1 00:00:00,280 --> 00:00:04,240 Speaker 1: This is a love letter to humanity. My name is 2 00:00:04,320 --> 00:00:07,720 Speaker 1: Josh Clark, and for the last few years I've been 3 00:00:07,760 --> 00:00:11,520 Speaker 1: thinking a lot about how the world might end, and 4 00:00:11,600 --> 00:00:14,680 Speaker 1: over the course of that time, I've come to seriously 5 00:00:14,760 --> 00:00:18,239 Speaker 1: believe that in a hundred or two years from now, 6 00:00:18,720 --> 00:00:21,720 Speaker 1: there's a really good chance that we humans won't be 7 00:00:21,760 --> 00:00:26,280 Speaker 1: around any longer, that we will have vanished forever from 8 00:00:26,360 --> 00:00:30,440 Speaker 1: the universe, and that it may be us who brings 9 00:00:30,440 --> 00:00:35,440 Speaker 1: about our own demise. This series is about the very 10 00:00:35,560 --> 00:00:39,760 Speaker 1: real ways that that could happen. It's meant to open 11 00:00:39,800 --> 00:00:44,080 Speaker 1: your eyes, hopefully get you to take these ideas seriously too, 12 00:00:44,440 --> 00:00:49,040 Speaker 1: and ideally get you to take action. But just as much, 13 00:00:49,720 --> 00:00:52,440 Speaker 1: I hope by pointing out just how close we are 14 00:00:52,560 --> 00:00:55,520 Speaker 1: to the brink of disaster, you come to feel the 15 00:00:55,520 --> 00:00:59,279 Speaker 1: way that I have about your fellow humans and humanity 16 00:00:59,320 --> 00:01:04,040 Speaker 1: as a whole. That we are flawed and ugly and brutal, 17 00:01:04,560 --> 00:01:07,880 Speaker 1: for sure, but that we are worth fighting to save, 18 00:01:08,640 --> 00:01:12,200 Speaker 1: even from ourselves. That the beauty and the love that 19 00:01:12,319 --> 00:01:16,160 Speaker 1: humans are capable of creating is greater than the worst 20 00:01:16,200 --> 00:01:20,160 Speaker 1: of our faults. That nothing we've done is worth letting 21 00:01:20,200 --> 00:01:25,319 Speaker 1: our entire species come to an untimely, impermanent end. It's 22 00:01:25,360 --> 00:01:28,479 Speaker 1: a bizarre thing to say, but I found it's worth saying. 23 00:01:29,360 --> 00:01:35,720 Speaker 1: Humans don't deserve to go extinct. This series is about 24 00:01:35,920 --> 00:01:39,640 Speaker 1: existential risks. We're not used to this kind of risk, 25 00:01:40,360 --> 00:01:43,400 Speaker 1: nor are we really equipped to deal with them. I'll 26 00:01:43,440 --> 00:01:46,120 Speaker 1: tell you a lot more about them as the series 27 00:01:46,160 --> 00:01:48,920 Speaker 1: goes on, but while you listen, try to keep in 28 00:01:48,960 --> 00:01:54,360 Speaker 1: mind that no horrible catastrophe, no world war, no epidemic 29 00:01:54,520 --> 00:01:58,520 Speaker 1: that's ever come before, nothing we've ever been through has 30 00:01:58,600 --> 00:02:03,280 Speaker 1: prepared us to take on existential risks. We have no 31 00:02:03,440 --> 00:02:06,680 Speaker 1: frame of reference for them, because the destruction they can 32 00:02:06,720 --> 00:02:11,799 Speaker 1: bring is unprecedented in the history of humanity. Yet, and 33 00:02:11,919 --> 00:02:15,000 Speaker 1: what maybe the weirdest turn of events in the history 34 00:02:15,040 --> 00:02:18,800 Speaker 1: of our species, A whole crop of these new existential 35 00:02:18,800 --> 00:02:23,840 Speaker 1: threats are suddenly looming in our near future. Each one 36 00:02:23,960 --> 00:02:27,280 Speaker 1: of them could bring about the sudden and permanent end 37 00:02:27,680 --> 00:02:32,200 Speaker 1: of the human race. This would be a particularly tragic thing. 38 00:02:33,200 --> 00:02:37,160 Speaker 1: We humans have only just begun to live. Human civilization 39 00:02:37,240 --> 00:02:40,600 Speaker 1: has been around for about ten thousand years. Think about 40 00:02:40,600 --> 00:02:44,959 Speaker 1: what we've accomplished in that relatively short time. Now, think 41 00:02:45,000 --> 00:02:47,160 Speaker 1: about what it might be like to be a human 42 00:02:47,200 --> 00:02:50,640 Speaker 1: after civilization has been around for a million years or 43 00:02:50,680 --> 00:02:54,160 Speaker 1: a billion. So not only are the lives of those 44 00:02:54,200 --> 00:02:57,080 Speaker 1: of us around today on the line, but we have 45 00:02:57,120 --> 00:02:59,799 Speaker 1: to remember the lives of all the humans to come 46 00:03:00,120 --> 00:03:04,080 Speaker 1: are as well, and the stakes for us avoiding extinction 47 00:03:04,160 --> 00:03:06,639 Speaker 1: in the next century might be even higher than that. 48 00:03:07,440 --> 00:03:10,200 Speaker 1: As we'll see in this episode, we humans may be 49 00:03:10,360 --> 00:03:15,240 Speaker 1: the only intelligent life in the entire universe. If we die, 50 00:03:15,760 --> 00:03:18,440 Speaker 1: so too does all the things that make us human, 51 00:03:18,880 --> 00:03:21,960 Speaker 1: All of the love and compassion, all of the inventiveness 52 00:03:21,960 --> 00:03:25,080 Speaker 1: and curiosity, all of it perishes with us, not just 53 00:03:25,200 --> 00:03:27,920 Speaker 1: here on Earth, but in the universe as a whole. 54 00:03:29,360 --> 00:03:33,440 Speaker 1: It's staggering to think, but the responsibility for our own lives, 55 00:03:33,960 --> 00:03:37,080 Speaker 1: for the future of the human race, and for intelligent 56 00:03:37,120 --> 00:03:41,280 Speaker 1: life in the universe appears to suddenly rest solely in 57 00:03:41,360 --> 00:03:45,520 Speaker 1: the hands of those of us alive today. It would 58 00:03:45,520 --> 00:03:47,920 Speaker 1: probably be good to know if we're alone or not, 59 00:03:48,280 --> 00:03:50,080 Speaker 1: just for the sake of knowing what's on the line 60 00:03:50,080 --> 00:03:54,880 Speaker 1: if we go extinct, So let's start there. As it 61 00:03:54,920 --> 00:03:58,720 Speaker 1: turns out, you should know an alien by now, so 62 00:03:58,800 --> 00:04:02,840 Speaker 1: should I. By this point in human history, everyone you 63 00:04:02,880 --> 00:04:05,880 Speaker 1: and I know should know an alien. We should know 64 00:04:05,960 --> 00:04:09,160 Speaker 1: them from work, from your kids school. They should be 65 00:04:09,200 --> 00:04:12,400 Speaker 1: our neighbors. Earth should be a melting pot of not 66 00:04:12,520 --> 00:04:17,719 Speaker 1: just human cultures, but extraterrestrial ones too. At the very least, 67 00:04:17,880 --> 00:04:20,240 Speaker 1: we should be certain by now that there are aliens 68 00:04:20,240 --> 00:04:22,880 Speaker 1: out there, just as sure as we know that there 69 00:04:22,880 --> 00:04:25,479 Speaker 1: are people living in France and Denmark. We should know 70 00:04:25,520 --> 00:04:29,000 Speaker 1: that there are aliens on proximous Centauri B or trappist 71 00:04:29,000 --> 00:04:33,359 Speaker 1: One F. And yet we don't, and you and I 72 00:04:33,400 --> 00:04:37,760 Speaker 1: don't know any aliens, which is actually very, very weird. 73 00:04:39,279 --> 00:04:41,800 Speaker 1: The reason why it's weird is that the universe we 74 00:04:41,880 --> 00:04:45,600 Speaker 1: live in is extremely old. It's nearly thirteen and a 75 00:04:45,600 --> 00:04:49,080 Speaker 1: half billion years old, and our galaxy, the Milky Way, 76 00:04:49,200 --> 00:04:53,719 Speaker 1: is extremely vast from the perspective of us humans. It 77 00:04:53,800 --> 00:04:55,960 Speaker 1: takes a beam of light a hundred thousand years to 78 00:04:56,000 --> 00:04:59,880 Speaker 1: cross it. And within our very old and very immense galaxy, 79 00:05:00,320 --> 00:05:03,800 Speaker 1: there are a lot of stars, between two hundred to 80 00:05:03,960 --> 00:05:09,720 Speaker 1: three hundred billion of them three hundred thousand million stars. 81 00:05:10,680 --> 00:05:13,240 Speaker 1: Working from the premise that our own stars, light and 82 00:05:13,320 --> 00:05:16,479 Speaker 1: heat helped raise life here on Earth, one would think 83 00:05:16,520 --> 00:05:20,800 Speaker 1: that somewhere among those three hundred thousand million stars out there, 84 00:05:20,839 --> 00:05:24,880 Speaker 1: the same thing would have happened. It happened again and again. 85 00:05:25,360 --> 00:05:28,320 Speaker 1: By all rights, even with just a slight fraction of 86 00:05:28,320 --> 00:05:31,360 Speaker 1: those stars growing life on a planet in orbit around it, 87 00:05:31,839 --> 00:05:35,120 Speaker 1: our galaxy should be teeming with life like mold on 88 00:05:35,160 --> 00:05:38,440 Speaker 1: a slice of bread. There's certainly been plenty of time 89 00:05:38,480 --> 00:05:41,520 Speaker 1: for it to happen. Here on Earth, life arose within 90 00:05:41,560 --> 00:05:44,280 Speaker 1: the last three and a half billion years and managed 91 00:05:44,320 --> 00:05:48,640 Speaker 1: to evolve from little strands of proteins into us, sentient 92 00:05:48,760 --> 00:05:51,120 Speaker 1: human beings who have come to wonder if the same 93 00:05:51,160 --> 00:05:55,039 Speaker 1: thing has happened elsewhere too. Since the galaxy is nearly 94 00:05:55,080 --> 00:05:57,480 Speaker 1: four times older than the time it took for intelligent 95 00:05:57,560 --> 00:06:00,400 Speaker 1: life to emerge here on Earth, it's had ample time 96 00:06:00,440 --> 00:06:03,600 Speaker 1: to emerge elsewhere in our galaxy too. So what we've 97 00:06:03,640 --> 00:06:06,440 Speaker 1: got is something of a mystery on our hands. The 98 00:06:06,560 --> 00:06:10,080 Speaker 1: universe is by far old enough and definitely large enough 99 00:06:10,560 --> 00:06:14,280 Speaker 1: to have produced intelligent life over and over and over again, 100 00:06:14,760 --> 00:06:18,880 Speaker 1: and yet we have not one iota of evidence that 101 00:06:19,000 --> 00:06:22,040 Speaker 1: we are anything but utterly alone in the Milky Way. 102 00:06:23,080 --> 00:06:26,080 Speaker 1: It's become increasingly clear that when we look out at 103 00:06:26,080 --> 00:06:31,320 Speaker 1: the night sky, there's nothing looking back at us. This 104 00:06:31,440 --> 00:06:33,640 Speaker 1: is the basis of what's come to be called the 105 00:06:33,680 --> 00:06:37,719 Speaker 1: Fermi paradox, and it begins, like so many great strange things. 106 00:06:38,040 --> 00:06:47,839 Speaker 1: Over lunch in the summer of nineteen fifty four physicists 107 00:06:47,920 --> 00:06:50,880 Speaker 1: ambled over to the Fuller Lodge, an old two story 108 00:06:50,960 --> 00:06:53,960 Speaker 1: boarding house made of human logs with a big, hulking 109 00:06:54,080 --> 00:06:57,760 Speaker 1: stackstone fireplace that you could practically stand up in. The 110 00:06:57,839 --> 00:07:00,560 Speaker 1: Fuller Lodge had been converted into a mess all for 111 00:07:00,600 --> 00:07:03,520 Speaker 1: the people working on the Manhattan Project at Los Alamos, 112 00:07:03,640 --> 00:07:07,680 Speaker 1: New Mexico. Taking a break from refining the most destructive 113 00:07:07,720 --> 00:07:10,160 Speaker 1: weapon the world has ever known into an even more 114 00:07:10,240 --> 00:07:14,080 Speaker 1: destructive one, these four physicists got into chatting about the 115 00:07:14,200 --> 00:07:18,400 Speaker 1: UFO fever that had recently gripped America. They dismissed the 116 00:07:18,440 --> 00:07:21,640 Speaker 1: idea that reports of UFOs were in fact alien in origin, 117 00:07:22,040 --> 00:07:25,160 Speaker 1: but they didn't dismiss the idea that it was possible 118 00:07:25,200 --> 00:07:28,440 Speaker 1: life could exist elsewhere in the universe. It was likely 119 00:07:28,520 --> 00:07:32,400 Speaker 1: that it did, they concluded. After the group had already 120 00:07:32,400 --> 00:07:35,280 Speaker 1: moved on to other topics, one of them, Enrico Fermi, 121 00:07:35,640 --> 00:07:39,880 Speaker 1: abruptly returned the conversation back to aliens. Where is everybody? 122 00:07:39,960 --> 00:07:42,800 Speaker 1: He asked, or perhaps, but have you ever wondered where 123 00:07:42,800 --> 00:07:46,960 Speaker 1: everybody is. The precise words were lost over time, but 124 00:07:47,080 --> 00:07:50,040 Speaker 1: Fermie's three lunch companions all recalled that they knew just 125 00:07:50,120 --> 00:07:53,360 Speaker 1: what he meant, and they grasped the implications as well. 126 00:07:53,880 --> 00:07:57,000 Speaker 1: There should be life all over our galaxy, and yet 127 00:07:57,000 --> 00:08:01,680 Speaker 1: there appears to be only us. Fairmi never formally explored 128 00:08:01,720 --> 00:08:04,280 Speaker 1: his question, but it's understandable why it came to be 129 00:08:04,360 --> 00:08:08,360 Speaker 1: named after him. As physicists go, Faremi was no slouch. 130 00:08:08,960 --> 00:08:12,520 Speaker 1: He presided over the first controlled nuclear reaction created in 131 00:08:12,560 --> 00:08:15,880 Speaker 1: a uranium pile of his design, constructed on a squash 132 00:08:15,920 --> 00:08:18,840 Speaker 1: court beneath the football field at the University of Chicago. 133 00:08:19,560 --> 00:08:22,400 Speaker 1: He calculated formula that helped answer the shape of matter 134 00:08:22,440 --> 00:08:25,200 Speaker 1: on the quantum level, and a family of quantum particles 135 00:08:25,200 --> 00:08:28,800 Speaker 1: are named after him Fairmians, and of course he helped 136 00:08:28,800 --> 00:08:32,560 Speaker 1: build the bomb. But more than Fairmi, it was an 137 00:08:32,559 --> 00:08:36,120 Speaker 1: American astronomer named Michael Hart who was really responsible for 138 00:08:36,160 --> 00:08:40,080 Speaker 1: the Fermi paradox. In the mid seventies, Heart wrote a 139 00:08:40,080 --> 00:08:44,439 Speaker 1: paper called the Explanation for the Absence of Extraterrestrials on Earth. 140 00:08:45,240 --> 00:08:48,840 Speaker 1: He summarized and organized the arguments against the paradox, which 141 00:08:48,880 --> 00:08:51,280 Speaker 1: come in a rainbow of colors with only a couple 142 00:08:51,280 --> 00:08:56,040 Speaker 1: of shapes, and Heart ultimately concluded this because life should 143 00:08:56,080 --> 00:08:59,040 Speaker 1: reasonably have emerged and be known to us by now. 144 00:08:59,559 --> 00:09:03,120 Speaker 1: The fact that it hasn't solves the family paradox. The 145 00:09:03,160 --> 00:09:09,120 Speaker 1: answer is that we are alone. Mystery solved. Michael Heart's 146 00:09:09,120 --> 00:09:11,680 Speaker 1: paper struck a blow in particular to the group most 147 00:09:11,720 --> 00:09:17,760 Speaker 1: diametrically opposed to his conclusions. City researchers set the search 148 00:09:17,840 --> 00:09:23,160 Speaker 1: for extraterrestrial intelligence is an offshoot of astronomy and astrobiology, 149 00:09:23,200 --> 00:09:26,640 Speaker 1: and back in the early sixties, astrobiology hit the scientific 150 00:09:26,679 --> 00:09:29,800 Speaker 1: scene like a bomb. It was an exciting new discipline 151 00:09:29,840 --> 00:09:33,760 Speaker 1: that treated the possibility of extraterrestrial life is real. In 152 00:09:33,840 --> 00:09:36,720 Speaker 1: sharp contrast to the people who agreed with Heart, the 153 00:09:36,800 --> 00:09:40,880 Speaker 1: astrobiologist camp was populated by optimists who reasoned that it 154 00:09:40,920 --> 00:09:44,120 Speaker 1: is simply too unlikely for life to evolved only once 155 00:09:44,200 --> 00:09:47,680 Speaker 1: throughout the entire universe. We just needed to hone the 156 00:09:47,720 --> 00:09:51,200 Speaker 1: way we search for aliens, and we would surely find them. 157 00:09:51,440 --> 00:09:55,240 Speaker 1: Cd He evolved is the intelligence gathering arm of astrobiology, 158 00:09:55,400 --> 00:09:58,840 Speaker 1: and set about listening for alien transmissions by aiming radio 159 00:09:58,880 --> 00:10:01,640 Speaker 1: telescopes at the center of galaxies that seemed likely to 160 00:10:01,679 --> 00:10:06,320 Speaker 1: host life. By the time Michael Hart published his paper 161 00:10:06,840 --> 00:10:09,760 Speaker 1: said he hadn't found anything, and Hart included in his 162 00:10:09,880 --> 00:10:12,480 Speaker 1: article that said he was an utter waste of time 163 00:10:12,520 --> 00:10:16,240 Speaker 1: and resources. By that time, many others, including some in 164 00:10:16,280 --> 00:10:19,880 Speaker 1: Congress who funded things like st tended to agree that 165 00:10:20,000 --> 00:10:25,319 Speaker 1: there is little justification for twelve million dollars taxpayer dollars 166 00:10:25,360 --> 00:10:28,760 Speaker 1: to be expended for this program. Madam President, I urge 167 00:10:28,800 --> 00:10:31,960 Speaker 1: my colleagues to vote in favor of this amendment, and 168 00:10:32,080 --> 00:10:35,320 Speaker 1: I reserve the balance of my time and yield the floor, 169 00:10:35,559 --> 00:10:38,520 Speaker 1: and I thank the chair. Yet neither hearts paper nor 170 00:10:38,640 --> 00:10:41,680 Speaker 1: sti's empty handed searches have settled the mystery of the 171 00:10:41,720 --> 00:10:46,080 Speaker 1: family paradox. Because we've gotten better at observing our universe, 172 00:10:46,520 --> 00:10:50,320 Speaker 1: this little mystery has only gotten more weird. Thanks to 173 00:10:50,360 --> 00:10:53,800 Speaker 1: space based telescopes like the Kepler and new methods we've 174 00:10:53,800 --> 00:10:56,840 Speaker 1: developed for watching stars, we found that there are a 175 00:10:56,960 --> 00:11:01,800 Speaker 1: mind boggling number of potential earthlike planetile there. To qualify 176 00:11:01,840 --> 00:11:04,319 Speaker 1: as a potential host for life, the planet has to 177 00:11:04,400 --> 00:11:07,360 Speaker 1: check some boxes. The star that it orbits has to 178 00:11:07,400 --> 00:11:09,680 Speaker 1: be of a certain type, and in what's called its 179 00:11:09,720 --> 00:11:12,720 Speaker 1: main sequence, it helps to be around the size of 180 00:11:12,720 --> 00:11:15,080 Speaker 1: our Sun, which is right in the middle. Size Wise, 181 00:11:15,720 --> 00:11:18,360 Speaker 1: big stars go through their fuel too quickly to give 182 00:11:18,400 --> 00:11:21,640 Speaker 1: life a reasonable amount of time to emerge. On the 183 00:11:21,679 --> 00:11:25,800 Speaker 1: other end, smaller stars don't burn quite warmly enough. The 184 00:11:25,880 --> 00:11:28,280 Speaker 1: planet has to be a particular distance from the star. 185 00:11:28,360 --> 00:11:31,040 Speaker 1: Too too close and any life would be burned to 186 00:11:31,080 --> 00:11:34,280 Speaker 1: a crisp Too far away, and the star's warmth couldn't 187 00:11:34,280 --> 00:11:38,440 Speaker 1: overcome the unbearable cold of outer space. Either way, the 188 00:11:38,520 --> 00:11:41,800 Speaker 1: conditions wouldn't allow for water to form or an atmosphere, 189 00:11:42,200 --> 00:11:45,120 Speaker 1: both of which we assume are requirements for life to emerge. 190 00:11:46,000 --> 00:11:48,080 Speaker 1: The planet needs to be in a spot relative to 191 00:11:48,120 --> 00:11:50,760 Speaker 1: the Sun that's not too hot and not too cold, 192 00:11:51,120 --> 00:11:54,080 Speaker 1: but just right for life. So it may not come 193 00:11:54,120 --> 00:11:56,600 Speaker 1: as much of a surprise that some astronomers call this 194 00:11:56,760 --> 00:12:00,600 Speaker 1: area the Goldilocks zone. Taking all of this in to account, 195 00:12:01,200 --> 00:12:05,360 Speaker 1: there are perhaps tens of billions of potentially habitable planets 196 00:12:05,640 --> 00:12:09,439 Speaker 1: in the Milky Way alone, and it gets even weirder. 197 00:12:10,240 --> 00:12:13,080 Speaker 1: Throughout the decades that people have attempted to resolve the 198 00:12:13,080 --> 00:12:17,800 Speaker 1: family paradox, those attempts have always been focused on our galaxy, specifically, 199 00:12:18,280 --> 00:12:20,360 Speaker 1: the rest of the universe is just too big to 200 00:12:20,440 --> 00:12:23,240 Speaker 1: allow for the time it would take for another civilization 201 00:12:23,480 --> 00:12:25,600 Speaker 1: to travel to the Milky Way and make its presence 202 00:12:25,640 --> 00:12:28,559 Speaker 1: known to us. So by leaving out the other hundred 203 00:12:28,600 --> 00:12:32,959 Speaker 1: billion galaxies in the universe and there's seventy billion trillion stars, 204 00:12:33,440 --> 00:12:36,440 Speaker 1: the idea that perhaps other life might exist outside our 205 00:12:36,480 --> 00:12:39,480 Speaker 1: own galaxy was allowed to stay aglow as a faint 206 00:12:39,520 --> 00:12:43,200 Speaker 1: member of possibility, But in two thousand thirteen that ember 207 00:12:43,280 --> 00:12:47,120 Speaker 1: was snuffed too. A pair of philosophers from Oxford figured 208 00:12:47,120 --> 00:12:49,160 Speaker 1: out that the math shows there has been plenty of 209 00:12:49,200 --> 00:12:53,040 Speaker 1: time for intergalactic civilizations to have evolved and traveled to 210 00:12:53,080 --> 00:12:57,559 Speaker 1: our galaxy too. This is one of those Oxford philosophers 211 00:12:57,720 --> 00:13:01,640 Speaker 1: under Samberg, actually suppose you wanted to go out and 212 00:13:01,760 --> 00:13:04,800 Speaker 1: colonized as far as you could, how far could you go? 213 00:13:05,520 --> 00:13:08,480 Speaker 1: And we found that you can literally do this over 214 00:13:08,600 --> 00:13:12,880 Speaker 1: billions of light years, which means that this is also 215 00:13:12,920 --> 00:13:15,960 Speaker 1: something aliens could have done. So if it's a bit 216 00:13:16,280 --> 00:13:19,200 Speaker 1: weird that we haven't noticed in the alien spreading across 217 00:13:19,240 --> 00:13:22,000 Speaker 1: the Milky Way, now we need to take into account. 218 00:13:22,040 --> 00:13:25,720 Speaker 1: But actually there are also millions or billions of galaxies 219 00:13:25,800 --> 00:13:28,640 Speaker 1: where aliens could have come from but they haven't shown 220 00:13:28,679 --> 00:13:31,880 Speaker 1: up yet. So when we finished that paper, we kind 221 00:13:31,880 --> 00:13:34,200 Speaker 1: of pointed out that we made the Fermi paradox a 222 00:13:34,200 --> 00:13:38,800 Speaker 1: million or a billion times worse. The Family paradox extends 223 00:13:38,840 --> 00:13:41,760 Speaker 1: not only to our galaxy, but it seems to the 224 00:13:42,000 --> 00:13:59,079 Speaker 1: entire visible universe. Hm to a lot of people who 225 00:13:59,120 --> 00:14:02,560 Speaker 1: think about this kind thing, it's simply too outlandish to 226 00:14:02,640 --> 00:14:04,840 Speaker 1: believe that we are the only intelligent life in the 227 00:14:05,000 --> 00:14:08,720 Speaker 1: entire universe, and so over the years, people have put 228 00:14:08,760 --> 00:14:12,080 Speaker 1: forth some interesting answers to the family paradox on the 229 00:14:12,080 --> 00:14:15,280 Speaker 1: basis that there is intelligent life out there, we just 230 00:14:15,320 --> 00:14:19,200 Speaker 1: don't know it yet. At the most basic level, the 231 00:14:19,280 --> 00:14:22,760 Speaker 1: arguments consists of the notions that aliens either can't or 232 00:14:22,880 --> 00:14:26,560 Speaker 1: won't make the trip to see us. Aliens have had 233 00:14:26,560 --> 00:14:29,480 Speaker 1: plenty of time to colonize the galaxy and even the universe, 234 00:14:29,520 --> 00:14:32,360 Speaker 1: as we've seen, even considering travel at less than the 235 00:14:32,400 --> 00:14:35,480 Speaker 1: speed of light, even travel at ten percent the speed 236 00:14:35,560 --> 00:14:37,440 Speaker 1: of light shall allow for the Milky Way to be 237 00:14:37,480 --> 00:14:41,400 Speaker 1: colonized in fifty million years at the most. But even 238 00:14:41,480 --> 00:14:44,200 Speaker 1: allowing for plenty of time to make the trip, it's 239 00:14:44,360 --> 00:14:47,880 Speaker 1: entirely possible that the trips between stars and galaxies is 240 00:14:47,920 --> 00:14:52,680 Speaker 1: extremely difficult, so difficult in fact, that no intelligent civilization 241 00:14:52,960 --> 00:14:56,480 Speaker 1: has ever successfully managed it, although plenty may have tried 242 00:14:56,520 --> 00:14:58,840 Speaker 1: and lost a lot of their people to be impossibly 243 00:14:58,840 --> 00:15:03,600 Speaker 1: hazardous trips before finally giving up. Space is far from empty. 244 00:15:04,040 --> 00:15:07,600 Speaker 1: It's full of tiny particles called cosmic dust, raw material 245 00:15:07,680 --> 00:15:10,800 Speaker 1: that planets are made from. There's a dust cycle out 246 00:15:10,800 --> 00:15:14,560 Speaker 1: in space where dust is blasted into space by exploding stars. 247 00:15:15,120 --> 00:15:18,200 Speaker 1: This dust fills space, and even though it consists of 248 00:15:18,240 --> 00:15:21,520 Speaker 1: extremely tiny particles, it would pose a hazard to any 249 00:15:21,560 --> 00:15:25,080 Speaker 1: spacecraft traveling at some significant fraction of the speed of light, 250 00:15:25,480 --> 00:15:28,480 Speaker 1: which again, remember something like six hundred and fifty million 251 00:15:28,560 --> 00:15:31,720 Speaker 1: miles an hour. Even a tenth of that is still 252 00:15:31,760 --> 00:15:35,320 Speaker 1: sixty five million miles per hour. At these speeds, the 253 00:15:35,360 --> 00:15:39,600 Speaker 1: spacecraft kinetic energy is so unimaginably huge that a collision 254 00:15:39,640 --> 00:15:42,600 Speaker 1: with even some tiny piece of matter would be catastrophic. 255 00:15:43,640 --> 00:15:47,080 Speaker 1: MT physicists calculated that impacting even a single grain of 256 00:15:47,120 --> 00:15:50,440 Speaker 1: cosmic dust would be tantamount to the explosion of something 257 00:15:50,480 --> 00:15:53,360 Speaker 1: like two and a half tons tons of T and 258 00:15:53,480 --> 00:15:58,720 Speaker 1: T aboard the ship, and cosmic dust is just one 259 00:15:58,800 --> 00:16:02,000 Speaker 1: hazard that space bearing species would have to overcome. There 260 00:16:02,000 --> 00:16:04,640 Speaker 1: are surely plenty of others that we haven't learned of yet. 261 00:16:05,640 --> 00:16:07,960 Speaker 1: This argument has a flaw to it, though, and I 262 00:16:07,960 --> 00:16:10,320 Speaker 1: want you to pay attention to it, because it's part 263 00:16:10,320 --> 00:16:13,000 Speaker 1: of a theme that really all arguments regarding the Family 264 00:16:13,000 --> 00:16:17,360 Speaker 1: paradox share. If the reason aliens haven't colonized the universe 265 00:16:17,800 --> 00:16:21,440 Speaker 1: is because it's extremely hard to travel between stars and galaxies, 266 00:16:21,960 --> 00:16:24,760 Speaker 1: that means that it is so hard that not one 267 00:16:24,880 --> 00:16:28,800 Speaker 1: single intelligent civilization managed to figure out a way around it, 268 00:16:29,400 --> 00:16:32,760 Speaker 1: not one out of the potentially millions or billions or 269 00:16:32,760 --> 00:16:35,560 Speaker 1: even trillions that may have evolved over the life of 270 00:16:35,600 --> 00:16:40,440 Speaker 1: the universe. This is important because to resolve the Family paradox, 271 00:16:40,680 --> 00:16:42,840 Speaker 1: it would take just one of them to have learned 272 00:16:42,840 --> 00:16:45,520 Speaker 1: how to survive the trip, to colonize the galaxy and 273 00:16:45,600 --> 00:16:48,200 Speaker 1: show us that we are not alone. And you can 274 00:16:48,280 --> 00:16:51,120 Speaker 1: argue that it would really only take one, one single 275 00:16:51,200 --> 00:16:55,080 Speaker 1: member of one single civilization of the potentially trillions of 276 00:16:55,120 --> 00:16:57,800 Speaker 1: them to make it to Earth and make their presence 277 00:16:57,840 --> 00:17:00,280 Speaker 1: known to us to have proof that we are the 278 00:17:00,280 --> 00:17:03,480 Speaker 1: only intelligent life in the universe, which makes the Fermi 279 00:17:03,600 --> 00:17:08,120 Speaker 1: paradox even stranger or more clearly settled, depending on your view. 280 00:17:09,720 --> 00:17:12,400 Speaker 1: The other side of that particular coin holds that other 281 00:17:12,480 --> 00:17:16,840 Speaker 1: civilizations could colonize the galaxy or even the universe, they 282 00:17:16,960 --> 00:17:19,879 Speaker 1: just don't want to. There are a lot of theories 283 00:17:19,920 --> 00:17:22,880 Speaker 1: as to why that might be. Now it's possible we're 284 00:17:22,920 --> 00:17:27,679 Speaker 1: anthropomorphizing aliens here. We humans will almost certainly colonize the 285 00:17:27,680 --> 00:17:30,639 Speaker 1: galaxy if we ever get the chance to. So, perhaps 286 00:17:30,720 --> 00:17:33,800 Speaker 1: we're relying too heavily on the assumption that any life would. 287 00:17:34,880 --> 00:17:38,040 Speaker 1: This is the senior astronomer at the Study Institute set 288 00:17:38,160 --> 00:17:43,360 Speaker 1: show Stack. All of this, all of this is based 289 00:17:43,520 --> 00:17:48,040 Speaker 1: on trying to guess, because that's really the correct verb, 290 00:17:48,400 --> 00:17:52,399 Speaker 1: to guess what is important to the extraterrestrials. And I 291 00:17:52,440 --> 00:17:55,640 Speaker 1: don't think that we're actually very good at that any 292 00:17:55,720 --> 00:17:58,800 Speaker 1: anymore than you know, the ancient Greeks would have been 293 00:17:58,880 --> 00:18:02,720 Speaker 1: very good at guessing it's important to century Americans. I 294 00:18:02,720 --> 00:18:05,760 Speaker 1: don't think that they could have seen foreseen the kinds 295 00:18:05,760 --> 00:18:08,680 Speaker 1: of things that would be important to us. Perhaps the 296 00:18:08,800 --> 00:18:12,280 Speaker 1: civilization develops to the point where it's technologically capable of 297 00:18:12,320 --> 00:18:16,720 Speaker 1: interstellar and intergalactic travel, it loses its taste for such things. 298 00:18:17,400 --> 00:18:21,919 Speaker 1: Perhaps the civilization goes philosophical and contemplative a race of 299 00:18:21,960 --> 00:18:24,560 Speaker 1: beings who prefer to spend their time thinking about the 300 00:18:24,600 --> 00:18:27,439 Speaker 1: meaning of life. You're solving the deepest mysteries of the 301 00:18:27,600 --> 00:18:32,440 Speaker 1: universe from home. But even the most inward focused society 302 00:18:32,600 --> 00:18:35,200 Speaker 1: would have good reason for expanding from their home planet. 303 00:18:35,960 --> 00:18:38,760 Speaker 1: As their population grew, they would need more and more 304 00:18:38,920 --> 00:18:42,119 Speaker 1: raw materials to keep them alive while they sat around 305 00:18:42,160 --> 00:18:46,879 Speaker 1: in contemplated life. It would be more space, more energy. 306 00:18:47,240 --> 00:18:49,679 Speaker 1: The need for scarce resources appears to be one of 307 00:18:49,720 --> 00:18:53,159 Speaker 1: the few universal commonalities that any civilization will have to 308 00:18:53,200 --> 00:18:56,080 Speaker 1: deal with. This is good. This means that we can 309 00:18:56,160 --> 00:18:59,320 Speaker 1: pretty confidently use this clue to predict the behavior of 310 00:18:59,359 --> 00:19:03,840 Speaker 1: any intelligen life. Then we humans run into limitations on 311 00:19:03,880 --> 00:19:06,680 Speaker 1: our ability to grow or make food, so we need 312 00:19:06,720 --> 00:19:09,480 Speaker 1: more space for that. We need space for our bodies 313 00:19:09,520 --> 00:19:12,760 Speaker 1: as well, since each person needs somewhere around one point 314 00:19:12,800 --> 00:19:16,359 Speaker 1: six one point seven meters of physical space to stand 315 00:19:16,440 --> 00:19:19,359 Speaker 1: up and extend our arms with him, plus we tend 316 00:19:19,359 --> 00:19:23,280 Speaker 1: to like a little extra to move around into. Requirements 317 00:19:23,320 --> 00:19:25,879 Speaker 1: like these mean we would eventually face the prospect of 318 00:19:25,880 --> 00:19:30,000 Speaker 1: either systematically curtailing our population growth to maintain no more 319 00:19:30,080 --> 00:19:33,160 Speaker 1: than what the Earth can support and based on all 320 00:19:33,200 --> 00:19:36,439 Speaker 1: current and historical data, we tend to overstrain the planet 321 00:19:36,520 --> 00:19:40,560 Speaker 1: rather than work within its confines, or we can spread out. 322 00:19:41,560 --> 00:19:44,600 Speaker 1: It's difficult to imagine that any advanced society faced with 323 00:19:44,640 --> 00:19:47,320 Speaker 1: resource pressures would not look out to at least their 324 00:19:47,320 --> 00:19:50,520 Speaker 1: own solar system as a source of material solutions to 325 00:19:50,560 --> 00:19:55,600 Speaker 1: their problems. This scenario extends further and further, both into 326 00:19:55,640 --> 00:19:59,719 Speaker 1: space and time. As the society continued to grow, they 327 00:19:59,720 --> 00:20:02,359 Speaker 1: would take up more and more space, and over long 328 00:20:02,480 --> 00:20:05,359 Speaker 1: enough spans of time, they should reasonably have colonized a 329 00:20:05,440 --> 00:20:08,080 Speaker 1: sizeable chunk of their galaxy, if not the whole thing, 330 00:20:08,600 --> 00:20:12,360 Speaker 1: even with their desire to remain inward over so many generations. 331 00:20:13,760 --> 00:20:16,359 Speaker 1: But maybe aliens have good reason to resist the urge 332 00:20:16,440 --> 00:20:21,000 Speaker 1: to spread out. Maybe they're hiding from something, Maybe they 333 00:20:21,000 --> 00:20:44,800 Speaker 1: know something that we don't know. One of the long 334 00:20:44,840 --> 00:20:48,600 Speaker 1: standing theories about why a civilization with the capability of 335 00:20:48,640 --> 00:20:51,320 Speaker 1: traveling to other stars would opt not to is the 336 00:20:51,359 --> 00:20:54,440 Speaker 1: idea that they might be afraid of something. Perhaps there's 337 00:20:54,520 --> 00:20:57,840 Speaker 1: some older civilization that doesn't like to compete for scarce 338 00:20:57,880 --> 00:21:02,560 Speaker 1: resources with young upstarts like ourselves, the first civilization to 339 00:21:02,640 --> 00:21:05,640 Speaker 1: have colonized the galaxy would have all the advantage over 340 00:21:05,680 --> 00:21:09,320 Speaker 1: any others that came later, even considering a hundred thousand 341 00:21:09,400 --> 00:21:12,560 Speaker 1: year head start, which though it's tough to remember that 342 00:21:12,680 --> 00:21:15,359 Speaker 1: the cosmic time scales we're dealing with here is the 343 00:21:15,400 --> 00:21:18,680 Speaker 1: blink of an eye, and earlier civilization would have time 344 00:21:18,720 --> 00:21:22,440 Speaker 1: to see the galaxy with things like berserker probes, hypothetical 345 00:21:22,480 --> 00:21:26,080 Speaker 1: type of self replicating space probe designed to attack and 346 00:21:26,200 --> 00:21:31,479 Speaker 1: destroy entire civilizations. These berserker probes would be capable of 347 00:21:31,520 --> 00:21:35,159 Speaker 1: strangling in the cradle the colonial aspirations of any younger 348 00:21:35,200 --> 00:21:39,159 Speaker 1: civilizations before they ever got started. Right about where we 349 00:21:39,320 --> 00:21:43,320 Speaker 1: humans are in our progress right now. What's ironic about 350 00:21:43,320 --> 00:21:46,360 Speaker 1: berserker probes is that they can produce their own solution 351 00:21:46,400 --> 00:21:50,480 Speaker 1: to the family paradox without even existing. We humans thought 352 00:21:50,520 --> 00:21:53,639 Speaker 1: of the possibility that they could exist, so it stands 353 00:21:53,680 --> 00:21:58,080 Speaker 1: to reason that other intelligent civilizations might too. It's possible 354 00:21:58,480 --> 00:22:00,920 Speaker 1: that part of the process of the umbing and intelligent 355 00:22:01,000 --> 00:22:04,320 Speaker 1: society engaged with the unknowns of the universe is to 356 00:22:04,359 --> 00:22:08,119 Speaker 1: start having second thoughts about signaling into the void and 357 00:22:08,200 --> 00:22:12,480 Speaker 1: instead to go silent. Eventually, every single one of these 358 00:22:12,480 --> 00:22:16,600 Speaker 1: societies might stop attempting to communicate and resigned to just 359 00:22:16,640 --> 00:22:20,800 Speaker 1: sitting and listening instead. So the universe could be teeming 360 00:22:20,920 --> 00:22:25,160 Speaker 1: with intelligent civilizations, each being quiet as a dormouse, each 361 00:22:25,240 --> 00:22:29,000 Speaker 1: listening and unaware of the existence of the others, and 362 00:22:29,000 --> 00:22:31,879 Speaker 1: the berserker probes wouldn't even have to exist beyond the 363 00:22:31,960 --> 00:22:35,359 Speaker 1: hypothetical for this solution to the family paradox to work. 364 00:22:36,359 --> 00:22:39,240 Speaker 1: But if berserker probes do exist, why wouldn't we have 365 00:22:39,320 --> 00:22:42,919 Speaker 1: had an unpleasant visit from them by now? Transmissions from 366 00:22:42,960 --> 00:22:45,480 Speaker 1: our radio and TV shows have been traveling through space 367 00:22:45,480 --> 00:22:47,879 Speaker 1: since we first started broadcasting here on Earth in the 368 00:22:47,920 --> 00:22:52,200 Speaker 1: early twentieth century, and steady researchers have been actively shouting 369 00:22:52,240 --> 00:22:56,520 Speaker 1: at other star systems with radio since the sixties. Probably 370 00:22:56,560 --> 00:22:59,720 Speaker 1: the most unsettling answer is that we did get their attention, 371 00:23:00,040 --> 00:23:02,400 Speaker 1: and they're on their way. They just haven't had time 372 00:23:02,440 --> 00:23:07,040 Speaker 1: to reach us yet, or perhaps they don't much care 373 00:23:07,080 --> 00:23:09,840 Speaker 1: about us so long as we stay here on Earth 374 00:23:10,280 --> 00:23:13,960 Speaker 1: or even within our own galaxy. In two thousand and seventeen, 375 00:23:14,000 --> 00:23:18,960 Speaker 1: Oxford philosophers Stuart Armstrong, Ander Samburg, and Milan Turkovich developed 376 00:23:18,960 --> 00:23:22,080 Speaker 1: a new explanation for the Fami paradox that says that 377 00:23:22,160 --> 00:23:25,679 Speaker 1: perhaps the universe does contain berserker probes, but rather than 378 00:23:25,760 --> 00:23:29,199 Speaker 1: actively patrolling the galaxy, they are posted on the outskirts 379 00:23:29,240 --> 00:23:33,880 Speaker 1: of some ancient civilizations state territory while the civilization sleeps. 380 00:23:35,240 --> 00:23:39,159 Speaker 1: This new idea, called the estivation hypothesis, supposes that the 381 00:23:39,200 --> 00:23:44,160 Speaker 1: civilization in question has reached a post biological state. Post 382 00:23:44,200 --> 00:23:48,000 Speaker 1: biological civilizations are their own can of worms entirely, and 383 00:23:48,040 --> 00:23:50,520 Speaker 1: we'll talk about them more later on. But what they 384 00:23:50,560 --> 00:23:54,480 Speaker 1: amount to is a species that has shed its biological form, 385 00:23:54,520 --> 00:23:57,600 Speaker 1: whether it's an upright bipedal form like us humans, a 386 00:23:57,720 --> 00:24:02,040 Speaker 1: giant root, vegetable, whatever, and has preserved its minds into 387 00:24:02,040 --> 00:24:06,680 Speaker 1: a computerized form. There are myriad advantages to this. Less 388 00:24:06,680 --> 00:24:09,359 Speaker 1: physical space is needed, you don't need to grow food. 389 00:24:09,800 --> 00:24:13,800 Speaker 1: But these civilizations are not free from scarcity either. Here's 390 00:24:13,840 --> 00:24:19,120 Speaker 1: philosopher Ander Samberg again. So suppose you're a really advanced civilization. 391 00:24:19,160 --> 00:24:21,400 Speaker 1: You've been around for millions of years, you kind of 392 00:24:21,440 --> 00:24:25,000 Speaker 1: explored in the galaxies, You've done most of a big 393 00:24:25,040 --> 00:24:28,040 Speaker 1: physical stuff. At this point, probably most of what you 394 00:24:28,080 --> 00:24:30,400 Speaker 1: want to do is going to be kind of cultural. 395 00:24:31,400 --> 00:24:34,119 Speaker 1: We have no idea as umus what an advancedivils might 396 00:24:34,160 --> 00:24:36,639 Speaker 1: want to do. But I think it's a pretty certain 397 00:24:36,720 --> 00:24:39,840 Speaker 1: bet that it's going to require competitions of some kind. 398 00:24:40,440 --> 00:24:45,160 Speaker 1: Information processing a k. A. Computing has its own requirements. 399 00:24:45,320 --> 00:24:49,399 Speaker 1: It needs energy and it produces waste heat, two huge 400 00:24:49,440 --> 00:24:52,640 Speaker 1: factors that a post biological society would come up against 401 00:24:52,920 --> 00:24:55,560 Speaker 1: as it uploaded more and more of its population to 402 00:24:55,680 --> 00:25:00,280 Speaker 1: a digitized format. Rather than food, water, and couple of 403 00:25:00,280 --> 00:25:03,879 Speaker 1: square meters of physical space, they would need processing power 404 00:25:04,080 --> 00:25:07,800 Speaker 1: and speed to keep their digitized minds humming along and 405 00:25:07,840 --> 00:25:11,560 Speaker 1: to simulate the world for them. So a post biological 406 00:25:11,600 --> 00:25:14,680 Speaker 1: society would have very good reason to colonize their galaxy 407 00:25:15,119 --> 00:25:18,520 Speaker 1: in search of more raw materials to build hardware and 408 00:25:18,600 --> 00:25:22,919 Speaker 1: to harness more energy from They will probably build massive 409 00:25:22,960 --> 00:25:27,200 Speaker 1: engineering projects to capture energy from entire stars, like through 410 00:25:27,240 --> 00:25:31,440 Speaker 1: some variation of Dicen spheres to a hypothetical energy collection 411 00:25:31,480 --> 00:25:34,600 Speaker 1: machine that could be constructed around a star to capture 412 00:25:34,640 --> 00:25:39,000 Speaker 1: some enormous fraction of its energy. They may deconstruct entire 413 00:25:39,080 --> 00:25:42,320 Speaker 1: planets to build those Dicen spheres, so they may have 414 00:25:42,440 --> 00:25:46,240 Speaker 1: energy and aces. But at some point a post biological 415 00:25:46,280 --> 00:25:51,600 Speaker 1: society might strike upon a seemingly insurmountable truth about information processing. 416 00:25:52,280 --> 00:25:56,240 Speaker 1: Regardless of how efficient it is, computing produces some amount 417 00:25:56,280 --> 00:25:59,119 Speaker 1: of waste heat. This can be tricky enough with a 418 00:25:59,160 --> 00:26:01,760 Speaker 1: single server him here on Earth in the early twenty 419 00:26:01,800 --> 00:26:04,800 Speaker 1: one century, those racks of servers have to be cooled 420 00:26:04,800 --> 00:26:07,119 Speaker 1: with fans, and the room has to be air conditioned. 421 00:26:07,400 --> 00:26:09,800 Speaker 1: So that means that not only is the actual process 422 00:26:09,840 --> 00:26:13,840 Speaker 1: of computing taking up energy, there's an additional energy expenditure 423 00:26:14,000 --> 00:26:17,640 Speaker 1: required to keep the hardware cool. Heat is the sworn 424 00:26:17,800 --> 00:26:22,800 Speaker 1: enemy of efficient information processing, and efficient information processing would 425 00:26:22,800 --> 00:26:26,200 Speaker 1: be the lifeblood in the oxygen to a healthy post 426 00:26:26,280 --> 00:26:30,199 Speaker 1: biological society, So keeping heat to a minimum would be 427 00:26:30,280 --> 00:26:34,360 Speaker 1: of the utmost importance. You may say, and I would 428 00:26:34,400 --> 00:26:38,439 Speaker 1: agree with you. That's certainly a post biological civilization with 429 00:26:38,520 --> 00:26:41,840 Speaker 1: a hundred thousand or million or billion year head start 430 00:26:41,920 --> 00:26:45,480 Speaker 1: on us would have almost certainly figured out better, more efficient, 431 00:26:45,720 --> 00:26:49,240 Speaker 1: and less heat producing methods for information processing than the 432 00:26:49,240 --> 00:26:52,479 Speaker 1: computers we humans have hit upon today. It would be 433 00:26:52,520 --> 00:26:54,800 Speaker 1: one of the more surprising things in this whole series 434 00:26:54,960 --> 00:26:57,720 Speaker 1: if that weren't the case. But when you begin to 435 00:26:57,760 --> 00:27:00,280 Speaker 1: scale up from the level of server room on word 436 00:27:00,560 --> 00:27:04,119 Speaker 1: to capturing the energy of an entire star, even an 437 00:27:04,160 --> 00:27:09,439 Speaker 1: almost efficient computer will still have a massive waste heat issue, 438 00:27:09,880 --> 00:27:12,760 Speaker 1: and that post biological society will have to deal with it, 439 00:27:13,680 --> 00:27:16,680 Speaker 1: and that problem is compounded with each new star and 440 00:27:16,760 --> 00:27:20,320 Speaker 1: each new piece of hardware that's added. Since you have 441 00:27:20,359 --> 00:27:23,080 Speaker 1: a finite amount of energy, even if you're a really 442 00:27:23,119 --> 00:27:27,440 Speaker 1: big supercivilization, that means that the total amount of competition 443 00:27:27,480 --> 00:27:29,399 Speaker 1: you can do is going to be set by temperature. 444 00:27:30,000 --> 00:27:32,879 Speaker 1: So if you wait until the universe gets colder, you 445 00:27:32,880 --> 00:27:36,800 Speaker 1: can get much more competition done. Some people have suggested 446 00:27:36,840 --> 00:27:39,720 Speaker 1: that perhaps the edge of the galaxy, which butts up 447 00:27:39,760 --> 00:27:43,480 Speaker 1: against the coldest regions of intergalactic space, is the best 448 00:27:43,480 --> 00:27:46,399 Speaker 1: place to look for other civilizations, since they will have 449 00:27:46,440 --> 00:27:48,920 Speaker 1: likely set up shot there to deal with their massive 450 00:27:48,920 --> 00:27:52,399 Speaker 1: waste heat problem. But that Oxford group realized that the 451 00:27:52,440 --> 00:27:55,840 Speaker 1: optimal place for a post biological society to best deal 452 00:27:55,880 --> 00:27:59,600 Speaker 1: with their waste heat is somewhere in time, not space. 453 00:28:00,080 --> 00:28:18,440 Speaker 1: M One popular suggestion for the expiration data of the 454 00:28:18,520 --> 00:28:22,640 Speaker 1: universe comes about ten billion thousand years from now via 455 00:28:22,680 --> 00:28:26,119 Speaker 1: the heat death of the universe. Every bit of energy 456 00:28:26,160 --> 00:28:28,359 Speaker 1: in the universe was released in the Big Bang some 457 00:28:28,560 --> 00:28:32,720 Speaker 1: thirteen point seven billion years ago, and the ninete century 458 00:28:33,000 --> 00:28:36,760 Speaker 1: we humans it upon the laws of thermodynamics, which had 459 00:28:36,800 --> 00:28:40,760 Speaker 1: some bad news about that energy. Over time periods, that 460 00:28:40,920 --> 00:28:44,360 Speaker 1: energy will cease as the heat differentials that produce it 461 00:28:44,840 --> 00:28:49,360 Speaker 1: begin to equalize. As every atom in the universe slowly 462 00:28:49,480 --> 00:28:53,680 Speaker 1: stops moving, the universe will cool, and eventually the universe 463 00:28:53,720 --> 00:28:56,960 Speaker 1: will experience the death of heat, and with the cessation 464 00:28:57,040 --> 00:28:59,479 Speaker 1: of the movement of atoms and the particles that make 465 00:28:59,520 --> 00:29:04,440 Speaker 1: them up, not life, not computing, nothing will be possible 466 00:29:04,480 --> 00:29:09,200 Speaker 1: any longer. Long before the expiration date, the universe will 467 00:29:09,240 --> 00:29:12,480 Speaker 1: still be alive with energy, but much much colder than 468 00:29:12,520 --> 00:29:17,160 Speaker 1: it is now. So particularly clever post biological society might 469 00:29:17,240 --> 00:29:19,960 Speaker 1: realize that the energy they have available to them could 470 00:29:20,000 --> 00:29:23,000 Speaker 1: be captured and stored for use later on, when the 471 00:29:23,120 --> 00:29:27,640 Speaker 1: universe is colder and computing is, by extension far more efficient. 472 00:29:28,400 --> 00:29:31,440 Speaker 1: So perhaps they built themselves a galaxy's worth of Dyson's 473 00:29:31,520 --> 00:29:34,160 Speaker 1: fears to collect and store the energy from their stars 474 00:29:34,160 --> 00:29:36,600 Speaker 1: while the society went to sleep for a billion or 475 00:29:36,600 --> 00:29:40,920 Speaker 1: so years. Even a peaceful post biological society would be 476 00:29:40,960 --> 00:29:44,000 Speaker 1: forced to protect their energy allotment and their hardware while 477 00:29:44,000 --> 00:29:46,719 Speaker 1: they slept, and so they would almost certainly post some 478 00:29:46,760 --> 00:29:50,120 Speaker 1: sort of guard like berserker probes to watch over them 479 00:29:50,160 --> 00:29:52,960 Speaker 1: and the civilization they'd arranged in store for themselves while 480 00:29:53,000 --> 00:29:58,040 Speaker 1: they slept. Estivation is a kind of hibernation that some 481 00:29:58,120 --> 00:30:01,960 Speaker 1: animals do when it's hot out, and the estivation hypothesis 482 00:30:02,000 --> 00:30:05,400 Speaker 1: goes fairly far and entering the family paradox. We haven't 483 00:30:05,400 --> 00:30:09,560 Speaker 1: been colonized by other civilizations because they're sleeping, So the 484 00:30:09,680 --> 00:30:13,560 Speaker 1: estivation hypothesis is that advanced civilizations might actually think that 485 00:30:13,800 --> 00:30:17,160 Speaker 1: it's too sweltering hot right now, it's three degrees above 486 00:30:17,360 --> 00:30:22,480 Speaker 1: absolute zero, so they decide to just hide and estivate 487 00:30:23,120 --> 00:30:26,920 Speaker 1: until it's cold enough. So in about one point five 488 00:30:27,000 --> 00:30:30,440 Speaker 1: trillion years, it turns out that the universe stops getting 489 00:30:30,440 --> 00:30:34,200 Speaker 1: colder because of the background radiation from the horizon, and 490 00:30:34,240 --> 00:30:36,400 Speaker 1: at that point it might be rational for the super 491 00:30:36,440 --> 00:30:39,960 Speaker 1: civilizision of wake up and they kind of feel the nice, 492 00:30:39,960 --> 00:30:43,680 Speaker 1: crisp autumn air or in this case, the very cold 493 00:30:43,800 --> 00:30:48,440 Speaker 1: vacuum of a very far future, and start really running recipilizations. 494 00:30:48,920 --> 00:30:50,840 Speaker 1: And this might be an explanation of why we're not 495 00:30:50,880 --> 00:30:54,920 Speaker 1: seeing any but it doesn't fully resolve the family paradox either. 496 00:30:55,440 --> 00:30:57,960 Speaker 1: We should still be able to observe their dicense fears 497 00:30:58,080 --> 00:31:02,239 Speaker 1: or other massive engineering projects encircling a star with an 498 00:31:02,320 --> 00:31:05,760 Speaker 1: energy capturing devices no small feat. We should be able 499 00:31:05,800 --> 00:31:08,080 Speaker 1: to sense such a thing, And indeed, the team of 500 00:31:08,160 --> 00:31:11,280 Speaker 1: Japanese researchers scanned a portion of the sky to look 501 00:31:11,320 --> 00:31:14,640 Speaker 1: for telltale signs of dicense fheares stars that produce a 502 00:31:14,680 --> 00:31:17,760 Speaker 1: normal amount of heat but are unnaturally dim or even 503 00:31:17,800 --> 00:31:22,400 Speaker 1: totally dark. They didn't find any, So it doesn't look 504 00:31:22,480 --> 00:31:26,680 Speaker 1: exactly like the universe is currently full of sleeping elder 505 00:31:26,720 --> 00:31:32,000 Speaker 1: civilizations looking for Disonian artifacts. These massive engineering projects is 506 00:31:32,040 --> 00:31:35,840 Speaker 1: a proposed new branch of CETI. Whether civilization is active, 507 00:31:35,960 --> 00:31:40,360 Speaker 1: sleeping or extinct, the projects they created would likely endure, 508 00:31:40,920 --> 00:31:43,480 Speaker 1: and if we can find those, we found our answer 509 00:31:43,480 --> 00:31:46,880 Speaker 1: to the family paradox. But yet again we have found 510 00:31:46,880 --> 00:31:50,160 Speaker 1: nothing of the sort. We have an uncovered one scrap 511 00:31:50,200 --> 00:31:54,080 Speaker 1: of evidence the universe has ever been colonized. The Fermi 512 00:31:54,200 --> 00:31:59,080 Speaker 1: paradox stands stronger than ever. But what if what we're 513 00:31:59,080 --> 00:32:02,640 Speaker 1: seeing is an actually the reality of the universe. What 514 00:32:02,680 --> 00:32:06,440 Speaker 1: if we're being actively manipulated that somewhere out there the 515 00:32:06,560 --> 00:32:10,120 Speaker 1: universe is indeed teeming with life, that there are widespread 516 00:32:10,120 --> 00:32:13,720 Speaker 1: engineering projects that litter the galaxies. We just can't see 517 00:32:13,760 --> 00:32:16,640 Speaker 1: any of it because we're being prevented from seeing things 518 00:32:16,720 --> 00:32:20,040 Speaker 1: as they really are. This is the basis of a 519 00:32:20,120 --> 00:32:23,920 Speaker 1: family of answers to the Family paradox called the Zoo hypothesis, 520 00:32:24,600 --> 00:32:27,560 Speaker 1: thought up in nine three by m I t astronomer 521 00:32:27,640 --> 00:32:30,960 Speaker 1: John Ball. It supposes that we humans are being kept 522 00:32:31,000 --> 00:32:34,400 Speaker 1: without our knowledge and some sort of cosmic zoo, and 523 00:32:34,440 --> 00:32:39,640 Speaker 1: being observed, maybe even studied, without our awareness. Perhaps we're 524 00:32:39,640 --> 00:32:42,520 Speaker 1: being kept in a kind of nature preserve until we 525 00:32:42,600 --> 00:32:45,800 Speaker 1: reach some crucial point in our evolution when the secrets 526 00:32:45,840 --> 00:32:49,680 Speaker 1: of the universe will be revealed to us. Or maybe 527 00:32:49,720 --> 00:32:52,520 Speaker 1: we're meant to stay in a naturally preserved state forever. 528 00:32:53,360 --> 00:32:55,680 Speaker 1: Maybe the rest of the universe has been paved over 529 00:32:55,760 --> 00:32:59,920 Speaker 1: with dicens fears, every other available planet stripped and deconstructed 530 00:33:00,040 --> 00:33:03,640 Speaker 1: for materials, and out of a sense of intergalactic nostalgia, 531 00:33:04,040 --> 00:33:06,840 Speaker 1: our planet and the life on it, including us, has 532 00:33:06,880 --> 00:33:10,760 Speaker 1: been selected to be kept in a pristine state. The 533 00:33:10,840 --> 00:33:14,320 Speaker 1: Zoo hypothesis has some holes in it too, mostly the 534 00:33:14,360 --> 00:33:17,240 Speaker 1: same as any other solution to the Family paradox. It 535 00:33:17,280 --> 00:33:20,680 Speaker 1: would take only one member of one civilization to shatter it. 536 00:33:21,600 --> 00:33:25,040 Speaker 1: The Zoo hypothesis presumes some sort of star Trek like 537 00:33:25,280 --> 00:33:28,120 Speaker 1: prime directive to leave us alone, and it would have 538 00:33:28,200 --> 00:33:31,680 Speaker 1: to be firmly upheld by all other civilizations in this 539 00:33:31,960 --> 00:33:34,960 Speaker 1: galactic club, keeping us in the dark for as long 540 00:33:35,000 --> 00:33:38,200 Speaker 1: as humans have been around. There are no options. The 541 00:33:38,280 --> 00:33:41,680 Speaker 1: prime directive is not a matter of degrees, it is 542 00:33:41,720 --> 00:33:45,560 Speaker 1: an absolute, one would think. Some people object to this 543 00:33:45,680 --> 00:33:48,959 Speaker 1: dismissal of the zoo hypothesis. They point to things like 544 00:33:49,280 --> 00:33:54,479 Speaker 1: UFO sightings and historical documentation of inexplicable phenomena like the 545 00:33:54,520 --> 00:33:58,880 Speaker 1: fifteen sixty one Cathedral of Light over Nuremberg, Germany. All 546 00:33:58,920 --> 00:34:01,480 Speaker 1: of this is evidence of past non compliance with this 547 00:34:01,600 --> 00:34:05,720 Speaker 1: prohibition on contact with us humans. It's also possible that 548 00:34:05,800 --> 00:34:08,920 Speaker 1: Earth was visited in human prehistory as well, and that 549 00:34:09,000 --> 00:34:12,440 Speaker 1: there's just no surviving evidence of it. Or maybe we 550 00:34:12,520 --> 00:34:15,640 Speaker 1: have received messages and just don't know it yet. Perhaps 551 00:34:15,680 --> 00:34:18,360 Speaker 1: they are encoded in our DNA, waiting for us to 552 00:34:18,400 --> 00:34:21,960 Speaker 1: find them and make sense of it. There is something 553 00:34:22,080 --> 00:34:26,360 Speaker 1: very disconcerting about the zoo hypothesis, the idea that knowledge 554 00:34:26,400 --> 00:34:29,040 Speaker 1: we would very much like to have is being kept 555 00:34:29,080 --> 00:34:31,800 Speaker 1: from us without our say in the matter, through ways 556 00:34:31,840 --> 00:34:35,200 Speaker 1: we may never hope to overcome on our own. But 557 00:34:35,600 --> 00:34:38,640 Speaker 1: I don't know. Is that better or worse than the alternative? 558 00:34:39,480 --> 00:34:41,759 Speaker 1: Is the idea that we are being manipulated by a 559 00:34:41,760 --> 00:34:45,960 Speaker 1: galactic club of civilizations better or worse than the idea 560 00:34:46,040 --> 00:34:50,000 Speaker 1: that there are no other civilizations at all. There is 561 00:34:50,040 --> 00:34:54,319 Speaker 1: a very reasonable alternative explanation to the Faramie paradox, one 562 00:34:54,360 --> 00:34:56,720 Speaker 1: that requires us to make the fewest leaps of faith 563 00:34:56,760 --> 00:35:00,800 Speaker 1: to reach it. That we are utterly and entirely alone 564 00:35:01,160 --> 00:35:06,080 Speaker 1: in the universe. This is Oxford philosopher Toby Ord. There 565 00:35:06,080 --> 00:35:10,160 Speaker 1: are about two hundred billion stars in our galaxy the 566 00:35:10,239 --> 00:35:15,960 Speaker 1: Milky Way. So if the chance of life or intelligent 567 00:35:16,040 --> 00:35:19,520 Speaker 1: life evolving around any one of those stars was was 568 00:35:19,560 --> 00:35:22,120 Speaker 1: even you know, one in a billion, you'd expect that 569 00:35:22,200 --> 00:35:26,200 Speaker 1: to be about two hundred stars in our galaxy that 570 00:35:26,239 --> 00:35:29,600 Speaker 1: have involved intelligent life. And yet when we look around, 571 00:35:29,640 --> 00:35:32,040 Speaker 1: we see no signs of this, and we also don't 572 00:35:32,040 --> 00:35:34,400 Speaker 1: see any signs of it in other galaxies um that 573 00:35:34,440 --> 00:35:38,160 Speaker 1: we have looked at. Some people think that this is 574 00:35:38,560 --> 00:35:42,480 Speaker 1: a paradoxical result, but I think it's actually much more 575 00:35:42,520 --> 00:35:46,680 Speaker 1: likely that the that it's just that there aren't any 576 00:35:47,560 --> 00:35:51,520 Speaker 1: As Michael Hart puts it, in this Our universe is 577 00:35:51,560 --> 00:35:54,239 Speaker 1: too big and too old for it not to be 578 00:35:54,320 --> 00:35:57,640 Speaker 1: teeming with life by now. That we've not seen evidence 579 00:35:57,680 --> 00:36:02,440 Speaker 1: of other civilizations suggests that they do not exist, but 580 00:36:02,520 --> 00:36:05,600 Speaker 1: that's not to say they never did. Perhaps we don't 581 00:36:05,600 --> 00:36:09,799 Speaker 1: see other intelligent civilizations because none of them have survived. 582 00:36:24,000 --> 00:36:26,160 Speaker 1: On the next episode of the End of the World 583 00:36:26,160 --> 00:36:29,360 Speaker 1: with Josh Clark, the great filter is whatever is in 584 00:36:29,400 --> 00:36:33,040 Speaker 1: the way, whatever makes it hard for any one piece 585 00:36:33,120 --> 00:36:37,279 Speaker 1: of ordinary dead matter to produce expanding, lasting life. If 586 00:36:37,320 --> 00:36:40,320 Speaker 1: we are alone in the universe, then perhaps there's something 587 00:36:40,440 --> 00:36:43,840 Speaker 1: that's killed off every other civilization before it could spread 588 00:36:43,840 --> 00:36:47,040 Speaker 1: from its home planet. And if that's true, can we 589 00:36:47,120 --> 00:36:48,720 Speaker 1: expect the same in our future?