1 00:00:08,600 --> 00:00:11,920 Speaker 1: Hey, Kelly, I've been thinking about something you said to me. 2 00:00:12,280 --> 00:00:15,120 Speaker 1: Oh okay, what did I say? Well, when you moved 3 00:00:15,160 --> 00:00:17,239 Speaker 1: to the Science Farm awhile ago, you said that I 4 00:00:17,280 --> 00:00:20,200 Speaker 1: was welcome to come visit. But then last episode you 5 00:00:20,360 --> 00:00:25,439 Speaker 1: officially retracted that invitation. Well, yeah I did because you 6 00:00:25,440 --> 00:00:27,520 Speaker 1: said you were going to tell my kids that shooting 7 00:00:27,560 --> 00:00:30,440 Speaker 1: stars might kill them. So I think I was justified. 8 00:00:30,760 --> 00:00:33,159 Speaker 1: All right, Well, then it's now my official goal to 9 00:00:33,360 --> 00:00:36,400 Speaker 1: earn back an invitation. Okay, but like it's not a 10 00:00:36,440 --> 00:00:39,840 Speaker 1: super high bar. Just don't give my kids nightmares. Well 11 00:00:40,040 --> 00:00:41,880 Speaker 1: do your kids want to hear about how the sun 12 00:00:41,960 --> 00:00:44,640 Speaker 1: is going to explode one day? So you know, I'm 13 00:00:44,680 --> 00:00:47,600 Speaker 1: thinking that maybe you should just wait until they grow 14 00:00:47,720 --> 00:00:50,360 Speaker 1: up and move away, and then you can come visit, 15 00:00:50,960 --> 00:00:55,840 Speaker 1: assuming they move away before the sun explodes, I hope. So. 16 00:00:57,360 --> 00:00:59,240 Speaker 1: As much as we love our kids, we do want 17 00:00:59,280 --> 00:01:18,400 Speaker 1: them to move away eventually, eventually. Yes, Hi, I'm Daniel. 18 00:01:18,440 --> 00:01:21,800 Speaker 1: I'm a particle physicist and a professor at U C Irvine, 19 00:01:21,880 --> 00:01:24,560 Speaker 1: and I don't like scaring children, but I do like 20 00:01:24,640 --> 00:01:30,679 Speaker 1: telling them the truth. I'm Kelly Wayner Smith um an 21 00:01:30,760 --> 00:01:35,160 Speaker 1: edgeunt professor at Rice University, and I prefer lying to them. 22 00:01:35,240 --> 00:01:37,840 Speaker 1: What you lie to your kids. What if they ask 23 00:01:37,920 --> 00:01:39,840 Speaker 1: you a science question you don't know the answer, you 24 00:01:39,880 --> 00:01:41,840 Speaker 1: just make one up. No, in that case, I tell 25 00:01:41,880 --> 00:01:44,160 Speaker 1: them the truth. That's important, you know. But one of 26 00:01:44,160 --> 00:01:46,840 Speaker 1: them does still believe in Santa And now we'll not 27 00:01:46,880 --> 00:01:51,200 Speaker 1: be listening to this episode. What if they ask you 28 00:01:51,280 --> 00:01:54,720 Speaker 1: a science question that has a scary answer, It depends 29 00:01:54,720 --> 00:01:56,320 Speaker 1: on it if I think they can handle it or not. 30 00:01:56,640 --> 00:01:58,200 Speaker 1: And it depends on what I want to go to 31 00:01:58,240 --> 00:02:00,320 Speaker 1: bed that night, because I might be up late doing 32 00:02:00,320 --> 00:02:03,240 Speaker 1: the explaining. There's lots of things to consider. Well, then 33 00:02:03,280 --> 00:02:05,320 Speaker 1: let's hope they don't ask you about when the sun 34 00:02:05,480 --> 00:02:08,320 Speaker 1: is gonna But welcome to the podcast Daniel and Jorge 35 00:02:08,480 --> 00:02:11,480 Speaker 1: Explain the Universe, in which we try to teach you 36 00:02:11,680 --> 00:02:15,760 Speaker 1: everything about the universe, scary or not, the things that 37 00:02:15,840 --> 00:02:18,200 Speaker 1: will keep you up at night, worried about whether you 38 00:02:18,200 --> 00:02:20,320 Speaker 1: will survive, and the things that make you feel like 39 00:02:20,360 --> 00:02:24,120 Speaker 1: the universe is a comfortable, cozy places all set up 40 00:02:24,160 --> 00:02:26,320 Speaker 1: for you to have a good time. We talk about 41 00:02:26,360 --> 00:02:28,640 Speaker 1: black holes, we talk about quirks. We talk about the 42 00:02:28,639 --> 00:02:31,160 Speaker 1: future of the human race and whether it has a 43 00:02:31,200 --> 00:02:35,919 Speaker 1: future or not. Dark stuff, My friend and co host 44 00:02:36,040 --> 00:02:38,440 Speaker 1: Jorge can't be here today, so we are joined by 45 00:02:38,520 --> 00:02:41,160 Speaker 1: Kelly Weener Smith, who is trying to teach you things 46 00:02:41,200 --> 00:02:44,880 Speaker 1: without scaring your children. I feel like maybe I need 47 00:02:44,919 --> 00:02:46,960 Speaker 1: to defend that decision, but I'm just gonna let it go. 48 00:02:47,120 --> 00:02:49,400 Speaker 1: Sometimes kids don't need to be scared. You get to 49 00:02:49,400 --> 00:02:51,800 Speaker 1: spend your whole adulthood being scared about stuff. You know 50 00:02:52,040 --> 00:02:54,160 Speaker 1: you're right, And the thing I love about the universe 51 00:02:54,240 --> 00:02:57,360 Speaker 1: is that it doesn't really care about our feelings. It's 52 00:02:57,440 --> 00:03:00,840 Speaker 1: just crazy. It's just bonkers. It's just doing its thing, 53 00:03:01,120 --> 00:03:03,560 Speaker 1: whether that means it's threatening to tear you apart and 54 00:03:03,600 --> 00:03:07,440 Speaker 1: blow you away, or whether it's created this wonderful environment 55 00:03:07,480 --> 00:03:09,720 Speaker 1: for you to relax in and sip your market riata 56 00:03:09,760 --> 00:03:12,320 Speaker 1: while you listen to a podcast. The universe doesn't care 57 00:03:12,400 --> 00:03:14,480 Speaker 1: either way. You know, it's really good that you went 58 00:03:14,520 --> 00:03:18,480 Speaker 1: into physics and not like psychiatry or something. And how 59 00:03:18,560 --> 00:03:21,440 Speaker 1: how are your kids turning out? My kids so far 60 00:03:21,520 --> 00:03:24,160 Speaker 1: are not sociopaths, you know, but hey, we need to 61 00:03:24,160 --> 00:03:26,960 Speaker 1: collect more data. No, my strategy has always been to 62 00:03:27,040 --> 00:03:31,040 Speaker 1: answer their questions honestly, though I will admit if their 63 00:03:31,160 --> 00:03:35,520 Speaker 1: questions bring up something awkward or uncomfortable or maybe age inappropriate. 64 00:03:35,600 --> 00:03:38,120 Speaker 1: I'll try to deflect the question once or twice, but 65 00:03:38,160 --> 00:03:40,760 Speaker 1: if they really insist, if they drill in for an answer, 66 00:03:40,880 --> 00:03:42,600 Speaker 1: I'm giving it to them. Well, you know, we should 67 00:03:42,600 --> 00:03:45,040 Speaker 1: both be trying to collect more systematic data, and we'll 68 00:03:45,040 --> 00:03:47,360 Speaker 1: see if you were kids or my kids handle the 69 00:03:47,400 --> 00:03:51,400 Speaker 1: future better. I see whose kids grew up weirder, like 70 00:03:51,440 --> 00:03:53,960 Speaker 1: the children of a physicist or the children of a 71 00:03:54,000 --> 00:03:58,360 Speaker 1: cartoonist and parasitologist. I don't know. Both sets have stiff 72 00:03:58,360 --> 00:04:02,800 Speaker 1: odds overcoming their parents are doing to them, I think exactly. 73 00:04:02,840 --> 00:04:05,960 Speaker 1: And it's a weird universe out there, and one that 74 00:04:06,000 --> 00:04:08,640 Speaker 1: sort of defines the context of our lives. The more 75 00:04:08,720 --> 00:04:11,320 Speaker 1: we learn about how the universe works and how our 76 00:04:11,360 --> 00:04:14,280 Speaker 1: neighborhood has been put together, the more we understand how 77 00:04:14,360 --> 00:04:17,400 Speaker 1: fragile our existence on this rock is. That's right, you know. 78 00:04:17,440 --> 00:04:19,280 Speaker 1: The more we talk, the more I'm wondering if maybe 79 00:04:19,279 --> 00:04:22,280 Speaker 1: you should be lying to me. Also, forget the kids. 80 00:04:23,080 --> 00:04:25,440 Speaker 1: I'm not sure I can handle this, but alright, alright, 81 00:04:25,480 --> 00:04:27,359 Speaker 1: let's see how I do today. All right, If this 82 00:04:27,480 --> 00:04:29,560 Speaker 1: podcast keeps you, feel free to call me at two 83 00:04:29,600 --> 00:04:32,839 Speaker 1: am and I'll tell you even scarier things about the universe. 84 00:04:33,000 --> 00:04:38,599 Speaker 1: I'll pass. Thanks, you're like an anti friend. Well, something 85 00:04:38,640 --> 00:04:41,280 Speaker 1: I think that people should be more worried about and 86 00:04:41,360 --> 00:04:44,400 Speaker 1: more scared of is sort of the context of our 87 00:04:44,520 --> 00:04:46,920 Speaker 1: situation here. You know. I think a lot of people 88 00:04:46,960 --> 00:04:50,200 Speaker 1: think about the solar system as something old, something that's 89 00:04:50,240 --> 00:04:52,560 Speaker 1: been there for a long time, like a mountain that's 90 00:04:52,600 --> 00:04:55,400 Speaker 1: survived millions and millions of years. But the truth is 91 00:04:55,440 --> 00:04:58,240 Speaker 1: that the solar system is actually a very chaotic and 92 00:04:58,360 --> 00:05:01,039 Speaker 1: dynamic place. It hasn't a we've looked the way that 93 00:05:01,080 --> 00:05:03,159 Speaker 1: it does today, and it will not always look the 94 00:05:03,160 --> 00:05:05,440 Speaker 1: way that it does today. And in the future. Is 95 00:05:05,440 --> 00:05:07,240 Speaker 1: it going to be less nice to us than it 96 00:05:07,320 --> 00:05:09,040 Speaker 1: is right now? Because last time we talked to you 97 00:05:09,080 --> 00:05:11,160 Speaker 1: told me that shooting stars were trying to kill us. 98 00:05:12,200 --> 00:05:15,800 Speaker 1: It gets worse, I don't know about worse. It's going 99 00:05:15,880 --> 00:05:18,120 Speaker 1: to get different, for sure, sort of in the science 100 00:05:18,120 --> 00:05:20,640 Speaker 1: fiction movie plot twists sort of a way. I mean, 101 00:05:20,720 --> 00:05:22,919 Speaker 1: I think there's something that people don't appreciate, which is 102 00:05:22,920 --> 00:05:26,280 Speaker 1: that our solar system hasn't even existed for the whole 103 00:05:26,360 --> 00:05:30,000 Speaker 1: length of the universe. The universe is like fourteen billion 104 00:05:30,080 --> 00:05:33,120 Speaker 1: years old. Our solar systems only four and a half billion, 105 00:05:33,520 --> 00:05:36,960 Speaker 1: which means the first nine billion years our Sun didn't 106 00:05:37,040 --> 00:05:41,120 Speaker 1: even exist, Like there was nothing like our Solar system. 107 00:05:41,160 --> 00:05:45,320 Speaker 1: So we're relative newcomers in the universe. We're not even 108 00:05:45,360 --> 00:05:49,240 Speaker 1: middle aged, and we might just be here for a blip. 109 00:05:49,320 --> 00:05:50,599 Speaker 1: And as you and I have talked about on the 110 00:05:50,640 --> 00:05:53,480 Speaker 1: podcast a couple of times, the Solar system itself has 111 00:05:53,520 --> 00:05:56,920 Speaker 1: seen a lot of transformations. People think that maybe Jupiter 112 00:05:57,040 --> 00:05:59,400 Speaker 1: was formed closer to the Sun, or maybe it formed 113 00:05:59,400 --> 00:06:02,480 Speaker 1: far out and then migrated in and then migrated back 114 00:06:02,520 --> 00:06:06,159 Speaker 1: out the outer Solar system, ejecting some other planets along 115 00:06:06,200 --> 00:06:08,640 Speaker 1: the way. Our Solar system might have had other planets 116 00:06:08,640 --> 00:06:11,880 Speaker 1: which are now lost to us, like siblings that were 117 00:06:11,880 --> 00:06:15,160 Speaker 1: rejected by our parents. But surely when the Sun realizes 118 00:06:15,240 --> 00:06:17,679 Speaker 1: that humans are on the Earth, the whole Solar system 119 00:06:17,720 --> 00:06:21,360 Speaker 1: is going to start behaving for us. Right. I don't 120 00:06:21,360 --> 00:06:24,120 Speaker 1: think the Sun cares at all about us, and I 121 00:06:24,120 --> 00:06:26,720 Speaker 1: think it's amazing that we have sort of evolved on 122 00:06:26,839 --> 00:06:30,960 Speaker 1: this rock under these conditions which have been fairly stable 123 00:06:31,080 --> 00:06:34,200 Speaker 1: over the last few billion years. But we're also very 124 00:06:34,240 --> 00:06:37,800 Speaker 1: dependent on those conditions. If they change even just a 125 00:06:37,839 --> 00:06:41,320 Speaker 1: little bit, then life on Earth could be very, very different. 126 00:06:41,440 --> 00:06:43,240 Speaker 1: When is that going to happen? Do we know? It 127 00:06:43,279 --> 00:06:46,880 Speaker 1: turns out that the conditions are constantly changing. The Sun 128 00:06:47,040 --> 00:06:50,400 Speaker 1: is getting brighter and brighter every year. Originally for us, 129 00:06:50,480 --> 00:06:53,119 Speaker 1: it's pretty slow, but as we think deep, deep into 130 00:06:53,120 --> 00:06:56,760 Speaker 1: the future of humanity, conditions could change a lot over 131 00:06:56,839 --> 00:06:59,920 Speaker 1: millions or billions of years. And I hope at least 132 00:07:00,120 --> 00:07:02,760 Speaker 1: that our children and our children's children and our children's 133 00:07:02,800 --> 00:07:06,000 Speaker 1: children's children's children's children are around in billions or billions 134 00:07:06,040 --> 00:07:08,760 Speaker 1: of years to scare each other with crazy stories about 135 00:07:08,760 --> 00:07:12,040 Speaker 1: the future. Me too, but probably they're gonna have to 136 00:07:12,040 --> 00:07:15,000 Speaker 1: be pretty clever to stick around for that long. They 137 00:07:15,000 --> 00:07:17,080 Speaker 1: are going to have to be pretty clever if we 138 00:07:17,160 --> 00:07:20,120 Speaker 1: want to outlast our cosmic conditions, if we want a 139 00:07:20,160 --> 00:07:23,880 Speaker 1: society that lasts for millions or billions of years, then 140 00:07:23,960 --> 00:07:26,240 Speaker 1: the clock is ticking. We're going to have to figure 141 00:07:26,320 --> 00:07:29,680 Speaker 1: this out before our conditions changed. I mean, we've only 142 00:07:29,720 --> 00:07:33,960 Speaker 1: ever lived here on Earth under these circumstances, so we're 143 00:07:33,960 --> 00:07:36,560 Speaker 1: gonna have to do some pretty clever engineering if we're 144 00:07:36,560 --> 00:07:39,000 Speaker 1: going to figure out how to live in the future 145 00:07:39,080 --> 00:07:41,440 Speaker 1: of our own solar system. Well, I sure hope we're 146 00:07:41,480 --> 00:07:43,440 Speaker 1: smart to figure that out. It might depend on how 147 00:07:43,480 --> 00:07:45,720 Speaker 1: long we have to figure it out. But I'm keeping 148 00:07:45,720 --> 00:07:48,840 Speaker 1: my fingers crossed exactly, And that's precisely what we'll be 149 00:07:48,880 --> 00:07:51,960 Speaker 1: talking about today. So on the podcast, we'll be asking 150 00:07:52,000 --> 00:08:01,320 Speaker 1: the question can the Earth survive when the sun expands? 151 00:08:04,320 --> 00:08:06,800 Speaker 1: How do you feel, Kelly about this sort of apocalyptic 152 00:08:06,880 --> 00:08:10,920 Speaker 1: scenarios we've been imagining recently on the podcast, asteroid impacts, 153 00:08:11,080 --> 00:08:14,080 Speaker 1: nuclear disasters. Yeah, well, you know, I gotta say I'm 154 00:08:14,080 --> 00:08:16,880 Speaker 1: starting to have this feeling of anxiety when our monthly 155 00:08:17,120 --> 00:08:20,520 Speaker 1: time to record together comes, you know, to what extent 156 00:08:20,640 --> 00:08:23,040 Speaker 1: is my conversation with Daniel going to amp up the 157 00:08:23,080 --> 00:08:26,880 Speaker 1: existential dread in my life? So here we go again 158 00:08:26,920 --> 00:08:29,680 Speaker 1: for another roller coaster ride. Well, that's one way to 159 00:08:29,720 --> 00:08:31,240 Speaker 1: look at it. The other way to look at it 160 00:08:31,320 --> 00:08:34,440 Speaker 1: is like, what is physics going to do to save us? Right? 161 00:08:34,760 --> 00:08:37,760 Speaker 1: We are constantly thinking about the deep future of humanity 162 00:08:37,800 --> 00:08:40,520 Speaker 1: and wondering what we have to do today to make 163 00:08:40,520 --> 00:08:43,240 Speaker 1: sure that we are prepared for those eventualities, to make 164 00:08:43,280 --> 00:08:46,400 Speaker 1: sure that those humans living many many years from now 165 00:08:46,520 --> 00:08:50,200 Speaker 1: can build on our work and survive. Yeah, I suppose 166 00:08:50,240 --> 00:08:52,400 Speaker 1: I should be. I should be thanking the physicists for 167 00:08:52,480 --> 00:08:54,960 Speaker 1: figuring out these problems way ahead of time, so we 168 00:08:55,000 --> 00:08:57,600 Speaker 1: have a long lead time to try to do something 169 00:08:57,640 --> 00:09:00,280 Speaker 1: about it. Exactly. The thing to really be scared about 170 00:09:00,480 --> 00:09:03,079 Speaker 1: are the things business haven't yet figured out that we'll 171 00:09:03,120 --> 00:09:05,559 Speaker 1: probably kill us all m This is why we need 172 00:09:05,600 --> 00:09:08,880 Speaker 1: more money for the sciences, exactly. It's always the unknown 173 00:09:08,960 --> 00:09:12,199 Speaker 1: unknowns that'd kill you that, right, I mean you well, 174 00:09:12,240 --> 00:09:14,960 Speaker 1: you know, we we've also talked about how the nonns 175 00:09:15,040 --> 00:09:16,800 Speaker 1: will kill you. So it sounds like there's a lot 176 00:09:16,840 --> 00:09:18,760 Speaker 1: of things that can kill you. There are a lot 177 00:09:18,760 --> 00:09:20,600 Speaker 1: of things that can kill you, but there are also 178 00:09:20,800 --> 00:09:22,839 Speaker 1: a lot of things we can do, I think, to 179 00:09:22,920 --> 00:09:29,240 Speaker 1: our physicist and engineers to maybe save our tissues. It's 180 00:09:29,240 --> 00:09:31,240 Speaker 1: been a long time since I've heard the wood tushies. 181 00:09:32,040 --> 00:09:34,240 Speaker 1: Is that what you said? That tusses? Yeah, I'm trying 182 00:09:34,240 --> 00:09:36,560 Speaker 1: to be family friendly here. I'm hoping if kids are 183 00:09:36,600 --> 00:09:39,000 Speaker 1: listening to the podcast, you know that we're not scarring 184 00:09:39,000 --> 00:09:41,880 Speaker 1: them in multiple ways. We're just scaring them about extinction 185 00:09:41,920 --> 00:09:44,520 Speaker 1: of humanity. Right, So we talk about death, but no 186 00:09:44,720 --> 00:09:48,760 Speaker 1: foul words for hyenees. Got it. Hey, we're Americans were 187 00:09:48,800 --> 00:09:51,400 Speaker 1: totally inconsistent about these things. Yeah, I'm not sure you 188 00:09:51,480 --> 00:09:54,880 Speaker 1: understand your audience perfectly, but that's all right. Let's move forward. 189 00:09:56,120 --> 00:09:59,680 Speaker 1: So today we're wondering how humanity will survive and whether 190 00:09:59,720 --> 00:10:02,760 Speaker 1: we can preserve the Earth as a place for humanity 191 00:10:02,800 --> 00:10:06,560 Speaker 1: to live on as the Sun's condition changes, as the 192 00:10:06,600 --> 00:10:09,720 Speaker 1: Sun goes through its evolution to a larger and large 193 00:10:09,760 --> 00:10:13,040 Speaker 1: or star and eventually collapses into a white dwarf. And 194 00:10:13,080 --> 00:10:15,960 Speaker 1: as usual, I was wondering whether people are aware of 195 00:10:16,000 --> 00:10:19,599 Speaker 1: this issue and whether they had thought about plans humanity 196 00:10:19,679 --> 00:10:22,959 Speaker 1: might have to survive it. And so as usual, I 197 00:10:23,080 --> 00:10:26,120 Speaker 1: called on our list of volunteers to answer random and 198 00:10:26,160 --> 00:10:29,840 Speaker 1: difficult physics questions without any opportunity to do any research 199 00:10:29,920 --> 00:10:32,240 Speaker 1: for googling. So if that sounds like a lot of 200 00:10:32,280 --> 00:10:34,719 Speaker 1: fun to you, please don't be shy. We'd love if 201 00:10:34,720 --> 00:10:37,640 Speaker 1: you've participated in the future. Just right to me. Two 202 00:10:37,760 --> 00:10:41,079 Speaker 1: questions at Daniel and Jorge dot com. So let's hear 203 00:10:41,120 --> 00:10:43,200 Speaker 1: what they had to say. I think it would probably 204 00:10:43,400 --> 00:10:48,319 Speaker 1: survive um because it wouldn't necessarily change how the orbit 205 00:10:48,880 --> 00:10:51,880 Speaker 1: is functioning. If the it's just kind of generally swallowed up. 206 00:10:52,440 --> 00:10:58,439 Speaker 1: So would it survive well, not as a grain water 207 00:10:58,720 --> 00:11:04,640 Speaker 1: filled planet. It maybe as a roasted lump of rock 208 00:11:05,280 --> 00:11:10,040 Speaker 1: that Earth like an object, probably will survive like a rock, 209 00:11:10,400 --> 00:11:16,559 Speaker 1: but no formal life probably would survive. Hopefully, by then 210 00:11:17,440 --> 00:11:23,800 Speaker 1: we can develop the technology to move the Sun whenever 211 00:11:23,840 --> 00:11:28,800 Speaker 1: we want, whenever it's good for it and for us, 212 00:11:29,240 --> 00:11:37,280 Speaker 1: probably to a different solar system. So everybody go, study, study, study, study. 213 00:11:37,600 --> 00:11:39,360 Speaker 1: We need to do something with the Sun. As far 214 00:11:39,400 --> 00:11:44,520 Speaker 1: as I know, the Sun will eventually become a red giant, 215 00:11:45,360 --> 00:11:51,120 Speaker 1: and I heard that when the Sun will expands, its 216 00:11:51,200 --> 00:11:56,160 Speaker 1: diameter will encompass the current orbit of the Earth. So 217 00:11:56,480 --> 00:12:02,120 Speaker 1: it doesn't seem to be any salvation for us unless 218 00:12:02,200 --> 00:12:07,560 Speaker 1: we build some massive rocket boosters and steer the Earth 219 00:12:08,440 --> 00:12:13,760 Speaker 1: away from from the expanding Sun. But maybe we will 220 00:12:13,800 --> 00:12:16,640 Speaker 1: have blown ourselves up by then. I think it all 221 00:12:16,679 --> 00:12:19,400 Speaker 1: depends on the ratio of the temperature loss to the 222 00:12:19,559 --> 00:12:23,560 Speaker 1: size increase. I know red giants are cooler um, but 223 00:12:23,679 --> 00:12:27,040 Speaker 1: I don't know if there is a set ratio in 224 00:12:27,160 --> 00:12:30,760 Speaker 1: terms of the growth of the um Sun compared to 225 00:12:30,800 --> 00:12:34,160 Speaker 1: the heat loss. So I think if it ends up 226 00:12:34,200 --> 00:12:37,320 Speaker 1: being perfect, I mean, we can have a climate similar 227 00:12:37,360 --> 00:12:40,280 Speaker 1: to what we're having now, where yeah, the Sun is closer, 228 00:12:40,360 --> 00:12:42,319 Speaker 1: but it's given off less heat. Yeah, but we need 229 00:12:42,360 --> 00:12:45,440 Speaker 1: some pretty big technology, you know. I think the person 230 00:12:45,480 --> 00:12:48,319 Speaker 1: who said but we'll have blown ourselves up by then, 231 00:12:48,400 --> 00:12:51,080 Speaker 1: so we don't need to worry has been listening to 232 00:12:51,080 --> 00:12:55,400 Speaker 1: too much of your podcast. Maybe, but why is that 233 00:12:55,559 --> 00:12:58,640 Speaker 1: something not to worry about, Like don't worry about the 234 00:12:58,640 --> 00:13:01,800 Speaker 1: sun exploding, worry about us blowing ourselves up instead, or 235 00:13:01,880 --> 00:13:04,840 Speaker 1: just like fatalistic, like, look, we're all gonna die anyway, 236 00:13:04,840 --> 00:13:07,880 Speaker 1: so don't even worry about anything. Oh, I could see 237 00:13:07,880 --> 00:13:09,600 Speaker 1: it either way, though. I think they have a point 238 00:13:09,640 --> 00:13:11,560 Speaker 1: that there's a lot of things we should worry about 239 00:13:11,600 --> 00:13:14,560 Speaker 1: maybe first, but I you know, I suppose we can 240 00:13:14,600 --> 00:13:17,040 Speaker 1: divide and conquer. There's enough humans to address all these 241 00:13:17,080 --> 00:13:20,240 Speaker 1: problems exactly. And I like that some people are hopeful, 242 00:13:20,280 --> 00:13:23,080 Speaker 1: you know, that we'll have some good technology that maybe 243 00:13:23,120 --> 00:13:25,160 Speaker 1: we'll figure it out. Yeah. I like that you have 244 00:13:25,280 --> 00:13:28,400 Speaker 1: You've got a mix of optimists pessimists, and you know, 245 00:13:28,440 --> 00:13:30,840 Speaker 1: maybe one of them is a realist thrown in there. 246 00:13:31,280 --> 00:13:33,000 Speaker 1: So I guess we'll just have to see. So how 247 00:13:33,000 --> 00:13:35,680 Speaker 1: about you give us a little bit more information on 248 00:13:35,840 --> 00:13:38,880 Speaker 1: what the problem is and like how long we've got 249 00:13:38,920 --> 00:13:41,760 Speaker 1: to solve it. Yeah, that's a great idea, Like people 250 00:13:41,840 --> 00:13:44,800 Speaker 1: might be wondering, why won't the Sun just sit there 251 00:13:44,800 --> 00:13:47,839 Speaker 1: burning forever? Right, It's always looked the same to you. 252 00:13:48,000 --> 00:13:51,880 Speaker 1: It hasn't changed a lot over the ten fifty years 253 00:13:51,880 --> 00:13:54,400 Speaker 1: that you've been alive and looking up at it. Why 254 00:13:54,480 --> 00:13:56,719 Speaker 1: is it suddenly going to change? The answer is that 255 00:13:56,760 --> 00:14:00,320 Speaker 1: the Sun is really a delicate balancing act. Like what's 256 00:14:00,320 --> 00:14:03,480 Speaker 1: going on inside the sun? Why is it possible for 257 00:14:03,520 --> 00:14:06,360 Speaker 1: you to get warmed by this ball of plasma that's 258 00:14:06,480 --> 00:14:10,520 Speaker 1: ninety million miles away. Well, inside the Sun, there's incredible 259 00:14:10,559 --> 00:14:14,560 Speaker 1: gravitational pressure. Gravity is pulling on all the molecules of 260 00:14:14,600 --> 00:14:16,840 Speaker 1: the Sun, all that hydrogen, a little bit of helium 261 00:14:16,880 --> 00:14:20,240 Speaker 1: and other stuff, and squeezing it down, and in doing so, 262 00:14:20,320 --> 00:14:24,520 Speaker 1: it creates the conditions for fusion. Fusion squeezes two protons together, 263 00:14:24,560 --> 00:14:28,400 Speaker 1: for example, the nuclei of hydrogen atoms. Those protons don't 264 00:14:28,440 --> 00:14:31,360 Speaker 1: typically like to get together because they're both positively charged. 265 00:14:31,720 --> 00:14:34,640 Speaker 1: But if it's enough gravitational pressure, they get squeezed together, 266 00:14:34,680 --> 00:14:37,120 Speaker 1: and all of a sudden, boom, they fused together and 267 00:14:37,120 --> 00:14:39,560 Speaker 1: you get helium. It's actually a little bit more complicated. 268 00:14:39,600 --> 00:14:43,160 Speaker 1: Sometimes you have four protons involved, you get two helium atoms. 269 00:14:43,160 --> 00:14:46,280 Speaker 1: But the upshot is that you make heavier elements out 270 00:14:46,280 --> 00:14:49,160 Speaker 1: of lighter elements, and you also get energy in return, 271 00:14:49,480 --> 00:14:53,160 Speaker 1: and that energy keeps the Sun from collapsing, right, Like, 272 00:14:53,240 --> 00:14:55,800 Speaker 1: why doesn't the Sun just run away into a black hole? 273 00:14:55,880 --> 00:14:58,680 Speaker 1: Because that energy from fusion is providing like a back pressure. 274 00:14:58,760 --> 00:15:01,360 Speaker 1: So the Sun itself is in this balancing act as 275 00:15:01,400 --> 00:15:05,000 Speaker 1: this tug of war between two dramatic forces in the universe, 276 00:15:05,400 --> 00:15:09,200 Speaker 1: fusion pushing out and gravity pulling in. And so this 277 00:15:09,280 --> 00:15:12,160 Speaker 1: is a fairly efficient way of doing things, isn't it. 278 00:15:12,160 --> 00:15:15,280 Speaker 1: And that's why we're trying to make fusion power work 279 00:15:15,360 --> 00:15:17,240 Speaker 1: on Earth, Like, so, what is it going to take 280 00:15:17,240 --> 00:15:19,080 Speaker 1: a long time to burn up because of that? Or 281 00:15:19,080 --> 00:15:21,800 Speaker 1: am I sort of not understanding? Yeah, fusion is very 282 00:15:21,840 --> 00:15:24,320 Speaker 1: efficient and very clean and very nice, and if we 283 00:15:24,360 --> 00:15:26,720 Speaker 1: could make that happen here on Earth, we would love to. 284 00:15:27,080 --> 00:15:29,240 Speaker 1: There's a bunch of efforts to try to make that happen. 285 00:15:29,640 --> 00:15:32,840 Speaker 1: Magnetized fusion we could create like a little mini star 286 00:15:33,000 --> 00:15:36,240 Speaker 1: inside a magnetic bottle. And then there's laser fusion, where 287 00:15:36,360 --> 00:15:39,200 Speaker 1: use zapp pellets with really high intensity lasers and hope 288 00:15:39,200 --> 00:15:42,360 Speaker 1: that they implode and fuse so far, we haven't gotten 289 00:15:42,360 --> 00:15:45,120 Speaker 1: any of those things working because these conditions are hard 290 00:15:45,200 --> 00:15:47,560 Speaker 1: to establish. The Sun is doing a pretty good job 291 00:15:47,560 --> 00:15:50,840 Speaker 1: of it, and it's steadily turning hydrogen into helium, but 292 00:15:50,880 --> 00:15:53,680 Speaker 1: it's a really big ball of hydrogen, and so it's 293 00:15:53,680 --> 00:15:56,360 Speaker 1: gonna take a long long time. The lifetime of a 294 00:15:56,400 --> 00:15:59,400 Speaker 1: star depends a little bit on how much mass it has. 295 00:16:00,040 --> 00:16:02,200 Speaker 1: The more massive it is, the hotter it is at 296 00:16:02,200 --> 00:16:05,160 Speaker 1: the core, and the faster fusion happens. The smaller it is, 297 00:16:05,200 --> 00:16:07,080 Speaker 1: the cooler it is at the core, and the slower 298 00:16:07,120 --> 00:16:10,000 Speaker 1: fusion happens. So like a really really big star, like 299 00:16:10,040 --> 00:16:12,240 Speaker 1: some of the earliest stars in the universe that were 300 00:16:12,280 --> 00:16:14,800 Speaker 1: like three hundred times the mass of the Sun, might 301 00:16:14,840 --> 00:16:17,680 Speaker 1: just burn for millions of years, and a really small 302 00:16:17,720 --> 00:16:21,120 Speaker 1: star might burn for billions and billions or even trillions 303 00:16:21,120 --> 00:16:23,400 Speaker 1: of years. Whoa, and so so where are we on 304 00:16:23,480 --> 00:16:25,840 Speaker 1: that that spectrum? How long do we get to burn? 305 00:16:26,200 --> 00:16:28,160 Speaker 1: So we think that our son is going to burn 306 00:16:28,160 --> 00:16:31,120 Speaker 1: for about ten billion years total. So this is sort 307 00:16:31,120 --> 00:16:32,600 Speaker 1: of like a light bulb. You know, you put it 308 00:16:32,600 --> 00:16:34,680 Speaker 1: in the ceiling, you know it's gonna burn for weeks 309 00:16:34,800 --> 00:16:36,840 Speaker 1: or months or years, depending on the kind that you have. 310 00:16:37,280 --> 00:16:40,320 Speaker 1: Our sun is like a ten billion year light bulb, 311 00:16:40,680 --> 00:16:44,000 Speaker 1: and we're about five billion years in, which means we've 312 00:16:44,000 --> 00:16:47,680 Speaker 1: got about five billion more years of the Sun successfully 313 00:16:47,680 --> 00:16:50,680 Speaker 1: balancing fusion and gravity. You know, the light bulbs in 314 00:16:50,720 --> 00:16:52,800 Speaker 1: our house never last as long as they're supposed to, 315 00:16:52,880 --> 00:16:55,320 Speaker 1: So I hope the physicists are doing a better job 316 00:16:55,640 --> 00:16:59,240 Speaker 1: than the people who give the light bulb ratings. But okay, 317 00:16:59,280 --> 00:17:02,000 Speaker 1: so we're about of the way there. That's that's a 318 00:17:02,000 --> 00:17:04,399 Speaker 1: little bit scary. It is a little bit scary, right. 319 00:17:04,440 --> 00:17:07,000 Speaker 1: It makes you feel like, oh my gosh, we're halfway done. 320 00:17:07,119 --> 00:17:09,280 Speaker 1: What have we done with ourselves so far? Right? What 321 00:17:09,400 --> 00:17:13,040 Speaker 1: if we accomplished? You know, I mean, we build the 322 00:17:13,080 --> 00:17:15,720 Speaker 1: Golden gate Bridge and all some buildings, and we discovered 323 00:17:15,720 --> 00:17:17,960 Speaker 1: a lot of the secrets of the universe. But there's 324 00:17:18,000 --> 00:17:20,199 Speaker 1: so much left to do and not that much time. 325 00:17:20,400 --> 00:17:22,720 Speaker 1: And one of the issues is that the next five 326 00:17:22,760 --> 00:17:24,960 Speaker 1: billion years are not going to be exactly like the 327 00:17:25,040 --> 00:17:27,280 Speaker 1: last five billion. It's not like a light bulb that 328 00:17:27,359 --> 00:17:30,080 Speaker 1: just burns nicely and then one day it pops and 329 00:17:30,119 --> 00:17:33,000 Speaker 1: goes out. The Sun is going to change steadily over 330 00:17:33,040 --> 00:17:35,600 Speaker 1: the next few billion years. Oh so, like, how how 331 00:17:35,600 --> 00:17:37,840 Speaker 1: long do we have to solve the problem or to 332 00:17:37,960 --> 00:17:40,120 Speaker 1: like figure out what we're gonna do. Not the full 333 00:17:40,160 --> 00:17:43,760 Speaker 1: four billion, maybe more like a billion years. One of 334 00:17:43,800 --> 00:17:46,600 Speaker 1: the issues is that as the Sun burns, it makes 335 00:17:46,600 --> 00:17:49,720 Speaker 1: more helium, and the helium is heavier than the hydrogen, 336 00:17:49,800 --> 00:17:52,360 Speaker 1: so it sinks to the core of the Sun. This 337 00:17:52,440 --> 00:17:54,520 Speaker 1: makes the core of the Sun more dense, which means 338 00:17:54,520 --> 00:17:57,919 Speaker 1: more gravity and increases the temperature, which makes the Sun hotter. 339 00:17:58,400 --> 00:18:02,200 Speaker 1: So the Sun is getting hotter Italy. Every hundred million years, 340 00:18:02,200 --> 00:18:05,000 Speaker 1: the Sun gets about one percent brighter. You might think, well, 341 00:18:05,040 --> 00:18:07,560 Speaker 1: one percent, what's the big deal? One percent can make 342 00:18:07,600 --> 00:18:10,560 Speaker 1: a big difference in the overall energy deposited on the 343 00:18:10,560 --> 00:18:13,960 Speaker 1: Earth and totally change our climate. And that compounds every 344 00:18:14,040 --> 00:18:16,480 Speaker 1: hundred million years. It's one percent brighter, So like in 345 00:18:16,520 --> 00:18:19,680 Speaker 1: a billion or two billion years, we think the surface 346 00:18:19,760 --> 00:18:22,080 Speaker 1: of the Earth will be at a hundred C. That's 347 00:18:22,080 --> 00:18:25,440 Speaker 1: like the boiling point of water. Oh my gosh, Okay, 348 00:18:25,480 --> 00:18:27,600 Speaker 1: so we need we need to find a solution way 349 00:18:27,600 --> 00:18:30,800 Speaker 1: before that. Is it just going to be hotter or 350 00:18:30,840 --> 00:18:32,959 Speaker 1: is this I feel like I remember pictures of the 351 00:18:32,960 --> 00:18:35,960 Speaker 1: Sun expanding while this happens, Or is I guess that's 352 00:18:35,960 --> 00:18:38,320 Speaker 1: part of the whole process. So the Sun is like 353 00:18:38,720 --> 00:18:42,760 Speaker 1: seven hundred thousand kilometers in radius, right, which seems pretty big, 354 00:18:42,920 --> 00:18:45,560 Speaker 1: But as time goes on, it's going to expand to 355 00:18:45,600 --> 00:18:50,120 Speaker 1: about two hundred times that radius. So the outer edges 356 00:18:50,160 --> 00:18:51,640 Speaker 1: of the Sun are going to get pushed out by 357 00:18:51,680 --> 00:18:55,760 Speaker 1: all this extra fusion energy. And that's about one au right, 358 00:18:55,800 --> 00:18:59,320 Speaker 1: that's right about where the Earth orbits. Oh my gosh, 359 00:18:59,320 --> 00:19:02,280 Speaker 1: So it's gonna oil or oceans off, and then it's 360 00:19:02,280 --> 00:19:05,840 Speaker 1: going to engulf like all of the Earth. It sort 361 00:19:05,840 --> 00:19:08,200 Speaker 1: of seems like it in a naive calculation. The radius 362 00:19:08,200 --> 00:19:10,240 Speaker 1: of the Sun is now the same as the radius 363 00:19:10,240 --> 00:19:13,280 Speaker 1: of the Earth's orbit, so we'll be like flying through 364 00:19:13,320 --> 00:19:16,280 Speaker 1: the outer layers of the Sun. But it's actually a 365 00:19:16,280 --> 00:19:20,199 Speaker 1: tiny bit more complicated than that, because as it gets larger, 366 00:19:20,400 --> 00:19:22,800 Speaker 1: it also loses mass, Like some of its mass just 367 00:19:22,840 --> 00:19:26,320 Speaker 1: gets blown out past the Solar system. So the Sun 368 00:19:26,320 --> 00:19:29,240 Speaker 1: will lose some of this mass, right, Like the final 369 00:19:29,280 --> 00:19:31,439 Speaker 1: white dwarf that's left over in the end doesn't have 370 00:19:31,520 --> 00:19:33,120 Speaker 1: all the mass of the Sun. Some of it's been 371 00:19:33,119 --> 00:19:35,440 Speaker 1: lost by getting blown out. So that means that as 372 00:19:35,480 --> 00:19:38,960 Speaker 1: the Sun expands, it's gravity actually weakens a little bit, 373 00:19:39,560 --> 00:19:42,080 Speaker 1: and so it's tug on the Earth weakens a little bit, 374 00:19:42,160 --> 00:19:44,879 Speaker 1: so the Earth will actually drift out naturally to a 375 00:19:45,000 --> 00:19:48,119 Speaker 1: larger radius. It's orbit will get enlarged because the Sun's 376 00:19:48,160 --> 00:19:50,400 Speaker 1: gravity is getting weaker. So for a moment, I had 377 00:19:50,400 --> 00:19:52,800 Speaker 1: this little glimmer of hope, thinking, like, you know, the 378 00:19:52,800 --> 00:19:54,880 Speaker 1: Earth is going to move away, and maybe we'll move 379 00:19:54,880 --> 00:19:57,199 Speaker 1: away fast enough that the oceans aren't going to burn up. 380 00:19:57,320 --> 00:20:01,000 Speaker 1: But you, being you, you're gonna go ahead and squash 381 00:20:01,119 --> 00:20:03,679 Speaker 1: that right and and tell me that even if the 382 00:20:03,720 --> 00:20:06,160 Speaker 1: Earth keeps a little bit ahead of the Sun, we're 383 00:20:06,160 --> 00:20:07,720 Speaker 1: still all going to be dead, right, because it's still 384 00:20:07,720 --> 00:20:10,119 Speaker 1: going to boil off our oceans. Well, Kelly, I mean, 385 00:20:10,160 --> 00:20:12,280 Speaker 1: do you want the truth or do you want to 386 00:20:12,400 --> 00:20:15,400 Speaker 1: feel good about the universe? You can't always get both. 387 00:20:15,600 --> 00:20:18,919 Speaker 1: Obviously I want to feel good about the but but 388 00:20:19,119 --> 00:20:21,080 Speaker 1: you're going to give me the truth. So people have 389 00:20:21,160 --> 00:20:23,240 Speaker 1: done some studies to try to understand what's going to 390 00:20:23,320 --> 00:20:26,280 Speaker 1: happen here. It turns out that the sun expansion outpaces 391 00:20:26,320 --> 00:20:29,440 Speaker 1: the sun losing mass, and so even though the Earth 392 00:20:29,480 --> 00:20:32,080 Speaker 1: would start to drift out to a higher radius, it's 393 00:20:32,119 --> 00:20:34,320 Speaker 1: going to get caught by the outer surfaces of the 394 00:20:34,359 --> 00:20:36,960 Speaker 1: Sun before it can do that. And one of the 395 00:20:37,040 --> 00:20:40,520 Speaker 1: issues is that once you are skimming over the surface 396 00:20:40,600 --> 00:20:43,120 Speaker 1: of the Sun, you're not really in a simple orbit 397 00:20:43,160 --> 00:20:46,440 Speaker 1: anymore because now there's drag. Right, You're like flying through 398 00:20:46,560 --> 00:20:49,240 Speaker 1: plasma of the Sun that slows you down. In our 399 00:20:49,280 --> 00:20:51,639 Speaker 1: current orbit, we don't really hit very much, right, and 400 00:20:51,640 --> 00:20:53,720 Speaker 1: we don't lose a lot of kinetic energy as we 401 00:20:53,760 --> 00:20:55,760 Speaker 1: go around. But this is gonna be like flying through 402 00:20:55,760 --> 00:20:58,040 Speaker 1: the outer surfaces of the Sun, sort of like a 403 00:20:58,080 --> 00:21:01,399 Speaker 1: spaceship experiencing drag. It flies in too low an orbit, 404 00:21:01,560 --> 00:21:04,480 Speaker 1: it gets pulled down into the planet. So even a 405 00:21:04,520 --> 00:21:07,399 Speaker 1: tiny little bit of getting engulfed by the Sun means 406 00:21:07,400 --> 00:21:10,879 Speaker 1: the Earth eventually just plummets directly into the Sun. I 407 00:21:10,880 --> 00:21:13,240 Speaker 1: shouldn't have asked, how is that for sleeping at night? 408 00:21:13,320 --> 00:21:21,000 Speaker 1: Exactly all right, So now the Earth has been absorbed 409 00:21:21,040 --> 00:21:23,919 Speaker 1: by the Sun. What happens after that? The Sun is 410 00:21:23,920 --> 00:21:26,520 Speaker 1: non as red giant phase, it's very bright as a 411 00:21:26,640 --> 00:21:29,320 Speaker 1: huge radius, and now it moves to the next stage, 412 00:21:29,480 --> 00:21:32,760 Speaker 1: which is that it begins to fuse helium. So mostly 413 00:21:32,760 --> 00:21:36,040 Speaker 1: at the core we have hydrogen that's fusing into helium. 414 00:21:36,080 --> 00:21:38,400 Speaker 1: But if the Sun has enough mass, and Ours does. 415 00:21:38,680 --> 00:21:41,800 Speaker 1: Eventually it will reach a temperature where helium itself can 416 00:21:41,840 --> 00:21:44,439 Speaker 1: get fused into heavier stuff. Now, if we have an 417 00:21:44,520 --> 00:21:47,919 Speaker 1: even more massive star tens or hundreds of times the 418 00:21:47,960 --> 00:21:50,160 Speaker 1: mass of the Sun, this could go into the next 419 00:21:50,200 --> 00:21:52,800 Speaker 1: stage where helium then fuses into something else, which then 420 00:21:52,800 --> 00:21:54,760 Speaker 1: fuses into something else, and you get elements all the 421 00:21:54,760 --> 00:21:57,520 Speaker 1: way up there, like iron in the heaviest of stars. 422 00:21:57,520 --> 00:21:59,840 Speaker 1: Ours isn't big enough to do that. We can only 423 00:22:00,000 --> 00:22:03,560 Speaker 1: achieve helium fusion. But when that happens, it's really awesome 424 00:22:03,920 --> 00:22:06,880 Speaker 1: because the whole stage just lasts for a few seconds. 425 00:22:06,920 --> 00:22:10,640 Speaker 1: It's like we fuse hydrogen for billions of years, accumulating 426 00:22:10,680 --> 00:22:13,560 Speaker 1: all this helium ash, and then once the helium is 427 00:22:13,560 --> 00:22:15,840 Speaker 1: ready to fuse, we burn through that in just a 428 00:22:15,880 --> 00:22:19,879 Speaker 1: few seconds, creating this incredible helium flash. Oh my gosh. 429 00:22:19,960 --> 00:22:23,600 Speaker 1: Is this where galactic cosmic radiation comes from in bigger 430 00:22:23,680 --> 00:22:26,800 Speaker 1: stars where they make iron ions and then shoot them 431 00:22:26,800 --> 00:22:28,800 Speaker 1: out or is that a different process? I think that's 432 00:22:28,800 --> 00:22:31,359 Speaker 1: a different process. This helium flash turns out to me 433 00:22:31,600 --> 00:22:35,120 Speaker 1: entirely internal to the star because the star is opaque 434 00:22:35,119 --> 00:22:37,880 Speaker 1: to this radiation. So even though it releases like as 435 00:22:38,000 --> 00:22:41,000 Speaker 1: much light as the entire Milky Way, like as much 436 00:22:41,000 --> 00:22:43,879 Speaker 1: as billions of stars. It's all internally absorbed, so you 437 00:22:43,880 --> 00:22:46,280 Speaker 1: can't actually see it from the outside. But it's very 438 00:22:46,320 --> 00:22:49,520 Speaker 1: cool this helium flash which just last for seconds. I 439 00:22:49,600 --> 00:22:52,320 Speaker 1: love the discrepancy there, and like how long we burn hydrogen, 440 00:22:52,480 --> 00:22:55,240 Speaker 1: how long we burn helium? And in other stars where 441 00:22:55,240 --> 00:22:58,399 Speaker 1: you continue, then these cycles get shorter and shorter, and 442 00:22:58,440 --> 00:23:01,080 Speaker 1: so you're like fusing iron for a very very small 443 00:23:01,119 --> 00:23:03,480 Speaker 1: amount of time before the star starts to go out. 444 00:23:03,640 --> 00:23:06,520 Speaker 1: That is incredible. Yeah, and it's really fascinating. Okay, so 445 00:23:06,560 --> 00:23:09,840 Speaker 1: we've we've lost the Earth, but there are proposals for 446 00:23:09,920 --> 00:23:12,919 Speaker 1: going to other places. So I want to know is 447 00:23:13,040 --> 00:23:15,920 Speaker 1: anything in the Solar System going to be left when 448 00:23:15,920 --> 00:23:19,240 Speaker 1: this is done? The Solar System will probably be totally unrecognizable. 449 00:23:19,520 --> 00:23:22,600 Speaker 1: I mean, remember that the Sun's weakening gravity also has 450 00:23:22,640 --> 00:23:26,520 Speaker 1: impacts on other planets, right, So Jupiter and Saturn, for example, 451 00:23:26,760 --> 00:23:30,399 Speaker 1: will get much larger orbits because the Sun's gravity it 452 00:23:30,480 --> 00:23:33,119 Speaker 1: gets weaker as it loses a little bit of its mass, 453 00:23:33,240 --> 00:23:34,720 Speaker 1: and this is going to create a lot of chaos 454 00:23:34,800 --> 00:23:38,360 Speaker 1: for the Solar System. Anytime Jupiter does anything, it creates chaos, 455 00:23:38,640 --> 00:23:41,720 Speaker 1: and now you're moving Jupiter and Saturn like two entirely 456 00:23:41,760 --> 00:23:45,360 Speaker 1: new orbits. Probably they will eject all the other planets 457 00:23:45,359 --> 00:23:48,520 Speaker 1: in the Solar System, bye by Neptune, by by Uranus, 458 00:23:48,520 --> 00:23:50,959 Speaker 1: bye by Pluto, whether or not you call it a planet, 459 00:23:51,040 --> 00:23:55,120 Speaker 1: they're all probably gone. And why it's always Jupiter. Jupiter 460 00:23:55,200 --> 00:23:57,280 Speaker 1: is the big bully of the Solar System. And in 461 00:23:57,359 --> 00:23:59,720 Speaker 1: some of these simulations I've seen, we're basically left with 462 00:24:00,200 --> 00:24:03,760 Speaker 1: Jupiter right as the only planet now. And then after 463 00:24:03,800 --> 00:24:06,879 Speaker 1: the Sun is done expanding, then it collapses into a 464 00:24:06,920 --> 00:24:09,159 Speaker 1: white dwarf, and that's what's left behind. You have this 465 00:24:09,280 --> 00:24:12,760 Speaker 1: hot lob of glowing helium fusion products. You have some helium, 466 00:24:12,880 --> 00:24:15,520 Speaker 1: some carbon maybe, and that's all that's left. And the 467 00:24:15,560 --> 00:24:18,600 Speaker 1: outer layers that were the red giant I'll get blown out. 468 00:24:19,080 --> 00:24:22,280 Speaker 1: And so you have like Jupiter, solo planet orbiting this 469 00:24:22,359 --> 00:24:25,040 Speaker 1: hot lump of helium and carbon. Does it just keep 470 00:24:25,080 --> 00:24:27,639 Speaker 1: glowing for eternity? Does does something else happen to it 471 00:24:27,720 --> 00:24:30,359 Speaker 1: after that? So it's not fusing anymore, but it's still 472 00:24:30,440 --> 00:24:33,000 Speaker 1: really really hot. So I think about what happens to 473 00:24:33,080 --> 00:24:36,200 Speaker 1: like a lump of hot stuff in space. It's glowing 474 00:24:36,280 --> 00:24:39,439 Speaker 1: which means it's losing energy, so it's cooling down, but 475 00:24:39,480 --> 00:24:43,879 Speaker 1: it happens really slowly. So scientists think that a white dwarf, eventually, 476 00:24:43,960 --> 00:24:47,359 Speaker 1: after trillions of years, will cool down so it's not 477 00:24:47,440 --> 00:24:50,560 Speaker 1: glowing anymore, and they call that a black dwarf. But 478 00:24:50,680 --> 00:24:53,680 Speaker 1: our universe isn't old enough to have any black dwarfs 479 00:24:53,680 --> 00:24:55,639 Speaker 1: in it. So we have a bunch of white dwarves, 480 00:24:55,640 --> 00:24:57,919 Speaker 1: but none of them have cooled yet because our universe 481 00:24:57,960 --> 00:25:00,800 Speaker 1: is still so young on that time, do we have 482 00:25:00,920 --> 00:25:04,000 Speaker 1: an estimate for when we might find the first black dwarf? 483 00:25:04,280 --> 00:25:07,560 Speaker 1: Trillions of years. These things can stay hot in space 484 00:25:07,600 --> 00:25:10,560 Speaker 1: for a long long time. Remember, in space, it is 485 00:25:10,600 --> 00:25:13,360 Speaker 1: actually harder to lose your energy, to lose your heat 486 00:25:13,520 --> 00:25:15,760 Speaker 1: than it is here on Earth because there is no air. 487 00:25:16,119 --> 00:25:18,639 Speaker 1: All you can do is radiated away. There's no like 488 00:25:18,760 --> 00:25:21,959 Speaker 1: wind to come and cool you down. Got it. Okay, Well, 489 00:25:22,680 --> 00:25:24,560 Speaker 1: now you have made it so it will be tough 490 00:25:24,640 --> 00:25:26,760 Speaker 1: for me to sleep at night. But we still have 491 00:25:26,920 --> 00:25:30,520 Speaker 1: some time left on this podcast, and so after this break, 492 00:25:30,560 --> 00:25:32,360 Speaker 1: I'm going to ask you to tell me if there's 493 00:25:32,359 --> 00:25:48,240 Speaker 1: any prospects for survival. Okay, we're back from the break. 494 00:25:49,200 --> 00:25:51,760 Speaker 1: What kind of options do we have for being proactive 495 00:25:51,760 --> 00:25:53,439 Speaker 1: about this problem? Because you know, if I was going 496 00:25:53,480 --> 00:25:55,480 Speaker 1: to tell my kids about a problem, I'd want to 497 00:25:55,480 --> 00:25:57,800 Speaker 1: make sure I had some strategies I can tell them 498 00:25:57,800 --> 00:26:00,720 Speaker 1: about so they felt like they had so control over 499 00:26:00,760 --> 00:26:03,639 Speaker 1: the situation. Yeah, there are a lot of clever people 500 00:26:03,720 --> 00:26:06,679 Speaker 1: thinking deeply about these problems, and I think it's super 501 00:26:06,680 --> 00:26:08,439 Speaker 1: fun to think about problems that you don't need to 502 00:26:08,440 --> 00:26:10,800 Speaker 1: solve for millions or billions of years, because you know, 503 00:26:10,920 --> 00:26:13,240 Speaker 1: the technology is going to be different in a million 504 00:26:13,320 --> 00:26:16,320 Speaker 1: years and people will have better ideas. But that only 505 00:26:16,400 --> 00:26:19,119 Speaker 1: happens if we start thinking about it now, right, we 506 00:26:19,359 --> 00:26:22,800 Speaker 1: have to begin those explorations. You start with the bad ideas, 507 00:26:22,840 --> 00:26:24,920 Speaker 1: and those generate the good ideas. That's sort of like 508 00:26:25,040 --> 00:26:27,480 Speaker 1: the way my research happens. A student comes into my 509 00:26:27,560 --> 00:26:30,120 Speaker 1: office and we sort of brainstorm bad ideas until one 510 00:26:30,119 --> 00:26:32,600 Speaker 1: of them turns into a good idea. So it's important 511 00:26:32,600 --> 00:26:35,440 Speaker 1: that we dig into this stuff now, and the ideas 512 00:26:35,440 --> 00:26:38,200 Speaker 1: are sort of categorized by like what time scale we're 513 00:26:38,200 --> 00:26:41,240 Speaker 1: talking about, you know, before, for example, the sun actually 514 00:26:41,280 --> 00:26:44,879 Speaker 1: grows to have the radius of the orbit of the Earth, 515 00:26:45,080 --> 00:26:47,760 Speaker 1: we still have to worry about things getting hotter right 516 00:26:47,800 --> 00:26:50,640 Speaker 1: like before five billion years from now when we risk 517 00:26:50,720 --> 00:26:54,520 Speaker 1: being engulfed, we still need to survive somehow without our 518 00:26:54,560 --> 00:26:57,000 Speaker 1: oceans boiling. You know, it almost seems like we should 519 00:26:57,040 --> 00:26:59,280 Speaker 1: start worrying about what your planet does when it gets hotter, 520 00:26:59,440 --> 00:27:03,040 Speaker 1: like you know now anyway, Yeah, that's right. We have 521 00:27:03,119 --> 00:27:05,960 Speaker 1: other reasons to worry about how to keep the Earth cool, 522 00:27:06,040 --> 00:27:08,760 Speaker 1: like how do you build a planet wide cooling system? 523 00:27:08,960 --> 00:27:10,920 Speaker 1: And so this is something people are thinking about, and 524 00:27:10,960 --> 00:27:13,960 Speaker 1: it's something you could actually get started on, like tomorrow. 525 00:27:14,280 --> 00:27:19,119 Speaker 1: Some of these strategies, like geo engineering, involves spraying things 526 00:27:19,160 --> 00:27:23,720 Speaker 1: into the atmosphere to reflect more of the Sun's light. Basically, 527 00:27:23,960 --> 00:27:26,200 Speaker 1: even though the Sun is going to get hotter and brighter, 528 00:27:26,400 --> 00:27:28,639 Speaker 1: we just want less of that energy to fall on 529 00:27:28,680 --> 00:27:31,080 Speaker 1: the Earth and we should be okay. These kinds of 530 00:27:31,080 --> 00:27:33,400 Speaker 1: proposals always make me a little nervous because I feel 531 00:27:33,440 --> 00:27:37,040 Speaker 1: like we still don't understand what causes climate. And if 532 00:27:37,080 --> 00:27:40,720 Speaker 1: you do something like you know, spraying particles are blocking 533 00:27:40,760 --> 00:27:43,320 Speaker 1: part of the sun, there's just as good a chance 534 00:27:43,320 --> 00:27:45,359 Speaker 1: that you're going to mess something up. But here's hoping 535 00:27:45,840 --> 00:27:48,000 Speaker 1: we figure this all out soon. So what kind of 536 00:27:48,000 --> 00:27:50,400 Speaker 1: stuff are we thinking of trying to spray up there. 537 00:27:50,600 --> 00:27:52,960 Speaker 1: It's definitely a Rube Goldberg device, right. We have no 538 00:27:53,000 --> 00:27:54,920 Speaker 1: idea how these things are working, and we're like, huh, 539 00:27:55,040 --> 00:27:57,520 Speaker 1: let's just add another gear over here and see what happens. 540 00:27:57,760 --> 00:28:01,320 Speaker 1: One thing that people are thinking about is sulfur. Sulfur 541 00:28:01,440 --> 00:28:04,359 Speaker 1: is very reflective and not that expensive, and we have 542 00:28:04,400 --> 00:28:06,400 Speaker 1: a lot of it. So if you just like spread 543 00:28:06,400 --> 00:28:09,840 Speaker 1: a bunch of sulfur into the upper atmosphere, that would 544 00:28:09,840 --> 00:28:13,200 Speaker 1: effectively reflect a lot of the light that is hitting 545 00:28:13,200 --> 00:28:15,960 Speaker 1: the earth and cool it down. This is something people 546 00:28:16,000 --> 00:28:18,800 Speaker 1: are thinking about, like for climate change today, and what 547 00:28:18,840 --> 00:28:21,600 Speaker 1: we're talking about today on the podcast is effectively climate 548 00:28:21,680 --> 00:28:24,600 Speaker 1: change writ large the sun getting much much brighter and 549 00:28:24,640 --> 00:28:27,919 Speaker 1: a lot more energy. So the same kinds of solutions 550 00:28:27,960 --> 00:28:30,000 Speaker 1: are being considered, but this would have a lot of 551 00:28:30,040 --> 00:28:32,560 Speaker 1: weird effects on the climate on the Earth, and would 552 00:28:32,560 --> 00:28:34,800 Speaker 1: they stay where we put them? They would not necessarily 553 00:28:34,840 --> 00:28:37,080 Speaker 1: stay where we put them, and there are currents up 554 00:28:37,080 --> 00:28:39,920 Speaker 1: there right. Also, these things would eventually drift back down, 555 00:28:39,920 --> 00:28:43,000 Speaker 1: so we need to continuously pump sulfur into the atmosphere 556 00:28:43,040 --> 00:28:45,120 Speaker 1: to replace it. And it would also change a lot 557 00:28:45,200 --> 00:28:47,400 Speaker 1: what it's like to be on the Earth. If we 558 00:28:47,480 --> 00:28:50,440 Speaker 1: had this like diffuse shield, it would bounce the Sun's 559 00:28:50,560 --> 00:28:53,360 Speaker 1: light around a lot, so you wouldn't necessarily like see 560 00:28:53,400 --> 00:28:56,320 Speaker 1: a sun in the sky. It's like the whole sky 561 00:28:56,400 --> 00:28:58,760 Speaker 1: would go from being blue with like a yellow sun 562 00:28:58,760 --> 00:29:02,760 Speaker 1: in it just being like white glow. This honestly isn't 563 00:29:02,760 --> 00:29:05,840 Speaker 1: sounding like a great idea to me so far. It's 564 00:29:05,880 --> 00:29:07,520 Speaker 1: sort of like, you know on a cloudy day, how 565 00:29:07,560 --> 00:29:10,080 Speaker 1: it can feel bright even though you can't see the sun. 566 00:29:10,400 --> 00:29:12,880 Speaker 1: It would be a very different experience of being a human. 567 00:29:13,280 --> 00:29:14,960 Speaker 1: And the other issue is that it wouldn't have a 568 00:29:15,000 --> 00:29:17,920 Speaker 1: constant effect everywhere on the Earth. It would change the climate. 569 00:29:18,120 --> 00:29:20,200 Speaker 1: Parts of the Earth would get hotter and other parts 570 00:29:20,200 --> 00:29:22,760 Speaker 1: would get colder. So even though on average you might 571 00:29:22,880 --> 00:29:25,400 Speaker 1: keep the same temperature, the tropics would be cooler and 572 00:29:25,400 --> 00:29:27,600 Speaker 1: the high latitudes would be a little bit warmer. And 573 00:29:27,640 --> 00:29:30,280 Speaker 1: that would have all sorts of crazy effects like flooding 574 00:29:30,320 --> 00:29:34,120 Speaker 1: certain areas, making other areas drier. And I'm pretty sure 575 00:29:34,160 --> 00:29:36,520 Speaker 1: that you know, different countries would have different opinions about 576 00:29:36,520 --> 00:29:39,200 Speaker 1: like who gets a drought this year? Yeah, well, I mean, 577 00:29:39,200 --> 00:29:42,280 Speaker 1: I suppose it's it's all better than the oceans boiling, 578 00:29:42,560 --> 00:29:45,000 Speaker 1: But it doesn't sound ideal, and hopefully by then we're 579 00:29:45,040 --> 00:29:48,040 Speaker 1: all getting along really well. So well refugees are fleeing 580 00:29:48,080 --> 00:29:51,240 Speaker 1: around the planets, they'll be welcomed with open arms. Yeah. 581 00:29:51,320 --> 00:29:53,040 Speaker 1: I don't have a lot of hope for us coming 582 00:29:53,120 --> 00:29:56,880 Speaker 1: up with communal compromises to these big decisions. So, but 583 00:29:56,960 --> 00:29:58,880 Speaker 1: you know, this is the kind of strategy people are 584 00:29:58,920 --> 00:30:02,360 Speaker 1: thinking about for sort of short term geo engineering of 585 00:30:02,480 --> 00:30:05,120 Speaker 1: preventing the Earth from getting toasted. All right, so that 586 00:30:05,480 --> 00:30:09,160 Speaker 1: messing with our atmosphere is one method which sounds a 587 00:30:09,200 --> 00:30:12,360 Speaker 1: little scary. Can we stop the Sun before it gets 588 00:30:12,440 --> 00:30:15,280 Speaker 1: to our atmosphere? Yeah, some people are thinking about like 589 00:30:15,360 --> 00:30:19,120 Speaker 1: building massive space mirrors to reflect the light. Right, so 590 00:30:19,160 --> 00:30:23,400 Speaker 1: instead of geo engineering, like, let's have massive space engineering projects. 591 00:30:23,800 --> 00:30:25,600 Speaker 1: And the idea is that all you need to do 592 00:30:25,840 --> 00:30:29,440 Speaker 1: is counteract, Like currently two percent of the energy that 593 00:30:29,560 --> 00:30:33,000 Speaker 1: comes to the Earth would solve our global warming problem. 594 00:30:33,280 --> 00:30:35,120 Speaker 1: And then in the future you need more and more 595 00:30:35,200 --> 00:30:37,560 Speaker 1: to protect ourselves from the growing sun. But you know, 596 00:30:37,600 --> 00:30:40,640 Speaker 1: there are attractive places to put this in space. You've 597 00:30:40,640 --> 00:30:43,880 Speaker 1: probably heard of the L two lagrange point, which is 598 00:30:43,880 --> 00:30:47,880 Speaker 1: a gravitationally stable place where the James Web space telescope 599 00:30:47,960 --> 00:30:50,160 Speaker 1: is it's like along the line between the Sun and 600 00:30:50,200 --> 00:30:52,360 Speaker 1: the Earth. For example, it keeps the Earth between it 601 00:30:52,560 --> 00:30:54,960 Speaker 1: and the Sun. So it's a stable place where the 602 00:30:55,040 --> 00:30:57,720 Speaker 1: James Webb could stay in the shadow of the Earth. 603 00:30:57,920 --> 00:31:01,680 Speaker 1: There's another one, the l one lagrange point, is between 604 00:31:01,720 --> 00:31:04,080 Speaker 1: the Earth and the Sun and it's also stable, so 605 00:31:04,080 --> 00:31:07,000 Speaker 1: you put something there and it will remain between the 606 00:31:07,040 --> 00:31:08,600 Speaker 1: Earth and the Sun. So you could build like a 607 00:31:08,640 --> 00:31:11,440 Speaker 1: shield and put it at the l one point and 608 00:31:11,480 --> 00:31:15,959 Speaker 1: the Earth has like a little parasol. How cute and charming, 609 00:31:16,240 --> 00:31:18,320 Speaker 1: But it would probably have to be huge. It sounds 610 00:31:18,360 --> 00:31:20,480 Speaker 1: like a tough engineering problem. But we've got like a 611 00:31:20,520 --> 00:31:22,680 Speaker 1: billion years. How how big would it need to be. 612 00:31:22,920 --> 00:31:25,480 Speaker 1: The l One point is four times the distance from 613 00:31:25,480 --> 00:31:28,160 Speaker 1: the Earth to the Moon, so it's pretty far away 614 00:31:28,560 --> 00:31:30,960 Speaker 1: and that makes it a challenge, right because the further 615 00:31:31,040 --> 00:31:33,400 Speaker 1: away it is from the Earth, the bigger it has 616 00:31:33,440 --> 00:31:36,240 Speaker 1: to be. And imagine like a shield at the Earth. 617 00:31:36,560 --> 00:31:38,520 Speaker 1: You could be the size of the Earth and totally 618 00:31:38,560 --> 00:31:40,880 Speaker 1: block the Sun. But as that shield gets closer and 619 00:31:40,920 --> 00:31:43,280 Speaker 1: closer to the Sun, it needs to get bigger and 620 00:31:43,320 --> 00:31:46,600 Speaker 1: bigger to effectively shield the Earth. Like an earth size 621 00:31:46,600 --> 00:31:49,480 Speaker 1: shield at the Sun would basically do nothing. So the 622 00:31:49,640 --> 00:31:52,240 Speaker 1: l one point is four times the Earth Moon distance. 623 00:31:52,360 --> 00:31:56,200 Speaker 1: So you need a shield that's like a million square kilometers, 624 00:31:56,360 --> 00:31:59,520 Speaker 1: have to be basically as big as the Moon. And 625 00:31:59,560 --> 00:32:01,280 Speaker 1: do you have to worry about like, you know, so 626 00:32:01,320 --> 00:32:05,120 Speaker 1: there's stuff shooting around in space, you know, running into 627 00:32:05,120 --> 00:32:07,160 Speaker 1: stuff and causing problems. Do you have to worry I 628 00:32:07,200 --> 00:32:08,960 Speaker 1: guess you'd have to worry about it poking a hole 629 00:32:09,080 --> 00:32:11,040 Speaker 1: or something big enough hitting it and moving it out 630 00:32:11,040 --> 00:32:13,400 Speaker 1: of orbits or is there nothing big enough that could 631 00:32:13,440 --> 00:32:16,040 Speaker 1: move something four times the moon? No, there is definitely 632 00:32:16,080 --> 00:32:18,240 Speaker 1: something big enough, and that's the Sun. Like you build 633 00:32:18,240 --> 00:32:20,880 Speaker 1: a big shield that is that wide, it's basically a 634 00:32:20,920 --> 00:32:23,360 Speaker 1: solar sale and it'll just fly away, right, And so 635 00:32:23,520 --> 00:32:26,760 Speaker 1: you have to worry about this somehow, right, Like if 636 00:32:26,880 --> 00:32:29,760 Speaker 1: it's reflective, then it's going to get pushed away by 637 00:32:29,760 --> 00:32:32,200 Speaker 1: the Sun, even if it's just like black, and then 638 00:32:32,200 --> 00:32:34,280 Speaker 1: it's going to absorb all that energy. It's going to 639 00:32:34,360 --> 00:32:37,160 Speaker 1: get overheated and it's still going to absorb all that momentum. 640 00:32:37,280 --> 00:32:39,400 Speaker 1: And so people have really worried about how to design 641 00:32:39,440 --> 00:32:42,200 Speaker 1: this thing. And there's a guy, Roger Angel, who has 642 00:32:42,240 --> 00:32:44,920 Speaker 1: this idea instead of like a big sheets like make 643 00:32:45,000 --> 00:32:48,760 Speaker 1: it a screen, and so instead of absorbing the light 644 00:32:48,880 --> 00:32:51,640 Speaker 1: or reflecting the light, it's like just bend the light. 645 00:32:51,960 --> 00:32:54,600 Speaker 1: So it's like a huge lens, but built out of 646 00:32:54,640 --> 00:32:58,000 Speaker 1: these little rings, each of which deflects light away from 647 00:32:58,000 --> 00:33:00,240 Speaker 1: the earth, so it doesn't get any momentum pressure or 648 00:33:00,360 --> 00:33:02,200 Speaker 1: it just sort of like bends some of the light 649 00:33:02,240 --> 00:33:04,800 Speaker 1: out of our path. That's pretty cool. And what would 650 00:33:04,840 --> 00:33:07,080 Speaker 1: this change the amount of light that the whole Earth 651 00:33:07,120 --> 00:33:09,719 Speaker 1: gets or would this be like, you know, the southern 652 00:33:09,760 --> 00:33:12,920 Speaker 1: hemisphere gets as much light, Like is it going to 653 00:33:13,000 --> 00:33:16,440 Speaker 1: be evenly distributed? That's a great question. Probably wouldn't be. 654 00:33:16,440 --> 00:33:18,840 Speaker 1: I think you'd probably get most deflection at the center, 655 00:33:19,160 --> 00:33:21,120 Speaker 1: and other places would get some of the light that 656 00:33:21,120 --> 00:33:23,080 Speaker 1: would have gone to the equator we go to higher 657 00:33:23,120 --> 00:33:26,480 Speaker 1: latitudes for example. That's a good question. But even this 658 00:33:26,520 --> 00:33:30,280 Speaker 1: would still need to be really big, Like initial designs 659 00:33:30,320 --> 00:33:34,640 Speaker 1: for this kind of shield would require twenty million tons 660 00:33:34,680 --> 00:33:37,360 Speaker 1: of mass. Oh my gosh, I mean that's going to 661 00:33:37,440 --> 00:33:40,480 Speaker 1: be incredibly expensive, but I guess all the world's governments 662 00:33:40,480 --> 00:33:45,120 Speaker 1: would probably pitch in. Hopefully, Elon Musk and his generations 663 00:33:45,120 --> 00:33:47,959 Speaker 1: of descendants have driven the cost down to like a 664 00:33:47,960 --> 00:33:50,640 Speaker 1: penny per pound or something by that point, I don't know. 665 00:33:50,720 --> 00:33:53,360 Speaker 1: There are ideas about building this thing on the moon 666 00:33:53,600 --> 00:33:56,240 Speaker 1: and then launching it from there, but you know, we're 667 00:33:56,280 --> 00:33:59,320 Speaker 1: talking about an incredible space industry, and you know, we 668 00:33:59,400 --> 00:34:02,400 Speaker 1: are far far away from being able to build anything 669 00:34:02,400 --> 00:34:04,480 Speaker 1: on the moon. Even getting people to the Moon right 670 00:34:04,480 --> 00:34:07,440 Speaker 1: now is challenging for us. Another idea I read about, 671 00:34:07,440 --> 00:34:09,919 Speaker 1: which is really cool, is to develop a new kind 672 00:34:09,920 --> 00:34:13,840 Speaker 1: of launch technology, magnetic launch, when you basically have like 673 00:34:13,880 --> 00:34:17,239 Speaker 1: an aluminum tube and a magnetic field rises up the 674 00:34:17,280 --> 00:34:19,920 Speaker 1: tube and pushes a piece of metal up into space. 675 00:34:20,120 --> 00:34:22,680 Speaker 1: It's sort of like a maglev version of a train, 676 00:34:22,800 --> 00:34:25,640 Speaker 1: but vertical. So first you'd process the aluminum out of 677 00:34:25,640 --> 00:34:28,600 Speaker 1: the regulars and then you'd shoot it. He's in one 678 00:34:28,600 --> 00:34:31,480 Speaker 1: of these canons. Yeah, but this is technology that's like 679 00:34:31,680 --> 00:34:34,360 Speaker 1: very speculative. People have like worked on the theory of it, 680 00:34:34,400 --> 00:34:36,640 Speaker 1: but nobody's ever built one of these things before. But 681 00:34:36,719 --> 00:34:38,759 Speaker 1: you know, this is like, how could we solve this one? 682 00:34:38,760 --> 00:34:41,640 Speaker 1: Are the biggest problems involved? You know, this is passing 683 00:34:41,640 --> 00:34:43,920 Speaker 1: it off to the engineers. Were like, in theory, if 684 00:34:43,920 --> 00:34:46,280 Speaker 1: we put a shield in l one, that might work. 685 00:34:46,520 --> 00:34:48,480 Speaker 1: Let's let the engineers figure out how to build it. 686 00:34:48,640 --> 00:34:50,879 Speaker 1: So you said that L one is stable, Is it 687 00:34:50,920 --> 00:34:53,960 Speaker 1: perfectly stable? Like if you put those rings there, are 688 00:34:53,960 --> 00:34:57,000 Speaker 1: they really going to stay there forever? They are not. Unfortunately, 689 00:34:57,239 --> 00:35:01,000 Speaker 1: these places are quasi stable, right. Stay Able technically means 690 00:35:01,160 --> 00:35:02,879 Speaker 1: you get pushed away from it a little bit, then 691 00:35:02,920 --> 00:35:06,000 Speaker 1: the force naturally restores you to the original location, whereas 692 00:35:06,080 --> 00:35:08,960 Speaker 1: unstable at the opposite unstable means that as soon as 693 00:35:09,000 --> 00:35:11,560 Speaker 1: you deviate from it a tiny little bit, then you 694 00:35:11,640 --> 00:35:14,560 Speaker 1: get further away. Like a pencil balancing on its tip 695 00:35:14,840 --> 00:35:18,240 Speaker 1: is unstable. It could balance there if a state exactly vertical, 696 00:35:18,480 --> 00:35:20,719 Speaker 1: as soon as it leans over a little bit, then 697 00:35:20,800 --> 00:35:23,560 Speaker 1: the game is over. So these things are quasi stable, 698 00:35:23,560 --> 00:35:26,799 Speaker 1: which means some deviations get pushed back and some deviations 699 00:35:26,840 --> 00:35:30,279 Speaker 1: don't get pushed back, and eventually we'll lose them all, 700 00:35:30,520 --> 00:35:33,719 Speaker 1: so we'll need to continuously be shooting up new elements 701 00:35:33,760 --> 00:35:35,560 Speaker 1: of it. And the good news is you don't just 702 00:35:35,640 --> 00:35:38,680 Speaker 1: need like one big piece. It's okay to have like 703 00:35:38,920 --> 00:35:42,680 Speaker 1: two thousand or two million small little lenses that each 704 00:35:42,760 --> 00:35:45,280 Speaker 1: blur the sun's light a little bit, so it's okay 705 00:35:45,280 --> 00:35:47,960 Speaker 1: to continuously lose them and then build more, but it 706 00:35:48,000 --> 00:35:50,879 Speaker 1: means a continuing expense. Let's make sure we don't mess 707 00:35:50,960 --> 00:35:53,200 Speaker 1: up those lenses and then all end up like ants 708 00:35:53,239 --> 00:35:57,719 Speaker 1: under some kids, magnifying less. Al Right, So any of 709 00:35:57,760 --> 00:36:00,479 Speaker 1: these methods that we've just talked about are just buying 710 00:36:00,560 --> 00:36:03,160 Speaker 1: us time. So this is to try to reduce the 711 00:36:03,200 --> 00:36:06,640 Speaker 1: temperature increase as the Sun is getting closer, but the 712 00:36:06,680 --> 00:36:09,120 Speaker 1: Earth is still going to get engulfed. So we need 713 00:36:09,239 --> 00:36:12,360 Speaker 1: some way to outrun the Sun, some bigger solutions. So 714 00:36:12,400 --> 00:36:14,640 Speaker 1: we're gonna need something else. What are some of these 715 00:36:14,680 --> 00:36:18,560 Speaker 1: longer term solutions. Yeah, you're right. Eventually we want to 716 00:36:18,600 --> 00:36:21,600 Speaker 1: move the Earth somehow in order to avoid it getting 717 00:36:21,640 --> 00:36:24,880 Speaker 1: engulfed and dropping into the Sun. And you know, this 718 00:36:24,920 --> 00:36:27,080 Speaker 1: is a really fun idea, and it appears a lot 719 00:36:27,080 --> 00:36:29,440 Speaker 1: of times in science fiction, which means a lot of 720 00:36:29,440 --> 00:36:31,840 Speaker 1: people have thought about it. You know, science fiction authors 721 00:36:31,840 --> 00:36:35,640 Speaker 1: really do contribute to these problems by thinking through the details. 722 00:36:35,680 --> 00:36:38,160 Speaker 1: And here we really benefit from the fact that the 723 00:36:38,200 --> 00:36:41,480 Speaker 1: Sun's intensity, the amount of light you get falls very 724 00:36:41,560 --> 00:36:44,160 Speaker 1: quickly as you get further away. Right, it's not like 725 00:36:44,320 --> 00:36:46,920 Speaker 1: twice as far away you get half the sunlight. Twice 726 00:36:46,920 --> 00:36:49,240 Speaker 1: as far away you get a quarter of the sunlight. 727 00:36:49,320 --> 00:36:51,480 Speaker 1: And so if you want to remove like one percent 728 00:36:51,600 --> 00:36:54,400 Speaker 1: of the Sun's intensity of its lubidosity, you only need 729 00:36:54,440 --> 00:36:57,360 Speaker 1: to move the Earth half a percent further away. And 730 00:36:57,360 --> 00:36:59,799 Speaker 1: if you increase the radius less than ten percent, you 731 00:37:00,120 --> 00:37:03,560 Speaker 1: like twenty or more reduction in the Sun's light. So 732 00:37:03,600 --> 00:37:06,640 Speaker 1: the universe is against us, but for once, math and 733 00:37:06,719 --> 00:37:11,200 Speaker 1: physics are kind of on our side exactly. Then the 734 00:37:11,280 --> 00:37:15,080 Speaker 1: question is how do you get the Earth into another orbit? Right? 735 00:37:15,120 --> 00:37:17,520 Speaker 1: This is complicated. The Earth is a big mass with 736 00:37:17,680 --> 00:37:20,839 Speaker 1: a lot of kinetic energy. Moving it is not going 737 00:37:20,880 --> 00:37:23,520 Speaker 1: to be something that you can do easily. So people 738 00:37:23,520 --> 00:37:25,920 Speaker 1: have thought of a few different scenarios here. One of 739 00:37:25,960 --> 00:37:30,040 Speaker 1: my favorites is to use a gravitational slingshot. Like you 740 00:37:30,080 --> 00:37:34,600 Speaker 1: know how sometimes we send satellites around Jupiter to whizz 741 00:37:34,640 --> 00:37:37,960 Speaker 1: around and change their direction or even change their speed. Well, 742 00:37:37,960 --> 00:37:40,960 Speaker 1: that actually changes the flight path of Jupiter, right, It 743 00:37:41,040 --> 00:37:43,759 Speaker 1: steals a little bit of energy from Jupiter. So the 744 00:37:43,800 --> 00:37:45,960 Speaker 1: idea is to do sort of the opposite is to 745 00:37:46,040 --> 00:37:50,040 Speaker 1: send a big asteroid near the Earth, send it around 746 00:37:50,040 --> 00:37:52,680 Speaker 1: the Earth to sort of like push the Earth out right, 747 00:37:52,719 --> 00:37:55,200 Speaker 1: to like change the orbit of the Earth. I can't 748 00:37:55,200 --> 00:37:59,960 Speaker 1: imagine how that could go wrong. Tell that to your kids. 749 00:38:00,040 --> 00:38:03,239 Speaker 1: I'm sure they'll believe it. Well. In this case, people 750 00:38:03,280 --> 00:38:06,400 Speaker 1: have thought about an asteroid like a hundred kilometers y 751 00:38:06,640 --> 00:38:10,440 Speaker 1: something weighing like ten to the nine, And if you 752 00:38:10,480 --> 00:38:13,520 Speaker 1: have it like counterbalancing around the Earth, it could slowly 753 00:38:13,560 --> 00:38:16,600 Speaker 1: get pulled out and use Jupiter's gravity a little bit also, 754 00:38:16,760 --> 00:38:18,800 Speaker 1: and you get the Earth out to a larger radius. 755 00:38:18,960 --> 00:38:21,200 Speaker 1: And of course you need a whole different set of 756 00:38:21,239 --> 00:38:23,680 Speaker 1: physicists trying to figure out how you go about moving 757 00:38:23,719 --> 00:38:26,160 Speaker 1: an asteroid carefully. But that sounds like a fun problem 758 00:38:26,239 --> 00:38:28,720 Speaker 1: to solve. And I'm pretty sure that sixty two miles 759 00:38:28,800 --> 00:38:31,200 Speaker 1: is more than an extinction level event. If you mess 760 00:38:31,280 --> 00:38:34,080 Speaker 1: it up right, it is exactly. So that's danger number 761 00:38:34,080 --> 00:38:37,520 Speaker 1: one is oops, you killed everybody. Danger number two is 762 00:38:37,560 --> 00:38:40,560 Speaker 1: you miscalculated, and now the Earth doesn't have a larger radius. 763 00:38:40,600 --> 00:38:43,239 Speaker 1: It's got no radius. It's just getting ejected from the 764 00:38:43,280 --> 00:38:47,160 Speaker 1: Solar System and it's now flying free in dark dark space. 765 00:38:47,480 --> 00:38:50,359 Speaker 1: That's failure mode number two, neither of which you can 766 00:38:50,400 --> 00:38:53,440 Speaker 1: recover from. It's not like oops, let's try again or 767 00:38:53,480 --> 00:38:56,799 Speaker 1: something right. These are one time only mistakes. Yeah, we 768 00:38:56,800 --> 00:38:59,440 Speaker 1: should be investing in science more. But there's a cleverness 769 00:38:59,480 --> 00:39:02,640 Speaker 1: I like that because instead of moving the Earth now 770 00:39:02,719 --> 00:39:05,440 Speaker 1: you just have to move a hundred kilometer asteroid, which 771 00:39:05,480 --> 00:39:08,880 Speaker 1: seems easier I guess than moving the entire Earth. But 772 00:39:09,000 --> 00:39:11,080 Speaker 1: some folks are working on that, you know, they say, 773 00:39:11,120 --> 00:39:14,160 Speaker 1: how could we actually move the whole earth further out? 774 00:39:14,600 --> 00:39:18,399 Speaker 1: Like could you build engines like rocket engines and put 775 00:39:18,440 --> 00:39:21,520 Speaker 1: them on the south pole and fire them up and 776 00:39:21,560 --> 00:39:24,799 Speaker 1: like treat the whole earth as a spaceship move it 777 00:39:24,880 --> 00:39:28,040 Speaker 1: out to a larger radius. Well, I guess that you 778 00:39:28,160 --> 00:39:30,960 Speaker 1: also have to be pretty careful about not not messing up. 779 00:39:31,000 --> 00:39:33,640 Speaker 1: How much of an increase in radius are we talking. Well, 780 00:39:33,680 --> 00:39:35,680 Speaker 1: if you increase the radius by like four or something 781 00:39:35,719 --> 00:39:38,520 Speaker 1: per cent, then the energy you receive drops by like 782 00:39:38,600 --> 00:39:41,080 Speaker 1: ten percent. And you know, as the Sun gets larger 783 00:39:41,120 --> 00:39:43,799 Speaker 1: and larger over the next few billion years, we could 784 00:39:43,800 --> 00:39:46,640 Speaker 1: just like keep moving the Earth. One way to think 785 00:39:46,640 --> 00:39:49,120 Speaker 1: about it is that right now the Earth is in 786 00:39:49,120 --> 00:39:51,360 Speaker 1: the habitable region, right we have just about the right 787 00:39:51,400 --> 00:39:53,880 Speaker 1: amount of energy falling on the surface so that we 788 00:39:53,920 --> 00:39:56,920 Speaker 1: can survive. But as the Sun gets brighter and bigger, 789 00:39:57,239 --> 00:39:59,799 Speaker 1: the habitable zone changes, and so we could just sort 790 00:39:59,840 --> 00:40:03,160 Speaker 1: of cruise the Earth gradually, so we always stay in 791 00:40:03,239 --> 00:40:06,200 Speaker 1: the sweet spot. And if global warming hasn't killed us 792 00:40:06,200 --> 00:40:08,120 Speaker 1: by then, the amount of fossil fuels we're going to 793 00:40:08,200 --> 00:40:11,520 Speaker 1: have to burn to move the entire planet will probably 794 00:40:11,560 --> 00:40:14,600 Speaker 1: finish the job. Well, you know, people have talked about 795 00:40:14,680 --> 00:40:17,799 Speaker 1: using like a solar array, building one that's like ten 796 00:40:17,880 --> 00:40:21,480 Speaker 1: to the fifteen square meters, which captures a tiny fraction 797 00:40:21,520 --> 00:40:25,120 Speaker 1: of the Sun's energy, but that's ten times the surface 798 00:40:25,200 --> 00:40:28,000 Speaker 1: area of the Earth. And remember we talked about space 799 00:40:28,040 --> 00:40:30,680 Speaker 1: based solar power and you were pretty skeptical that we 800 00:40:30,680 --> 00:40:35,080 Speaker 1: could even like power Australia's refrigerators using space based technology. 801 00:40:35,480 --> 00:40:38,239 Speaker 1: Now we're talking about building a space based solar power 802 00:40:38,320 --> 00:40:41,440 Speaker 1: network that's ten times the surface area of the Earth, 803 00:40:41,640 --> 00:40:44,000 Speaker 1: and so that seems a little ambitious. Well, you know, 804 00:40:44,040 --> 00:40:47,040 Speaker 1: we've got some time. Are we just moving away or 805 00:40:47,080 --> 00:40:49,040 Speaker 1: at some point are we moving back in again? Like, 806 00:40:49,080 --> 00:40:50,399 Speaker 1: do we need to be able to go in both 807 00:40:50,400 --> 00:40:54,200 Speaker 1: directions long term? We do, absolutely, because what happens in 808 00:40:54,239 --> 00:40:55,840 Speaker 1: the very far future is that we just have that 809 00:40:55,880 --> 00:40:58,120 Speaker 1: white dwarf, right, and then we need to get pretty 810 00:40:58,160 --> 00:41:00,120 Speaker 1: close because the white dwarf is not going to be 811 00:41:00,200 --> 00:41:03,480 Speaker 1: that hot and there are habitable regions around white dwarfs. 812 00:41:03,480 --> 00:41:07,960 Speaker 1: In fact, astronomers found white dwarfs with planets before. In fact, 813 00:41:08,040 --> 00:41:11,640 Speaker 1: recently they found one it's called w D ten fifty 814 00:41:11,719 --> 00:41:14,680 Speaker 1: four to to six, that they think has a planet 815 00:41:14,760 --> 00:41:17,879 Speaker 1: in its habitable zone where the surface of it could 816 00:41:17,880 --> 00:41:21,520 Speaker 1: have like liquid water. So technically it is possible to 817 00:41:21,560 --> 00:41:24,799 Speaker 1: have a planet in orbit around a white dwarf. But 818 00:41:24,840 --> 00:41:27,000 Speaker 1: the plan would then be to have the Earth go 819 00:41:27,280 --> 00:41:29,719 Speaker 1: further out as the Sun expands, and then when the 820 00:41:29,719 --> 00:41:32,719 Speaker 1: Sun collapses again, to move the Earth back into the 821 00:41:32,760 --> 00:41:37,080 Speaker 1: now shrinking habitable zone. So I really like my schedule, 822 00:41:37,160 --> 00:41:39,800 Speaker 1: and I make three year plans and five year plans, 823 00:41:40,040 --> 00:41:42,719 Speaker 1: and I'm feeling like, if we're changing how far the 824 00:41:42,719 --> 00:41:45,279 Speaker 1: Earth is from the Sun, we're probably changing how long 825 00:41:45,320 --> 00:41:47,640 Speaker 1: a year is, and that's really going to mess up 826 00:41:48,000 --> 00:41:51,160 Speaker 1: my scheduling. Is this going to be a problem. This 827 00:41:51,239 --> 00:41:54,319 Speaker 1: is gonna be a big problem. Absolutely. For example, we 828 00:41:54,360 --> 00:41:56,760 Speaker 1: move the orbit of the Earth out by five percent 829 00:41:56,880 --> 00:41:59,680 Speaker 1: or something, the year is going to be fifteen percent 830 00:41:59,800 --> 00:42:02,360 Speaker 1: longer because our orbital speed is going to be slower. 831 00:42:02,480 --> 00:42:04,600 Speaker 1: Remember that the further away you are from the Sun, 832 00:42:04,640 --> 00:42:06,920 Speaker 1: the less the Sun pulls on you. And so the 833 00:42:06,960 --> 00:42:09,120 Speaker 1: slower you need to be going to be in orbit. 834 00:42:09,560 --> 00:42:11,799 Speaker 1: And so for example, in some of these scenarios, the 835 00:42:12,040 --> 00:42:15,080 Speaker 1: year is now four hundred and eighteen days. That's when 836 00:42:15,080 --> 00:42:17,600 Speaker 1: we're out at the larger radius, and then we bring 837 00:42:17,600 --> 00:42:20,080 Speaker 1: the Earth back in the year could be very short, right, 838 00:42:20,120 --> 00:42:22,239 Speaker 1: it could be several weeks long. So you could be 839 00:42:22,280 --> 00:42:25,360 Speaker 1: having birthdays like all the time. Oh nice, Although I 840 00:42:25,600 --> 00:42:28,600 Speaker 1: don't necessarily want to feel like I'm aging too much quicker. 841 00:42:29,400 --> 00:42:32,000 Speaker 1: I think I prefer the four hundred and eighteen day version. 842 00:42:32,040 --> 00:42:33,880 Speaker 1: I'll get much more done every year. I don't know. 843 00:42:33,920 --> 00:42:35,399 Speaker 1: Then you could, like, you know, live to the year 844 00:42:35,440 --> 00:42:37,920 Speaker 1: six hundred or something. Right, we could all have biblical ages. 845 00:42:41,000 --> 00:42:43,839 Speaker 1: That sounds great. We should bring back biblical names too. 846 00:42:44,120 --> 00:42:47,200 Speaker 1: They were more epic, although not more epic than waiters. 847 00:42:47,239 --> 00:42:49,120 Speaker 1: And I just want to comment that there's an idea 848 00:42:49,200 --> 00:42:52,440 Speaker 1: in a popular science fiction story called The Wandering Earth 849 00:42:52,520 --> 00:42:55,240 Speaker 1: where people move the Earth out of the Solar system. 850 00:42:55,239 --> 00:42:57,279 Speaker 1: They give up on the Sun entirely, and they're like, 851 00:42:57,520 --> 00:42:59,920 Speaker 1: let's just move to a different star, and there they 852 00:43:00,040 --> 00:43:03,960 Speaker 1: build these enormous engines, these plasma thrusters that pushed the 853 00:43:03,960 --> 00:43:06,600 Speaker 1: Earth like out of the Solar System to another planet, 854 00:43:06,600 --> 00:43:09,239 Speaker 1: like treat the whole Earth as a spaceship. And these 855 00:43:09,280 --> 00:43:12,799 Speaker 1: are crazy, these plasma engines they build. I read an 856 00:43:12,800 --> 00:43:15,239 Speaker 1: interview with a guy at JPL who works on these 857 00:43:15,280 --> 00:43:17,680 Speaker 1: kind of thrusters, and he was skeptical because he said 858 00:43:17,680 --> 00:43:21,240 Speaker 1: that it would require of the mass of the Earth 859 00:43:21,320 --> 00:43:23,439 Speaker 1: to be used as fuel. So I think that would 860 00:43:23,480 --> 00:43:26,120 Speaker 1: have some serious drawbacks. Yeah, I think maybe the math 861 00:43:26,200 --> 00:43:29,120 Speaker 1: on that one is not in our favor. So you 862 00:43:29,120 --> 00:43:31,279 Speaker 1: you told me that after we get to the point 863 00:43:31,320 --> 00:43:35,279 Speaker 1: where the Earth has been enveloped, everything's gonna go crazy, 864 00:43:35,440 --> 00:43:38,280 Speaker 1: and like, who knows what's going to survive, but probably 865 00:43:38,400 --> 00:43:42,880 Speaker 1: Jupiter is gonna survive. So rather than trying to do 866 00:43:42,920 --> 00:43:46,720 Speaker 1: these engineering solutions, which seemed like if you don't get perfect, 867 00:43:46,719 --> 00:43:48,200 Speaker 1: there's a big chance you're going to fail, and we've 868 00:43:48,239 --> 00:43:51,040 Speaker 1: never tried anything like this before, maybe we should just 869 00:43:51,520 --> 00:43:55,640 Speaker 1: move to Jupiter. But that's not an option. Are Jupiter's 870 00:43:55,719 --> 00:43:58,279 Speaker 1: moons still going to be around? Well, you know, it's 871 00:43:58,280 --> 00:44:00,960 Speaker 1: a good idea because Jupiter is likely to stay in 872 00:44:01,040 --> 00:44:04,280 Speaker 1: the habitable zone. Like in the new Sun, the habital 873 00:44:04,440 --> 00:44:07,400 Speaker 1: zone will probably include Jupiter, So it's not a terrible idea. 874 00:44:07,800 --> 00:44:09,720 Speaker 1: And you know, I know somebody who's writing a book 875 00:44:09,800 --> 00:44:13,040 Speaker 1: on space settlements, and so I should ask you, for example, 876 00:44:13,360 --> 00:44:16,080 Speaker 1: like could we build floating colonies in the clouds of 877 00:44:16,120 --> 00:44:18,719 Speaker 1: Jupiter or could we settle on Io and use the 878 00:44:18,760 --> 00:44:23,440 Speaker 1: like underground oceans and the underground tectonics to extract the energy? 879 00:44:23,480 --> 00:44:25,520 Speaker 1: What do you think about all that? Well, so we 880 00:44:25,560 --> 00:44:28,640 Speaker 1: are focusing on more near term, which we think is 881 00:44:28,680 --> 00:44:32,240 Speaker 1: going to focus on the Moon or Mars or rotating 882 00:44:32,239 --> 00:44:35,080 Speaker 1: space stations. So I haven't thought too much about the 883 00:44:35,080 --> 00:44:39,360 Speaker 1: moons of Jupiter. There are some that have like nicer 884 00:44:39,640 --> 00:44:42,680 Speaker 1: ish conditions, and couldn't you have some of the stuff 885 00:44:42,960 --> 00:44:45,560 Speaker 1: that life needs. But at the end of the day, 886 00:44:45,560 --> 00:44:47,879 Speaker 1: they don't seem so nice. But maybe they'll seem nice 887 00:44:47,920 --> 00:44:50,600 Speaker 1: when we're in the habitable zone billions of years from now. 888 00:44:50,640 --> 00:44:53,480 Speaker 1: What do you think I'm imagining you designing a pamphlet 889 00:44:53,520 --> 00:44:55,400 Speaker 1: for people to move to these colonies and you call 890 00:44:55,480 --> 00:45:01,200 Speaker 1: it nice ish better than death moons of Jupiter. I 891 00:45:01,200 --> 00:45:03,399 Speaker 1: think it's pretty unlikely. And I think it comes back 892 00:45:03,400 --> 00:45:05,400 Speaker 1: to something you often say, which is that people think 893 00:45:05,440 --> 00:45:08,680 Speaker 1: about colonization, but they always assume that the Earth is 894 00:45:08,719 --> 00:45:11,839 Speaker 1: going to be there as the core of the infrastructure. Like, yeah, 895 00:45:11,880 --> 00:45:14,759 Speaker 1: maybe we could send people to Mars next year, but 896 00:45:14,760 --> 00:45:16,640 Speaker 1: they're not going to be self sustaining for a long 897 00:45:16,760 --> 00:45:20,040 Speaker 1: time to rely on shipments from Earth and technology from 898 00:45:20,040 --> 00:45:22,400 Speaker 1: Earth for a long time. So it'd be hard to 899 00:45:22,440 --> 00:45:25,240 Speaker 1: imagine sending up colonies on Io or something and having 900 00:45:25,239 --> 00:45:27,680 Speaker 1: them be self sustaining in a way that could support 901 00:45:27,719 --> 00:45:31,000 Speaker 1: like billions of people. So I think that scenario is 902 00:45:31,040 --> 00:45:35,920 Speaker 1: like maybe dozens, hundreds thousands of people survive, but not 903 00:45:36,080 --> 00:45:38,279 Speaker 1: the whole human race. I think most people are gonna 904 00:45:38,320 --> 00:45:39,759 Speaker 1: lose out if we have to move to the moons 905 00:45:39,760 --> 00:45:42,600 Speaker 1: of Jupiter. I think the space settlement advocates would tell 906 00:45:42,600 --> 00:45:45,160 Speaker 1: you that that's why we need to start now working 907 00:45:45,239 --> 00:45:48,320 Speaker 1: on these technologies. And also, if you can build rotating 908 00:45:48,360 --> 00:45:51,680 Speaker 1: space stations, those are more movable, so you build those 909 00:45:51,719 --> 00:45:53,680 Speaker 1: out of the stuff in the asteroids, and then that's 910 00:45:53,719 --> 00:45:56,760 Speaker 1: easier to move closer or away from the Sun, depending 911 00:45:56,800 --> 00:45:59,480 Speaker 1: on you know where the best places that at any 912 00:45:59,520 --> 00:46:02,719 Speaker 1: particular moment, that'll be much easier than moving the entire Earth. Yeah, 913 00:46:02,760 --> 00:46:07,040 Speaker 1: I agree, let's start building. Well. To me, you that 914 00:46:07,160 --> 00:46:09,840 Speaker 1: still brings a whole new set of problems about what 915 00:46:09,920 --> 00:46:12,200 Speaker 1: we'll be able to peacefully move out into space or 916 00:46:12,200 --> 00:46:14,760 Speaker 1: what we kill ourselves before any of this becomes a problem. 917 00:46:14,920 --> 00:46:16,960 Speaker 1: But you know, some people believe more in humans than 918 00:46:17,000 --> 00:46:20,000 Speaker 1: I do, so so we'll see. So we have mostly 919 00:46:20,040 --> 00:46:23,640 Speaker 1: been talking about trying to get away from the Sun 920 00:46:23,840 --> 00:46:27,040 Speaker 1: as it expands. Next, we're gonna have to figure out 921 00:46:27,040 --> 00:46:30,360 Speaker 1: how to survive when the Sun becomes a white dwarf. 922 00:46:30,800 --> 00:46:46,600 Speaker 1: But let's chat about that after the break. Okay, So 923 00:46:46,920 --> 00:46:50,839 Speaker 1: let's imagine that somehow humanity has managed to avoid having 924 00:46:50,840 --> 00:46:53,759 Speaker 1: our oceans boiled off, We've managed to outrun the sun. 925 00:46:54,680 --> 00:46:57,600 Speaker 1: What comes next the Sun becomes a white dwarf, and 926 00:46:57,640 --> 00:47:00,520 Speaker 1: how do we eke out in existence then? So it 927 00:47:00,560 --> 00:47:02,680 Speaker 1: would be cool if we were around to see the 928 00:47:02,719 --> 00:47:05,239 Speaker 1: helium flash of the Sun, or send probes in there 929 00:47:05,320 --> 00:47:07,440 Speaker 1: or something. It would be pretty awesome to study that. 930 00:47:07,600 --> 00:47:09,920 Speaker 1: After that that, basically the Sun collapses. It's sort of 931 00:47:09,960 --> 00:47:13,120 Speaker 1: like a mini supernova. You have this shock wave which 932 00:47:13,160 --> 00:47:15,120 Speaker 1: blows out a lot of the layers of the Sun 933 00:47:15,440 --> 00:47:18,040 Speaker 1: and then you're left with just this core, this hot 934 00:47:18,120 --> 00:47:20,640 Speaker 1: lump of stuff, the white dwarf. So, as we talked 935 00:47:20,640 --> 00:47:23,120 Speaker 1: about a little bit earlier, we need to then somehow 936 00:47:23,200 --> 00:47:26,440 Speaker 1: move the Earth or our colonies or whatever we're living 937 00:47:26,480 --> 00:47:29,880 Speaker 1: in closer, because it's gonna be a lot colder. If 938 00:47:29,880 --> 00:47:32,600 Speaker 1: you're out in Jupiter's radius right now and the Sun 939 00:47:32,640 --> 00:47:35,560 Speaker 1: becomes a white dwarf, you're gonna get almost no energy. 940 00:47:35,840 --> 00:47:38,560 Speaker 1: So if you want to grow your space salads, for example, 941 00:47:38,880 --> 00:47:41,279 Speaker 1: then you're gonna have to move everything much closer in. 942 00:47:41,560 --> 00:47:43,759 Speaker 1: And the other technology is basically the same. You know, 943 00:47:43,840 --> 00:47:48,200 Speaker 1: find another asteroid to gravitationally slingshot yourself closer to the Sun, 944 00:47:48,600 --> 00:47:51,839 Speaker 1: or turn that rocket engine around that you build and 945 00:47:51,920 --> 00:47:54,200 Speaker 1: pointed the other way and just fly the Earth towards 946 00:47:54,239 --> 00:47:57,399 Speaker 1: the Sun. Though that seems pretty terrifying to me. Yeah, 947 00:47:57,440 --> 00:47:59,959 Speaker 1: you gotta hope you don't overshoot, but you could fee 948 00:48:00,040 --> 00:48:03,440 Speaker 1: ably get enough heat and sunlight if you managed to 949 00:48:03,440 --> 00:48:06,439 Speaker 1: get close enough, You definitely could write. White dwarves are 950 00:48:06,560 --> 00:48:09,000 Speaker 1: pretty hot. They do give off a lot of light. 951 00:48:09,360 --> 00:48:11,360 Speaker 1: I mean there are regions near a white dwarf that 952 00:48:11,400 --> 00:48:14,160 Speaker 1: are too hot for us to survive, which means that 953 00:48:14,200 --> 00:48:16,719 Speaker 1: there is a habitable zone there. Right, You couldn't get 954 00:48:16,760 --> 00:48:19,600 Speaker 1: just the right distance from a white dwarf, It is possible. 955 00:48:19,719 --> 00:48:22,400 Speaker 1: The good news is white dwarfs last for a long, 956 00:48:22,520 --> 00:48:26,000 Speaker 1: long time, right, trillions of years, and so that could 957 00:48:26,000 --> 00:48:28,960 Speaker 1: be a pretty good long term scenario. All right, I'm 958 00:48:29,000 --> 00:48:31,160 Speaker 1: like in this, but it also sounds like there's that 959 00:48:31,239 --> 00:48:34,400 Speaker 1: complicated phase where we're sort of needing to do a 960 00:48:34,440 --> 00:48:36,560 Speaker 1: lot of moving and we're hoping that all of that 961 00:48:36,800 --> 00:48:40,239 Speaker 1: doesn't destroy the climate on Earth. Maybe at some point 962 00:48:40,239 --> 00:48:44,200 Speaker 1: we should just like try a whole different system and 963 00:48:44,239 --> 00:48:46,480 Speaker 1: move to a move near a different star. What do 964 00:48:46,520 --> 00:48:48,239 Speaker 1: we need to do to make that happen? I think 965 00:48:48,239 --> 00:48:50,600 Speaker 1: you're right, And if we're thinking very long term, then 966 00:48:50,640 --> 00:48:54,120 Speaker 1: we have to think about other options and other stars. Currently, 967 00:48:54,239 --> 00:48:57,479 Speaker 1: getting to another star is very tricky, right, We're talking 968 00:48:57,520 --> 00:49:01,120 Speaker 1: about building like generation ships that move less than the 969 00:49:01,160 --> 00:49:04,760 Speaker 1: speed of light to take tens or hundreds of years 970 00:49:04,800 --> 00:49:07,920 Speaker 1: to get to proximate centauri. And they're still like, what 971 00:49:08,080 --> 00:49:10,920 Speaker 1: fraction of the human race can you really fit onto ships? 972 00:49:11,239 --> 00:49:13,960 Speaker 1: Thousands of people maybe millions of people? You have a 973 00:49:13,960 --> 00:49:16,759 Speaker 1: lottery where like one in a thousand people gets to 974 00:49:16,760 --> 00:49:20,080 Speaker 1: go and everybody else like stays behind to die. Sounds 975 00:49:20,120 --> 00:49:24,000 Speaker 1: pretty sad. It's bleak. It's bleak, exactly. I think if 976 00:49:24,040 --> 00:49:26,840 Speaker 1: we're talking about technology and millions and billions of years. 977 00:49:27,080 --> 00:49:29,520 Speaker 1: Then we get to think about things that are theoretically 978 00:49:29,560 --> 00:49:31,840 Speaker 1: allowed right now, but we haven't figured out how to 979 00:49:31,880 --> 00:49:34,320 Speaker 1: do things we like to talk about in this podcast 980 00:49:34,320 --> 00:49:38,040 Speaker 1: a lot like wormholes and warp drives. These are things 981 00:49:38,080 --> 00:49:41,000 Speaker 1: that we think are allowed, that the physics of them 982 00:49:41,480 --> 00:49:43,920 Speaker 1: says it's possible that we don't have a recipe for 983 00:49:43,960 --> 00:49:46,279 Speaker 1: how to build a warp driver, how to construct or 984 00:49:46,320 --> 00:49:49,600 Speaker 1: even find a wormhole, or to know if they're even traversible. 985 00:49:49,840 --> 00:49:53,080 Speaker 1: But you know, fund basic physics for another thousand years 986 00:49:53,080 --> 00:49:55,160 Speaker 1: and we'll probably figure a lot of that out. So 987 00:49:55,280 --> 00:49:57,919 Speaker 1: you know, if we're talking about deep future and speculation, 988 00:49:58,360 --> 00:50:00,520 Speaker 1: then physics could open a lot of in doors for 989 00:50:00,640 --> 00:50:03,719 Speaker 1: how to get two other stars without actually having a 990 00:50:03,800 --> 00:50:06,080 Speaker 1: fly there on a big fat ship. But I used 991 00:50:06,080 --> 00:50:08,680 Speaker 1: to really like watching Doctor Who, and I'm pretty sure 992 00:50:08,719 --> 00:50:11,440 Speaker 1: that on Doctor Who there was a point where time 993 00:50:11,719 --> 00:50:14,600 Speaker 1: ends and at some point you're going to have the 994 00:50:14,680 --> 00:50:17,680 Speaker 1: death of all stars, And so is there anything we 995 00:50:17,719 --> 00:50:19,960 Speaker 1: can do? Can we make it until then? And then 996 00:50:20,000 --> 00:50:23,240 Speaker 1: what happens? Right, if we're thinking about the really deep future, 997 00:50:23,680 --> 00:50:26,120 Speaker 1: like all of the stars are burning and most of 998 00:50:26,160 --> 00:50:28,520 Speaker 1: them have burned out, then we do think the universe 999 00:50:28,560 --> 00:50:31,160 Speaker 1: will get darker, right Like, most of the university is 1000 00:50:31,200 --> 00:50:34,160 Speaker 1: hydrogen and that will continue to burn stars. But at 1001 00:50:34,160 --> 00:50:37,520 Speaker 1: some point the universe stops making stars, right Like, in 1002 00:50:37,640 --> 00:50:41,160 Speaker 1: order for stars to form, the gas that coalesces that 1003 00:50:41,239 --> 00:50:43,440 Speaker 1: builds a solar system has to be kind of cold, 1004 00:50:43,600 --> 00:50:46,000 Speaker 1: needs to be able to collapse. It can't be too hot. 1005 00:50:46,040 --> 00:50:48,120 Speaker 1: And we don't really understand, but we see that in 1006 00:50:48,200 --> 00:50:50,319 Speaker 1: galaxies when they get to a certain age, they just 1007 00:50:50,400 --> 00:50:53,960 Speaker 1: stop making stars. This is called quenching, and so we 1008 00:50:54,000 --> 00:50:56,560 Speaker 1: don't really understand it, but we do suspect that the 1009 00:50:56,640 --> 00:51:00,880 Speaker 1: universe is past its prime. In Star Make game, that like, 1010 00:51:00,920 --> 00:51:03,880 Speaker 1: the rate of new stars being formed is dropping. So 1011 00:51:03,920 --> 00:51:06,000 Speaker 1: as you say, that suggests that in the far far 1012 00:51:06,120 --> 00:51:09,480 Speaker 1: future we may not have any more stars. And some 1013 00:51:09,520 --> 00:51:12,080 Speaker 1: people imagine that what will be left with is just 1014 00:51:12,120 --> 00:51:14,440 Speaker 1: a bunch of black holes, right that used to be 1015 00:51:14,480 --> 00:51:17,160 Speaker 1: the centers of galaxies that have now swallowed up all 1016 00:51:17,239 --> 00:51:19,600 Speaker 1: those stars. And then dark energy is going to push 1017 00:51:19,680 --> 00:51:23,040 Speaker 1: those black holes apart. Remember that the universe is expanding, 1018 00:51:23,120 --> 00:51:26,359 Speaker 1: and that expansion is accelerating, and so the deep deep 1019 00:51:26,400 --> 00:51:29,080 Speaker 1: future is a bunch of black holes that are super 1020 00:51:29,160 --> 00:51:31,400 Speaker 1: duper far apart from each other, and no light in 1021 00:51:31,440 --> 00:51:34,040 Speaker 1: the universe at all. You know what, I want my 1022 00:51:34,160 --> 00:51:36,680 Speaker 1: kids to stay home living with us for a really 1023 00:51:36,719 --> 00:51:38,960 Speaker 1: long time so that you never come visit me either. 1024 00:51:41,400 --> 00:51:44,200 Speaker 1: But you know, there are possible ways to survive that future. 1025 00:51:44,320 --> 00:51:46,399 Speaker 1: We talked to the podcast recently about how to take 1026 00:51:46,520 --> 00:51:50,160 Speaker 1: energy from black holes. Black holes have this region around 1027 00:51:50,160 --> 00:51:53,640 Speaker 1: them called the ergosphere, which is ergo means work right, 1028 00:51:54,040 --> 00:51:56,480 Speaker 1: or ergs like an energy And turns out you can 1029 00:51:56,600 --> 00:51:59,920 Speaker 1: drop stuff into the ergo spheres outside the event horizon, 1030 00:52:00,239 --> 00:52:01,920 Speaker 1: so it'll come back to you and it will come 1031 00:52:01,920 --> 00:52:04,920 Speaker 1: back with more energy. So you can like drop rocks 1032 00:52:05,080 --> 00:52:07,239 Speaker 1: near a black hole and they'll whizz around and come 1033 00:52:07,280 --> 00:52:10,160 Speaker 1: back with more energy. So you can extract energy from 1034 00:52:10,200 --> 00:52:12,640 Speaker 1: black holes and use that to power you know, your 1035 00:52:12,760 --> 00:52:16,200 Speaker 1: underground salad farm or whatever you need to survive in 1036 00:52:16,200 --> 00:52:18,440 Speaker 1: the deep deep future. All right now, I want them 1037 00:52:18,440 --> 00:52:22,080 Speaker 1: to move out again. But you know, we're talking about 1038 00:52:22,120 --> 00:52:25,760 Speaker 1: something like a hundred trillion years from now, and the 1039 00:52:25,920 --> 00:52:28,319 Speaker 1: error bars on that are huge because it's always very 1040 00:52:28,360 --> 00:52:30,919 Speaker 1: difficult to predict far far in the future, and also 1041 00:52:30,960 --> 00:52:33,239 Speaker 1: because we just don't know what dark energy is going 1042 00:52:33,280 --> 00:52:36,239 Speaker 1: to do. Remember that we see the universe expanding We 1043 00:52:36,320 --> 00:52:39,279 Speaker 1: know that expansion is accelerating, but we don't understand it, 1044 00:52:39,280 --> 00:52:41,640 Speaker 1: which means that we can't accurately predict what it's going 1045 00:52:41,680 --> 00:52:44,320 Speaker 1: to do. So any speculation about the far far future 1046 00:52:44,320 --> 00:52:49,839 Speaker 1: comes with a huge galaxy sized asterisk and job security physicists. 1047 00:52:51,360 --> 00:52:53,040 Speaker 1: But you know, I think the lesson to take home 1048 00:52:53,320 --> 00:52:57,520 Speaker 1: is that while the future of our neighborhood is dynamic 1049 00:52:57,640 --> 00:52:59,719 Speaker 1: and changing and it won't always be the way that 1050 00:52:59,760 --> 00:53:01,960 Speaker 1: it is today, it's going to be different, and we 1051 00:53:02,040 --> 00:53:06,239 Speaker 1: have clever ways to maybe survive that human ingenuity might 1052 00:53:06,280 --> 00:53:10,320 Speaker 1: allow us to persist millions, billions, even trillions of years 1053 00:53:10,320 --> 00:53:12,840 Speaker 1: into the future. You know, human beings have done pretty 1054 00:53:12,880 --> 00:53:15,439 Speaker 1: amazing things that the fact that we have rovers going 1055 00:53:15,480 --> 00:53:19,120 Speaker 1: around studying Mars makes me optimistic about humanity in general. 1056 00:53:19,200 --> 00:53:22,799 Speaker 1: So I'm keeping my fingers crossed. We haven't died out yet, right, 1057 00:53:22,840 --> 00:53:25,920 Speaker 1: If you're listening to this podcast, that means that humans 1058 00:53:25,960 --> 00:53:32,200 Speaker 1: have still survived. Is that not hopeful enough for your Kelly? 1059 00:53:32,440 --> 00:53:34,720 Speaker 1: That's as hopeful as we can get on this show. 1060 00:53:35,000 --> 00:53:38,120 Speaker 1: So that's that's fine, alright. So remember that our time 1061 00:53:38,160 --> 00:53:40,880 Speaker 1: here on Earth is precious, and that the Earth's time 1062 00:53:40,920 --> 00:53:44,359 Speaker 1: around the Sun is also precious and short lived. And 1063 00:53:44,520 --> 00:53:47,759 Speaker 1: on this podcast, we're all hopeful that you folks out there, 1064 00:53:48,000 --> 00:53:50,839 Speaker 1: those young people thinking about signs and wanting to become 1065 00:53:50,880 --> 00:53:53,520 Speaker 1: business or engineers, will come up with the solutions to 1066 00:53:53,600 --> 00:53:58,480 Speaker 1: save us all. Otherwise we die. And somehow I became 1067 00:53:58,520 --> 00:54:03,280 Speaker 1: the optimist in this episode. So thanks for tuning in, everybody, 1068 00:54:03,400 --> 00:54:05,600 Speaker 1: and thank you Kelly very much for joining us, Thanks 1069 00:54:05,600 --> 00:54:08,040 Speaker 1: for having me. Have a nice week, everyone, alright, tune 1070 00:54:08,080 --> 00:54:18,440 Speaker 1: in next time. Thanks for listening, and remember that Daniel 1071 00:54:18,480 --> 00:54:21,000 Speaker 1: and Jorge explained. The Universe is a production of I 1072 00:54:21,239 --> 00:54:24,640 Speaker 1: Heart Radio. For more podcast For my heart Radio, visit 1073 00:54:24,680 --> 00:54:28,200 Speaker 1: the I heart Radio app, Apple Podcasts, or wherever you 1074 00:54:28,280 --> 00:54:29,800 Speaker 1: listen to your favorite shows.