1 00:00:25,120 --> 00:00:16,080 [Music] 2 00:00:27,280 --> 00:00:25,130 maximum likelihood methods are more 3 00:00:30,940 --> 00:00:27,290 familiar from things like parameter 4 00:00:33,060 --> 00:00:30,950 estimation problems where you have a 5 00:00:35,860 --> 00:00:33,070 large body of data and you have a 6 00:00:39,070 --> 00:00:35,870 rigorous mathematical model that 7 00:00:40,870 --> 00:00:39,080 connects them observations to parameter 8 00:00:43,030 --> 00:00:40,880 values and you're trying to find the 9 00:00:47,380 --> 00:00:43,040 best fit to a lot of conflicting 10 00:00:50,230 --> 00:00:47,390 measurements however you can also use it 11 00:00:53,350 --> 00:00:50,240 in a more qualitative situation as long 12 00:01:00,270 --> 00:00:53,360 as you can decide whether one hypothesis 13 00:01:03,479 --> 00:01:00,280 is more likely than a competitor and the 14 00:01:06,789 --> 00:01:03,489 upshot is that even when you have 15 00:01:10,810 --> 00:01:06,799 multiple components for a hypothesis as 16 00:01:14,559 --> 00:01:10,820 long as at each stage you are choosing 17 00:01:18,209 --> 00:01:14,569 the most likely alternative by the end 18 00:01:20,260 --> 00:01:18,219 of the process you have the most likely 19 00:01:22,660 --> 00:01:20,270 hypothesis among the various 20 00:01:26,080 --> 00:01:22,670 possibilities you can't say anything 21 00:01:30,160 --> 00:01:26,090 about how likely it is in any absolute 22 00:01:33,099 --> 00:01:30,170 sense or whether it's how much it's more 23 00:01:37,499 --> 00:01:33,109 likely than its rivals you can just say 24 00:01:45,219 --> 00:01:42,609 so the the ETI problem I prefer that to 25 00:01:47,410 --> 00:01:45,229 UFOs because of course there are UFOs 26 00:01:51,519 --> 00:01:47,420 anybody anything that you can't identify 27 00:01:53,739 --> 00:01:51,529 as an unidentified flying object but the 28 00:01:55,510 --> 00:01:53,749 hypothesis that interests most people is 29 00:01:58,980 --> 00:01:55,520 that some of these unidentified flying 30 00:02:02,129 --> 00:01:58,990 objects are be our vehicles operated by 31 00:02:04,899 --> 00:02:02,139 extraterrestrial intelligences and as 32 00:02:08,589 --> 00:02:04,909 was sort of implied by my build up I'm 33 00:02:12,610 --> 00:02:08,599 not trying to estimate the likelihood 34 00:02:15,369 --> 00:02:12,620 that the ETI hypothesis is true my 35 00:02:18,580 --> 00:02:15,379 discussion here is suppose we stipulate 36 00:02:19,970 --> 00:02:18,590 that these are extraterrestrial vehicles 37 00:02:24,050 --> 00:02:19,980 what can we 38 00:02:26,420 --> 00:02:24,060 infer about the ETI from what's been 39 00:02:30,500 --> 00:02:26,430 seen of them what are the most likely 40 00:02:33,680 --> 00:02:30,510 properties a general principle I'll be 41 00:02:35,770 --> 00:02:33,690 using is that the known is more likely 42 00:02:39,589 --> 00:02:35,780 than the speculative if there's 43 00:02:42,500 --> 00:02:39,599 something that we know is real it's more 44 00:02:45,229 --> 00:02:42,510 likely than something that we only know 45 00:02:47,240 --> 00:02:45,239 is possible on the other hand if there's 46 00:02:49,759 --> 00:02:47,250 something that we know is possible 47 00:02:52,699 --> 00:02:49,769 that's more likely than something that 48 00:02:58,309 --> 00:02:52,709 we simply have not yet proven to be 49 00:03:01,449 --> 00:02:58,319 impossible there is however a a caveat 50 00:03:04,119 --> 00:03:01,459 that yeah applying this unthinkingly 51 00:03:07,309 --> 00:03:04,129 will always lead to perfectly mundane 52 00:03:11,809 --> 00:03:07,319 explanations for everything so it has to 53 00:03:14,289 --> 00:03:11,819 be consistent with the evidence now 54 00:03:16,339 --> 00:03:14,299 reviewing what the relevant evidence is 55 00:03:18,259 --> 00:03:16,349 would require a book 56 00:03:22,699 --> 00:03:18,269 fortunately Peter Stewart has written 57 00:03:24,530 --> 00:03:22,709 the book so I don't have to but the this 58 00:03:28,309 --> 00:03:24,540 current discussion is based on some very 59 00:03:30,409 --> 00:03:28,319 general summary observations there is a 60 00:03:34,009 --> 00:03:30,419 lot of eyewitness testimony some of it 61 00:03:37,159 --> 00:03:34,019 extremely high quality to things that 62 00:03:39,409 --> 00:03:37,169 look like aircraft or aerial vehicles 63 00:03:43,240 --> 00:03:39,419 that aren't aren't identifiable with any 64 00:03:45,920 --> 00:03:43,250 human culture or technology there's 65 00:03:48,800 --> 00:03:45,930 instrument recordings video tapes 66 00:03:51,470 --> 00:03:48,810 similar comments there are somewhat 67 00:03:54,349 --> 00:03:51,480 fewer but some cases of physical 68 00:03:56,420 --> 00:03:54,359 evidence left behind some of this I want 69 00:03:59,629 --> 00:03:56,430 quality witness testimony attests to 70 00:04:02,539 --> 00:03:59,639 seeing occupants who sometimes exit the 71 00:04:05,210 --> 00:04:02,549 vehicles when occupants are reported 72 00:04:07,009 --> 00:04:05,220 they're almost always humanoid they may 73 00:04:10,059 --> 00:04:07,019 or may not be described as wearing what 74 00:04:12,470 --> 00:04:10,069 appears to be environmental protection 75 00:04:15,050 --> 00:04:12,480 supposed vehicles in some sightings 76 00:04:18,680 --> 00:04:15,060 undertake maneuvers that are well beyond 77 00:04:22,000 --> 00:04:18,690 our technical capability there are some 78 00:04:25,279 --> 00:04:22,010 areas of evidence that I am ignoring I 79 00:04:27,439 --> 00:04:25,289 am not paying attention to any reports 80 00:04:29,959 --> 00:04:27,449 of voluntary boarding of vehicles by 81 00:04:33,140 --> 00:04:29,969 humans or of abductions by vehicles 82 00:04:34,940 --> 00:04:33,150 although it belatedly occurs to me 83 00:04:39,770 --> 00:04:34,950 that it actually wouldn't make much 84 00:04:41,780 --> 00:04:39,780 difference to my conclusions one one 85 00:04:44,090 --> 00:04:41,790 element that I'm disregarding that would 86 00:04:47,720 --> 00:04:44,100 make a difference is reports some of 87 00:04:49,910 --> 00:04:47,730 which have been made at the SSE - that 88 00:04:52,160 --> 00:04:49,920 the ETS are in fact known to an in 89 00:04:53,690 --> 00:04:52,170 regular contact with human governments 90 00:04:55,850 --> 00:04:53,700 and pursuing various kinds of 91 00:04:58,640 --> 00:04:55,860 clandestine cooperation 92 00:05:02,570 --> 00:04:58,650 the reason I'm ignoring that is that 93 00:05:04,310 --> 00:05:02,580 conspiracy theories are not science in 94 00:05:06,560 --> 00:05:04,320 the first place I would say their 95 00:05:09,080 --> 00:05:06,570 intrinsic likelihood as the great 96 00:05:12,290 --> 00:05:09,090 conspiracy is very low it's shared by 97 00:05:15,470 --> 00:05:12,300 mutually hostile regimes over decades 98 00:05:17,890 --> 00:05:15,480 while regimes have changed and yet 99 00:05:20,210 --> 00:05:17,900 despite this apparent worldwide 100 00:05:22,520 --> 00:05:20,220 overwhelming power the conspiracy is 101 00:05:24,560 --> 00:05:22,530 somehow failing to silence the brave 102 00:05:28,910 --> 00:05:24,570 whistleblowers who are trying to expose 103 00:05:32,180 --> 00:05:28,920 it basically believing in the great 104 00:05:36,050 --> 00:05:32,190 conspiracy is evidence transcendent any 105 00:05:38,840 --> 00:05:36,060 behavior whatsoever is compatible with 106 00:05:41,060 --> 00:05:38,850 the notion that it's due to a conspiracy 107 00:05:43,790 --> 00:05:41,070 however mysterious it is it's what the 108 00:05:48,140 --> 00:05:43,800 conspiracy wants so it can never be 109 00:05:53,720 --> 00:05:48,150 refuted it is non falsifiable it has no 110 00:05:55,700 --> 00:05:53,730 place in scientific discourse now I and 111 00:05:58,690 --> 00:05:55,710 having multiple components of the theory 112 00:06:01,970 --> 00:05:58,700 here are the big ones 113 00:06:02,630 --> 00:06:01,980 do these et eyes have faster than light 114 00:06:04,790 --> 00:06:02,640 travel 115 00:06:06,290 --> 00:06:04,800 do they have reaction with drives did 116 00:06:09,770 --> 00:06:06,300 they have some form of inertia or 117 00:06:12,170 --> 00:06:09,780 gravity control what can we infer about 118 00:06:13,750 --> 00:06:12,180 their biology and where are they coming 119 00:06:22,430 --> 00:06:13,760 from 120 00:06:24,500 --> 00:06:22,440 well FTA FTL travel is a simple one our 121 00:06:26,660 --> 00:06:24,510 current physics absolutely limits 122 00:06:29,780 --> 00:06:26,670 material objects to speeds less than 123 00:06:31,850 --> 00:06:29,790 light there are lots of potential 124 00:06:34,220 --> 00:06:31,860 loopholes in that but none of those 125 00:06:36,260 --> 00:06:34,230 loopholes have been demonstrated to 126 00:06:39,080 --> 00:06:36,270 actually happen in the world that we 127 00:06:42,980 --> 00:06:39,090 live in they are all speculative so 128 00:06:45,200 --> 00:06:42,990 provisional conclusion unless we are 129 00:06:48,140 --> 00:06:45,210 faced with totally incompatible 130 00:06:52,960 --> 00:06:48,150 it is more likely that the ETI do not 131 00:06:58,969 --> 00:06:52,970 have FTL travel reaction --less drops 132 00:07:01,520 --> 00:06:58,979 now in in virtually all cases the things 133 00:07:03,529 --> 00:07:01,530 that are cited fly around and maneuver 134 00:07:05,870 --> 00:07:03,539 they're not showing jet exhaust they're 135 00:07:07,820 --> 00:07:05,880 not showing rocket exhaust they're not 136 00:07:11,390 --> 00:07:07,830 showing any kind of exhaust typically 137 00:07:13,939 --> 00:07:11,400 and when people get a close enough view 138 00:07:16,219 --> 00:07:13,949 to report some details of the object 139 00:07:20,050 --> 00:07:16,229 structure there's nothing that looks 140 00:07:23,980 --> 00:07:20,060 like a rocket venturi or a jet engine 141 00:07:26,870 --> 00:07:23,990 now on the other hand from from physics 142 00:07:32,029 --> 00:07:26,880 the third law of motion has not been 143 00:07:35,029 --> 00:07:32,039 repealed according to known physics you 144 00:07:38,779 --> 00:07:35,039 you can't accelerate without throwing 145 00:07:41,779 --> 00:07:38,789 something the other way so does the lack 146 00:07:43,879 --> 00:07:41,789 of a of an observed exhaust mean that we 147 00:07:46,700 --> 00:07:43,889 have to give that up and the answer is 148 00:07:49,879 --> 00:07:46,710 no a few years ago I presented a paper 149 00:07:53,810 --> 00:07:49,889 on neutrino rocketry it remains the case 150 00:07:57,830 --> 00:07:53,820 that if that it is possible to produce a 151 00:07:59,810 --> 00:07:57,840 collimated jet of neutrinos that would 152 00:08:02,570 --> 00:07:59,820 exert an unbalanced force on its 153 00:08:04,730 --> 00:08:02,580 generator and that is an exhaust that 154 00:08:06,770 --> 00:08:04,740 none of our instrumentation would see 155 00:08:09,710 --> 00:08:06,780 and of course our eyes wouldn't either 156 00:08:11,930 --> 00:08:09,720 so since the there is also other 157 00:08:14,529 --> 00:08:11,940 possibilities which I'm not going to go 158 00:08:17,149 --> 00:08:14,539 into right now because of limited time 159 00:08:19,850 --> 00:08:17,159 but since the evidence does not rule it 160 00:08:24,620 --> 00:08:19,860 out it is more likely that ETI vehicles 161 00:08:26,629 --> 00:08:24,630 are using reaction drives then there's 162 00:08:29,240 --> 00:08:26,639 the question of being able to control 163 00:08:32,569 --> 00:08:29,250 inertia or have some sort of internal 164 00:08:34,010 --> 00:08:32,579 gravity system to accommodate these some 165 00:08:38,269 --> 00:08:34,020 of these extraordinarily violent 166 00:08:41,779 --> 00:08:38,279 maneuvers and once again I'm coming down 167 00:08:45,220 --> 00:08:41,789 on the side that we don't have to go to 168 00:08:48,290 --> 00:08:45,230 exotic physics because there there are 169 00:08:51,170 --> 00:08:48,300 known techniques which are almost at the 170 00:08:53,810 --> 00:08:51,180 level of practical application where you 171 00:08:57,019 --> 00:08:53,820 could get humans to survive tremendous 172 00:08:58,400 --> 00:08:57,029 g-forces basically the idea is fill up 173 00:09:02,119 --> 00:08:58,410 all of your internal 174 00:09:05,059 --> 00:09:02,129 spaces with a liquid of roughly neutral 175 00:09:06,680 --> 00:09:05,069 buoyancy and then to a first 176 00:09:07,970 --> 00:09:06,690 approximation you don't care about 177 00:09:10,340 --> 00:09:07,980 gravity you don't care about 178 00:09:12,499 --> 00:09:10,350 acceleration there will be some limits 179 00:09:16,369 --> 00:09:12,509 because muscle and bone and fat aren't 180 00:09:18,740 --> 00:09:16,379 all exactly the same density and at the 181 00:09:21,889 --> 00:09:18,750 moment the big technological hurdle is 182 00:09:25,730 --> 00:09:21,899 getting a fluid that can oxygenate the 183 00:09:30,460 --> 00:09:25,740 lungs without desiccating them to the 184 00:09:32,869 --> 00:09:30,470 point that that you die of asphyxiation 185 00:09:35,900 --> 00:09:32,879 after the fluid is removed and you try 186 00:09:37,970 --> 00:09:35,910 to get back to breathing air that has 187 00:09:39,920 --> 00:09:37,980 been a very frequent problem with test 188 00:09:41,929 --> 00:09:39,930 animals in this kind of medium and 189 00:09:49,309 --> 00:09:41,939 that's why it hasn't really been tested 190 00:09:52,340 --> 00:09:49,319 in humans yet okay now for biology the 191 00:09:54,369 --> 00:09:52,350 occupants that have been reported most 192 00:09:57,170 --> 00:09:54,379 reports say they're humanoid 193 00:09:59,629 --> 00:09:57,180 they can function in earthly conditions 194 00:10:01,970 --> 00:09:59,639 with and they don't while they may be 195 00:10:03,730 --> 00:10:01,980 wearing protection they don't need so 196 00:10:08,360 --> 00:10:03,740 much protection that the body shape is 197 00:10:10,249 --> 00:10:08,370 unrecognizable now here the evidential 198 00:10:13,040 --> 00:10:10,259 value is limited even if the witness 199 00:10:15,319 --> 00:10:13,050 testimony is totally reliable for one 200 00:10:17,300 --> 00:10:15,329 thing a nonhuman on a non humanoid 201 00:10:20,269 --> 00:10:17,310 occupant might not be recognized as an 202 00:10:22,780 --> 00:10:20,279 occupant for another thing the humanoids 203 00:10:25,429 --> 00:10:22,790 that have been reported and described 204 00:10:28,160 --> 00:10:25,439 could perfectly well be telepresence 205 00:10:32,679 --> 00:10:28,170 robots or bio engineered life-forms 206 00:10:36,249 --> 00:10:32,689 purpose-built for exploration however 207 00:10:40,220 --> 00:10:36,259 even granted that that the value of the 208 00:10:42,530 --> 00:10:40,230 observations is limited it's not zero so 209 00:10:44,629 --> 00:10:42,540 it is at least provisionally more likely 210 00:10:46,610 --> 00:10:44,639 that vehicle occupants are water-based 211 00:10:50,720 --> 00:10:46,620 oxygen breathers capable of handling 212 00:10:52,939 --> 00:10:50,730 earth gravity and now where do they come 213 00:10:54,949 --> 00:10:52,949 from the occupants can function in 214 00:10:57,170 --> 00:10:54,959 earth-like environments no such 215 00:10:59,509 --> 00:10:57,180 environments occur naturally in any 216 00:11:02,269 --> 00:10:59,519 other body I mean in this solar system 217 00:11:04,519 --> 00:11:02,279 and that seems to spawn four 218 00:11:07,759 --> 00:11:04,529 possibilities they're comfortable in 219 00:11:10,670 --> 00:11:07,769 widely variable environments or they're 220 00:11:12,350 --> 00:11:10,680 from Earth or they're from artificial 221 00:11:15,850 --> 00:11:12,360 habitats in the solar system 222 00:11:19,639 --> 00:11:15,860 or they're from another solar system 223 00:11:22,759 --> 00:11:19,649 okay could could they be able to handle 224 00:11:24,819 --> 00:11:22,769 any environment well what we know of 225 00:11:27,620 --> 00:11:24,829 biology doesn't seem to agree with that 226 00:11:32,240 --> 00:11:27,630 extremophiles have colonized every 227 00:11:35,150 --> 00:11:32,250 environment that exists on earth but no 228 00:11:38,230 --> 00:11:35,160 extrema file is adapted to all extreme 229 00:11:40,660 --> 00:11:38,240 environments algae can grow on in ice 230 00:11:45,670 --> 00:11:40,670 thermophiles can grow in boiling water 231 00:11:48,259 --> 00:11:45,680 they don't cross over so given an 232 00:11:50,810 --> 00:11:48,269 organism that can survive typical earth 233 00:11:52,819 --> 00:11:50,820 surface conditions it is more likely 234 00:11:56,680 --> 00:11:52,829 that it will be killed by typical 235 00:12:02,480 --> 00:11:56,690 conditions on other solar system bodies 236 00:12:04,400 --> 00:12:02,490 so is ETI really T I mean on the face of 237 00:12:06,410 --> 00:12:04,410 it the most likely explanation for a 238 00:12:07,730 --> 00:12:06,420 human shape human-sized being who 239 00:12:10,280 --> 00:12:07,740 functions well in earth-like conditions 240 00:12:12,139 --> 00:12:10,290 is that it really is a human being from 241 00:12:14,329 --> 00:12:12,149 Earth ah 242 00:12:16,190 --> 00:12:14,339 I consider this incompatible with 243 00:12:20,780 --> 00:12:16,200 evidence but the evidence in this case 244 00:12:23,090 --> 00:12:20,790 is negative we don't know of any human 245 00:12:26,329 --> 00:12:23,100 civilization that has these technical 246 00:12:28,910 --> 00:12:26,339 capabilities and believing that it could 247 00:12:30,380 --> 00:12:28,920 be hidden given how crowded the world is 248 00:12:32,960 --> 00:12:30,390 and how much of it is settled in under 249 00:12:35,750 --> 00:12:32,970 continuous observation requires a return 250 00:12:40,970 --> 00:12:35,760 to the great conspiracy theory see a 251 00:12:43,900 --> 00:12:40,980 dozen or so slides back now doesn't the 252 00:12:47,569 --> 00:12:43,910 evidence also rule out solar system or 253 00:12:50,600 --> 00:12:47,579 origin the thing is unlike Earth the 254 00:12:52,670 --> 00:12:50,610 solar system contains vast regions where 255 00:12:55,579 --> 00:12:52,680 a high-tech civilization could flourish 256 00:12:58,790 --> 00:12:55,589 without being detected by our current 257 00:13:01,340 --> 00:12:58,800 technology even in the asteroid belt 258 00:13:03,829 --> 00:13:01,350 which is only to astronomical to three 259 00:13:06,800 --> 00:13:03,839 astronomical units away an astronomical 260 00:13:08,870 --> 00:13:06,810 unit is the radius of Earth's orbit it's 261 00:13:10,970 --> 00:13:08,880 estimated that only about two-thirds of 262 00:13:14,930 --> 00:13:10,980 asteroids larger than 1 kilometer have 263 00:13:16,490 --> 00:13:14,940 been detected we've also realized that 264 00:13:19,670 --> 00:13:16,500 there's a lot of stuff out in the Kuiper 265 00:13:22,710 --> 00:13:19,680 belt at about 50 astronomical units 266 00:13:26,500 --> 00:13:22,720 which is much harder to detect 267 00:13:29,050 --> 00:13:26,510 then on the other hand wouldn't 268 00:13:34,030 --> 00:13:29,060 artificial habitats be easier to spot 269 00:13:38,380 --> 00:13:34,040 than rocks and I see that we have some 270 00:13:41,140 --> 00:13:38,390 spacing issues here sorry the answer is 271 00:13:44,770 --> 00:13:41,150 basically that given the constraints 272 00:13:47,470 --> 00:13:44,780 from a that that a space going habitats 273 00:13:49,960 --> 00:13:47,480 suffers there are strong reasons to 274 00:13:52,660 --> 00:13:49,970 think that it would not be putting out a 275 00:13:54,940 --> 00:13:52,670 lot of radiation it would not be 276 00:13:56,560 --> 00:13:54,950 particularly more visible than a natural 277 00:13:59,530 --> 00:13:56,570 body and it might very well be less 278 00:14:03,160 --> 00:13:59,540 visible but I reserved the details for 279 00:14:07,570 --> 00:14:03,170 an appendix which I'll get to if if I 280 00:14:09,970 --> 00:14:07,580 move fast enough so an advanced 281 00:14:11,950 --> 00:14:09,980 civilization using space-based resources 282 00:14:16,090 --> 00:14:11,960 within the solar system is compatible 283 00:14:18,520 --> 00:14:16,100 with the observation then there's the 284 00:14:22,060 --> 00:14:18,530 question of solar or extrasolar origin 285 00:14:24,550 --> 00:14:22,070 and just as a side note origin here I 286 00:14:27,130 --> 00:14:24,560 don't mean where they evolved I mean 287 00:14:29,080 --> 00:14:27,140 where they're living now what is the 288 00:14:32,320 --> 00:14:29,090 spot from which the vehicles start their 289 00:14:34,330 --> 00:14:32,330 missions well the nearest stars are over 290 00:14:36,880 --> 00:14:34,340 a quarter of a million astronomical 291 00:14:40,330 --> 00:14:36,890 units away whereas even a quaver belt 292 00:14:43,540 --> 00:14:40,340 habitat is only 50 astronomical units 293 00:14:46,270 --> 00:14:43,550 away no matter what their technology is 294 00:14:47,950 --> 00:14:46,280 the longer trip is an enormous ly 295 00:14:54,340 --> 00:14:47,960 greater investment of effort and 296 00:14:57,760 --> 00:14:54,350 resources so the the the conclusion 297 00:14:59,800 --> 00:14:57,770 there is that the most likely hypothesis 298 00:15:01,780 --> 00:14:59,810 among those four competitors is that 299 00:15:06,100 --> 00:15:01,790 they live in artificial habitats within 300 00:15:08,830 --> 00:15:06,110 our solar system summing up they do not 301 00:15:11,740 --> 00:15:08,840 have FTL travel they live in somewhat 302 00:15:13,570 --> 00:15:11,750 earth-like conditions these conditions 303 00:15:15,220 --> 00:15:13,580 are artificially maintained in deep 304 00:15:17,230 --> 00:15:15,230 space habitats and they use 305 00:15:19,720 --> 00:15:17,240 inconspicuous reaction drives for 306 00:15:21,760 --> 00:15:19,730 propulsion now was that the five-minute 307 00:15:24,600 --> 00:15:21,770 warning I just got then I have time 308 00:15:28,120 --> 00:15:24,610 enough to at least go on to appendix 1 309 00:15:30,310 --> 00:15:28,130 some additional inferences there 310 00:15:32,740 --> 00:15:30,320 naturally their civilization is 311 00:15:37,090 --> 00:15:32,750 naturally in conspicuous to our current 312 00:15:42,190 --> 00:15:39,949 this may be sufficient to explain their 313 00:15:44,150 --> 00:15:42,200 non observation or they may be 314 00:15:48,319 --> 00:15:44,160 intentionally stealthy as well that's 315 00:15:50,780 --> 00:15:48,329 appendix 2 okay I see I should have gone 316 00:15:53,540 --> 00:15:50,790 with the PDF form we do know that they 317 00:15:55,400 --> 00:15:53,550 have not chosen to be conspicuous if 318 00:15:58,490 --> 00:15:55,410 they chose to reveal themselves we'd all 319 00:16:01,069 --> 00:15:58,500 know about it instantly so their policy 320 00:16:03,949 --> 00:16:01,079 the policy of the ETI civilization as a 321 00:16:06,500 --> 00:16:03,959 whole therefore it must be either to 322 00:16:08,269 --> 00:16:06,510 avoid making themselves obvious or to 323 00:16:13,910 --> 00:16:08,279 actually make an effort not to be 324 00:16:15,740 --> 00:16:13,920 obvious and yet individual vehicles have 325 00:16:17,600 --> 00:16:15,750 been spotted some times with multiple 326 00:16:20,180 --> 00:16:17,610 instruments and observers on numerous 327 00:16:22,310 --> 00:16:20,190 occasions the controller's of these 328 00:16:24,199 --> 00:16:22,320 vehicles are either deliberately acting 329 00:16:26,690 --> 00:16:24,209 in opposition to their civilizations 330 00:16:29,960 --> 00:16:26,700 policies or they are incompetent at 331 00:16:32,750 --> 00:16:29,970 carrying out those policies ah 332 00:16:35,600 --> 00:16:32,760 and hence the slide titled dissidents or 333 00:16:38,329 --> 00:16:35,610 dolts it would seem to follow that ETI 334 00:16:40,509 --> 00:16:38,339 civilization like our own is unable to 335 00:16:43,730 --> 00:16:40,519 instill unanimity of purpose or 336 00:16:47,920 --> 00:16:43,740 uniformity of skill even in individuals 337 00:16:53,269 --> 00:16:51,230 now you may recall from my neutrino 338 00:16:57,110 --> 00:16:53,279 rocketry talk that one of the downsides 339 00:17:00,380 --> 00:16:57,120 of that drive is that any vehicle using 340 00:17:02,720 --> 00:17:00,390 it is a potential Gigaton ball the 341 00:17:05,390 --> 00:17:02,730 implications of having such devices in 342 00:17:10,610 --> 00:17:05,400 the hands of ideological red rebels or 343 00:17:12,890 --> 00:17:10,620 incompetence are not comfortable I think 344 00:17:13,100 --> 00:17:12,900 I've got a couple of minutes yes thank 345 00:17:16,039 --> 00:17:13,110 you 346 00:17:20,990 --> 00:17:16,049 so appendix - why would they be hard to 347 00:17:23,240 --> 00:17:21,000 see okay we can I spot objects in space 348 00:17:24,860 --> 00:17:23,250 just generally from their emissions or 349 00:17:27,140 --> 00:17:24,870 from the reflection of emissions of 350 00:17:28,429 --> 00:17:27,150 other sources I'm going to assume that 351 00:17:32,539 --> 00:17:28,439 there's nothing involved that's big 352 00:17:34,190 --> 00:17:32,549 enough to use gravitational lensing most 353 00:17:35,990 --> 00:17:34,200 asteroid observation is done with 354 00:17:39,110 --> 00:17:36,000 visible light which asteroids reflect 355 00:17:41,090 --> 00:17:39,120 but do not admit IR telescopes can also 356 00:17:44,000 --> 00:17:41,100 track things by their thermal emissions 357 00:17:47,490 --> 00:17:44,010 now artificial bodies will also reflect 358 00:17:51,040 --> 00:17:47,500 and will also emit thermal radiation 359 00:17:52,570 --> 00:17:51,050 however if it's an artificial habitat 360 00:17:55,000 --> 00:17:52,580 for something that likes to live around 361 00:17:57,730 --> 00:17:55,010 liquid water if it's located in the 362 00:17:59,710 --> 00:17:57,740 asteroid belt or farther out it has to 363 00:18:02,770 --> 00:17:59,720 be maintaining an internal temperature 364 00:18:04,930 --> 00:18:02,780 that's a lot higher than the blackbody 365 00:18:07,720 --> 00:18:04,940 at equilibrium temperature from sunlight 366 00:18:10,090 --> 00:18:07,730 at their location so that means it's 367 00:18:12,430 --> 00:18:10,100 designers will want to trap radiation 368 00:18:16,510 --> 00:18:12,440 and they'll want to radiate as little 369 00:18:18,580 --> 00:18:16,520 waste heat as they possibly can so the 370 00:18:20,530 --> 00:18:18,590 side facing the Sun is going to have as 371 00:18:22,750 --> 00:18:20,540 lower reflectivity as possible because 372 00:18:24,940 --> 00:18:22,760 they want to catch whatever they can and 373 00:18:27,220 --> 00:18:24,950 when they're radiating waste heat 374 00:18:30,400 --> 00:18:27,230 they'll want to use the most efficient 375 00:18:33,610 --> 00:18:30,410 heat sink available which is the 2.7 376 00:18:35,950 --> 00:18:33,620 Kelvin background of the open sky away 377 00:18:42,880 --> 00:18:35,960 from the Sun which also happens to be 378 00:18:45,930 --> 00:18:42,890 the side away from us regarding 379 00:18:48,010 --> 00:18:45,940 propulsion from in atmosphere 380 00:18:50,020 --> 00:18:48,020 observations we think that they're 381 00:18:52,690 --> 00:18:50,030 probably using drives that don't show a 382 00:18:53,980 --> 00:18:52,700 visible exhaust even if there's 383 00:18:57,580 --> 00:18:53,990 something different between in 384 00:18:59,530 --> 00:18:57,590 atmosphere and deep space propulsion the 385 00:19:02,560 --> 00:18:59,540 kinds of rockets we're accustomed to are 386 00:19:05,320 --> 00:19:02,570 very inefficient I mean the glare and 387 00:19:09,790 --> 00:19:05,330 the shine doesn't add anything to the 388 00:19:11,560 --> 00:19:09,800 thrust so an optimal reaction Drive is 389 00:19:14,650 --> 00:19:11,570 going to be tightly collimated it's 390 00:19:17,920 --> 00:19:14,660 going to be in extremely internally cold 391 00:19:19,680 --> 00:19:17,930 if we're not going to see it unless it 392 00:19:23,110 --> 00:19:19,690 hits something 393 00:19:27,040 --> 00:19:23,120 similarly talking we're using broadcast 394 00:19:29,200 --> 00:19:27,050 radio all the time we're also all living 395 00:19:30,850 --> 00:19:29,210 on the same planet the farther you have 396 00:19:33,700 --> 00:19:30,860 to send a message the more inefficient 397 00:19:35,620 --> 00:19:33,710 it is to broadcast whatever technology 398 00:19:37,570 --> 00:19:35,630 they use for signaling they're almost 399 00:19:39,460 --> 00:19:37,580 certainly using tight beams that will 400 00:19:43,770 --> 00:19:39,470 only see if we happen to be in the beam 401 00:19:46,050 --> 00:19:43,780 path now that's just the natural 402 00:19:48,280 --> 00:19:46,060 considerations for a space-based 403 00:19:50,440 --> 00:19:48,290 civilization what if they're actually 404 00:19:53,290 --> 00:19:50,450 hiding that would imply that they're 405 00:19:55,900 --> 00:19:53,300 even more careful about their signaling 406 00:19:57,910 --> 00:19:55,910 and drive beam paths and they're going 407 00:19:59,830 --> 00:19:57,920 to make an effort to make sure that 408 00:20:00,760 --> 00:19:59,840 nothing points than anything where 409 00:20:04,420 --> 00:20:00,770 somebody might see 410 00:20:06,880 --> 00:20:04,430 you now why would they be hiding just 411 00:20:08,740 --> 00:20:06,890 going through this very quickly it may 412 00:20:10,360 --> 00:20:08,750 be that they don't want to damage us it 413 00:20:12,310 --> 00:20:10,370 may be that they think we're dangerous 414 00:20:13,870 --> 00:20:12,320 we can rule out the possibility that 415 00:20:15,730 --> 00:20:13,880 they're hostile if they wanted to get 416 00:20:19,990 --> 00:20:15,740 rid of us they they could immediately 417 00:20:20,000 --> 00:20:28,560 [Applause] 418 00:20:33,530 --> 00:20:31,690 into UI did anybody miss the moderators 419 00:20:40,940 --> 00:20:33,540 privilege yes 420 00:20:49,340 --> 00:20:46,760 thank you very much I made two comments 421 00:20:51,320 --> 00:20:49,350 one is I think one it's helpful to 422 00:20:53,080 --> 00:20:51,330 distinguish I'll hold the mic close 423 00:20:54,980 --> 00:20:53,090 there okay it's helping distinguish 424 00:20:57,890 --> 00:20:54,990 ordinary physics from extraordinary 425 00:21:00,160 --> 00:20:57,900 physics and if you consider 426 00:21:02,810 --> 00:21:00,170 extraordinary physics and of course 427 00:21:05,660 --> 00:21:02,820 considerations about time of travel and 428 00:21:08,300 --> 00:21:05,670 resources have become irrelevant in this 429 00:21:10,400 --> 00:21:08,310 context mitre also bear in mind reports 430 00:21:14,600 --> 00:21:10,410 of objects appearing out of nowhere and 431 00:21:18,860 --> 00:21:14,610 then vanishing suggesting that we live 432 00:21:20,090 --> 00:21:18,870 in a very complex space-time okay all 433 00:21:23,930 --> 00:21:20,100 right 434 00:21:27,620 --> 00:21:23,940 once you consider extraordinary physics 435 00:21:31,460 --> 00:21:27,630 possibly involving other space-time 436 00:21:38,410 --> 00:21:31,470 manifolds the other point I want to make 437 00:21:42,860 --> 00:21:38,420 is that analysis of of databases 438 00:21:46,280 --> 00:21:42,870 show a strong relationship to local 439 00:21:54,320 --> 00:21:46,290 sidereal time and that points towards 440 00:21:56,150 --> 00:21:54,330 origin outside the solar system my 441 00:21:58,420 --> 00:21:56,160 response to that sorry I forgot for a 442 00:22:01,160 --> 00:21:58,430 moment that I didn't need that mic is 443 00:22:04,550 --> 00:22:01,170 that with regard to extraordinary 444 00:22:07,370 --> 00:22:04,560 physics of course it is very easy to 445 00:22:09,260 --> 00:22:07,380 explain things by invoking extraordinary 446 00:22:13,250 --> 00:22:09,270 physics in terms of a likelihood 447 00:22:16,090 --> 00:22:13,260 analysis I felt compelled to stick with 448 00:22:19,340 --> 00:22:16,100 the principle that known physics is 449 00:22:21,610 --> 00:22:19,350 intrinsically more likely than 450 00:22:23,780 --> 00:22:21,620 extraordinary physics unless 451 00:22:27,320 --> 00:22:23,790 observations are completely incompatible 452 00:22:30,920 --> 00:22:27,330 with known physics regarding satiereal 453 00:22:37,640 --> 00:22:30,930 time correlations I will simply note 454 00:22:40,120 --> 00:22:37,650 that a a a a paper belt habitat is going 455 00:22:44,090 --> 00:22:40,130 to have a longer orbit than Pluto's 456 00:22:47,150 --> 00:22:44,100 which means more than two to three 457 00:22:49,400 --> 00:22:47,160 centuries which means that a single 458 00:22:51,800 --> 00:22:49,410 origin point somewhere out in the Kuiper 459 00:22:53,840 --> 00:22:51,810 belt would only have moved across a 460 00:22:58,370 --> 00:22:53,850 small patch of sky in the 461 00:23:01,100 --> 00:22:58,380 we've been making observations thank you 462 00:23:04,330 --> 00:23:01,110 for your stunning use of logic that was 463 00:23:08,390 --> 00:23:04,340 really interesting regarding the the 464 00:23:10,549 --> 00:23:08,400 propulsion force probably you're 465 00:23:13,100 --> 00:23:10,559 familiar with all the ways lifters that 466 00:23:16,820 --> 00:23:13,110 are on the Internet we have one in the 467 00:23:20,000 --> 00:23:16,830 lab you just attached to wires to 468 00:23:22,279 --> 00:23:20,010 conductors on a lightweight frame to 469 00:23:24,620 --> 00:23:22,289 10,000 volts and it lifts like a genie 470 00:23:27,860 --> 00:23:24,630 and ours lifts up about a meter or so 471 00:23:31,010 --> 00:23:27,870 but I've seen some of them lifting up 5 472 00:23:33,230 --> 00:23:31,020 or 10 meters is this a possibility it's 473 00:23:36,080 --> 00:23:33,240 very simple you just need a high voltage 474 00:23:38,930 --> 00:23:36,090 source and I suppose if these are 475 00:23:40,820 --> 00:23:38,940 developed further than what what the 476 00:23:43,990 --> 00:23:40,830 hobbyists have been able to do you could 477 00:23:46,510 --> 00:23:44,000 get substantial lift out of that 478 00:23:49,850 --> 00:23:46,520 possible electromagnetic drive 479 00:23:51,680 --> 00:23:49,860 mechanisms that interact with the 480 00:23:56,270 --> 00:23:51,690 atmosphere or the Earth's magnetic 481 00:23:59,930 --> 00:23:56,280 fields are among the possibilities that 482 00:24:10,710 --> 00:23:59,940 I glossed over for lack of time so yes 483 00:24:18,310 --> 00:24:15,820 hi York known physics to you and all of 484 00:24:20,620 --> 00:24:18,320 us I think now includes the ability to 485 00:24:23,169 --> 00:24:20,630 shift subtly the probabilities of events 486 00:24:30,480 --> 00:24:23,179 is it possible that they got here and 487 00:24:33,520 --> 00:24:30,490 travelled by an improbable ax T Drive I 488 00:24:36,180 --> 00:24:33,530 am afraid I have to class that with 489 00:24:40,659 --> 00:24:36,190 extraordinary physics mostly because 490 00:24:43,750 --> 00:24:40,669 experiments in parapsychology show that 491 00:24:46,750 --> 00:24:43,760 there is some sort of disconnect between 492 00:24:49,240 --> 00:24:46,760 the probabilities of relatively 493 00:24:52,740 --> 00:24:49,250 infrequent events like bits being 494 00:24:57,570 --> 00:24:52,750 processed and the probabilities for 495 00:25:01,299 --> 00:24:57,580 elementary interactions I pair showed a 496 00:25:04,419 --> 00:25:01,309 1 in 10,000 probability shift from RNG s 497 00:25:07,690 --> 00:25:04,429 if I can do a 1 in 10,000 probability 498 00:25:09,310 --> 00:25:07,700 shift in molecules I can slam that door 499 00:25:16,690 --> 00:25:09,320 and hold it shut against the battering 500 00:25:19,090 --> 00:25:16,700 ram we don't see that in the lab york 501 00:25:21,159 --> 00:25:19,100 regarding conspiracy theories I think 502 00:25:23,049 --> 00:25:21,169 Richard Nixon said that you're not 503 00:25:26,680 --> 00:25:23,059 paranoid if they really are out to get 504 00:25:30,850 --> 00:25:26,690 you the converse of that is that you 505 00:25:32,860 --> 00:25:30,860 even if they are out to get you paranoia 506 00:25:36,190 --> 00:25:32,870 is still unhealthy and dysfunctional 507 00:25:37,990 --> 00:25:36,200 thinking but more seriously if the 508 00:25:40,390 --> 00:25:38,000 extraterrestrials are hiding their 509 00:25:41,850 --> 00:25:40,400 presence isn't that a kind of conspiracy 510 00:25:45,010 --> 00:25:41,860 theory ah 511 00:25:47,980 --> 00:25:45,020 no because I'm not postulating that 512 00:25:49,960 --> 00:25:47,990 there's a human conspiracy that has 513 00:25:51,850 --> 00:25:49,970 somehow managed to infiltrate every 514 00:25:56,080 --> 00:25:51,860 major government on earth while still 515 00:25:57,789 --> 00:25:56,090 hiding itself if they're hiding there 516 00:26:02,950 --> 00:25:57,799 they're way out there where they're hard 517 00:26:03,760 --> 00:26:02,960 to see ok thank you very much York good 518 00:26:07,810 --> 00:26:03,770 presentation 519 00:26:11,460 --> 00:26:07,820 [Applause]