 --> 02:21:55,200 do you think we don't spend enough time 3041 02:22:00,389 --> 02:21:58,560 in books talking about the missteps so 3042 02:22:02,389 --> 02:22:00,399 for example here's how the person 3043 02:22:05,750 --> 02:22:02,399 arrived at this proof they originally 3044 02:22:07,429 --> 02:22:05,760 thought of it like so this didn't work 3045 02:22:08,950 --> 02:22:07,439 or would that just bloat the book 3046 02:22:11,910 --> 02:22:08,960 unnecessarily 3047 02:22:13,030 --> 02:22:11,920 it would probably bloat the book 3048 02:22:19,030 --> 02:22:13,040 but 3049 02:22:23,670 --> 02:22:19,040 [Music] 3050 02:22:25,830 --> 02:22:23,680 and when i say motivate okay so 3051 02:22:27,429 --> 02:22:25,840 so some story is 3052 02:22:29,349 --> 02:22:27,439 should be told 3053 02:22:31,110 --> 02:22:29,359 like when you present 3054 02:22:32,950 --> 02:22:31,120 a proof 3055 02:22:36,389 --> 02:22:32,960 there should always be some plausible 3056 02:22:38,950 --> 02:22:36,399 discovery story how could this proof 3057 02:22:41,670 --> 02:22:38,960 have been found 3058 02:22:43,510 --> 02:22:41,680 it doesn't have to be a a historically 3059 02:22:45,990 --> 02:22:43,520 accurate 3060 02:22:48,389 --> 02:22:46,000 uh story 3061 02:22:51,270 --> 02:22:48,399 but but but but there has to be some 3062 02:22:54,230 --> 02:22:51,280 story explaining that this proof could 3063 02:22:56,150 --> 02:22:54,240 have been found by humans it wasn't 3064 02:22:59,270 --> 02:22:56,160 created by some 3065 02:23:00,349 --> 02:22:59,280 supernatural entity 3066 02:23:02,870 --> 02:23:00,359 this question 3067 02:23:05,110 --> 02:23:02,880 cx770 asks does he believe in the 3068 02:23:08,309 --> 02:23:05,120 concept of god 3069 02:23:13,990 --> 02:23:11,030 okay this one's a tangential question 3070 02:23:15,990 --> 02:23:14,000 bill mcgonicle asks ramanujan said that 3071 02:23:19,429 --> 02:23:16,000 he learned from his goddess 3072 02:23:20,630 --> 02:23:19,439 others suggest well ramona john said 3073 02:23:22,790 --> 02:23:20,640 that he learned from his goddess by 3074 02:23:24,950 --> 02:23:22,800 meditating and praying or came to him in 3075 02:23:28,309 --> 02:23:24,960 dreams some of his 3076 02:23:33,190 --> 02:23:28,319 formulas esoteric formulas what does 3077 02:23:38,469 --> 02:23:36,230 can speak from ramanu for ramanujan 3078 02:23:39,990 --> 02:23:38,479 i tend to be a 3079 02:23:40,950 --> 02:23:40,000 rationalist 3080 02:23:42,389 --> 02:23:40,960 uh 3081 02:23:43,349 --> 02:23:42,399 atheist 3082 02:23:46,870 --> 02:23:43,359 uh 3083 02:23:52,230 --> 02:23:49,270 if i think hard about something i either 3084 02:23:55,670 --> 02:23:52,240 solve it or don't but there's there's no 3085 02:23:57,670 --> 02:23:55,680 there are no miracles in business 3086 02:23:59,750 --> 02:23:57,680 another question this one this is my 3087 02:24:03,030 --> 02:23:59,760 question are there some relatively 3088 02:24:05,990 --> 02:24:03,040 elementary concepts that you've recently 3089 02:24:07,030 --> 02:24:06,000 had a new insight on so for example my i 3090 02:24:09,990 --> 02:24:07,040 don't know if you know my brother 3091 02:24:13,750 --> 02:24:10,000 sebastian he's a professor at u of t as 3092 02:24:15,750 --> 02:24:13,760 well in math finance he was telling me 3093 02:24:17,990 --> 02:24:15,760 kurt you know only recently maybe last 3094 02:24:20,469 --> 02:24:18,000 year i thought i realized oh the 3095 02:24:22,230 --> 02:24:20,479 triangle inequality is actually about a 3096 02:24:24,230 --> 02:24:22,240 triangle he would only just use the 3097 02:24:26,389 --> 02:24:24,240 formula 3098 02:24:28,309 --> 02:24:26,399 also recently okay the jacobian 3099 02:24:29,670 --> 02:24:28,319 determinant the jaycobian is actually 3100 02:24:33,910 --> 02:24:29,680 like 3101 02:24:34,950 --> 02:24:33,920 that point 3102 02:24:37,030 --> 02:24:34,960 doing 3103 02:24:38,710 --> 02:24:37,040 close instead of just okay think of it 3104 02:24:40,550 --> 02:24:38,720 as an abstraction of slopes and stuff 3105 02:24:42,469 --> 02:24:40,560 yeah so do you have an example 3106 02:24:44,630 --> 02:24:42,479 sorry of what of things that i've only 3107 02:24:46,230 --> 02:24:44,640 recently understood no no no of 3108 02:24:48,070 --> 02:24:46,240 something you have understood you've 3109 02:24:49,510 --> 02:24:48,080 used before but then maybe you've come 3110 02:24:51,510 --> 02:24:49,520 to a different understanding of you and 3111 02:24:52,790 --> 02:24:51,520 you say oh that's an interesting way of 3112 02:24:54,790 --> 02:24:52,800 thinking about it i didn't see that 3113 02:24:57,510 --> 02:24:54,800 before 3114 02:24:58,950 --> 02:24:57,520 it happens all the time well i wish it 3115 02:25:01,429 --> 02:24:58,960 would have happened all the times when 3116 02:25:03,030 --> 02:25:01,439 it happens it's a great day not all day 3117 02:25:04,790 --> 02:25:03,040 is a great day but there is the 3118 02:25:05,910 --> 02:25:04,800 occasional great day 3119 02:25:07,990 --> 02:25:05,920 uh 3120 02:25:14,710 --> 02:25:08,000 you know every time you learn some 3121 02:25:20,469 --> 02:25:17,750 a higher meaning it's it's or more 3122 02:25:22,389 --> 02:25:20,479 meaning than you thought it's great news 3123 02:25:25,190 --> 02:25:22,399 it happens all the time in the life in 3124 02:25:27,110 --> 02:25:25,200 the professional life of a 3125 02:25:28,630 --> 02:25:27,120 scientist 3126 02:25:32,010 --> 02:25:28,640 though not every day 3127 02:25:32,020 --> 02:25:35,830 [Music] 3128 02:25:39,349 --> 02:25:37,110 well 3129 02:25:41,590 --> 02:25:39,359 uh 3130 02:25:43,990 --> 02:25:41,600 i'll give you an example which somehow 3131 02:25:47,110 --> 02:25:44,000 which i think also partially involves 3132 02:25:50,469 --> 02:25:47,120 you so um 3133 02:25:53,270 --> 02:25:50,479 a few years ago i was asked to give a 3134 02:25:56,070 --> 02:25:53,280 10 minutes talk or something 3135 02:25:57,830 --> 02:25:56,080 uh to a i'm 3136 02:25:59,349 --> 02:25:57,840 i don't even remember what was the event 3137 02:26:00,950 --> 02:25:59,359 but you were there 3138 02:26:03,670 --> 02:26:00,960 oh you remember that 3139 02:26:05,349 --> 02:26:03,680 mentorship event or something like that 3140 02:26:07,590 --> 02:26:05,359 i don't remember that's what that was 3141 02:26:09,750 --> 02:26:07,600 that's right and i thought what would i 3142 02:26:11,750 --> 02:26:09,760 talk about and i 3143 02:26:14,150 --> 02:26:11,760 well okay the truth is that i have some 3144 02:26:16,870 --> 02:26:14,160 list of uh 3145 02:26:17,910 --> 02:26:16,880 ready-made topics that i can talk about 3146 02:26:19,990 --> 02:26:17,920 you know 3147 02:26:22,550 --> 02:26:20,000 if you ask me to talk in front of high 3148 02:26:25,590 --> 02:26:22,560 school students i sort of have a number 3149 02:26:28,550 --> 02:26:25,600 of topics that are ready okay 3150 02:26:31,030 --> 02:26:28,560 uh but nothing really fit 3151 02:26:33,030 --> 02:26:31,040 and also sometimes i i get bored of 3152 02:26:35,670 --> 02:26:33,040 myself 3153 02:26:37,670 --> 02:26:35,680 so i have to occasionally add something 3154 02:26:40,710 --> 02:26:37,680 so i said okay why don't i talk about a 3155 02:26:43,110 --> 02:26:40,720 prisoner's dilemma 3156 02:26:45,910 --> 02:26:43,120 and um 3157 02:26:48,550 --> 02:26:45,920 so i i mentioned the prisoner's dilemma 3158 02:26:51,110 --> 02:26:48,560 in five minutes or so 3159 02:26:53,830 --> 02:26:51,120 and it's a very light map right it's 3160 02:26:56,230 --> 02:26:53,840 hardly math it's so light that it's 3161 02:26:58,950 --> 02:26:56,240 hardly math 3162 02:27:00,309 --> 02:26:58,960 but then i realized that it's that it 3163 02:27:03,190 --> 02:27:00,319 has a 3164 02:27:04,950 --> 02:27:03,200 profound i i guess the economists have 3165 02:27:07,270 --> 02:27:04,960 always understood that 3166 02:27:09,910 --> 02:27:07,280 they always thought it was important but 3167 02:27:12,309 --> 02:27:09,920 i realized it only relatively recently 3168 02:27:13,590 --> 02:27:12,319 so that was what is it three four years 3169 02:27:16,550 --> 02:27:13,600 ago 3170 02:27:18,790 --> 02:27:16,560 uh i only then understood how 3171 02:27:21,670 --> 02:27:18,800 profoundly 3172 02:27:23,990 --> 02:27:21,680 important it is 3173 02:27:28,070 --> 02:27:25,030 you know 3174 02:27:30,469 --> 02:27:28,080 the prisoner's dilemma is some numerical 3175 02:27:34,790 --> 02:27:30,479 example 3176 02:27:40,070 --> 02:27:36,150 you have 3177 02:27:42,469 --> 02:27:40,080 two sides two people a and b 3178 02:27:44,389 --> 02:27:42,479 and they can choose whether to 3179 02:27:48,150 --> 02:27:44,399 cooperate or 3180 02:27:51,190 --> 02:27:48,160 betray each one chooses independently 3181 02:27:53,990 --> 02:27:51,200 whether to cooperate with the other or 3182 02:27:57,830 --> 02:27:54,000 betray the other 3183 02:28:01,830 --> 02:27:57,840 and if you look at the numbers 3184 02:28:05,110 --> 02:28:01,840 each one no matter what the other does 3185 02:28:07,670 --> 02:28:05,120 would prefer to betray 3186 02:28:11,270 --> 02:28:07,680 and as a result both of them would 3187 02:28:17,510 --> 02:28:14,950 and the overall outcome is worse to both 3188 02:28:19,349 --> 02:28:17,520 of them again i'm not describing the 3189 02:28:20,710 --> 02:28:19,359 whole thing i'm not telling the numbers 3190 02:28:23,510 --> 02:28:20,720 i'm just saying 3191 02:28:26,950 --> 02:28:23,520 there is this situation where if each 3192 02:28:32,469 --> 02:28:26,960 one acts selfishly 3193 02:28:32,479 --> 02:28:35,190 and 3194 02:28:38,790 --> 02:28:36,389 well 3195 02:28:42,630 --> 02:28:38,800 it has huge philosophical implications 3196 02:28:43,590 --> 02:28:42,640 you know there is a whole a whole um 3197 02:28:46,070 --> 02:28:43,600 uh 3198 02:28:47,590 --> 02:28:46,080 political class 3199 02:28:49,910 --> 02:28:47,600 that believes 3200 02:28:52,630 --> 02:28:49,920 that people should be acting selfishly 3201 02:28:55,750 --> 02:28:52,640 because if each one acts selfishly it's 3202 02:28:56,710 --> 02:28:55,760 actually for the best of the 3203 02:28:57,590 --> 02:28:56,720 uh 3204 02:29:01,670 --> 02:28:57,600 for 3205 02:29:05,190 --> 02:29:01,680 that's somehow the foundation of the 3206 02:29:06,870 --> 02:29:05,200 belief in free markets 3207 02:29:09,349 --> 02:29:06,880 uh so 3208 02:29:12,710 --> 02:29:09,359 uh uh 3209 02:29:15,110 --> 02:29:12,720 so so yes i am actually still a great 3210 02:29:17,510 --> 02:29:15,120 believer in free markets 3211 02:29:19,910 --> 02:29:17,520 i actually still greatly believe that 3212 02:29:22,950 --> 02:29:19,920 free markets are a good thing 3213 02:29:24,790 --> 02:29:22,960 but there is a little asterisk 3214 02:29:28,389 --> 02:29:24,800 sorry that's not duality that's an 3215 02:29:31,590 --> 02:29:28,399 asterisk so there is a little asterisk 3216 02:29:34,950 --> 02:29:31,600 asterisk and the asterisk says 3217 02:29:38,870 --> 02:29:34,960 provided somebody arranges so that free 3218 02:29:41,429 --> 02:29:38,880 markets when each one acts selfishly 3219 02:29:42,550 --> 02:29:41,439 you will not be led into prisoners 3220 02:29:47,349 --> 02:29:42,560 dilemma 3221 02:29:48,830 --> 02:29:47,359 you will be you'll be you'll stay out 3222 02:29:54,550 --> 02:29:48,840 and 3223 02:29:57,670 --> 02:29:54,560 benefit 3224 02:30:02,790 --> 02:29:57,680 the overall good so i mean this asterisk 3225 02:30:07,670 --> 02:30:05,270 ah sorry i well okay yes yes yes i get 3226 02:30:10,230 --> 02:30:07,680 it anyway uh 3227 02:30:11,990 --> 02:30:10,240 and you think it's a small asterisk but 3228 02:30:14,550 --> 02:30:12,000 the more you think about it you realize 3229 02:30:18,309 --> 02:30:14,560 it's actually a huge asterisk 3230 02:30:20,950 --> 02:30:18,319 it completely changes the picture 3231 02:30:23,910 --> 02:30:20,960 and it's much much much more common 3232 02:30:25,349 --> 02:30:23,920 you think of it as an esoteric example 3233 02:30:26,790 --> 02:30:25,359 but then you realize that it's 3234 02:30:28,790 --> 02:30:26,800 everywhere 3235 02:30:30,469 --> 02:30:28,800 so it's actually a very very big 3236 02:30:31,349 --> 02:30:30,479 asterisk 3237 02:30:32,550 --> 02:30:31,359 and 3238 02:30:35,349 --> 02:30:32,560 um 3239 02:30:36,710 --> 02:30:35,359 i think i realized it relatively 3240 02:30:38,469 --> 02:30:36,720 recently 3241 02:30:40,230 --> 02:30:38,479 i'm honored that you remember that i 3242 02:30:42,150 --> 02:30:40,240 didn't think that uh i'm honored to even 3243 02:30:44,710 --> 02:30:42,160 be a footnote in your memory 3244 02:30:45,750 --> 02:30:44,720 oh don't be silly 3245 02:30:48,150 --> 02:30:45,760 okay 3246 02:30:51,910 --> 02:30:48,160 what have you applied also this question 3247 02:30:55,590 --> 02:30:51,920 comes from harinav harinavis harinivis 3248 02:30:58,389 --> 02:30:55,600 sorry harinivis p asks has drawer 3249 02:31:02,150 --> 02:30:58,399 applied the principles of mathematics to 3250 02:31:08,710 --> 02:31:03,670 like let's give an example of a 3251 02:31:12,950 --> 02:31:10,630 well okay i mean 3252 02:31:15,830 --> 02:31:12,960 i can give two answers okay 3253 02:31:17,830 --> 02:31:15,840 one answer is uh well i don't know if 3254 02:31:19,110 --> 02:31:17,840 it's the principles of mathematics but 3255 02:31:20,870 --> 02:31:19,120 you know 3256 02:31:27,670 --> 02:31:20,880 uh 3257 02:31:29,270 --> 02:31:27,680 there was a claim going on and it's been 3258 02:31:31,190 --> 02:31:29,280 going around and in fact it's still 3259 02:31:33,429 --> 02:31:31,200 going around 3260 02:31:36,950 --> 02:31:33,439 uh that uh 3261 02:31:38,550 --> 02:31:36,960 you that the bible contains predictions 3262 02:31:41,030 --> 02:31:38,560 in code 3263 02:31:45,190 --> 02:31:41,040 so if you read the bible with letter 3264 02:31:49,429 --> 02:31:45,200 skips if you read every tenth letter 3265 02:31:51,510 --> 02:31:49,439 you will occasionally find a word 3266 02:31:55,349 --> 02:31:51,520 that's not surprising 3267 02:31:57,349 --> 02:31:55,359 but the claim was that these words 3268 02:32:00,389 --> 02:31:57,359 where 3269 02:32:01,990 --> 02:32:00,399 that that it actually happens more than 3270 02:32:04,950 --> 02:32:02,000 statistics would 3271 02:32:07,830 --> 02:32:04,960 uh predict and that these words have 3272 02:32:09,429 --> 02:32:07,840 messages in them 3273 02:32:13,590 --> 02:32:09,439 and uh 3274 02:32:15,270 --> 02:32:13,600 and there was a group of people in 3275 02:32:16,150 --> 02:32:15,280 jerusalem 3276 02:32:18,230 --> 02:32:16,160 that 3277 02:32:19,830 --> 02:32:18,240 published a paper and in fact it passed 3278 02:32:24,150 --> 02:32:19,840 peer review 3279 02:32:26,230 --> 02:32:24,160 uh but so so they published a paper 3280 02:32:27,190 --> 02:32:26,240 in which they 3281 02:32:29,670 --> 02:32:27,200 uh 3282 02:32:32,630 --> 02:32:29,680 supposedly proved this fact 3283 02:32:34,790 --> 02:32:32,640 they did careful statistical analysis 3284 02:32:36,150 --> 02:32:34,800 again carefully in quotes 3285 02:32:39,030 --> 02:32:36,160 uh 3286 02:32:40,870 --> 02:32:39,040 and and and and and showed that the 3287 02:32:42,550 --> 02:32:40,880 effect was real 3288 02:32:45,349 --> 02:32:42,560 and therefore 3289 02:32:46,469 --> 02:32:45,359 the bible uh must have been written by 3290 02:32:48,950 --> 02:32:46,479 god 3291 02:32:51,349 --> 02:32:48,960 because no human could have put this 3292 02:32:53,510 --> 02:32:51,359 information into the bible 3293 02:32:55,590 --> 02:32:53,520 it's information information that was 3294 02:32:57,910 --> 02:32:55,600 not did not even exist at the time that 3295 02:33:00,710 --> 02:32:57,920 the bible was written 3296 02:33:02,230 --> 02:33:00,720 and therefore in prayer and so so god 3297 02:33:03,429 --> 02:33:02,240 wrote the bible 3298 02:33:10,070 --> 02:33:03,439 uh 3299 02:33:12,710 --> 02:33:10,080 there is a god and that god loves hebrew 3300 02:33:14,710 --> 02:33:12,720 more than she loves japanese i 3301 02:33:17,990 --> 02:33:14,720 understand yeah uh you know this would 3302 02:33:19,590 --> 02:33:18,000 be the greatest discovery in if it was 3303 02:33:21,590 --> 02:33:19,600 true it would have been the greatest 3304 02:33:23,349 --> 02:33:21,600 discovery in the history of science and 3305 02:33:25,190 --> 02:33:23,359 i'm not kidding 3306 02:33:28,389 --> 02:33:25,200 right i mean there's no longer an 3307 02:33:30,230 --> 02:33:28,399 argument between atheism and tazin 3308 02:33:33,030 --> 02:33:30,240 pays and wins 3309 02:33:35,429 --> 02:33:33,040 my role was to debunk this 3310 02:33:38,950 --> 02:33:35,439 is this real life or not 3311 02:33:42,630 --> 02:33:38,960 i don't know i me and a group of people 3312 02:33:44,469 --> 02:33:42,640 read critically these assertions that go 3313 02:33:45,670 --> 02:33:44,479 that were good enough that they passed 3314 02:33:48,630 --> 02:33:45,680 peer review 3315 02:33:50,309 --> 02:33:48,640 in a respectable journal and we found 3316 02:33:55,030 --> 02:33:50,319 gaps 3317 02:33:57,750 --> 02:33:55,040 that the same peer-reviewed journal 3318 02:34:00,630 --> 02:33:57,760 accepted our paper too 3319 02:34:02,950 --> 02:34:00,640 okay so you know in some sense my role 3320 02:34:04,950 --> 02:34:02,960 was negative right what could have been 3321 02:34:07,670 --> 02:34:04,960 the greatest discovery in the history of 3322 02:34:09,910 --> 02:34:07,680 science a proof that there is god and 3323 02:34:10,790 --> 02:34:09,920 it's the hebrew god 3324 02:34:13,030 --> 02:34:10,800 uh 3325 02:34:14,870 --> 02:34:13,040 was debunked maybe it's a negative 3326 02:34:17,590 --> 02:34:14,880 discovery but 3327 02:34:19,590 --> 02:34:17,600 well i mean even maybe my effect well my 3328 02:34:22,469 --> 02:34:19,600 part was negative i've killed a great 3329 02:34:26,870 --> 02:34:22,479 discovery but that's also a 3330 02:34:30,870 --> 02:34:26,880 a valuable thing to do i mean to kill a 3331 02:34:32,790 --> 02:34:30,880 uh the other thing is uh 3332 02:34:36,710 --> 02:34:32,800 otherwise 3333 02:34:39,349 --> 02:34:36,720 mathematics plays an extremely limited 3334 02:34:41,910 --> 02:34:39,359 role in my life 3335 02:34:44,389 --> 02:34:41,920 other than my professional life if you 3336 02:34:46,950 --> 02:34:44,399 ex if you cut out 3337 02:34:48,950 --> 02:34:46,960 uh the eight hours a day that i work on 3338 02:34:51,510 --> 02:34:48,960 mathematics mathematics has no role in 3339 02:34:54,309 --> 02:34:51,520 my life or hardly any role so i mean you 3340 02:34:56,710 --> 02:34:54,319 do and in fact also almost no role in 3341 02:35:00,389 --> 02:34:56,720 your life so basically 3342 02:35:03,830 --> 02:35:00,399 you know if you um 3343 02:35:07,030 --> 02:35:03,840 you give change in restaurants you uh so 3344 02:35:08,309 --> 02:35:07,040 so or in when shops sorry you add 15 3345 02:35:09,830 --> 02:35:08,319 percent 3346 02:35:11,670 --> 02:35:09,840 tip 3347 02:35:12,750 --> 02:35:11,680 that's about the math you need in real 3348 02:35:16,389 --> 02:35:12,760 life 3349 02:35:18,950 --> 02:35:16,399 multiplication you don't need 3350 02:35:22,950 --> 02:35:21,910 but if you're a carpenter you probably 3351 02:35:25,270 --> 02:35:22,960 need it 3352 02:35:27,750 --> 02:35:25,280 right you need to 3353 02:35:30,710 --> 02:35:27,760 tiles or you know if you're a trade 3354 02:35:33,429 --> 02:35:30,720 person you need to tile a certain room 3355 02:35:36,070 --> 02:35:33,439 this the room is five by six right how 3356 02:35:38,469 --> 02:35:36,080 many tiles do you need so multiplication 3357 02:35:41,030 --> 02:35:38,479 trade people need but but but but people 3358 02:35:41,870 --> 02:35:41,040 like me don't need 3359 02:35:45,190 --> 02:35:41,880 um 3360 02:35:48,550 --> 02:35:45,200 trigonometry well maybe architect nitric 3361 02:35:51,190 --> 02:35:48,560 architecture trigonometry some parts of 3362 02:35:52,630 --> 02:35:51,200 engineering and we get more and more 3363 02:35:54,710 --> 02:35:52,640 esoteric 3364 02:35:56,790 --> 02:35:54,720 need higher and higher mathematics 3365 02:35:59,750 --> 02:35:56,800 without the very high mathematics 3366 02:36:02,469 --> 02:35:59,760 without general relativity 3367 02:36:05,030 --> 02:36:02,479 gps satellites wouldn't work so in some 3368 02:36:07,270 --> 02:36:05,040 sense we use mathematics every day 3369 02:36:09,670 --> 02:36:07,280 but we're not the engineers who design 3370 02:36:12,870 --> 02:36:09,680 gps city live seat satellites gps 3371 02:36:14,950 --> 02:36:12,880 satellites were designed by a group of 3372 02:36:16,710 --> 02:36:14,960 a very small group of people somewhere 3373 02:36:17,750 --> 02:36:16,720 in some 3374 02:36:19,750 --> 02:36:17,760 you know 3375 02:36:22,070 --> 02:36:19,760 design bureau 3376 02:36:25,190 --> 02:36:22,080 and they use high-level mathematics so 3377 02:36:27,670 --> 02:36:25,200 so so but my real life 3378 02:36:29,349 --> 02:36:27,680 high level mathematics 3379 02:36:32,070 --> 02:36:29,359 is almost nothing 3380 02:36:34,309 --> 02:36:32,080 except once sorry the bible codes and 3381 02:36:37,670 --> 02:36:34,319 another time 3382 02:36:42,150 --> 02:36:37,680 and i've given talks with this title 3383 02:36:44,309 --> 02:36:42,160 so uh the title was uh the 3384 02:36:45,429 --> 02:36:44,319 hardest 3385 02:36:54,230 --> 02:36:45,439 uh 3386 02:36:56,309 --> 02:36:54,240 ever 3387 02:36:57,190 --> 02:36:56,319 really 3388 02:36:59,670 --> 02:36:57,200 yeah 3389 02:37:02,150 --> 02:36:59,680 and if you google this title probably 3390 02:37:02,950 --> 02:37:02,160 you'll be able to find a video of that 3391 02:37:05,670 --> 02:37:02,960 talk 3392 02:37:07,990 --> 02:37:05,680 and you'll find that one time 3393 02:37:10,469 --> 02:37:08,000 where 3394 02:37:13,110 --> 02:37:10,479 it was actually in my professional life 3395 02:37:15,910 --> 02:37:13,120 but in a meta way 3396 02:37:18,389 --> 02:37:15,920 so not my research but something about 3397 02:37:21,110 --> 02:37:18,399 how to present my research i ended up 3398 02:37:23,990 --> 02:37:21,120 using a very high level mathematics 3399 02:37:26,550 --> 02:37:24,000 hyperbolic geometry in fact 3400 02:37:29,190 --> 02:37:26,560 so one time it happened anyway what was 3401 02:37:33,030 --> 02:37:29,200 your next question 3402 02:37:35,110 --> 02:37:33,040 why does it take 360 pages of abstruse 3403 02:37:36,469 --> 02:37:35,120 symbols to prove that one plus one 3404 02:37:38,550 --> 02:37:36,479 equals two 3405 02:37:40,790 --> 02:37:38,560 occam's razor says we can cut this we 3406 02:37:42,550 --> 02:37:40,800 can just say one plus one equals two 3407 02:37:44,070 --> 02:37:42,560 because every single last one of us 3408 02:37:46,150 --> 02:37:44,080 believes it does 3409 02:37:47,750 --> 02:37:46,160 so what do you make of that why is it so 3410 02:37:50,070 --> 02:37:47,760 complex to prove something simple like 3411 02:37:51,110 --> 02:37:50,080 one plus one equals two do we even need 3412 02:38:02,630 --> 02:37:51,120 that 3413 02:38:07,429 --> 02:38:03,990 so 3414 02:38:12,830 --> 02:38:09,030 let me answer the 3415 02:38:16,469 --> 02:38:12,840 let me answer a different question 3416 02:38:19,510 --> 02:38:16,479 uh you know so one plus one equals two 3417 02:38:21,910 --> 02:38:19,520 so the the reference is probably to uh 3418 02:38:24,790 --> 02:38:21,920 work of uh russell 3419 02:38:24,800 --> 02:38:29,990 basically 3420 02:38:36,550 --> 02:38:32,950 if your axiom system is 3421 02:38:37,990 --> 02:38:36,560 very very very basic 3422 02:38:40,469 --> 02:38:38,000 and 3423 02:38:45,349 --> 02:38:40,479 um 3424 02:38:49,590 --> 02:38:47,030 primitive in a way very very 3425 02:38:52,150 --> 02:38:49,600 simple-minded and you want your axiom 3426 02:38:55,190 --> 02:38:52,160 system to be very very very basic 3427 02:38:58,469 --> 02:38:55,200 then it might be that even proving one 3428 02:39:01,349 --> 02:38:58,479 plus one equal to would be difficult 3429 02:39:03,670 --> 02:39:01,359 but it will be a part of the build up 3430 02:39:07,830 --> 02:39:03,680 and later you will be uh 3431 02:39:13,510 --> 02:39:10,870 but the truth is it's silly okay but let 3432 02:39:15,349 --> 02:39:13,520 me give you an another example okay so 3433 02:39:17,190 --> 02:39:15,359 uh you know there is the intermediate 3434 02:39:22,150 --> 02:39:17,200 value theorem 3435 02:39:25,349 --> 02:39:22,160 that if you have a function 3436 02:39:26,550 --> 02:39:25,359 continuous function so if f is 3437 02:39:30,389 --> 02:39:26,560 continuous 3438 02:39:35,270 --> 02:39:30,399 and it's negative here and positive here 3439 02:39:41,190 --> 02:39:38,550 uh we teach it in week seven 3440 02:39:43,270 --> 02:39:41,200 maybe i don't know of undergraduate 3441 02:39:45,270 --> 02:39:43,280 calculus maybe it's just week five or 3442 02:39:46,469 --> 02:39:45,280 maybe it's week nine i don't remember 3443 02:39:47,750 --> 02:39:46,479 okay 3444 02:39:50,150 --> 02:39:47,760 you can ask 3445 02:39:50,950 --> 02:39:50,160 this is so idiotic 3446 02:39:52,469 --> 02:39:50,960 right 3447 02:39:58,230 --> 02:39:52,479 why 3448 02:40:00,950 --> 02:39:58,240 prove the obvious that if you go 3449 02:40:04,070 --> 02:40:00,960 continuously from here to here you'll be 3450 02:40:09,990 --> 02:40:07,030 and the answer 3451 02:40:12,150 --> 02:40:10,000 is that when you prove the intermediate 3452 02:40:14,790 --> 02:40:12,160 value theorem 3453 02:40:16,950 --> 02:40:14,800 you are not actually proving the 3454 02:40:20,230 --> 02:40:16,960 intermediate value theorem 3455 02:40:23,429 --> 02:40:20,240 you are actually testing 3456 02:40:25,030 --> 02:40:23,439 your definition of continuity 3457 02:40:27,750 --> 02:40:25,040 you're testing 3458 02:40:33,110 --> 02:40:27,760 your abstract setup 3459 02:40:35,110 --> 02:40:33,120 your language you're testing 3460 02:40:38,230 --> 02:40:35,120 uh 3461 02:40:40,790 --> 02:40:38,240 you know the the machinery of for every 3462 02:40:43,750 --> 02:40:40,800 epsilon there exists a delta such that 3463 02:40:46,790 --> 02:40:43,760 blah blah blah if you could not prove 3464 02:40:50,469 --> 02:40:46,800 the intermediate value theorem 3465 02:40:53,110 --> 02:40:50,479 you'd be rejecting the abstract system 3466 02:40:56,710 --> 02:40:53,120 not the intermediate value theorem you'd 3467 02:40:57,590 --> 02:40:56,720 be rejecting this not that 3468 02:40:59,590 --> 02:40:57,600 so 3469 02:41:01,910 --> 02:40:59,600 the seven weeks were not about the 3470 02:41:03,030 --> 02:41:01,920 intermediate value theorem they were 3471 02:41:05,750 --> 02:41:03,040 about 3472 02:41:08,469 --> 02:41:05,760 this for every epsilon there exists 3473 02:41:10,870 --> 02:41:08,479 delta and then you can ask 3474 02:41:13,510 --> 02:41:10,880 what's for every epsilon there exists 3475 02:41:15,110 --> 02:41:13,520 delta for why do we need this well we 3476 02:41:17,110 --> 02:41:15,120 don't need it to prove the intermediate 3477 02:41:19,030 --> 02:41:17,120 value theorem the intermediate value 3478 02:41:21,030 --> 02:41:19,040 theorem was testing this 3479 02:41:23,670 --> 02:41:21,040 what do we need it for 3480 02:41:24,710 --> 02:41:23,680 and the answer is well there are later 3481 02:41:25,670 --> 02:41:24,720 things 3482 02:41:29,349 --> 02:41:25,680 like 3483 02:41:33,510 --> 02:41:29,359 uh e to the x is equal to sum of x to 3484 02:41:35,750 --> 02:41:33,520 the n divided by n factorial 3485 02:41:37,429 --> 02:41:35,760 which is this by the way looks innocent 3486 02:41:39,670 --> 02:41:37,439 and people think they understand it but 3487 02:41:42,230 --> 02:41:39,680 it's actually a miracle 3488 02:41:43,910 --> 02:41:42,240 and this miracle depends on well it 3489 02:41:46,389 --> 02:41:43,920 doesn't depend but i mean there are 3490 02:41:48,469 --> 02:41:46,399 maybe other ways to reach there but but 3491 02:41:50,550 --> 02:41:48,479 but you you will believe this miracle 3492 02:41:52,710 --> 02:41:50,560 miracle after you've understood this 3493 02:41:53,510 --> 02:41:52,720 system 3494 02:41:58,389 --> 02:41:53,520 so 3495 02:41:59,429 --> 02:41:58,399 didn't go from 3496 02:42:03,190 --> 02:41:59,439 uh 3497 02:42:04,870 --> 02:42:03,200 here to here 3498 02:42:07,590 --> 02:42:04,880 to here 3499 02:42:10,790 --> 02:42:07,600 but more like this was known it 3500 02:42:14,150 --> 02:42:10,800 validated this and then uh we could use 3501 02:42:17,830 --> 02:42:16,150 the podcast is now finished if you'd 3502 02:42:21,030 --> 02:42:17,840 like to support conversations like this 3503 02:42:25,110 --> 02:42:21,040 then do consider going to patreon.com 3504 02:42:27,750 --> 02:42:25,120 c-u-r-t j-a-i-m-u-n-g-a-l 3505 02:42:29,510 --> 02:42:27,760 that is kurt jaimungle it's support from 3506 02:42:31,349 --> 02:42:29,520 the patrons and from the sponsors that