WEBVTT - Galactic Civilization’s End 0:00:03.040 --> 0:00:05.840 Welcome to Stuff to Blow Your Mind from how Stuff 0:00:05.840 --> 0:00:14.239 Works dot com. Hey you welcome to Stuff to Blow 0:00:14.280 --> 0:00:17.240 your Mind. My name is Robert Lamb and I'm Joe McCormick. 0:00:17.280 --> 0:00:19.960 And today we're going to be looking at a question 0:00:20.200 --> 0:00:23.520 about the future a sort of today will be a 0:00:23.520 --> 0:00:26.520 speculative out ing. So the question that we want to 0:00:26.520 --> 0:00:29.240 start with today is the broad one, and then we'll 0:00:29.280 --> 0:00:32.640 break it down into specific, specific ways of looking at 0:00:32.680 --> 0:00:37.239 this question. The question is how long could a technological 0:00:37.280 --> 0:00:40.920 civilization last? And notice that I just used the word 0:00:41.040 --> 0:00:46.760 civilization and technological not necessarily human civilization, since time and 0:00:46.800 --> 0:00:49.480 space scales the kind we're talking about could really blur 0:00:49.600 --> 0:00:51.559 the lines of what it means for a civilization to 0:00:51.600 --> 0:00:56.160 be human or consistently any one biological species. So for now, 0:00:56.200 --> 0:00:59.360 I'd say, let's just define civilization as something like a 0:00:59.440 --> 0:01:04.040 continue this tradition of intelligent behavior. Uh, if you've got 0:01:04.080 --> 0:01:07.640 something like that, Assume a civilization like ours leaves Earth 0:01:07.959 --> 0:01:11.040 and spreads out to colonize other star systems and becomes 0:01:11.040 --> 0:01:14.560 a presence on the galactic stage. How long could a 0:01:14.640 --> 0:01:18.640 civilization like that actually survive into the future. You kind 0:01:18.640 --> 0:01:22.120 of have to think of of civilization as a virus 0:01:22.160 --> 0:01:25.880 spreading through this uh, this galactic and ultimately I as 0:01:25.880 --> 0:01:29.760 a universal host. How how far could it spread? How 0:01:29.800 --> 0:01:33.680 long could it maintain the infection? Um? And it's it 0:01:34.080 --> 0:01:36.880 is challenging at times just to think about it because 0:01:36.920 --> 0:01:40.920 we we can't help but extrapolate what we have now 0:01:40.920 --> 0:01:42.560 and what we know, and we have to do that 0:01:42.600 --> 0:01:45.440 in order to to sort of scale up the model 0:01:45.480 --> 0:01:49.800 of what a galactic civilization might look like. Um. And 0:01:49.800 --> 0:01:52.960 at the because I think back to Star Trek for instance. 0:01:52.960 --> 0:01:56.920 You know, Star Trek is essentially a show about clipper ships. 0:01:57.720 --> 0:02:01.560 It's about seafaring individuals. It's just extrapolated into space and 0:02:01.600 --> 0:02:04.480 then uh, you know, with a lot of cool science 0:02:05.200 --> 0:02:10.080 science and science fictional elements explored within it, exploring the 0:02:10.120 --> 0:02:12.720 planets of potted plants. Yeah. But but ultimately it is 0:02:12.880 --> 0:02:15.560 it is based on the model of the president in 0:02:15.560 --> 0:02:18.200 the past. Um. And then then there's also this this 0:02:18.280 --> 0:02:23.359 element too of just um you know, uh, grandiose pride 0:02:23.400 --> 0:02:26.920 and human accomplishment to to wonder where will we be 0:02:27.600 --> 0:02:30.600 uh in this distant age. It reminds me of of 0:02:30.639 --> 0:02:34.560 a quote from J. M. Coats. He's waiting for the barbarians, 0:02:35.080 --> 0:02:38.560 and which he writes, quote one thought alone preoccupies the 0:02:38.639 --> 0:02:42.760 submerged mind of empire, how not to end, how not 0:02:42.960 --> 0:02:47.320 to die, how to prolong its era. I think that's 0:02:47.400 --> 0:02:51.280 quite true, though, I mean the conception of empire that 0:02:51.360 --> 0:02:54.600 we have is so time limited. I mean people who 0:02:54.600 --> 0:02:56.840 are trying to prolong the empires that were used to 0:02:56.880 --> 0:02:59.519 thinking about, say Cotsy probably has in mind something like 0:02:59.600 --> 0:03:03.760 the British Empire um. That is an empire that, even 0:03:03.800 --> 0:03:06.160 though it existed for a long period of time, was 0:03:06.280 --> 0:03:10.080 on the scale of you know, people's recognizable descendants. You know, 0:03:10.280 --> 0:03:12.600 you would be saying, I want to hand on my 0:03:12.760 --> 0:03:16.640 empire to my child, or my grandchild or my great grandchild. 0:03:17.160 --> 0:03:19.720 Do you do you want to hand on your empire 0:03:19.840 --> 0:03:24.280 to something that is maybe not even recognizably the same 0:03:24.320 --> 0:03:27.320 species as you a million years down the road. Yeah. 0:03:27.400 --> 0:03:29.639 It kind of becomes the situation where one is, say 0:03:29.639 --> 0:03:34.240 passing on a typewriter or or some other piece of technology, 0:03:34.280 --> 0:03:36.200 where you're like, this has been in our family for years, 0:03:36.560 --> 0:03:38.320 and then you're like, well, thanks, but it's and it 0:03:38.440 --> 0:03:41.000 is now obsolete. It is it is kind of useless. 0:03:41.040 --> 0:03:43.600 It's it's actually of more value perhaps now as a 0:03:43.800 --> 0:03:47.360 mere museum piece or just as a metal to be recycled. 0:03:47.440 --> 0:03:50.520 That's true, I guess it. Also it sort of works 0:03:50.520 --> 0:03:53.560 out how you don't have to care about that thing 0:03:53.720 --> 0:03:55.720 that's a million years down the road, whether or not 0:03:55.840 --> 0:03:58.160 you think of that as your direct descendant or not, 0:03:58.560 --> 0:04:02.119 because you care about next generation, and that generation will 0:04:02.120 --> 0:04:05.480 always care about the next generation. It's just an echo 0:04:05.600 --> 0:04:08.880 through through time and space. Yeah. I think one of 0:04:08.880 --> 0:04:10.400 the important things to deep in mind and all of 0:04:10.440 --> 0:04:14.240 this is just to what extent to things UH scale up, 0:04:14.840 --> 0:04:17.360 you know, because we think about the empires and the 0:04:17.560 --> 0:04:20.480 technology we have today and UH, I think is what 0:04:20.520 --> 0:04:24.000 As we proceed through this discussion, it will be reminded 0:04:24.000 --> 0:04:27.880 time and time again that that that human life, human empires, 0:04:28.320 --> 0:04:31.360 they don't really scale up when you start applying them 0:04:31.360 --> 0:04:35.279 to even even at the interplanetary stage, things begin to 0:04:35.279 --> 0:04:37.360 get a little difficult. But certainly when you get beyond 0:04:38.000 --> 0:04:40.839 beyond that, when you talk about UH, an empire that 0:04:40.960 --> 0:04:45.200 spans solar systems or or or manages to spread throughout 0:04:45.200 --> 0:04:50.520 an entire galaxy and human life as well, there are challenges. Obviously, 0:04:50.560 --> 0:04:52.839 there are challenges when we think of of what we 0:04:52.880 --> 0:04:55.120 have now, and even if you achieve some sort of 0:04:55.160 --> 0:04:59.760 biological or digital immortality, um, it's it's difficult to put 0:04:59.760 --> 0:05:02.599 that in context. Yeah. Now, one of the first questions 0:05:02.640 --> 0:05:05.000 that you might ask is, well, how long would it take? 0:05:05.040 --> 0:05:08.000 How long is it gonna take for a galactic civilization 0:05:08.080 --> 0:05:10.640 to emerge? Okay, we gotta get there before we can 0:05:10.720 --> 0:05:13.760 ask how long it will exist or survive? Right, Yeah, 0:05:13.800 --> 0:05:17.040 And this is something that science fiction and authors often 0:05:17.120 --> 0:05:19.200 kind of hatch you out, depending on how into you 0:05:19.240 --> 0:05:23.719 know defining a timeline they are. Now. In his book Cosmos, 0:05:23.839 --> 0:05:27.640 Carl Sagan commented on the Drake equation. Right. So, the 0:05:27.720 --> 0:05:29.920 Drake equation we we've talked about on the show before, 0:05:29.960 --> 0:05:33.160 but if you'll recall, it's essentially an equation put together 0:05:33.520 --> 0:05:36.480 to come up with a rough estimate based on some 0:05:36.480 --> 0:05:39.680 some variables where you can plug in your assumptions for 0:05:39.720 --> 0:05:44.120 the answers UH to figure out how many technological civilizations 0:05:44.120 --> 0:05:46.760 you would expect to find in a galaxy. So basically, 0:05:47.440 --> 0:05:50.680 the short version is you take the number of planets 0:05:50.720 --> 0:05:53.719 that there could be life on and then multiply that 0:05:53.839 --> 0:05:58.360 by some probabilities like the fraction of planets where life emerges, 0:05:58.760 --> 0:06:02.039 the fraction of the is where intelligent life evolves, the 0:06:02.080 --> 0:06:06.400 fraction that's capable of interstellar communication, and the years a 0:06:06.480 --> 0:06:10.920 civilization tends to remain detectable before for whatever reason, uh 0:06:11.080 --> 0:06:14.840 disappearing right. And Sagan pointed out that civilizations might tend 0:06:14.839 --> 0:06:18.479 to destroy themselves soon after reaching the technological phase, but 0:06:18.520 --> 0:06:21.240 that at least some civilizations might learn to live with 0:06:21.320 --> 0:06:24.720 high technology. He figured that, using the Drake equation, if 0:06:24.839 --> 0:06:28.640 just one percent of all emergent technological civilization survived this 0:06:28.839 --> 0:06:34.000 technological adolescence, then there could be millions of civilizations out there. Now, 0:06:34.000 --> 0:06:37.400 there don't appear to be millions of civilizations out there 0:06:37.560 --> 0:06:39.400 well as far as we know, as far as we know. 0:06:39.520 --> 0:06:42.880 But but here's the thing. Sagan and William Newman calculated 0:06:42.920 --> 0:06:45.279 that if a mill that if a million years ago 0:06:45.440 --> 0:06:49.360 a space faring civilization emerged two hundred light years away 0:06:49.440 --> 0:06:53.280 from us and spread outward, survey ships would only just 0:06:53.400 --> 0:06:55.880 now be entering our solar system. And then what would 0:06:55.920 --> 0:06:58.120 that even look like? What would a million year old 0:06:58.160 --> 0:07:02.480 civilization uh, you know manifest as uh? I mean, our 0:07:02.480 --> 0:07:05.000 current and only model outside of sci fi dreams is 0:07:05.480 --> 0:07:07.760 our civilization. It's me. And it's a mere you know, 0:07:07.880 --> 0:07:10.160 tens of thousands of years old, and we've only been 0:07:10.200 --> 0:07:13.440 a technological civilization for a few centuries. So what would 0:07:13.440 --> 0:07:17.040 these presumed immortals even be interested in when it comes 0:07:17.080 --> 0:07:20.160 to exploring and colonizing new worlds? Would they have would 0:07:20.160 --> 0:07:22.600 would they be interested in that at all? Would they 0:07:22.600 --> 0:07:25.560 sort of would they perhaps give up on their colonization efforts, 0:07:26.000 --> 0:07:29.880 uh after they realize that they need to perhaps extend 0:07:29.920 --> 0:07:32.760 their their energy and other directions. It's a good question. 0:07:32.840 --> 0:07:37.000 I mean, I think that it helps, um it helps 0:07:37.000 --> 0:07:40.440 when trying to imagine the future behavior of civilizations, whether 0:07:40.560 --> 0:07:44.120 alien or ours, to try to have as few assumptions 0:07:44.160 --> 0:07:48.520 baked in as possible. And so you can make assumptions 0:07:48.600 --> 0:07:51.520 maybe about what alien psychology might be, like, what their 0:07:51.640 --> 0:07:55.400 their directives are an exploration, but all of those are 0:07:55.680 --> 0:07:57.920 somewhat fallible. One of the things I think we can 0:07:58.080 --> 0:08:01.000 bank on as an assumption about future your civilizations is 0:08:01.040 --> 0:08:04.360 that they will need energy. That that's that's a that's 0:08:04.360 --> 0:08:07.440 a kind of ground level assumption that just you can 0:08:07.520 --> 0:08:10.800 count on that. But then how how might their goals change? 0:08:10.880 --> 0:08:12.680 Like they have energy, they could have all the energy, 0:08:13.080 --> 0:08:16.320 certainly in a world, in a solar system, in across 0:08:16.400 --> 0:08:19.400 multiple systems. But then what do they really want to 0:08:19.440 --> 0:08:21.520 do with it? And and indeed do they want to 0:08:21.560 --> 0:08:24.520 survive the long term challenges of life in our universe 0:08:24.800 --> 0:08:27.920 with their goals understanding? And even experience of time and 0:08:27.960 --> 0:08:32.320 space differ from what we humans value and experience today. Uh, 0:08:32.360 --> 0:08:34.719 it could be, but once you get into those scenarios, 0:08:34.760 --> 0:08:37.520 it's just hard to it's hard to predict anything with 0:08:37.559 --> 0:08:40.079 any confidence. Yeah, I mean so, yeah, this is where 0:08:40.080 --> 0:08:43.120 you get into the really the domain of science fiction. Um, 0:08:43.160 --> 0:08:45.080 I don't Oh, and there's plenty of great science fiction 0:08:45.120 --> 0:08:48.280 along these lines. Yeah. I'm reminded of the various advanced 0:08:48.320 --> 0:08:53.160 Elder civilizations in Ian Ebanks culture books. Um, because beyond 0:08:53.320 --> 0:08:57.920 the the high level involved civilizations that engage with other 0:08:57.960 --> 0:09:01.560 galactic civilizations in these books, there are what's known as 0:09:01.600 --> 0:09:06.160 the sublime. The sublime these are advanced civilizations that basically, 0:09:06.240 --> 0:09:09.400 at some point they just left all of their their 0:09:09.480 --> 0:09:13.440 works behind because they've left the known dimensions of space 0:09:13.480 --> 0:09:16.760 time behind to take up residents in several higher dimensions 0:09:16.880 --> 0:09:20.760 higher dimensions. Now, does this what assumes string theory or 0:09:20.800 --> 0:09:24.000 something like that, in which they're they're tiny higher dimensions 0:09:24.000 --> 0:09:27.600 where you can somehow bacond your consciousness into some kind 0:09:27.640 --> 0:09:30.960 of substrate that can transcend into those hidden dimensions. Well, 0:09:30.960 --> 0:09:33.400 that's where my mind goes to, especially since we've we've 0:09:33.480 --> 0:09:37.920 very recently spoken about dimensions and string theory. Uh. Now 0:09:37.960 --> 0:09:40.600 I haven't I haven't read some of at least one 0:09:40.640 --> 0:09:43.440 of the key books that deals with the sublime in 0:09:43.559 --> 0:09:47.200 the culture A series. But it's basically the idea that 0:09:47.200 --> 0:09:50.600 that suddenly that this particular group has reached a level 0:09:50.600 --> 0:09:54.319 of technological and cultural advancement where they're not even playing 0:09:54.360 --> 0:09:56.520 the same game as we are, that they are perhaps 0:09:56.559 --> 0:09:59.600 not even really experiencing the universe in the same way 0:09:59.640 --> 0:10:02.040 as we are, and they just kind of leave it behind. 0:10:02.720 --> 0:10:06.200 Uh indeed, like a like like like something emerging from 0:10:06.240 --> 0:10:09.200 a chrysalis and uh in taking off into a new 0:10:09.600 --> 0:10:12.400 realm of being. And but in doing this, at the 0:10:12.440 --> 0:10:16.360 same time, it's possible that sublimation uh might actually protect 0:10:16.360 --> 0:10:19.080 them from the truly long term environmental risks of living 0:10:19.080 --> 0:10:21.080 in our universe. So maybe it accomplishes the same go 0:10:21.960 --> 0:10:24.920 But of course that is that is the benefit afforded 0:10:24.960 --> 0:10:27.000 by playing in the realm of imagination. We don't know 0:10:27.040 --> 0:10:29.560 if anything like that is possible or not. So let's 0:10:29.720 --> 0:10:33.160 get into some of the long term environmental challenges of 0:10:33.160 --> 0:10:35.720 of life in a hostile universe. Well, I guess first 0:10:35.760 --> 0:10:38.640 we should look just the planetary level. Yeah, let's start 0:10:38.720 --> 0:10:41.480 with with Earth itself, right, So there are a number 0:10:41.480 --> 0:10:44.079 of factors to consider here, the most obvious being threats 0:10:44.120 --> 0:10:47.000 from within and threats from beyond. So we certainly have 0:10:47.080 --> 0:10:50.199 the ability to drastically damage the life sustaining properties of 0:10:50.240 --> 0:10:54.839 planet Earth. In fact, we are we are currently doing that. Yes, yes, 0:10:55.360 --> 0:10:59.480 with with say greenhouse gas emissions leading to global climate change, 0:10:59.520 --> 0:11:04.000 we are verely hampering the Earth's ability to sustain a 0:11:04.040 --> 0:11:07.000 civilization like ours far into the future. Yeah, the results 0:11:07.000 --> 0:11:10.520 can be catastrophic. Now, could we actually wipe out all 0:11:10.640 --> 0:11:13.679 life on the planet if such an evil aim possessed us? 0:11:14.400 --> 0:11:17.320 I think we would probably have a hard time doing that. 0:11:17.400 --> 0:11:21.120 I mean, life is pretty resilient, but we could come 0:11:21.480 --> 0:11:24.920 frighteningly close. I've seen some estimates for how a large 0:11:25.000 --> 0:11:30.400 enough nuclear war uh could could severely damage and wipe out, 0:11:30.559 --> 0:11:32.680 you know, a significant number of of life forms on 0:11:32.679 --> 0:11:36.360 our planet. I also read get this, um how even 0:11:36.520 --> 0:11:41.040 even an extremely powerful detonation in the Mariana Trench could 0:11:41.120 --> 0:11:43.920 collapse the food chain and wipe out most plant and 0:11:43.960 --> 0:11:48.439 animal life specifically. And this is according to uh x 0:11:48.559 --> 0:11:52.400 k c D s Randall Monroe uh x k c 0:11:52.559 --> 0:11:57.240 d as a science blog and comic series online. Uh He, 0:11:57.280 --> 0:12:00.680 according to his calculations, a fifty three million in megatun 0:12:00.720 --> 0:12:03.880 explosion down in the trench might just do the trick. 0:12:03.960 --> 0:12:06.040 This would be equal to the chicks Aloop impact that 0:12:06.080 --> 0:12:09.400 occurred roughly sixty six million years ago, which led to 0:12:09.559 --> 0:12:14.200 the Cretaceous Paleogene extinction event, and that killed sev of 0:12:14.240 --> 0:12:17.480 all animal and plant species. That was the size of 0:12:17.480 --> 0:12:19.720 a city, and it had the power of a billion 0:12:19.960 --> 0:12:23.200 nuclear bombs. And this brings us to the extinction events 0:12:23.200 --> 0:12:27.120 that can occur due to unchecked space collisions. Yeah, now 0:12:27.120 --> 0:12:29.520 there's there's actually been some evidence to support the idea 0:12:29.600 --> 0:12:32.880 that there's a a twenty six million year cycle linking 0:12:32.920 --> 0:12:36.760 comet showers and global die offs. Yeah, there are people 0:12:36.800 --> 0:12:39.839 who pause it all kinds of like like periods of 0:12:39.880 --> 0:12:42.600 space impacts and what the causes of those might be. 0:12:42.679 --> 0:12:45.840 But one thing we can say is that space impacts 0:12:45.840 --> 0:12:48.520 are just a statistics game. I mean, you're it's just 0:12:48.600 --> 0:12:52.920 a waiting game. Like you know, every so many years, 0:12:52.960 --> 0:12:56.520 you're you're pretty much statistically guaranteed to get X number 0:12:56.840 --> 0:12:59.760 of powerful storms that hit a certain part of the world. 0:13:00.080 --> 0:13:02.000 Space impacts are the same way. There are a bunch 0:13:02.000 --> 0:13:04.640 of objects out there, they're flying around, and you can 0:13:04.679 --> 0:13:07.960 just calculate it out over certain periods of time, statistically 0:13:07.960 --> 0:13:10.559 you're going to be hit by X number of objects 0:13:10.559 --> 0:13:13.520 above a certain mass. So when you're we're talking about 0:13:13.559 --> 0:13:17.959 a human civilization, uh, surviving however many you know, thousands 0:13:18.040 --> 0:13:20.439 upon thousands upon thousands of years, certainly reaching like the 0:13:20.559 --> 0:13:25.080 million or two million. Your point. If you want life 0:13:25.200 --> 0:13:29.800 to continue on Earth, then you have to do something 0:13:29.920 --> 0:13:34.160 about the potential impacts. Because defense, Yeah, you gotta have 0:13:34.200 --> 0:13:38.040 planetary defense, which is something that uh that people are 0:13:38.080 --> 0:13:41.079 working on. Uh we've discussed it on the show before. 0:13:41.080 --> 0:13:43.400 It's still not as much of a priority as it 0:13:43.440 --> 0:13:47.079 should be. You have all of these uh, these politicians 0:13:47.880 --> 0:13:51.520 out there, you know, making campaign promises and talking about 0:13:51.600 --> 0:13:55.120 what they're gonna do for for for to improve everyone's life, 0:13:55.360 --> 0:13:58.120 and it always floors me that this is not something 0:13:58.160 --> 0:14:00.319 that people take up because this is one of the 0:14:00.400 --> 0:14:03.160 This is perhaps the only, or at least one of 0:14:03.160 --> 0:14:05.240 the very few causes where we can say this is 0:14:05.280 --> 0:14:07.959 something we can do to save the world. This is 0:14:08.000 --> 0:14:10.840 something we can do to protect the planet. Yeah, what 0:14:10.840 --> 0:14:13.880 what if there? That was like a what if that 0:14:13.960 --> 0:14:18.240 was a campaign platform? It was basically civilization level defense. 0:14:18.400 --> 0:14:22.840 So your your campaign platform is fight climate change, protect 0:14:22.840 --> 0:14:25.960 the planet from space object impacts, and let's say the 0:14:25.960 --> 0:14:28.560 other big one would be prepared for the next superflu 0:14:30.520 --> 0:14:32.080 It makes sense to me, I mean, I guess the 0:14:32.080 --> 0:14:35.560 the the the counter argument here is that most these 0:14:35.600 --> 0:14:40.160 are these are generally longer term threats. Uh, so people 0:14:40.200 --> 0:14:44.200 are going to be less inclined to let it impact 0:14:44.200 --> 0:14:49.800 their voting behavior. It's frustrating. But anyway, uh some other 0:14:49.880 --> 0:14:52.600 problems that, of course so be as we've discussed before. 0:14:52.760 --> 0:14:55.240 Venus offers an example of this of a sort of 0:14:55.240 --> 0:14:58.800 worst case runaway greenhouse effect that could leave a planet, 0:14:58.840 --> 0:15:01.840 even a planet like Earth, uninhabitable, And there are also 0:15:01.960 --> 0:15:06.200 various long term scenarios involving the world's oceans, the magnetosphere, 0:15:06.600 --> 0:15:08.200 which if you listen to the show, you know that 0:15:08.240 --> 0:15:12.320 the magnetosphere plays a vital role in protecting our planet 0:15:12.400 --> 0:15:15.560 from silver and cosmic radiation, and if something were to 0:15:15.600 --> 0:15:19.320 happen to that, then we're unprotected. There are also biological 0:15:19.360 --> 0:15:23.160 threats from within Earth's biosphere. That's right. You have to 0:15:23.200 --> 0:15:28.080 consider the likes of Peter Ward's media hYP hypothesis. I 0:15:28.160 --> 0:15:30.760 was actually not familiar with this. This is a kind 0:15:30.800 --> 0:15:35.720 of an opposite of the Gaia hypothesis and uh, the 0:15:35.760 --> 0:15:41.360 Medeia hypothesis is that multicellular life is a suicidal superorganism 0:15:41.480 --> 0:15:44.880 leading to microbial triggered mass extinctions. I mean, whether you 0:15:44.920 --> 0:15:48.520 buy the framing is a suicidal superorganism, it is clear 0:15:48.640 --> 0:15:51.120 that there have been times in the past where life 0:15:51.200 --> 0:15:54.800 on Earth caused massive extinctions of other types of life 0:15:54.800 --> 0:15:57.360 on Earth. I mean, we think about the oxygenation of 0:15:57.360 --> 0:15:59.920 our atmosphere that we are now adapted to was initially 0:16:00.080 --> 0:16:03.520 tragedy that killed killed off tons of life, and then 0:16:03.520 --> 0:16:06.360 of course we've seen this this particular primate species rise 0:16:06.480 --> 0:16:09.600 up and uh and and alter the atmosphere from a 0:16:09.720 --> 0:16:12.560 very early time. And then of course there are the 0:16:12.640 --> 0:16:15.960 outside context problems to consider, which, of course is a 0:16:16.080 --> 0:16:18.720 term that was coined by Ian M. Banks but has 0:16:18.760 --> 0:16:24.560 been used since then by various other authors and even scientists. 0:16:24.760 --> 0:16:27.800 You call them outside context problems to consider, but sort 0:16:27.800 --> 0:16:30.480 of the nature of them means that what you can't 0:16:30.520 --> 0:16:33.960 consider the right right. Yeah. Banks said that an outside 0:16:33.960 --> 0:16:36.960 context problem is the sort of thing most civilizations encounter 0:16:37.120 --> 0:16:39.920 just once, in which they tend to encounter rather in 0:16:39.960 --> 0:16:43.080 the same way as sentence encounters a full stop. Um. 0:16:43.640 --> 0:16:46.000 So yeah, if we could. The classic example, of course 0:16:46.120 --> 0:16:49.880 is um, if you have a primitive terrestrial society and 0:16:49.960 --> 0:16:54.840 then uh, a colonial force shows up with advanced technology, 0:16:55.160 --> 0:16:57.440 you know, and then to extrapolate that into space, an 0:16:57.480 --> 0:17:00.320 alien civilization shows up with it with advanced head ology. 0:17:00.360 --> 0:17:02.440 But of course, when the thing about the the alien 0:17:02.480 --> 0:17:06.480 consideration is that a lot of very intelligent folks have 0:17:06.520 --> 0:17:10.520 thought about this problem. There are even some rudimentary plans 0:17:10.560 --> 0:17:13.760 in place to deal with it when it occurs, you know, 0:17:13.760 --> 0:17:16.639 people who think about first contact. So it's not really 0:17:16.880 --> 0:17:20.679 a completely outside contact problem. Yeah. You could look at 0:17:20.680 --> 0:17:23.200 a lot of science fiction as us doing our very 0:17:23.240 --> 0:17:27.880 best to use our imaginations to prepare for this potential conflict. Right. 0:17:28.400 --> 0:17:30.600 But one of the big hard limits for life on 0:17:30.760 --> 0:17:34.399 Earth uh and in our solar system itself, concerns the 0:17:34.440 --> 0:17:36.760 life cycle of our son. Now maybe we should take 0:17:36.760 --> 0:17:39.560 a quick break and then come back to UH to 0:17:39.720 --> 0:17:42.520 discuss and weep in anguish over the death of the Sun. 0:17:43.119 --> 0:17:47.679 Than alright, we're back. So we we've talked about the 0:17:47.680 --> 0:17:50.159 life cycle of the Sun before on this show, but 0:17:50.240 --> 0:17:54.080 just to refresh, this is basically how it it works. 0:17:54.080 --> 0:17:56.320 So our son has been going strong for four point 0:17:56.359 --> 0:17:59.400 five billion years and it has another five billion years 0:17:59.440 --> 0:18:03.320 left in the town. When the courts roughly speaking, roughly speaking, now, 0:18:03.320 --> 0:18:05.280 when the core runs out of hydrogen fuel, it's going 0:18:05.359 --> 0:18:08.240 to contract under the weight of gravity. Some hydrogen fusion 0:18:08.240 --> 0:18:10.199 will occur in the upper layers at this point. But 0:18:10.600 --> 0:18:13.240 as a depleted core contracts, it heats up, and this 0:18:13.320 --> 0:18:16.240 heats the upper layers of the Sun, causing them to expand. 0:18:16.280 --> 0:18:18.639 And as the outer layers expand, the radius of the 0:18:18.680 --> 0:18:21.200 Sun will increase and it will become a red giant. 0:18:21.440 --> 0:18:23.720 And the radius of the of a red giant son, 0:18:23.840 --> 0:18:27.240 our red giant son would be a hundred times what 0:18:27.320 --> 0:18:29.800 it is now. It's not good. Now, that's that's not 0:18:29.840 --> 0:18:33.000 good for anybody, because this would this would put the 0:18:33.560 --> 0:18:36.239 put the the the the outside of the Sun just 0:18:36.359 --> 0:18:39.399 beyond the Earth's orbit, and some scientists have estimated that 0:18:39.440 --> 0:18:41.680 this would just vaporize our planet, but there's also a 0:18:41.680 --> 0:18:44.480 good chance it would push Earth and its moon outward 0:18:44.560 --> 0:18:48.400 after consuming mercury and venus. In any case, whatever it does, 0:18:48.520 --> 0:18:51.679 it does not sound like a survivable event for the 0:18:51.720 --> 0:18:55.080 inhabitants of Earth. That's right, It's just it's it's bad news. 0:18:55.400 --> 0:18:57.760 And long before this happens, say in a mirror one 0:18:57.800 --> 0:19:00.520 to two billion years, the Earth is gonna go hot 0:19:00.640 --> 0:19:04.639 enough to to boil away its oceans as well. And 0:19:04.680 --> 0:19:07.680 if we're looking really long term, um, here's how it'll 0:19:07.680 --> 0:19:10.919 it'll all play out. According to Ethan Seagull, who wrote 0:19:11.160 --> 0:19:13.640 how our Solar System will end in the Far Future 0:19:13.640 --> 0:19:16.600 for Forbes. Uh. He says that in nine point five 0:19:16.600 --> 0:19:19.439 billion years, the sunile collapse into a white dwarf, and 0:19:19.480 --> 0:19:22.520 the remaining dead worlds will continue to orbit it, and 0:19:22.520 --> 0:19:26.000 eventually the white dwarf will go dark in the inevitable 0:19:26.040 --> 0:19:29.560 collision between it and another black dwarf will blast apart 0:19:29.640 --> 0:19:31.960 the remnants of our solar system. So all that and 0:19:32.000 --> 0:19:34.040 the Sun doesn't even get to turn into a black hole. 0:19:34.200 --> 0:19:36.120 That's right, the Sun will never get to turn into 0:19:36.160 --> 0:19:39.680 a black it's not massive enough. Uh, and yet it 0:19:39.720 --> 0:19:43.480 will wreak havoc. Nonetheless, So what's our fight or flight 0:19:43.520 --> 0:19:47.119 response here? Well, it obviously means if our civilization is 0:19:47.160 --> 0:19:51.159 going to survive into the realm of say billions of years, 0:19:51.200 --> 0:19:54.320 if you're on the billions order of magnitude for the future, 0:19:54.480 --> 0:19:57.320 we can't stay here, that's right. We've got to build ships, 0:19:57.320 --> 0:20:00.520 We've got to build colonies. We've got to estab colonies 0:20:00.520 --> 0:20:03.879 on other worlds and other systems as well. Or perhaps 0:20:03.920 --> 0:20:07.000 we do something to just move the Earth itself, because 0:20:07.000 --> 0:20:11.240 as we ascend the Kardashian scale, such things do theoretically 0:20:11.240 --> 0:20:14.119 become possible. Sure, at least in theory. For instance, we 0:20:14.119 --> 0:20:18.119 can harness comments and asteroids so they gravitationally slingshot past 0:20:18.200 --> 0:20:20.320 Earth and move us into a wider orbit away from 0:20:20.320 --> 0:20:23.960 the Sun. We could build planetary sunshades that have the 0:20:24.000 --> 0:20:27.879 same effect, or or very or even just sort of 0:20:27.920 --> 0:20:32.000 turn the Earth into a spaceship of sorts, you know, 0:20:32.080 --> 0:20:35.399 just take it with us. Well, there are versions, like, 0:20:35.560 --> 0:20:38.639 for example, there is one idea that's not for moving 0:20:38.760 --> 0:20:41.159 planets so much as it is for moving stars. But 0:20:41.200 --> 0:20:44.040 I wonder if similar principles could be applied to planets, 0:20:44.800 --> 0:20:48.439 where it's known as the Scatoff thruster if you're read 0:20:48.480 --> 0:20:51.160 about the Yeah, so this is for stars. But what 0:20:51.400 --> 0:20:53.560 it would do would be would be sort of a 0:20:53.720 --> 0:20:58.680 large reflective encasement for part of a star that would 0:20:58.720 --> 0:21:03.320 cause a positive radi asian pressure in one direction back 0:21:03.359 --> 0:21:06.160 against the star. And by reflecting all of this radiation 0:21:06.240 --> 0:21:08.280 back in the direction of the star, you could actually 0:21:08.320 --> 0:21:11.000 steer the movement of a star. One wonders if you 0:21:11.000 --> 0:21:14.240 could create some kind of similar solar sale like thing 0:21:14.520 --> 0:21:17.040 for a planet. Then again, the planet is not emitting 0:21:17.160 --> 0:21:18.879 radiation the way a star is, So I don't know, 0:21:18.920 --> 0:21:22.440 maybe maybe possible, maybe not, Yeah, or ultimately we could 0:21:22.440 --> 0:21:24.640 just leave it behind, move on to better worlds, make 0:21:24.680 --> 0:21:28.280 better worlds. Exodus from an uninhabitable Earth has been a 0:21:28.280 --> 0:21:31.960 sci fi staple for decades, going back at least to 0:21:32.000 --> 0:21:34.879 the nineteen thirties. That's when British sci fi author Olaf 0:21:35.320 --> 0:21:38.359 Stapleton wrote about it and uh during the events of 0:21:38.400 --> 0:21:41.639 Frank Herbert's Dune, Old Earth is said to be an 0:21:41.720 --> 0:21:45.480 uninhabited waste. Oh yeah, do they ever go there? I 0:21:45.520 --> 0:21:48.480 don't not. In the the original books that they might 0:21:48.600 --> 0:21:52.439 have something that takes place in the more recent Dune 0:21:52.560 --> 0:21:55.000 franchise books, but I have not read them, so I 0:21:55.000 --> 0:21:59.640 would love to hear from from hardcore Dune readers on that. Now. 0:22:00.119 --> 0:22:03.120 When it comes to moving the planet, though, we also 0:22:03.160 --> 0:22:05.960 see some work there in science fiction. Sci fi writer 0:22:06.119 --> 0:22:09.600 Stanley Schmidt explored it in nineteen and Ian M. Banks 0:22:09.640 --> 0:22:12.359 also wrote about it. So we're kind of climbing a 0:22:12.400 --> 0:22:16.639 Kardashian scale of destruction here. So planetary power and the 0:22:16.640 --> 0:22:19.800 ability to save one's planet in some sense, then solar 0:22:19.840 --> 0:22:22.720 system power and the ability to save oneself or roll 0:22:22.840 --> 0:22:25.960 with the changes to a single star system. But what 0:22:26.040 --> 0:22:28.440