1 00:00:03,889 --> 00:00:02,149 all right let's get into this what are 2 00:00:06,110 --> 00:00:03,899 natural units in order to understand 3 00:00:10,430 --> 00:00:06,120 what natural units are we want to know 4 00:00:14,690 --> 00:00:10,440 what are units so for example what is a 5 00:00:17,510 --> 00:00:14,700 meter or if you're being Canadian a 6 00:00:21,830 --> 00:00:17,520 meter I'm based in Toronto if that 7 00:00:25,370 --> 00:00:21,840 wasn't clear already what is a second 8 00:00:29,390 --> 00:00:27,050 now you'll get fairly frenzied if you 9 00:00:31,490 --> 00:00:29,400 think about this for quite some time as 10 00:00:34,310 --> 00:00:31,500 I have that is metaphysically what the 11 00:00:37,069 --> 00:00:34,320 heck is a second what is a meter what is 12 00:00:40,549 --> 00:00:37,079 length a science doesn't answer what is 13 00:00:42,770 --> 00:00:40,559 questions it's operational science is 14 00:00:44,209 --> 00:00:42,780 metaphysically agnostic meaning that it 15 00:00:46,010 --> 00:00:44,219 doesn't actually make a claim onto 16 00:00:47,930 --> 00:00:46,020 ontology it doesn't tell you what is 17 00:00:50,569 --> 00:00:47,940 instead science gives operational 18 00:00:52,250 --> 00:00:50,579 meanings so what is a second it says 19 00:00:54,170 --> 00:00:52,260 here the second is equal to the duration 20 00:00:56,270 --> 00:00:54,180 of nine one nine two six three one 21 00:00:58,430 --> 00:00:56,280 periods of the radiation corresponding 22 00:01:00,110 --> 00:00:58,440 to the transition between hyperfine 23 00:01:02,510 --> 00:01:00,120 levels of the unperturbed ground state 24 00:01:03,709 --> 00:01:02,520 of assisium atom a certain isotope of a 25 00:01:05,750 --> 00:01:03,719 system atom 26 00:01:09,890 --> 00:01:05,760 okay so then the natural question that 27 00:01:11,510 --> 00:01:09,900 comes up is why this number 28 00:01:14,750 --> 00:01:11,520 so why this and not some other number 29 00:01:17,210 --> 00:01:14,760 and the reason is because in London many 30 00:01:18,950 --> 00:01:17,220 decades ago someone in some back alley 31 00:01:20,810 --> 00:01:18,960 took methamphetamine on a Tuesday night 32 00:01:22,429 --> 00:01:20,820 and came up with that number now I'm not 33 00:01:24,649 --> 00:01:22,439 kidding it may as well be that to 34 00:01:26,030 --> 00:01:24,659 someone studying high energy physics in 35 00:01:27,950 --> 00:01:26,040 the same way that 36 00:01:31,609 --> 00:01:27,960 well what the heck is a kilogram what is 37 00:01:33,590 --> 00:01:31,619 a kilogram it means you go to Paris you 38 00:01:37,850 --> 00:01:33,600 go outside Paris actually it's on the 39 00:01:40,969 --> 00:01:39,649 and you deal with people being 40 00:01:42,890 --> 00:01:40,979 condescending too because you don't 41 00:01:45,410 --> 00:01:42,900 speak French then you duplicate this 42 00:01:47,990 --> 00:01:45,420 little metal slab that's in Paris you 43 00:01:49,670 --> 00:01:48,000 duplicate it 67 times so that you have 44 00:01:52,010 --> 00:01:49,680 68 of them in total 45 00:01:53,690 --> 00:01:52,020 I'm just being quick with my writing 68 46 00:01:56,270 --> 00:01:53,700 of them is in total and then you measure 47 00:01:58,190 --> 00:01:56,280 yourself on a scale and these two 48 00:02:00,350 --> 00:01:58,200 numbers will coincide that's what it 49 00:02:02,510 --> 00:02:00,360 means it's an operational definition now 50 00:02:06,469 --> 00:02:02,520 physicists like to use units that appear 51 00:02:10,790 --> 00:02:06,479 in nature so units that appear 52 00:02:12,350 --> 00:02:10,800 and those we call Natural units there's 53 00:02:14,330 --> 00:02:12,360 some controversy with what's considered 54 00:02:15,650 --> 00:02:14,340 natural because when someone comes to 55 00:02:17,390 --> 00:02:15,660 you with a 56 00:02:19,490 --> 00:02:17,400 some dish and they say this is a natural 57 00:02:21,229 --> 00:02:19,500 dish and that's unnatural well what do 58 00:02:23,270 --> 00:02:21,239 you mean that that those Doritos that 59 00:02:25,010 --> 00:02:23,280 are unnatural did they come from outside 60 00:02:26,390 --> 00:02:25,020 this universe from some void because 61 00:02:28,490 --> 00:02:26,400 it's in everything in this universe 62 00:02:30,770 --> 00:02:28,500 natural aren't we a product of Nature 63 00:02:33,110 --> 00:02:30,780 and so what we create is natural okay 64 00:02:35,089 --> 00:02:33,120 what a physicist means by natural is 65 00:02:37,010 --> 00:02:35,099 that it's invariants across the universe 66 00:02:39,290 --> 00:02:37,020 as far as we can tell to be extremely 67 00:02:41,869 --> 00:02:39,300 precise what we mean when we say natural 68 00:02:44,030 --> 00:02:41,879 units natural in the natural units is 69 00:02:45,530 --> 00:02:44,040 natural with respect to our current 70 00:02:48,229 --> 00:02:45,540 understanding in order to make certain 71 00:02:50,750 --> 00:02:48,239 equations simpler and remove arbitrary 72 00:02:56,270 --> 00:02:50,760 human qualities 73 00:02:58,430 --> 00:02:56,280 some sense even an electron is a human 74 00:03:00,830 --> 00:02:58,440 construct in the sense that it's there 75 00:03:02,809 --> 00:03:00,840 because it nature doesn't parse itself 76 00:03:05,570 --> 00:03:02,819 out into these elements I mean you can 77 00:03:07,369 --> 00:03:05,580 say elementary elementary seems to be an 78 00:03:08,449 --> 00:03:07,379 objective quality because of the way 79 00:03:10,009 --> 00:03:08,459 that we Define what an elementary 80 00:03:11,869 --> 00:03:10,019 particle is it's an irreducible 81 00:03:13,430 --> 00:03:11,879 representation of something so the fact 82 00:03:15,649 --> 00:03:13,440 that it's irreducible means if it could 83 00:03:17,570 --> 00:03:15,659 be reduced in this block Matrix form 84 00:03:19,610 --> 00:03:17,580 then we can just decompose it and we'd 85 00:03:21,949 --> 00:03:19,620 say those elements are Elementary but 86 00:03:24,050 --> 00:03:21,959 the reason why we set aside some special 87 00:03:27,050 --> 00:03:24,060 canonical place for the electron is 88 00:03:28,790 --> 00:03:27,060 because it's useful for us it makes our 89 00:03:31,009 --> 00:03:28,800 models easier to understand simpler 90 00:03:33,350 --> 00:03:31,019 outcomes razor Etc there's plenty of 91 00:03:34,910 --> 00:03:33,360 philosophy that undergirds natural this 92 00:03:36,410 --> 00:03:34,920 is not usually explained and you'll be 93 00:03:38,030 --> 00:03:36,420 led astray if you don't understand that 94 00:03:40,110 --> 00:03:38,040 point now here's another Point that's 95 00:03:42,470 --> 00:03:40,120 ordinarily not explained observables 96 00:03:44,050 --> 00:03:42,480 [Music] 97 00:03:47,270 --> 00:03:44,060 have 98 00:03:48,310 --> 00:03:47,280 null units 99 00:03:49,430 --> 00:03:48,320 there 100 00:03:54,410 --> 00:03:49,440 [Music] 101 00:03:58,850 --> 00:03:56,630 let's say slash ratios 102 00:04:01,009 --> 00:03:58,860 Okay now what's meant by that again when 103 00:04:02,750 --> 00:04:01,019 you say that you weigh 68 kilograms it 104 00:04:04,490 --> 00:04:02,760 means you take 68 of some other 105 00:04:08,869 --> 00:04:04,500 reference 106 00:04:11,089 --> 00:04:08,879 then you stack 68 of them and then you 107 00:04:14,570 --> 00:04:11,099 get yourself it's actually 68 it's not 108 00:04:16,490 --> 00:04:14,580 68 kilograms per se you can also think 109 00:04:18,289 --> 00:04:16,500 of this in another way if you wanted to 110 00:04:20,390 --> 00:04:18,299 speak to aliens which by the way is 111 00:04:23,030 --> 00:04:20,400 another topic on this channel not 112 00:04:26,689 --> 00:04:23,040 speaking to aliens per se but UFOs then 113 00:04:29,450 --> 00:04:26,699 it would be foolish to say I weigh 68 of 114 00:04:31,370 --> 00:04:29,460 some product from France now you can 115 00:04:32,570 --> 00:04:31,380 reverse this and imagine an alien is 116 00:04:34,370 --> 00:04:32,580 speaking to you and you say well how 117 00:04:36,890 --> 00:04:34,380 much does your craft weigh and they say 118 00:04:38,210 --> 00:04:36,900 oh it weighs four garbars and then 119 00:04:39,590 --> 00:04:38,220 you're like what the heck is a garvar 120 00:04:41,930 --> 00:04:39,600 then they say well that's how much 121 00:04:44,030 --> 00:04:41,940 liquid we release from our vorbins every 122 00:04:46,490 --> 00:04:44,040 two farkles it doesn't provide much 123 00:04:48,710 --> 00:04:46,500 information so instead we do what you 124 00:04:51,469 --> 00:04:48,720 see colloquially which is C equals H bar 125 00:04:53,030 --> 00:04:51,479 equals one okay let's get to some myths 126 00:04:55,310 --> 00:04:53,040 about natural units before exploring 127 00:04:58,490 --> 00:04:55,320 exactly what that means so firstly one 128 00:05:02,330 --> 00:04:58,500 of the myths is that we just simply set 129 00:05:03,770 --> 00:05:02,340 C to equal 1 to equal H bar this is a 130 00:05:06,230 --> 00:05:03,780 meaningless statement as it's written 131 00:05:09,350 --> 00:05:06,240 and the reason is it doesn't they can't 132 00:05:11,870 --> 00:05:09,360 equal one it means we're now using 133 00:05:14,030 --> 00:05:11,880 the speed of light and h-bar as a 134 00:05:15,530 --> 00:05:14,040 reference for some other quantity that 135 00:05:17,689 --> 00:05:15,540 we're trying to develop if you're 136 00:05:18,890 --> 00:05:17,699 confused about this now then that means 137 00:05:20,570 --> 00:05:18,900 you're thinking about this correctly 138 00:05:22,249 --> 00:05:20,580 because it's not ordinarily explained 139 00:05:24,409 --> 00:05:22,259 it's left ambiguous 140 00:05:26,689 --> 00:05:24,419 let's look at this let's imagine what is 141 00:05:27,529 --> 00:05:26,699 the speed of let's say some car on the 142 00:05:31,730 --> 00:05:27,539 highway 143 00:05:35,450 --> 00:05:31,740 equals we would say 100 144 00:05:39,409 --> 00:05:37,490 per hour 145 00:05:41,749 --> 00:05:39,419 these are the units 146 00:05:44,210 --> 00:05:41,759 and that's the magnitude with respect to 147 00:05:45,890 --> 00:05:44,220 those units so if I wanted to say what 148 00:05:47,510 --> 00:05:45,900 is the speed 149 00:05:49,370 --> 00:05:47,520 sorry that's already speed what is the 150 00:05:52,730 --> 00:05:49,380 speed of light 151 00:05:55,370 --> 00:05:52,740 what we mean is two nine nine seven nine 152 00:05:57,230 --> 00:05:55,380 two four five eight again it's one of 153 00:05:58,850 --> 00:05:57,240 those numbers you try to show how clever 154 00:06:02,629 --> 00:05:58,860 you are when you're a child by 155 00:06:05,930 --> 00:06:02,639 memorizing meters per second 156 00:06:08,990 --> 00:06:05,940 now look this is actually what C is C 157 00:06:11,990 --> 00:06:09,000 refers to all of this C doesn't just 158 00:06:13,850 --> 00:06:12,000 refer to the magnitude C refers to the 159 00:06:16,430 --> 00:06:13,860 entirety of it including the units so 160 00:06:19,129 --> 00:06:16,440 when someone says C equals one C equals 161 00:06:21,710 --> 00:06:19,139 one what they actually mean is that we 162 00:06:25,010 --> 00:06:21,720 are now using units where we've taken 163 00:06:28,670 --> 00:06:25,020 that two nine nine seven nine two four 164 00:06:30,830 --> 00:06:28,680 five eight meters per second and we've 165 00:06:33,469 --> 00:06:30,840 placed it in here so we've taken this 166 00:06:36,110 --> 00:06:33,479 guy and we've placed it in here see all 167 00:06:37,070 --> 00:06:36,120 of this is not ordinarily explained and 168 00:06:40,070 --> 00:06:37,080 it's because 169 00:06:42,529 --> 00:06:40,080 as an undergraduate you're especially 170 00:06:45,050 --> 00:06:42,539 used to writing with reference to a 171 00:06:47,029 --> 00:06:45,060 coordinate basis which is why I said try 172 00:06:48,590 --> 00:06:47,039 to do everything you can coordinate free 173 00:06:50,150 --> 00:06:48,600 if you have an instructor you're lucky 174 00:06:52,309 --> 00:06:50,160 enough to have an instructor you always 175 00:06:54,350 --> 00:06:52,319 ask how can you represent these 176 00:06:55,790 --> 00:06:54,360 equations coordinate free another way of 177 00:06:57,890 --> 00:06:55,800 thinking about this is that we have 178 00:07:00,050 --> 00:06:57,900 graphs in physics and math constantly 179 00:07:01,610 --> 00:07:00,060 plot and those etchings are akin to 180 00:07:04,189 --> 00:07:01,620 choosing a unit the fact that we put 181 00:07:06,650 --> 00:07:04,199 lines with etchings means we've chosen a 182 00:07:10,129 --> 00:07:06,660 coordinate so these etchings outward are 183 00:07:12,050 --> 00:07:10,139 it implicitly a choice of coordinates 184 00:07:13,909 --> 00:07:12,060 but nature but if you look again like I 185 00:07:15,469 --> 00:07:13,919 mentioned that there's no detector that 186 00:07:17,270 --> 00:07:15,479 can detect the coordinates much like if 187 00:07:18,830 --> 00:07:17,280 you take a picture with your phone and 188 00:07:20,930 --> 00:07:18,840 you then look at it on the screen and 189 00:07:22,430 --> 00:07:20,940 you zoom in you see pixels the pixels 190 00:07:24,050 --> 00:07:22,440 are an artifact of you taking a picture 191 00:07:26,390 --> 00:07:24,060 and trying to manipulate it in some 192 00:07:28,670 --> 00:07:26,400 manner the world itself is not pixelated 193 00:07:30,770 --> 00:07:28,680 unless you're to believe Thomas Campbell 194 00:07:32,510 --> 00:07:30,780 or Donald Hoffman another reason to 195 00:07:34,430 --> 00:07:32,520 think coordinate free is you'll start to 196 00:07:36,890 --> 00:07:34,440 construct constructions that actually 197 00:07:38,270 --> 00:07:36,900 depend on your coordinates when they in 198 00:07:39,710 --> 00:07:38,280 fact don't in nature and then you'll 199 00:07:42,529 --> 00:07:39,720 wonder why are you getting an incorrect 200 00:07:44,089 --> 00:07:42,539 answer so for example in physics and so 201 00:07:47,270 --> 00:07:44,099 on we often use 202 00:07:49,490 --> 00:07:47,280 let's see this and then we represent it 203 00:07:51,950 --> 00:07:49,500 in some symmetry this is how theoretical 204 00:07:53,330 --> 00:07:51,960 physicists generally reference matrices 205 00:07:55,850 --> 00:07:53,340 they don't like them so they call them 206 00:07:57,830 --> 00:07:55,860 symmetries these rows and columns but 207 00:07:59,870 --> 00:07:57,840 then you also would reference this same 208 00:08:02,570 --> 00:07:59,880 object 209 00:08:04,070 --> 00:08:02,580 with numbers in a similar manner 210 00:08:06,710 --> 00:08:04,080 however they transform completely 211 00:08:08,629 --> 00:08:06,720 differently so one is an endomorphism 212 00:08:10,370 --> 00:08:08,639 then the other is a two form or a 213 00:08:11,809 --> 00:08:10,380 bilinear form and they transform 214 00:08:13,670 --> 00:08:11,819 completely differently and which is why 215 00:08:15,710 --> 00:08:13,680 you have transpose which is it's not an 216 00:08:17,749 --> 00:08:15,720 ill-defined object but it's a strangely 217 00:08:21,409 --> 00:08:17,759 defined object the inverse of a matrix 218 00:08:24,950 --> 00:08:21,419 is more copacetic but the transpose is a 219 00:08:28,610 --> 00:08:24,960 strange one so this one is a two form a 220 00:08:30,890 --> 00:08:28,620 bilinear form the metric in the with the 221 00:08:33,230 --> 00:08:30,900 Einstein equations is a 2 4 is a 222 00:08:35,209 --> 00:08:33,240 bilinear form and also the determinants 223 00:08:37,250 --> 00:08:35,219 of endomorphism is a completely 224 00:08:39,290 --> 00:08:37,260 different object it's invariant compared 225 00:08:41,269 --> 00:08:39,300 to the determinants of a two form or a 226 00:08:43,130 --> 00:08:41,279 bilinear form and then as you start to 227 00:08:44,570 --> 00:08:43,140 understand this coordinate free you'll 228 00:08:46,190 --> 00:08:44,580 realize that there's a special place in 229 00:08:48,530 --> 00:08:46,200 hell for the person who developed the 230 00:08:50,930 --> 00:08:48,540 transpose it's an unwieldy object 231 00:08:52,610 --> 00:08:50,940 another one that will confuse you if you 232 00:08:54,350 --> 00:08:52,620 think in terms of coordinates is that 233 00:08:56,090 --> 00:08:54,360 the wave function you ordinarily think 234 00:09:01,190 --> 00:08:56,100 of the wave function that's going from 235 00:09:09,230 --> 00:09:03,050 to 236 00:09:12,350 --> 00:09:09,240 guy is a section 237 00:09:13,550 --> 00:09:12,360 on a c line bundle and you need to 238 00:09:15,470 --> 00:09:13,560 understand bundles in order to 239 00:09:16,970 --> 00:09:15,480 understand it coordinate free so that 240 00:09:18,410 --> 00:09:16,980 you can do not only polar coordinates 241 00:09:19,970 --> 00:09:18,420 and you wonder why the heck does the 242 00:09:21,290 --> 00:09:19,980 derivative change well that makes sense 243 00:09:22,670 --> 00:09:21,300 when you understand it in terms of a 244 00:09:25,550 --> 00:09:22,680 principal bundle and then the associated 245 00:09:27,110 --> 00:09:25,560 bundle but also in terms of no longer 246 00:09:29,269 --> 00:09:27,120 staying in Rd what if you want to move 247 00:09:30,590 --> 00:09:29,279 to a curved space for quantum mechanics 248 00:09:32,750 --> 00:09:30,600 what if you want to do quantum mechanics 249 00:09:34,730 --> 00:09:32,760 on a curved space this is why one should 250 00:09:36,410 --> 00:09:34,740 try their best to understand what the 251 00:09:38,210 --> 00:09:36,420 heck is going on without reference to 252 00:09:39,530 --> 00:09:38,220 coordinates and then go to coordinates 253 00:09:41,570 --> 00:09:39,540 when you're actually making a 254 00:09:43,610 --> 00:09:41,580 calculation that's why this is a myth we 255 00:09:45,350 --> 00:09:43,620 just simply set C to equal one to equal 256 00:09:46,970 --> 00:09:45,360 H bar by the way what is h bar well 257 00:09:48,829 --> 00:09:46,980 that's a bit more abstract you don't 258 00:09:51,170 --> 00:09:48,839 need to understand that for the sake of 259 00:09:53,329 --> 00:09:51,180 this video but this is an ill-defined 260 00:09:55,370 --> 00:09:53,339 equation there's actually a caveat here 261 00:09:57,110 --> 00:09:55,380 that will come into play later another 262 00:09:59,930 --> 00:09:57,120 way of thinking about it is imagine you 263 00:10:03,230 --> 00:09:59,940 have one USD one US dollar 264 00:10:06,710 --> 00:10:03,240 sometimes you would say it equals 127 265 00:10:08,389 --> 00:10:06,720 Yen it doesn't actually equal 127 Yen 266 00:10:11,150 --> 00:10:08,399 otherwise when you have a US dollar it 267 00:10:13,370 --> 00:10:11,160 would just be 127 Yen what it means is 268 00:10:14,870 --> 00:10:13,380 that there's something called value or 269 00:10:17,030 --> 00:10:14,880 some monetary equivalent that's another 270 00:10:18,710 --> 00:10:17,040 way of thinking about it conversion what 271 00:10:20,690 --> 00:10:18,720 it means that you go here with some 272 00:10:22,130 --> 00:10:20,700 mapping let's say m and then here with 273 00:10:23,570 --> 00:10:22,140 some mapping that's that's called let's 274 00:10:26,389 --> 00:10:23,580 say m Prime 275 00:10:28,430 --> 00:10:26,399 what it means is that you do 276 00:10:31,070 --> 00:10:28,440 let's say m Prime 277 00:10:33,290 --> 00:10:31,080 inverse see we have to make all these 278 00:10:34,790 --> 00:10:33,300 constructions now and then that's after 279 00:10:37,370 --> 00:10:34,800 you've already done M so you've gone 280 00:10:39,949 --> 00:10:37,380 from here and then you go back up there 281 00:10:41,389 --> 00:10:39,959 they're not the same so another way of 282 00:10:43,070 --> 00:10:41,399 thinking about this is imagine you want 283 00:10:44,389 --> 00:10:43,080 to change lengths instead of using 284 00:10:45,889 --> 00:10:44,399 meters because you think meters are 285 00:10:47,810 --> 00:10:45,899 strange for some reason you want to 286 00:10:49,970 --> 00:10:47,820 measure everyone in terms of Lady Gaga 287 00:10:51,350 --> 00:10:49,980 so you have Lady Gaga here which I'm 288 00:10:54,530 --> 00:10:51,360 going to call 289 00:10:55,970 --> 00:10:54,540 LG so now let's say we want to measure 290 00:10:59,030 --> 00:10:55,980 someone else let's say some let's say 291 00:11:01,790 --> 00:10:59,040 Goku so what is Goku Goku 292 00:11:03,889 --> 00:11:01,800 equals maybe one and a half Lady Gaga's 293 00:11:05,210 --> 00:11:03,899 in length so you take half of Lady Gaga 294 00:11:07,430 --> 00:11:05,220 and you stack that again on Lady Gaga 295 00:11:09,829 --> 00:11:07,440 and you get a Goku in terms of Link how 296 00:11:12,110 --> 00:11:09,839 about Tony Robbins well that's let's say 297 00:11:14,090 --> 00:11:12,120 two Lady Gaga's now what we're doing 298 00:11:16,490 --> 00:11:14,100 here is we're saying I'm going to make 299 00:11:18,410 --> 00:11:16,500 all my future length measurements in 300 00:11:20,990 --> 00:11:18,420 terms of Lady Gaga for whatever reason 301 00:11:23,030 --> 00:11:21,000 in the same way that generally speaking 302 00:11:24,769 --> 00:11:23,040 prices can be made in reference to the 303 00:11:26,870 --> 00:11:24,779 US dollar and then you do some 304 00:11:29,990 --> 00:11:26,880 conversion to find out its equivalent 305 00:11:31,190 --> 00:11:30,000 monetary value in some other currency in 306 00:11:32,750 --> 00:11:31,200 the same way what we're doing right here 307 00:11:34,790 --> 00:11:32,760 is we're referencing everyone's height 308 00:11:36,470 --> 00:11:34,800 in terms of Lady Gaga's height and it 309 00:11:39,470 --> 00:11:36,480 just as foolish as it would be to say 310 00:11:41,269 --> 00:11:39,480 Lady Gaga equals one equals the USD just 311 00:11:43,730 --> 00:11:41,279 as foolish as this equation is it's 312 00:11:45,889 --> 00:11:43,740 tantamount to saying C equals one equals 313 00:11:47,630 --> 00:11:45,899 H bar there's so much that goes into a 314 00:11:49,250 --> 00:11:47,640 statement like that that's just seeing 315 00:11:51,410 --> 00:11:49,260 that gives the impression oh physicists 316 00:11:53,269 --> 00:11:51,420 are just setting it equal to one so no 317 00:11:55,370 --> 00:11:53,279 this statement is foolish and what's 318 00:11:57,590 --> 00:11:55,380 underneath that is saying hey I'm going 319 00:11:58,910 --> 00:11:57,600 to now measure everything in terms of 320 00:12:01,310 --> 00:11:58,920 the speed of light so I want to measure 321 00:12:02,630 --> 00:12:01,320 my car maybe it's a millionth of the 322 00:12:03,769 --> 00:12:02,640 speed of light I don't know I don't want 323 00:12:05,449 --> 00:12:03,779 to do the calculation right now but 324 00:12:07,550 --> 00:12:05,459 let's say it's a millionth of a speed of 325 00:12:10,069 --> 00:12:07,560 light so then I say well the speed of 326 00:12:14,829 --> 00:12:10,079 walking let's say 327 00:12:20,509 --> 00:12:18,290 0.0005 I'm making this up of these speed 328 00:12:23,930 --> 00:12:20,519 of light units that's what it means okay 329 00:12:29,509 --> 00:12:23,940 so this is all including by the way this 330 00:12:32,810 --> 00:12:31,069 you have to understand what's lurking 331 00:12:34,130 --> 00:12:32,820 underneath so in this example the value 332 00:12:35,810 --> 00:12:34,140 is what's being referenced when I see 333 00:12:36,769 --> 00:12:35,820 the real world that's what I mean is 334 00:12:39,110 --> 00:12:36,779 that there's something else that's 335 00:12:42,050 --> 00:12:39,120 tangible that I'm trying to represent my 336 00:12:44,449 --> 00:12:42,060 quantity in reference to so from now on 337 00:12:46,490 --> 00:12:44,459 we're going to no longer say that this 338 00:12:48,110 --> 00:12:46,500 is moving at 500 meters per second we're 339 00:12:49,670 --> 00:12:48,120 going to say that this is moving at a 340 00:12:51,290 --> 00:12:49,680 fraction of the speed of light by the 341 00:12:53,870 --> 00:12:51,300 way this should be a definition and that 342 00:12:56,329 --> 00:12:53,880 refers to the entire object there not 343 00:12:57,949 --> 00:12:56,339 just this this is just the magnitude and 344 00:12:59,690 --> 00:12:57,959 that's where this is misleading because 345 00:13:01,430 --> 00:12:59,700 it's just showing you the magnitude how 346 00:13:03,470 --> 00:13:01,440 the heck can c equal this in the same 347 00:13:06,350 --> 00:13:03,480 way how the heck can Lady Gaga equal the 348 00:13:08,449 --> 00:13:06,360 US equals one that is myth number one 349 00:13:09,889 --> 00:13:08,459 now myth number two is that the 350 00:13:11,449 --> 00:13:09,899 advantage 351 00:13:13,610 --> 00:13:11,459 welcome to the theories of everything 352 00:13:15,410 --> 00:13:13,620 podcast you just watched a clip from a 353 00:13:16,730 --> 00:13:15,420 much larger two hour video Lesson 354 00:13:18,530 --> 00:13:16,740 including what to do with these natural 355 00:13:20,569 --> 00:13:18,540 units such as how to calculate the 356 00:13:22,910 --> 00:13:20,579 radius of a black hole in five seconds 357 00:13:24,110 --> 00:13:22,920 no joke as well as the vacuum energy of 358 00:13:26,210 --> 00:13:24,120 the universe as well as the pressure 359 00:13:28,370 --> 00:13:26,220 inside a neutron star some facts about 360 00:13:30,470 --> 00:13:28,380 extra dimensions and quantum gravity to 361 00:13:32,509 --> 00:13:30,480 watch it click here and also this video 362 00:13:33,829 --> 00:13:32,519 was sponsored by brilliant brilliant is 363 00:13:35,389 --> 00:13:33,839 a website where you can go to learn math 364 00:13:37,009 --> 00:13:35,399 science and engineering through these 365 00:13:38,930 --> 00:13:37,019 bite-sized Interactive Learning 366 00:13:40,970 --> 00:13:38,940 experiences I keep saying this on the 367 00:13:42,590 --> 00:13:40,980 show and I mean it that at some point I 368 00:13:45,050 --> 00:13:42,600 would like to speak to Chiara marletto 369 00:13:47,329 --> 00:13:45,060 or David Deutsch on Constructor Theory 370 00:13:49,550 --> 00:13:47,339 and that's heavily based in information 371 00:13:50,870 --> 00:13:49,560 Theory and thus as preparation for that 372 00:13:52,730 --> 00:13:50,880 I went through brillian's course on 373 00:13:55,490 --> 00:13:52,740 information Theory and random variables 374 00:13:57,710 --> 00:13:55,500 and from there I was able to finally see 375 00:13:59,269 --> 00:13:57,720 why the formula for entropy is the way 376 00:14:01,129 --> 00:13:59,279 that it is it's handed to you on high 377 00:14:02,930 --> 00:14:01,139 from above and it looks Baroque and 378 00:14:04,190 --> 00:14:02,940 highly manufactured but after going 379 00:14:06,710 --> 00:14:04,200 through their course you can see that 380 00:14:09,829 --> 00:14:06,720 it's an extremely organic choice for a 381 00:14:12,710 --> 00:14:09,839 formula visit the link brilliant.org toe 382 00:14:14,030 --> 00:14:12,720 to get 20 off your annual subscription I 383 00:14:16,850 --> 00:14:14,040 personally recommend that you don't stop 384 00:14:17,990 --> 00:14:16,860 before four lessons keep going even if 385 00:14:20,269 --> 00:14:18,000 you feel like you're not making progress 386 00:14:22,009 --> 00:14:20,279 on the first second or third go to four 387 00:14:24,050 --> 00:14:22,019 and you'll be extremely surprised that