WEBVTT - Classic episode - When will the sun explode? 0:00:04.600 --> 0:00:08.600 All the stars in the universe are constantly exploding nuclear bombs. 0:00:09.640 --> 0:00:10.560 That's a little frightening. 0:00:12.280 --> 0:00:14.640 Well, go out there and warm your toes on the 0:00:14.760 --> 0:00:17.960 you know, the thermonuclear fire of a huge bomb that's 0:00:18.000 --> 0:00:19.920 constantly exploding. That sounds cozy. 0:00:20.239 --> 0:00:23.000 It's like a contain and continual explosion. 0:00:24.040 --> 0:00:25.759 Yeah, you want to see a nuclear bomb go off, 0:00:26.160 --> 0:00:28.520 Go outside and look at the sun. I mean, not directly. 0:00:28.600 --> 0:00:33.840 Don't hurt yourself. You just made this advice. I shall 0:00:33.880 --> 0:00:36.800 attract that previod advice. Yeah, we'll ask them to edit 0:00:36.840 --> 0:00:50.040 it up. Hello, I'm Jorhek and I'm Daniel, and this 0:00:50.120 --> 0:00:53.199 is our show. Daniel and Jorge explain the universe. 0:00:53.640 --> 0:00:59.279 Explain the entire universe, especially all the stars inside of it. Now, 0:00:59.280 --> 0:01:01.920 I notice, Jorge, every time you introduce your our show, 0:01:02.520 --> 0:01:06.320 you're about to say the universe, and then you have 0:01:06.400 --> 0:01:07.720 to correct yourself and you're like, no. 0:01:07.640 --> 0:01:10.080 Actually, yeah, we're still bitter about that. You know. 0:01:12.520 --> 0:01:14.600 My real job, you know, is as a particle to exists. 0:01:14.959 --> 0:01:17.560 And I have five thousand collaborators. And when we write 0:01:17.560 --> 0:01:20.240 a paper, we put everybody's name on the paper. And 0:01:20.280 --> 0:01:24.360 the policy has put everybody's name alphabetical by last name, 0:01:24.920 --> 0:01:28.040 regardless of who contributed more or less or whatever. Somebody 0:01:28.040 --> 0:01:30.319 decided they didn't want to have the argument. Let's just 0:01:30.360 --> 0:01:31.320 make it alphabetical. 0:01:31.600 --> 0:01:31.920 Uh huh. 0:01:32.440 --> 0:01:34.320 And what that means is that there's some grad student 0:01:34.319 --> 0:01:36.520 who's first author on like every paper. 0:01:36.760 --> 0:01:39.640 Wow, it's like him or her at all. 0:01:39.720 --> 0:01:41.600 And it's sort of make some famous and also sort 0:01:41.640 --> 0:01:46.600 of infamous because people grumble about it. No pressure, no pressure. 0:01:46.680 --> 0:01:50.560 That's right in the Glaring Spotlight. But you know, today's 0:01:50.560 --> 0:01:54.480 episode actually relates to that, to Glaring Spotlights, because today 0:01:54.480 --> 0:01:57.400 we're talking about something very close to home. We're talking 0:01:57.440 --> 0:02:04.280 about how long the sun is going to live? 0:02:04.760 --> 0:02:07.360 How long do we have before it burns out or 0:02:07.720 --> 0:02:09.720 explodes or snuffs out? 0:02:09.880 --> 0:02:12.720 How many more projects can Daniel and Jorge or Jorge 0:02:12.800 --> 0:02:16.360 and Daniel do arguing about order until life on Earth 0:02:16.400 --> 0:02:18.560 is extinguished? Yeah, because the star is gone. 0:02:18.680 --> 0:02:20.919 Yeah, do you have time to clean out your garage 0:02:21.360 --> 0:02:23.960 or do that thing you've always wanted to do? Right 0:02:24.040 --> 0:02:27.359 that sequel to We Have No Idea, our book now 0:02:27.400 --> 0:02:29.400 available from Penguin Random Pass. 0:02:29.520 --> 0:02:33.400 That's right. So if you're currently procrastinating doing something you 0:02:33.400 --> 0:02:35.520 should do, then you're actually going to learn something today 0:02:35.520 --> 0:02:38.040 about how much time you have left to procrastinate? 0:02:38.280 --> 0:02:42.280 Right? Yep? So yeah, let's jump in for we as 0:02:42.360 --> 0:02:46.079 usual asked people on the street how long they thought 0:02:46.480 --> 0:02:49.000 that the sun would keep burning, And so the question 0:02:49.080 --> 0:02:52.040 is how long do you think the sun will keep burning? 0:02:52.600 --> 0:02:54.639 Play along at home, think of your answer, and then 0:02:54.680 --> 0:02:58.200 listen to these random on the street interviews. How long 0:02:58.240 --> 0:03:00.079 do you think our sun is going to continue to 0:03:00.160 --> 0:03:00.560 burn for? 0:03:01.120 --> 0:03:01.600 How long? 0:03:02.720 --> 0:03:07.519 I think a few billion years? I don't know millions, No, 0:03:07.560 --> 0:03:09.160 not millions, sorry. 0:03:09.120 --> 0:03:11.239 Probably a long time. I hope a long time. 0:03:11.840 --> 0:03:14.400 So like, doesn't this affect your plans? Come on, you 0:03:14.400 --> 0:03:14.920 should know this? 0:03:16.639 --> 0:03:18.680 All right? Well, I guess the first thing is that 0:03:18.800 --> 0:03:20.160 nobody seemed really concerned. 0:03:21.160 --> 0:03:25.000 That's right. Nobody's rushing home to finish up something before 0:03:25.040 --> 0:03:26.600 the sun snuffs out or explodes. 0:03:26.720 --> 0:03:29.600 Nobody's like, what the sun's gonna stop burning? At some point, 0:03:29.880 --> 0:03:32.400 everyone seemed to know about the idea that the sun 0:03:32.919 --> 0:03:33.919 won't shine forever. 0:03:34.320 --> 0:03:36.160 Oh that's a good point. I never even considered that 0:03:36.160 --> 0:03:39.520 that I would be the one informing people by asking 0:03:39.560 --> 0:03:42.280 the question that the sun was not gonna last forever. 0:03:42.760 --> 0:03:47.600 Oh my god, what what are you saying? No, everybody 0:03:47.640 --> 0:03:50.400 seems to know that already, but maybe nobody seemed concerned 0:03:50.440 --> 0:03:53.240 because everybody's answers were very far off in the future. 0:03:53.280 --> 0:03:55.800 Nobody said, I don't know ten years or one hundred years. 0:03:56.080 --> 0:03:59.440 Everybody's like random big number. Everybody feels like it's just 0:03:59.520 --> 0:04:01.600 so off off in the future, it doesn't matter. 0:04:03.800 --> 0:04:06.040 Well, let's maybe take a step back, like how the 0:04:06.160 --> 0:04:08.600 stars to inform, right, Like I imagine out in space, 0:04:08.680 --> 0:04:13.200 there's stuff like dust and little bits of rock, and 0:04:13.280 --> 0:04:15.960 at some point the gravity pulls them together, like there's 0:04:16.000 --> 0:04:18.960 some nearby each other until they clump together, and first 0:04:18.960 --> 0:04:21.120 it's a giant rock, and then it's an even bigger rock, 0:04:21.200 --> 0:04:23.640 and then it just gets more massive, and at some 0:04:23.680 --> 0:04:24.560 point what happens. 0:04:24.839 --> 0:04:27.720 Yeah, but it's not mostly rock. Stars are mostly made 0:04:27.760 --> 0:04:30.599 out of gas, mostly out of hydrogen. So in the 0:04:30.600 --> 0:04:33.160 Big Bang, most of the stuff that was formed after 0:04:33.200 --> 0:04:35.440 the Big Bang was hydrogen, a little bit helium and 0:04:35.480 --> 0:04:38.600 a few heavier elements, but mostly you just have huge 0:04:38.600 --> 0:04:41.919 clouds of gas formed in the early universe, Okay, and 0:04:41.960 --> 0:04:45.760 then gravity takes over and gravity slowly pulls those things together, 0:04:45.800 --> 0:04:49.480 as you said, and accumulates these gas clouds and then 0:04:49.480 --> 0:04:52.280 those gas clouds get pulled together by gravity, and they 0:04:52.320 --> 0:04:55.159 get squeezed together more and more until it gets denser 0:04:55.200 --> 0:04:59.000 and denser, and eventually it gets squeezed together by gravity 0:04:59.120 --> 0:05:01.359 enough that it starts to burn. And by burn, I 0:05:01.400 --> 0:05:03.880 mean fuse. I mean you have like nuclear bombs going 0:05:03.920 --> 0:05:06.920 off because of the pressure inside these big clumps of hydrogen. 0:05:07.240 --> 0:05:08.560 Right, but what do you mean they get dence and 0:05:08.600 --> 0:05:12.160 denswer like just more and more hydrogen atoms just kind 0:05:12.160 --> 0:05:14.160 of bunch up because they're all attracted to each other 0:05:14.200 --> 0:05:14.920 by gravity. 0:05:15.120 --> 0:05:17.240 Yeah, it's kind of about like a runaway process. I mean, 0:05:17.240 --> 0:05:20.880 if you had a perfectly smooth universe filled with hydrogen atoms, 0:05:21.240 --> 0:05:23.160 then no one would want to go anywhere because you'd 0:05:23.160 --> 0:05:25.400 be tugged in every direction at the same strength. 0:05:25.480 --> 0:05:28.080 Right, everybody would be attracted to everybody else equally. 0:05:28.120 --> 0:05:30.840 Yeah, that sounds like a good party, right, universe party, 0:05:30.960 --> 0:05:32.480 we're all attracted to each other. 0:05:32.920 --> 0:05:36.400 Yeah, created it's just a big by swinger party. 0:05:37.320 --> 0:05:39.760 That's right. Hey, you know the analogy works because we're 0:05:39.760 --> 0:05:40.920 going to talk about fusion. 0:05:40.640 --> 0:05:43.479 And fission, so and thinks are going to get hot. 0:05:43.880 --> 0:05:46.440 You don't want your relationship to go super heova later 0:05:46.520 --> 0:05:49.520 on in relationship advice from an astrophysicist. 0:05:50.080 --> 0:05:52.880 Yeah, yeah, they were just knocking out that to that advice, 0:05:53.120 --> 0:05:55.400 children go out and look at the sun. People have 0:05:55.480 --> 0:06:01.360 explosive relationships. This is our last episode by guys. 0:06:01.560 --> 0:06:04.600 Right, So, but there were little areas in the universe 0:06:04.640 --> 0:06:06.479 early on that were a little denser than others, and 0:06:06.480 --> 0:06:09.960 that's just because of quantum fluctuations. And then those areas 0:06:10.040 --> 0:06:13.200 were heavier because there's a little bit more stuff. Heavier, 0:06:13.240 --> 0:06:15.840 you have more gravitational pull than anywhere else. So then 0:06:15.839 --> 0:06:18.800 you start to attract more stuff, and the heavier you get, 0:06:18.800 --> 0:06:22.040 the denser region becomes, the more gravity it has, the 0:06:22.120 --> 0:06:24.680 stronger its ability to pull more stuff in, and then 0:06:24.720 --> 0:06:27.040 it gets heavier and heavier, and it's a runaway process 0:06:27.240 --> 0:06:29.640 where pretty soon it's accumulating stuff faster and faster. 0:06:29.880 --> 0:06:31.880 So you can imagine like at some point a giant 0:06:31.960 --> 0:06:35.960 ball of really compressed gas, right, Like maybe at the 0:06:36.040 --> 0:06:38.680 edges it's not as compressed, but in the middle, it's 0:06:38.720 --> 0:06:41.440 just everything's trying to push it together, right, But it 0:06:41.440 --> 0:06:45.800 doesn't immediately fuse because hydrogen atoms are also repelling each 0:06:45.839 --> 0:06:48.000 other at the same time, right, Like they're attracted by gravity, 0:06:48.040 --> 0:06:50.159 but they're repelling each other by other forces. 0:06:50.360 --> 0:06:52.080 That's right. Fusion is not easy to pull off. I 0:06:52.080 --> 0:06:53.839 mean we're trying to do it in experiments all the 0:06:53.839 --> 0:06:54.680 time here on Earth. 0:06:55.160 --> 0:06:57.120 Like it's like trying to squeeze two mantic together that 0:06:57.160 --> 0:06:59.400 are on the same polarity, right. 0:06:59.560 --> 0:07:01.800 Yeah, trying to make two kids share one ice cream 0:07:01.880 --> 0:07:02.200 or something. 0:07:02.360 --> 0:07:07.120 That's not a good idea. But the repelling they're being 0:07:07.160 --> 0:07:11.000 attracted by gravity, repelling by electronic forces. But at some point, 0:07:11.000 --> 0:07:13.960 if you get them close enough, then another force kicks in, right, 0:07:14.000 --> 0:07:16.440 And that's what kind of fuses them together. Is that true? 0:07:16.680 --> 0:07:19.440 Yeah, And that's when you access the strong nuclear force, 0:07:19.960 --> 0:07:22.679 and that fuses them together, and the strong nuclear force 0:07:23.000 --> 0:07:26.320 very strong then therefore its name. And when you do that, 0:07:26.360 --> 0:07:28.000 you release a huge amount of energy. 0:07:28.080 --> 0:07:30.480 And so that's what all of the energy is coming from, 0:07:30.560 --> 0:07:33.200 is just these hydrogen atoms fusing together. 0:07:33.400 --> 0:07:35.880 That's right. Almost all the light from all the stars 0:07:35.920 --> 0:07:39.880 in the universe is from hydrogen fusing together and creating 0:07:39.920 --> 0:07:41.920 all that energy and shooting it out into space. 0:07:42.080 --> 0:07:44.600 But is it like a kind of like a chain reaction, 0:07:44.800 --> 0:07:47.560 like you know, like a nuclear bomb, Like one explosion 0:07:47.680 --> 0:07:50.320 causes the next explosion. Is that what's happening inside a 0:07:50.360 --> 0:07:53.360 star or is it just just the pressure just kind 0:07:53.360 --> 0:07:55.480 of makes it like popcorn, It just makes all these 0:07:55.560 --> 0:07:56.520 kernels pop up up. 0:07:57.480 --> 0:07:59.840 So on Earth, it's a chain reaction you're thinking of 0:07:59.880 --> 0:08:03.200 like fission. Fission is the opposite process. And you break 0:08:03.200 --> 0:08:05.920 a nucleus up and it sprays out and stuff. I'm here. 0:08:05.960 --> 0:08:08.040 You just have a huge blob of hydrogen in the 0:08:08.040 --> 0:08:11.120 core and it's being squeezed by the outside and everything 0:08:11.120 --> 0:08:13.720 around it, and it gets really hot. And you know 0:08:13.760 --> 0:08:16.960 that's true of every object, like even the Earth. What's 0:08:16.960 --> 0:08:18.640 at the center of the Earth. It's not cold at 0:08:18.640 --> 0:08:20.840 the center of the Earth. It's hot, and it's hot 0:08:20.840 --> 0:08:22.800 for lots of reasons, but one major reason is that 0:08:22.840 --> 0:08:25.160 it's being squeezed by gravity. All that rock in the 0:08:25.200 --> 0:08:27.640 center of the Earth is being squeezed by all the 0:08:27.720 --> 0:08:30.560 rock on the outside, and it gets turned into lava. Right. 0:08:30.720 --> 0:08:33.480 Why is lava hot Because it's been squeezed by gravity. 0:08:33.840 --> 0:08:35.840 Gravity is pretty powerful if you give it enough time 0:08:35.840 --> 0:08:36.360 and stuff. 0:08:37.080 --> 0:08:40.120 So our cloud of hydrogen it just kind of suddenly ignites, 0:08:40.240 --> 0:08:43.720 or does it kind of like burns begins to burn slowly, 0:08:44.360 --> 0:08:46.720 like does the stargo like fish or is it? Is 0:08:46.760 --> 0:08:48.080 it kind of a long process? 0:08:48.320 --> 0:08:50.360 No? I think it It ignites pretty quickly once it 0:08:50.360 --> 0:08:54.200 gets going, And what happens depends on how big it is. 0:08:55.040 --> 0:08:57.720 So if you have a huge blob of gas, right 0:08:57.760 --> 0:09:03.240 and it forms an enormous ball of hydrogen, then it 0:09:03.240 --> 0:09:05.679 can burn really brightly and not for very long. If 0:09:05.679 --> 0:09:08.160 it's smaller, then it doesn't get to be big enough 0:09:08.160 --> 0:09:10.720 to burn like you know, like the Earth or Jupiter 0:09:10.840 --> 0:09:13.320 or something. Jupiter is like a star that never got 0:09:13.360 --> 0:09:15.960 started because it just wasn't big enough for the core 0:09:16.040 --> 0:09:16.800 to start burning. 0:09:17.000 --> 0:09:21.360 Oh, you need more stuff to basically weigh down and 0:09:21.400 --> 0:09:22.199 squeeze the middle. 0:09:22.640 --> 0:09:24.640 That's right. Yeah, the core of Jupiter is not being 0:09:24.679 --> 0:09:28.280 squeezed enough. I mean, it's massive gravitational pressure. You would 0:09:28.280 --> 0:09:30.199 not like it. It. Do not recommend it as a 0:09:30.240 --> 0:09:35.520 destination for your vacation, right, But yeah, that's right. There 0:09:35.520 --> 0:09:40.840 are some common sense warnings on this show. But it's 0:09:40.880 --> 0:09:43.640 not hot enough to start nuclear fusion. 0:09:44.000 --> 0:09:47.559 Okay, so then things say squeeze and you got a 0:09:47.600 --> 0:09:50.199 sun it Suddenly you have this big ball of gas 0:09:50.240 --> 0:09:51.559 that's burning in the middle. 0:09:51.400 --> 0:09:53.800 That's right, and it's burning through nuclear fusion. It's turning 0:09:53.880 --> 0:09:56.680 hydrogen into helium. Okay, cool, and I want to talk 0:09:56.679 --> 0:09:59.240 a little bit more about that, but first a quick break. 0:10:07.559 --> 0:10:11.880 That's how stars are born, not just in Hollywood. And 0:10:12.480 --> 0:10:14.520 and then it just keeps burning for a long time, right, 0:10:14.600 --> 0:10:17.079 until all the hydrogen turns into helium. 0:10:17.160 --> 0:10:19.760 Yeah, that's exactly right. You have fuel and you burn 0:10:19.800 --> 0:10:22.880 that fuel, and when you've done burning that fuel, you're done. 0:10:23.120 --> 0:10:26.439 But the interesting thing is that the output of fusion 0:10:26.520 --> 0:10:29.520 is helium, right, And so what happens is that you 0:10:29.559 --> 0:10:32.800 accumulate helium at the core of these stars, and then 0:10:32.920 --> 0:10:35.520 if it keeps going, if it gets big enough, then 0:10:35.559 --> 0:10:37.000 it can start to fuse helium. 0:10:37.320 --> 0:10:41.000 Oh and then that it's like it goes into secondary 0:10:41.320 --> 0:10:42.400 fuel burning mode. 0:10:42.640 --> 0:10:45.080 Yeah, exactly, it's burning helium because you can fuse helium 0:10:45.480 --> 0:10:47.880 into the element with number four, which I embarrassed and 0:10:48.160 --> 0:10:49.040 can't even remember. Is that? 0:10:50.280 --> 0:10:52.960 Okay, So we're talking about what happens to a star 0:10:53.679 --> 0:10:55.880 and at some point it makes it turns all the 0:10:55.960 --> 0:10:59.560 hydrogen into helium and eventually into iron, and that's kind 0:10:59.559 --> 0:11:02.240 of when that's kind of when a supernova happens, right. 0:11:02.840 --> 0:11:04.760 Yeah, Well, it doesn't necessarily happen to have to be 0:11:04.800 --> 0:11:08.120 a supernova depends on the mass of the star. So 0:11:08.240 --> 0:11:10.920 let's talk just to be specific about a star like hours, 0:11:11.160 --> 0:11:14.400 you know, the sunk and any object that's like about 0:11:14.440 --> 0:11:16.280 up to eight times the mass of the Sun is 0:11:16.280 --> 0:11:18.520 going to have an experience like our sun. And so 0:11:18.559 --> 0:11:20.760 what happens is it starts to burn hydrogen like we said, 0:11:21.240 --> 0:11:23.760 and then the hydrogen gets the core gets burned up 0:11:23.760 --> 0:11:25.360 and you get helium, and then you start to burn 0:11:25.400 --> 0:11:28.040 the hydrogen on the shell, and then the star starts 0:11:28.080 --> 0:11:31.800 to grow. It gets bigger, like physically larger in space. 0:11:32.679 --> 0:11:34.720 And the reason is that you're now burning the hydrogen 0:11:34.760 --> 0:11:36.959 on the outside and that the burning there is pushing 0:11:37.040 --> 0:11:39.760 stuff out. It's like the radiation pressure is making it grow. 0:11:41.160 --> 0:11:45.160 So the Sun will keep burning and then it'll expand 0:11:45.240 --> 0:11:48.440 and it'll cool, so it'll start to get larger and 0:11:48.480 --> 0:11:51.360 it'll turn into a red giant so giant meaning it 0:11:51.400 --> 0:11:53.960 gets bigger and red because it changes color. 0:11:54.000 --> 0:11:56.679 Because the color is related to the temperature, right, like, 0:11:56.720 --> 0:11:59.840 the cooler it is the red Like it's kind of counterintuitive, 0:12:00.440 --> 0:12:02.720 the colder it is the star is the redder it is. 0:12:02.760 --> 0:12:05.080 But then the hotter it is the bluer it looks. 0:12:04.920 --> 0:12:08.080 Right, yeah, and that's related to the wavelength of those lights. 0:12:08.160 --> 0:12:08.880 That light. Yeah. 0:12:09.000 --> 0:12:12.040 Yeah. Like if you could you press fast forward on 0:12:12.120 --> 0:12:14.320 life on Earth, you would see the Sun is this 0:12:14.480 --> 0:12:17.200 yellow dot. But eventually you'll see it grow and grow 0:12:17.240 --> 0:12:20.760 redder and then grow and eventually we'll take over ourn 0:12:20.880 --> 0:12:24.280 entire sky and at some point it'll just snuff us out. 0:12:24.440 --> 0:12:28.360 That's right. Eventually we will be in the sun. Earth 0:12:28.400 --> 0:12:32.360 will just get like eaten up by the Sun. Yeah exactly. 0:12:32.640 --> 0:12:34.839 But that's again billions of years in the future. It's 0:12:34.880 --> 0:12:36.000 like three billion years in. 0:12:35.920 --> 0:12:37.920 The future, three billion years. Yeah. 0:12:37.920 --> 0:12:40.880 And so before but before we even get snuffed up, 0:12:40.880 --> 0:12:42.959 you know, it'll get pretty hot and we wouldn't want 0:12:42.960 --> 0:12:43.880 to be around anyway. 0:12:43.960 --> 0:12:44.600 Oh I see. 0:12:44.760 --> 0:12:47.360 So first the ocean's boil and then we get snuffed up. 0:12:47.440 --> 0:12:50.480 Yeah wow. And then that's that's like the last phase 0:12:50.520 --> 0:12:53.520 before the Sun dies and then it's mostly used up 0:12:53.520 --> 0:12:55.560 its fuel and you know, it's like a fire. You 0:12:55.640 --> 0:12:57.280 use up the fuel and then the fire goes out. 0:12:57.520 --> 0:12:59.080 So everything turned to iron. 0:12:59.400 --> 0:13:02.040 Maybe it's not every star that can make iron, right, 0:13:02.040 --> 0:13:03.920 it depends on the size of it. Mostly iron is 0:13:03.920 --> 0:13:06.680 made in much bigger stars. So our star is not 0:13:06.720 --> 0:13:08.760 big enough to make iron, so we'll probably make helium 0:13:08.760 --> 0:13:10.880 and a little bit of lithium and a few other things. 0:13:11.120 --> 0:13:13.640 Oh I see. So some stars are bigger, so they 0:13:13.679 --> 0:13:17.120 have more pressure so they can cook iron, but ours 0:13:17.120 --> 0:13:18.200 cannot exactly. 0:13:18.200 --> 0:13:20.640 Ours is not by far one of the biggest stars 0:13:20.640 --> 0:13:25.360 in the universe. It's relatively modest. Yeah, okay, And then 0:13:25.400 --> 0:13:27.240 when it burns off all the hydrogen sort of on 0:13:27.280 --> 0:13:30.240 the outside, then it'll go out, and what we'll be 0:13:30.320 --> 0:13:32.480 left with is something they call a white dwarf, which 0:13:32.520 --> 0:13:36.760 is basically just meaning a big cool blob, something that's 0:13:36.840 --> 0:13:39.880 not burning anymore of what it's just sort of the 0:13:39.960 --> 0:13:42.560 leftover stuff. You know, you have enough elements there to 0:13:42.880 --> 0:13:45.160 sit there there. It's hot and so it's sort of glowing, 0:13:45.200 --> 0:13:47.480 but it's not actually burning anymore. And you'll have some 0:13:47.559 --> 0:13:50.160 helium and maybe some lithium and just be like a 0:13:50.200 --> 0:13:53.280 dense blob, but it won't be bright the same way, 0:13:53.480 --> 0:13:56.680 and it'll cool and eventually become a black dwarf, which 0:13:56.720 --> 0:13:58.319 means basically a big lump of. 0:13:58.320 --> 0:14:00.480 Rock, like just a giant meat right. 0:14:00.640 --> 0:14:02.920 Yeah, though mostly made of like frozen. 0:14:02.520 --> 0:14:04.480 Helium, frozen helium for real. 0:14:04.840 --> 0:14:07.240 Yeah, yeah, because mostly what mostly what the Sun is 0:14:07.240 --> 0:14:09.360 is burning hydrogen into helium. And again, some of that 0:14:09.400 --> 0:14:11.840 helium will get burned into heavier stuff, but most of 0:14:11.840 --> 0:14:12.600 it won't, I think. 0:14:12.760 --> 0:14:14.640 And so this is going to be like a giant 0:14:14.679 --> 0:14:15.960 ice ball the size of what. 0:14:16.520 --> 0:14:18.960 Oh, you'll be small, You'll be smaller than the current Sun. 0:14:19.360 --> 0:14:21.440 Oh I see, it's just the core. Yeah, just the 0:14:21.440 --> 0:14:23.160 core is left over because all the other stuff is 0:14:23.200 --> 0:14:26.320 blown out when it turns into a red giant. But yeah, 0:14:26.320 --> 0:14:28.400 some significant fraction of the mass of the Sun is 0:14:28.440 --> 0:14:30.800 going to end up left over as a white dwarf 0:14:30.840 --> 0:14:33.600 and then a black dwarf. Yeah, exactly. And you know 0:14:33.680 --> 0:14:36.560 that has a future. It could be that that then 0:14:36.640 --> 0:14:39.600 gets clustered together later on and becomes part of a 0:14:39.600 --> 0:14:42.120 new star. You know, a lot of the stuff that's 0:14:42.160 --> 0:14:45.080 in our star and in the Earth used to be 0:14:45.160 --> 0:14:47.840 inside of a star. And so you know, everything that 0:14:47.880 --> 0:14:50.440 we're that we're made out of is a remnant from 0:14:50.480 --> 0:14:53.440 a star that died. So if it wasn't for stars 0:14:53.840 --> 0:14:57.240 and these fusion furnaces making the heavier elements, then there 0:14:57.240 --> 0:14:59.040 wouldn't be anything else to make stuff out of. It 0:14:59.040 --> 0:15:01.960 would all just be hid helium. And so it's gravity 0:15:02.040 --> 0:15:04.880 squeezing this stuff together over billions of years that makes 0:15:05.080 --> 0:15:07.520 the heavier elements, and mostly in the bigger stars that 0:15:07.560 --> 0:15:09.520 you get up to like iron. You know, the bigger 0:15:09.520 --> 0:15:11.480 stars can do more exciting stuff. Like our sun is 0:15:11.520 --> 0:15:13.440 not going to go supernova, it's just not big enough. 0:15:13.800 --> 0:15:15.960 But a bigger star could have enough mass that it 0:15:16.040 --> 0:15:18.680 collapses and it pushes it together and it can create 0:15:18.720 --> 0:15:22.120 a supernova and then two weird things, either a black 0:15:22.120 --> 0:15:24.840 hole or a neutron star, which I think is one 0:15:24.840 --> 0:15:27.120 of the weirdest things in the universe. So it's more 0:15:27.120 --> 0:15:31.320 of an implosion than an explosion. Actually yeah, yeah, yeah, 0:15:31.360 --> 0:15:32.280 it's pretty crazy stuff. 0:15:32.360 --> 0:15:35.280 So you're saying that's when the heavier elements get mate, right. 0:15:35.440 --> 0:15:38.400 Yeah, in some of these supernovas, because you have heavy 0:15:38.400 --> 0:15:43.000 stuff flying around and it collides and it forms even 0:15:43.000 --> 0:15:46.080 heavier stuff, yeah right. And then but the heaviest stuff, 0:15:46.320 --> 0:15:48.360 like we were saying earlier, gold and all that stuff 0:15:48.560 --> 0:15:51.920 gets formed when two of those remnants collide, Like say 0:15:51.920 --> 0:15:54.560 you have one really massive star lives its whole life, 0:15:54.600 --> 0:15:57.720 has a great time, blows up, turns into a neutron star, 0:15:58.000 --> 0:16:00.480 and another one does the same thing, and then the 0:16:00.520 --> 0:16:03.360 two neutron stars are orbiting each other, and eventually, because 0:16:03.360 --> 0:16:05.440 they're so massive, they pull each other together and they 0:16:05.440 --> 0:16:08.400 collapse and they collide into each other, and it's in 0:16:08.440 --> 0:16:11.920 that collision that you can form the really heaviest stuff. 0:16:11.960 --> 0:16:14.720 So all the super heavy metals in the universe are 0:16:14.760 --> 0:16:16.320 made when neutron stars die. 0:16:16.440 --> 0:16:18.760 Wow, and that's why they're so rare, so that you 0:16:18.840 --> 0:16:22.640 need these crazy events just to make gold and titanium 0:16:22.680 --> 0:16:23.600 and all these elements. 0:16:23.640 --> 0:16:24.960 Right, yeah, that's right. 0:16:25.240 --> 0:16:27.280 But it's crazy that we have that stuff on Earth. 0:16:27.360 --> 0:16:28.200 Yeah right, I. 0:16:28.160 --> 0:16:29.680 Know, we have it here on Earth, and it's like 0:16:29.720 --> 0:16:33.400 the leftovers these incredible cosmic events that happened billions of 0:16:33.440 --> 0:16:36.640 years ago and then got sprayed out into the universe 0:16:37.680 --> 0:16:39.640 with enough time for them to like have a whole 0:16:39.640 --> 0:16:41.240 new life. You know. I love that everything in the 0:16:41.320 --> 0:16:44.920 universe is getting recycled, right, Like our solar system didn't 0:16:44.960 --> 0:16:47.920 even start forming until you know, five billion years ago, 0:16:48.320 --> 0:16:51.040 which is nine billion years into the party. Right. 0:16:51.320 --> 0:16:54.240 Yeah, let's talk about that, but first let's take a 0:16:54.280 --> 0:16:54.800 quick break. 0:17:03.080 --> 0:17:04.880 Right now. Is when the sun is like looking over 0:17:04.960 --> 0:17:07.320 that hot, sexy sun in the next solar system. 0:17:07.000 --> 0:17:08.520 And looking to buy a corvette. 0:17:08.600 --> 0:17:11.520 Right, Yeah, it's wondering, like do I look like a big, 0:17:11.560 --> 0:17:13.960 fat red giant and tell me I still look small, 0:17:14.000 --> 0:17:15.160 like a nice little yellow dwarf. 0:17:17.000 --> 0:17:17.960 Tell me I'm so hot. 0:17:18.040 --> 0:17:20.560 Yeah, exactly. And one thing that I think is really 0:17:20.600 --> 0:17:24.040 interesting is that the smaller star is the longer it lives. 0:17:24.440 --> 0:17:26.919 The bigger star is the shorter it lives. And the 0:17:26.960 --> 0:17:30.359 first stars in the universe were massive, they were incredible, 0:17:30.400 --> 0:17:32.480 and so they didn't live for very long. Like those 0:17:32.520 --> 0:17:35.400 first stars we talked about, none of those are around anymore. 0:17:35.800 --> 0:17:37.440 None of the stars that are in the universe now 0:17:37.560 --> 0:17:40.919 are first generation stars. They're all second, third, fourth generation, 0:17:41.000 --> 0:17:41.719 that kind of stuff. 0:17:42.160 --> 0:17:44.320 All the stars were seeing the night sky in like 0:17:44.440 --> 0:17:45.919 the pictures of galaxies. 0:17:45.920 --> 0:17:49.600 They're all None of those are among the first stars 0:17:49.640 --> 0:17:51.639 that were formed about one hundred million years that's the 0:17:51.640 --> 0:17:55.040 Big Bang. Yes, it's only recently people scientists even saw 0:17:55.119 --> 0:17:57.520 the light from those first stars. It's really hard to see. 0:17:58.160 --> 0:18:00.520 You have to use the infrared because the universe was 0:18:00.560 --> 0:18:02.960 so dense back then. But yeah, our star is made 0:18:02.960 --> 0:18:05.960 out of leftover bits from other stars earlier that burned 0:18:05.960 --> 0:18:06.679 and exploded. 0:18:07.320 --> 0:18:11.440 Wow. And recombined, right, and eventually you're saying, our big 0:18:11.480 --> 0:18:14.040 ice ball of the sun is going to recombine with 0:18:14.080 --> 0:18:15.720 something else maybe and form. 0:18:16.960 --> 0:18:19.440 But you can't do this forever, you know, Like there's 0:18:19.440 --> 0:18:23.080 a limited amount of hydrogen, and you need hydrogen to 0:18:23.440 --> 0:18:26.920 have these reactions to start. Eventually things get yeah, things 0:18:26.920 --> 0:18:29.440 get denser and denser, and you run out of fuel. 0:18:29.480 --> 0:18:32.119 So like think about the Milky Way galaxy. It's got 0:18:32.400 --> 0:18:36.280 enormous blobs of hydrogen gas. Still it's still making stars, 0:18:36.920 --> 0:18:39.040 but eventually it's going to run out, and then it's 0:18:39.040 --> 0:18:41.080 going to stop making stars. And those stars are going 0:18:41.160 --> 0:18:42.600 to burn for a while, but they're not going to 0:18:42.640 --> 0:18:43.159 burn forever. 0:18:43.359 --> 0:18:47.640 So eventually everything's going to be like iron and heavier. 0:18:47.280 --> 0:18:49.960 Metals, yeah, yeah, and then things will get dark. 0:18:50.600 --> 0:18:51.720