WEBVTT - What's inside a neutron star? 0:00:08.440 --> 0:00:11.760 Hey or hey, do you have strong opinions about pasta? 0:00:12.720 --> 0:00:15.400 I mean, like in my pro pasta or antipasta. Yeah, 0:00:15.440 --> 0:00:17.159 but I want to dig a little deeper, like, do 0:00:17.160 --> 0:00:20.160 you have opinions about all of the varieties? Yeah? No, 0:00:20.239 --> 0:00:22.040 I love that there are so many kinds of pasta, 0:00:22.160 --> 0:00:24.280 the more of the tastier. So then in the opinion 0:00:24.320 --> 0:00:27.440 of an artist, what is the prettiest pasta there is? 0:00:27.720 --> 0:00:30.760 M I try not to judge pasta bytes looks, you know, 0:00:30.880 --> 0:00:33.480 that seems kind of rude, So I just go by taste. Well, 0:00:33.520 --> 0:00:36.000 to me, it all tastes the same. I mean, fundamentally, 0:00:36.000 --> 0:00:38.760 it's all made of the same stuff. Though my kids 0:00:39.000 --> 0:00:41.400 insist that some of them are tastier than others. I 0:00:41.400 --> 0:00:44.400 think it's your kids. In an entire country called Italy 0:00:44.720 --> 0:00:46.600 would argue the same thing. I mean, it's all made 0:00:46.640 --> 0:00:48.479 of dough, right, which in the end just made of 0:00:48.479 --> 0:00:52.400 like protons, neutrons and electrons. How can it taste different? Can? 0:00:52.680 --> 0:00:54.680 We'll probably get a lot of hate mail from Italians 0:00:54.840 --> 0:00:57.240 because you know your physicist, right, Like, each pasta has 0:00:57.280 --> 0:01:01.280 a different cross section and a different ratio of volume 0:01:01.320 --> 0:01:04.680 to surface area. Right. Welcome to the physics of pasta podcasting. 0:01:04.800 --> 0:01:22.560 That's right, we're all postic. I am Jorge. I'm a 0:01:22.600 --> 0:01:25.759 cartoonists and the co author of Frequently Asked Questions about 0:01:25.800 --> 0:01:28.679 the Universe. Hi, I'm Daniel. I'm a particle physicist and 0:01:28.720 --> 0:01:31.560 a professor at u C Irvine. And I seriously can't 0:01:31.680 --> 0:01:34.720 taste the difference between different kinds of pasta. And I'm 0:01:34.720 --> 0:01:36.800 sure there are a lot of Italians right now feeling 0:01:36.920 --> 0:01:38.920 kind of sorry for you. You can't see. It's like 0:01:39.040 --> 0:01:42.320 nuts being able to see colors. I mean, I don't 0:01:42.319 --> 0:01:44.600 even understand the chemistry of it. Right once it gets 0:01:44.600 --> 0:01:46.920 into your mouth, it's just sauce and noodle. What does 0:01:46.959 --> 0:01:49.320 it matter what the shape of the noodle was when 0:01:49.320 --> 0:01:51.559 it was on your plate. Explain it to me. What's 0:01:51.560 --> 0:01:53.240 the science of it? Are you and those people that 0:01:53.280 --> 0:01:57.960 just blends all their food into smoothies, you know, salmon, steak, rice, 0:01:58.040 --> 0:01:59.960 whatever it just said, it's all going to get digested. 0:02:00.040 --> 0:02:02.320 It might as will blended together. No, I'm a big 0:02:02.360 --> 0:02:05.080 fan of texture. I get that absolutely, But you know, 0:02:05.120 --> 0:02:07.200 in the end, the noodles they don't taste different. They're 0:02:07.200 --> 0:02:09.120 not different texture when they go into your mouth. Maybe 0:02:09.120 --> 0:02:11.760 I'm overcooking them. I don't know. Yeah, I think if 0:02:11.760 --> 0:02:15.280 you overcook them, it's kind a big giant globe. But 0:02:15.440 --> 0:02:18.320 you know, it's like the ratio between the volume and 0:02:18.440 --> 0:02:20.920 the surface area, you know, makes the sauces kind of 0:02:21.000 --> 0:02:23.560 coat the pasta a little differently. Right, taste makes makes 0:02:23.560 --> 0:02:25.440 to taste different, I guess. So it definitely makes it 0:02:25.480 --> 0:02:27.640 look different, and it gives my kids an excuse to 0:02:27.680 --> 0:02:30.320 refuse to eat something like my son will not eat 0:02:30.400 --> 0:02:33.520 or Ka and my daughter will not eat Farfalla. And 0:02:33.520 --> 0:02:35.639 I'm like, look, it's just postable sauce on it. What's 0:02:35.639 --> 0:02:38.560 the big deal. Wow, your kids are pretty picky there. 0:02:38.600 --> 0:02:40.440 Maybe I should just blend it into a smoothie before 0:02:40.440 --> 0:02:41.959 I serve it to them. There you go. You could 0:02:41.960 --> 0:02:43.840 blend it and then make your own pasta. We do 0:02:43.880 --> 0:02:46.320 make our own pasta. Actually, sometimes we start from scratch, 0:02:46.360 --> 0:02:49.000 We make the dough, we roll it out. It's pretty fun. Yeah, 0:02:49.040 --> 0:02:50.760 it's kind of I guess. It's kind of like bread, right, 0:02:50.840 --> 0:02:54.720 Like all breads are basically flour and water. But you 0:02:54.760 --> 0:02:56.680 know you're gonna have a whole range of different breads 0:02:57.240 --> 0:02:58.960 and they all taste different. Oh my gosh, don't get 0:02:58.960 --> 0:03:01.640 into bread with me. Bread have very different mixtures of 0:03:01.639 --> 0:03:04.359 flower and water. You've got your moist breads, You've got 0:03:04.360 --> 0:03:06.400 your drier breads. You've got breads with more fat or 0:03:06.480 --> 0:03:09.880 less fat. It's totally different ingredients. That's what makes different 0:03:09.919 --> 0:03:12.920 kind of bread delicious. It's the same ingredients, isn't it. 0:03:12.960 --> 0:03:17.079 With different proportions? Oh, different proportions you mean, like different 0:03:17.080 --> 0:03:21.960 proportions of surface area volume. Alright, good point, but anyway, 0:03:22.400 --> 0:03:26.280 welcome to our I guess Culinary podcast. Daniel and Jorge 0:03:26.360 --> 0:03:29.120 Explain the Universe, a production of I Heart Radio in 0:03:29.160 --> 0:03:32.480 which to total lon experts argue about pasta when we 0:03:32.520 --> 0:03:36.080 really should be talking about the deepest questions in the universe. 0:03:36.400 --> 0:03:39.600 What shape do fundamental objects take? How do they come 0:03:39.640 --> 0:03:42.480 together to make this incredible universe with all of its 0:03:42.480 --> 0:03:45.680 amazing and different shapes. How do we get baseballs and 0:03:45.800 --> 0:03:49.280 fish and clouds and far falla and rikieta and spaghetti 0:03:49.320 --> 0:03:52.200 and cappellini and all the incredible shapes that we find 0:03:52.240 --> 0:03:54.720 here on our planet and the insane things going on 0:03:54.920 --> 0:03:58.640 inside our planet and inside stars and inside neutron stars 0:03:58.680 --> 0:04:01.360 and inside black hole. We dig into all of it 0:04:01.400 --> 0:04:05.000 for you. We codd with the delicious sauce of explanations 0:04:05.040 --> 0:04:07.560 and banana jokes and serve it up to you. That's right. 0:04:07.640 --> 0:04:10.560 It is a big, beautiful and delicious universe full of 0:04:10.600 --> 0:04:14.120 oodles and noodles of interesting things to learn and discover 0:04:14.280 --> 0:04:16.599 and to figure out how it works. Because somehow we 0:04:16.600 --> 0:04:19.080 are able to discover how things work in this universe 0:04:19.560 --> 0:04:22.280 using science. Absolutely, we think that it's possible to sit 0:04:22.320 --> 0:04:24.520 here on the crust of our planet and to just 0:04:24.640 --> 0:04:27.480 use our minds and our eyeballs to explore what's going 0:04:27.520 --> 0:04:30.920 on deep within our planet in conditions we could never 0:04:30.920 --> 0:04:34.520 replicate in our laboratories, and also what's going on inside 0:04:34.600 --> 0:04:37.800 crazy things out there in the universe. These our minds 0:04:37.800 --> 0:04:40.760 to try to extrapolate from the situations we can explore 0:04:40.839 --> 0:04:43.480 from the laws we have discovered, and wonder if those 0:04:43.520 --> 0:04:47.920 ideas and understandings hold up under very extreme conditions. Yeah, 0:04:47.960 --> 0:04:50.160 because that is one way to do science, is to 0:04:50.360 --> 0:04:54.120 observe things, and especially observe the crazy and the wild 0:04:54.240 --> 0:04:56.800 and the extreme situations out there in the universe, because 0:04:56.839 --> 0:04:59.040 they do teach us a lot about what can happen 0:04:59.160 --> 0:05:01.160 in the universe, even if you don't see it in 0:05:01.160 --> 0:05:03.680 an everyday basis, because one of our goals in physics 0:05:03.800 --> 0:05:05.720 is not to have a special set of rules for 0:05:05.800 --> 0:05:08.880 every situation. We don't want the physics of laundry and 0:05:08.960 --> 0:05:11.719 the physics of pasta, and the physics of air and 0:05:11.760 --> 0:05:14.760 the physics of water weight. That sounds like a great podcast. Actually, 0:05:15.160 --> 0:05:18.400 maybe we should do more of those rather than amplitus 0:05:18.480 --> 0:05:21.800 the physics of laundry. Yeah, I'll listen to that might 0:05:21.839 --> 0:05:24.599 give me some pointers, you know, like what are the 0:05:24.600 --> 0:05:28.000 physics of taking out post stains out of your white shirt? Wow? 0:05:28.120 --> 0:05:32.080 Crossover episode with our culinary podcast series. Yeah, well, that's fascinating. 0:05:32.320 --> 0:05:34.880 You know. All the different applications of physics in different 0:05:34.880 --> 0:05:38.359 conditions are interesting how these things emerge. But physics, you know, 0:05:38.400 --> 0:05:40.680 in the end, is reductionists. We want to go down 0:05:40.720 --> 0:05:43.520 to the lowest level. We want to understand a general 0:05:43.560 --> 0:05:46.640 theory about the universe that applies everywhere that you could 0:05:46.680 --> 0:05:49.800 take to your laundry or pasta or neutron star and 0:05:49.839 --> 0:05:51.880 say I can start from these rules and I can 0:05:51.960 --> 0:05:55.080 understand what's going on here, and the way to test that, 0:05:55.120 --> 0:05:57.440 the way to make sure that the ideas you have 0:05:57.480 --> 0:06:01.159 are not just specific to your pasta stains or to 0:06:01.240 --> 0:06:04.200 the experiments you do in your laboratory, but our general 0:06:04.520 --> 0:06:07.320 is to test them under extreme conditions, to say what 0:06:07.520 --> 0:06:10.040 happens if I make this really really dense or really 0:06:10.080 --> 0:06:12.920 really hot where we go really really fast. So that's 0:06:12.920 --> 0:06:16.000 why the extreme conditions are the best places to learn 0:06:16.440 --> 0:06:19.160 where your rules break down and to get clues about 0:06:19.200 --> 0:06:22.039 how to make new rules about the universe. Yeah, we 0:06:22.120 --> 0:06:23.960 like to look at extremes here on the podcast, and 0:06:24.000 --> 0:06:26.000 we have a whole series of extreme things that we've 0:06:26.000 --> 0:06:28.279 looked at in the universe, like the brightest things in 0:06:28.279 --> 0:06:30.640 the universe or the hottest things in the universe, and 0:06:30.680 --> 0:06:33.600 it usually comes down to only a couple of candidates. 0:06:33.720 --> 0:06:36.800 One of them are neutron stars. Neutron stars are one 0:06:36.800 --> 0:06:40.080 of the most amazing laboratories for physics in the universe 0:06:40.120 --> 0:06:42.120 because it's one of the few places where all of 0:06:42.160 --> 0:06:44.440 the forces are important. And we talk a lot in 0:06:44.480 --> 0:06:48.080 this podcast about quantum field theory and understanding three of 0:06:48.120 --> 0:06:51.599 the forces electromagnetism, the weak force, and the strong force. 0:06:51.760 --> 0:06:53.839 But we don't have many situations where we can put 0:06:53.839 --> 0:06:57.880 those three forces up against gravity because gravity is so weak. 0:06:58.279 --> 0:07:00.560 It's only really in the heart of black coals that 0:07:00.600 --> 0:07:03.479 gravity dominates and takes over. But in the inside of 0:07:03.520 --> 0:07:06.440 neutron stars, we think that gravity is just about as 0:07:06.480 --> 0:07:09.320 strong as these other forces. So it's a great laboratory 0:07:09.320 --> 0:07:12.160 for understanding how gravity and these other forces talk to 0:07:12.200 --> 0:07:15.160 each other and play together or don't play together. Yeah, 0:07:15.200 --> 0:07:17.760 we've talked about neutron stars before, but we've never sort 0:07:17.760 --> 0:07:20.800 of dug deeper into them to find out what it's 0:07:20.800 --> 0:07:22.600 all made out of on the inside. So to be 0:07:22.640 --> 0:07:29.640 on the program, we'll be asking the question what is 0:07:29.800 --> 0:07:34.960 inside a neutron star? And what would Italians call it? Neutrinos? No, 0:07:35.200 --> 0:07:37.600 that's taken. I think I know what the answer to 0:07:37.640 --> 0:07:39.800 this question is, though, Daniel, what's inside a neutron star? 0:07:40.200 --> 0:07:44.360 Isn't it just neutrons? Done? Thanks for joining us, see 0:07:44.360 --> 0:07:46.240 you next time. I thought you were gonna say what's 0:07:46.240 --> 0:07:49.040 inside a neutron star? One neutron star? I mean, that's 0:07:49.040 --> 0:07:51.240 like the ingredients, right, It's like what is pasta made 0:07:51.240 --> 0:07:53.960 out of pasta? Is that what you're saying? Is that 0:07:53.960 --> 0:07:57.880 what physics has come down to, giving up? Giving up? Yes, exactly. No, 0:07:58.000 --> 0:08:00.720 of course neutrons are inside a new tron star. But 0:08:00.800 --> 0:08:04.600 what are they doing. Man, what's the conditions? How dense 0:08:04.720 --> 0:08:07.720 are they? They form weird objects and shapes when they're 0:08:07.760 --> 0:08:11.480 in that crazy conditions. Are they even really still neutrons? 0:08:11.560 --> 0:08:14.360 Or they squeezed down into some other weird kind of matter, 0:08:14.440 --> 0:08:18.200 maybe even a quirk gluon plasma. Wait wait, neutron stars 0:08:18.280 --> 0:08:21.160 might not be made out of neutrons. I smell some 0:08:21.240 --> 0:08:24.400 misnaming here exactly. That is the question of the podcast, 0:08:24.480 --> 0:08:27.920 Our neutron stars fundamentally misnamed? That seems to be the 0:08:27.960 --> 0:08:30.000 mission of the entire program here. You're just trying to 0:08:30.040 --> 0:08:33.880 undermine people's confidence in physics, man or physicists. Is their 0:08:33.960 --> 0:08:36.839 confidence in physics? I mean, think about all the technology 0:08:36.880 --> 0:08:38.960 you're using to make this podcast and to listen to 0:08:38.960 --> 0:08:41.680 this podcast. All of that is based on fundamental physics 0:08:41.679 --> 0:08:44.880 that we understood through basic research. So I think, on 0:08:44.880 --> 0:08:46.920 one hand, we've been doing a pretty good job of 0:08:46.960 --> 0:08:50.280 exploring the universe and learning how to manipulate it for 0:08:50.320 --> 0:08:54.000 our benefit. On the other hand, we definitely don't understand 0:08:54.040 --> 0:08:56.680 a lot about the universe, so there's a huge amount 0:08:56.800 --> 0:08:59.120 left to discover. Yeah, I know, physics, it's just a 0:08:59.160 --> 0:09:01.760 big confident game, right, That's right. Keep paying us, and 0:09:01.760 --> 0:09:04.000 we'll keep teaching you the secrets of the universe. Except 0:09:04.000 --> 0:09:07.120 in this confidence game, the secrets are true, or at 0:09:07.200 --> 0:09:08.880 least as true as you think they can be. But 0:09:08.920 --> 0:09:11.160 I think maybe what you're saying that the question is 0:09:11.280 --> 0:09:13.400 in this episode is actually more like what's it like 0:09:13.559 --> 0:09:16.240 inside a neutron star? What's it like? You know, like, 0:09:16.280 --> 0:09:19.000 what's going on inside a neutron star? Yeah? Exactly. We 0:09:19.040 --> 0:09:21.960 did an episode on what's it like inside the Earth? 0:09:22.000 --> 0:09:24.440 What we dug into the crust and talked about, you know, 0:09:24.480 --> 0:09:26.720 the different layers. You could have answered that question what's 0:09:26.720 --> 0:09:29.240 inside the Earth by saying Earth, but that's not as 0:09:29.280 --> 0:09:32.080 satisfactory and answer. So, yeah, we want to understand like 0:09:32.120 --> 0:09:35.079 are there layers? There is it one big soup of neutrons? 0:09:35.240 --> 0:09:37.600 You know? Are there different phases of matter as you 0:09:37.640 --> 0:09:40.839 get crazy hot and dense? What is going on inside 0:09:40.880 --> 0:09:44.120 a neutron star? Can you find pasta inside? And apparently 0:09:44.160 --> 0:09:47.640 the answer is yes, there is pasta inside of neutron stars. 0:09:48.200 --> 0:09:50.840 If Michael Bay could film a movie about journey to 0:09:50.920 --> 0:09:53.920 the center of a neutron star, what would he show 0:09:53.920 --> 0:09:55.920 you on the screen? You would have to bring in 0:09:55.960 --> 0:09:59.360 some Italian consultants, because apparently the answer is pasta. Pasta 0:09:59.440 --> 0:10:02.199 is everywhere turns out to be the fundamental building block 0:10:02.240 --> 0:10:04.400 of the universe. Well, it's usually were wondering how many 0:10:04.400 --> 0:10:06.800 people out there had thought about this question, what's going 0:10:06.840 --> 0:10:09.440 on inside of a neutron star? So Daniel went out 0:10:09.480 --> 0:10:12.360 there to the wilds of the internet to get people's opinions. 0:10:12.480 --> 0:10:15.400 And I'm eternally grateful to our volunteers who answer these 0:10:15.480 --> 0:10:18.040 random questions and give us a sense for what people 0:10:18.080 --> 0:10:20.319 know and what they might be curious to learn about. 0:10:20.360 --> 0:10:22.440 Thank you very much. And if you are out there 0:10:22.520 --> 0:10:24.920 listening and they've never been on the podcast, we would 0:10:25.000 --> 0:10:28.000 love to have your voice to add it to our library. 0:10:28.040 --> 0:10:30.720 So please write to us two questions at Daniel and 0:10:30.880 --> 0:10:33.760 Jorge dot com. It's free, it's easy, it's fun. So 0:10:33.800 --> 0:10:35.960 think about it for a second. What kind of pasta 0:10:36.040 --> 0:10:38.360 would you like to see inside of a neutron star? 0:10:38.559 --> 0:10:40.640 And what do you think it's doing. Here's what people 0:10:40.679 --> 0:10:42.720 had to say. I've heard you guys talk about this 0:10:42.760 --> 0:10:45.760 in the past. Um, I know, like there is a 0:10:45.840 --> 0:10:49.800 crust and then as you go down deeper towards the core, 0:10:49.880 --> 0:10:54.839 there's like I think they call it quantum spaghetti. And 0:10:54.880 --> 0:10:57.640 then at the very center, I've heard you guys talk 0:10:57.720 --> 0:11:04.040 about luans, and the neutrons are no longer associated, so 0:11:04.080 --> 0:11:08.959 it's just like the soup of quarks and gluons floating around. Well, 0:11:09.000 --> 0:11:11.319 I would say it's pretty tight. I wouldn't want to 0:11:11.360 --> 0:11:15.600 be in there. Actually, in neutron stars are made out 0:11:15.640 --> 0:11:19.239 of nutrons, and the core I would think is the 0:11:19.320 --> 0:11:23.240 densest part of a star. So I would say there's 0:11:23.280 --> 0:11:27.640 a lot of nutrons, really really packed with nutrons. I 0:11:27.640 --> 0:11:31.400 would imagine it's hot and bright and chaotic, and if 0:11:31.480 --> 0:11:33.640 it had a high enough mass and you were actually 0:11:33.640 --> 0:11:36.120 inside it, then you might be able to find out 0:11:36.240 --> 0:11:42.280 what's in a black hole. Oh boy, very hot, very dense, 0:11:43.440 --> 0:11:46.480 very angry. I wouldn't want to be inside of a 0:11:46.520 --> 0:11:50.199 neutron star. A neutron star, other than a black hole, 0:11:50.480 --> 0:11:53.280 is the densest known object in the universe. It is 0:11:53.320 --> 0:11:56.199 so dense, in fact, that it has high enough pressure 0:11:56.559 --> 0:11:59.000 to merge to push all of the electrons and the 0:11:59.000 --> 0:12:02.960 protons together to form neutrons. Fusion is over, but it 0:12:03.120 --> 0:12:07.559 is very hot, and it is emanating very high frequency 0:12:07.640 --> 0:12:11.959 black body radiation, and I know it must be spinning 0:12:12.080 --> 0:12:15.160 very fast due to the laws of the conservation of 0:12:15.200 --> 0:12:22.199 angular momentum. Well, it's very compressed, extreme pressure, lots of heat, radiation, 0:12:22.800 --> 0:12:28.760 extreme electromagnetic fields, dizzy and spinning and death. I can 0:12:28.800 --> 0:12:33.120 only imagine that being inside a neutron star is like 0:12:33.240 --> 0:12:36.280 being inside of a bag of popcorn that is being 0:12:36.320 --> 0:12:38.680 cooked in the microwave. Um. There's a lot of pressure, 0:12:38.800 --> 0:12:43.319 a lot of build up, it's hot, and there's no escape. 0:12:43.920 --> 0:12:47.040 It seems like a prison. All right. People aren't painting 0:12:47.080 --> 0:12:49.920 a very pleasant picture here of neutron stars. Yeah, but 0:12:49.920 --> 0:12:51.920 they're reaching for a lot of food analogies. You know, 0:12:51.960 --> 0:12:54.800 we've got soup, We've got spaghetti, we even got popcorn. 0:12:54.920 --> 0:12:57.480 I guess did you pull people right before lunch or something. 0:12:59.520 --> 0:13:02.560 I think there's a deep and unexplored connection between physics 0:13:02.600 --> 0:13:04.960 and food, you know. I think that's what we're discovering 0:13:04.960 --> 0:13:06.960 here today because physicists like to eat a lot of 0:13:09.120 --> 0:13:11.840 or is that just your personal perspective, Daniel. You know 0:13:11.880 --> 0:13:13.800 I'm not a big eater. I don't eat anything actually 0:13:13.880 --> 0:13:16.480 during the day. I only eat at night, So you know, 0:13:16.520 --> 0:13:18.800 I can do physics all day long on an empty stomach. 0:13:18.840 --> 0:13:21.720 But I think that people reach for these analogies because 0:13:21.760 --> 0:13:25.360 they're trying to explain something weird and unfamiliar in terms 0:13:25.360 --> 0:13:27.280 of something that's familiar. And in the end, that's what 0:13:27.400 --> 0:13:30.360 physics is, right. We explain the unknown in terms of 0:13:30.360 --> 0:13:32.880 the known. So when you see something weird and new, 0:13:32.920 --> 0:13:35.360 you try to say that reminds me of and then 0:13:35.400 --> 0:13:37.760 you look for something familiar around you, like whatever you're 0:13:37.760 --> 0:13:40.400 having for lunch. Yeah, and most people here seem to 0:13:40.440 --> 0:13:43.000 have an idea that neutron stars are really hot and 0:13:43.120 --> 0:13:45.400 dance and compressed. A lot of the answers were sort 0:13:45.400 --> 0:13:49.040 of sort of people describing a pretty intense environment inside 0:13:49.040 --> 0:13:51.440 of a neutron star. Yes, exactly, And that's what get 0:13:51.520 --> 0:13:55.800 physicists excited, right, because we think it's a situation unlike 0:13:55.840 --> 0:13:58.839 any other in the universe, one that's very hard, if 0:13:58.840 --> 0:14:01.880 not impossible, to read create in our laboratory, and yet 0:14:01.960 --> 0:14:05.240 there it sits out there, actually doing its thing. And 0:14:05.280 --> 0:14:07.720 if we could know what was going on inside those 0:14:07.720 --> 0:14:10.520 neutron stars, we would have the answers to lots of 0:14:10.600 --> 0:14:14.080 questions about crazy conditions that we're curious about. You know, 0:14:14.200 --> 0:14:17.400 what happens when you squeeze these particles really close to 0:14:17.400 --> 0:14:19.680 each other, because remember that at the heart of a 0:14:19.680 --> 0:14:22.800 neutron star, these things are dominated by the strong force 0:14:23.040 --> 0:14:26.120 battling it out with gravity, and these are two forces 0:14:26.120 --> 0:14:28.520 that we do not understand very well. Of all of 0:14:28.560 --> 0:14:31.080 the fundamental forces in the universe. We understand the weak 0:14:31.120 --> 0:14:34.520 force and electromagnetism the best. We understand the strong force 0:14:34.520 --> 0:14:37.040 and gravity the worst. And so to get to see 0:14:37.040 --> 0:14:40.160 them fight it out helps us understand both of them. 0:14:40.320 --> 0:14:43.040 The strong mystery. Break it down for the audience here, 0:14:43.080 --> 0:14:46.080 what is exactly a neutron star. So a neutron star 0:14:46.280 --> 0:14:48.720 is one of the most amazing and weird objects in 0:14:48.720 --> 0:14:51.560 the universe, and it's also left over from one of 0:14:51.560 --> 0:14:54.680 the most dramatic kinds of events we have in the universe, 0:14:54.920 --> 0:14:57.040 which is a supernova. So you know, you start with 0:14:57.080 --> 0:15:00.600 a normal star which burns, and they have the typical 0:15:00.600 --> 0:15:04.200 battle between pressure from gravity squeezing in and fusion and 0:15:04.280 --> 0:15:07.480 radiation pushing out, and it burns for millions or billions 0:15:07.520 --> 0:15:09.840 of years, depending on its size, and at some point 0:15:09.960 --> 0:15:13.000 the core of it gets so heavy because it's fused 0:15:13.040 --> 0:15:17.320 all of these lighter elements and heavier elements carbon neon, oxygen. 0:15:17.560 --> 0:15:19.600 You work your way up the periodic table. At some 0:15:19.640 --> 0:15:22.040 point the core gets so heavy that gravity wins and 0:15:22.080 --> 0:15:25.520 the thing collapses. You get this shock wave that rushes 0:15:25.600 --> 0:15:28.360 in towards the heart of the star and then bounces 0:15:28.400 --> 0:15:30.920 back and comes out, and you get a supernova, and 0:15:30.920 --> 0:15:33.320 that blows out most of the stuff from the star. 0:15:33.760 --> 0:15:36.160 You know, huge amount of energy comes out in neutrinos 0:15:36.200 --> 0:15:38.720 and in photons and then just massive the stuff of 0:15:38.760 --> 0:15:42.440 the star. But it leaves behind this very very dense core. 0:15:42.600 --> 0:15:45.120 And so that's what the neutron star is. It's the 0:15:45.160 --> 0:15:48.840 remnant of a supernova from a super giant star. Yeah, 0:15:48.840 --> 0:15:51.040 that's something that I think, I know we've talked about before, 0:15:51.080 --> 0:15:53.000 but it's still pretty cool because I don't think a 0:15:53.000 --> 0:15:55.360 lot of people suld have realized that a supernova. You know, 0:15:55.440 --> 0:15:57.560 we think that maybe it's like an explosion or something 0:15:57.600 --> 0:16:00.880 reacts and explodes, but it's actually like what happens when 0:16:01.120 --> 0:16:04.480 stars and suns collapse. It's actually like the collapse of 0:16:04.480 --> 0:16:07.200 a star, and it's that collapse that kind of causes 0:16:07.320 --> 0:16:09.840 the big explosion. Yeah, you have the supersonic shock wave 0:16:09.840 --> 0:16:13.240 of traveling inwards and then traveling outwards, right it bounces 0:16:13.320 --> 0:16:16.000 back and explodes, and so it's a lot like you know, 0:16:16.040 --> 0:16:18.120 the way a fusion bomb works where we talked about 0:16:18.200 --> 0:16:21.280 laser fusion recently on the podcast, where you have this 0:16:21.440 --> 0:16:25.680 symmetric implosion which creates very fast runaway fusion which then 0:16:25.720 --> 0:16:29.240 triggers an explosion, right, and so it's really a dramatic end. 0:16:29.440 --> 0:16:32.480 It's incredible also the time scales, because these stars burned 0:16:32.520 --> 0:16:35.800 for millions or billions of years happily in almost a 0:16:35.840 --> 0:16:38.960 steady state, and then the end comes very quickly. You know, 0:16:39.040 --> 0:16:41.720 you think of cosmic objects having long time scales. You 0:16:41.760 --> 0:16:44.480 should do everything slowly, but when it dies, it dies 0:16:44.680 --> 0:16:48.040 very quickly, and it leaves behind these little remnants, these 0:16:48.080 --> 0:16:52.000 neutron stars, and they're super small, you know. These things 0:16:52.040 --> 0:16:56.640 have a radius of like ten to twenty kilometers, you know, 0:16:56.640 --> 0:16:58.920 so again we're talking about astrophysical objects. You used to 0:16:58.960 --> 0:17:02.240 thinking about like millions of kilometers. These things are billions 0:17:02.280 --> 0:17:04.199 of light years away, but we're talking about things like 0:17:04.280 --> 0:17:07.720 the size of Manhattan or Los Angeles, and yet they're 0:17:07.800 --> 0:17:10.520 super massive, like they still have the mass of an 0:17:10.680 --> 0:17:13.320 entire sun, like our sun. So these things of a 0:17:13.359 --> 0:17:16.640 mass of like one to maybe three masses of our 0:17:16.720 --> 0:17:20.359 Sun compressed into a tiny little space. Yeah, that's how 0:17:20.480 --> 0:17:22.920 That's exactly why I feel when I visit Manhattan actually 0:17:23.640 --> 0:17:26.720 super dance and compressing and hot as well. But what's 0:17:26.760 --> 0:17:28.800 interesting too is that, first of all, not every star 0:17:28.880 --> 0:17:34.600 goes supernova, and not every supernova turns into a neutron star. Right, 0:17:34.640 --> 0:17:37.240 that's right. The final fate of the star is determined 0:17:37.240 --> 0:17:40.240 almost entirely by how massive it was when it was born. 0:17:40.400 --> 0:17:43.360 If it has a mass between like ten and twenty 0:17:43.440 --> 0:17:45.920 or twenty five times the mass of our Sun, then 0:17:45.920 --> 0:17:48.800 it will go supernova and then go neutron star. If 0:17:48.800 --> 0:17:51.399 it has more mass than that, it'll go supernova, but 0:17:51.440 --> 0:17:53.919 it'll leave a black hole at the center instead of 0:17:53.920 --> 0:17:56.680 a neutron star. So if you have enough mass, then 0:17:56.720 --> 0:17:59.920 you can overcome even the strength of the neutron star 0:18:00.000 --> 0:18:03.119 and collapse it even further to a black hole. So 0:18:03.200 --> 0:18:06.280 gravity wins there if you add more mass. If you don't, 0:18:06.320 --> 0:18:08.600 if you had less mass, like less than ten times 0:18:08.640 --> 0:18:10.639 the mass of the Sun, then you don't get a supernova, 0:18:10.680 --> 0:18:12.240 and you get what's going to happen to our Sun, 0:18:12.280 --> 0:18:14.600 which is is just gonna leave behind the original core, 0:18:14.840 --> 0:18:17.280 which would be a white dwarf. So then for a 0:18:17.359 --> 0:18:20.480 neutron star, you start with a regular star that's about 0:18:20.480 --> 0:18:22.440 ten to twenty five times the mass of our sun. 0:18:22.520 --> 0:18:25.400 He's supernova that most of it I guess blows out 0:18:25.440 --> 0:18:27.560 in the supernova, but some of it, like one to 0:18:27.640 --> 0:18:30.679 three masses of our Sun, stays in the middle in 0:18:30.720 --> 0:18:33.400 this super duper dense state that I guess had its 0:18:33.440 --> 0:18:36.120 origin when the star collapse, right exactly, So you take 0:18:36.160 --> 0:18:38.639 the core of the star and you squeeze it down 0:18:38.720 --> 0:18:42.080 to this tiny little dot, this neutron star. So it's 0:18:42.119 --> 0:18:44.960 like a white dwarf that's been compressed by a supernova. 0:18:45.040 --> 0:18:47.000 And it's fascinating to me because it's like the last 0:18:47.000 --> 0:18:49.720 step before a black hole. You know, gravity is a 0:18:49.800 --> 0:18:52.680 runaway effect. If you only had gravity and no other 0:18:52.680 --> 0:18:55.600 forces in the universe, everything would eventually just collapse to 0:18:55.640 --> 0:18:57.600 a black hole to be nothing to stop it, because 0:18:57.720 --> 0:19:00.119 gravity just pull stuff in and it gets dense here 0:19:00.119 --> 0:19:02.560 and denser, and the denser gets the stronger it is, 0:19:02.600 --> 0:19:05.440 and then the stronger it is, the denser gets etcetera, etcetera. 0:19:05.520 --> 0:19:07.359 So the way to avoid becoming a black hole is 0:19:07.400 --> 0:19:10.119 to have something pushed back against gravity. So a star 0:19:10.480 --> 0:19:13.040 doesn't collapse into a black hole while it's burning because 0:19:13.040 --> 0:19:16.040 the fusion provides pressure outwards. The Earth doesn't collapse into 0:19:16.040 --> 0:19:18.960 a black hole right now because all that dirt has 0:19:19.080 --> 0:19:22.439 structural integrity. As the mass gets stronger and stronger, you 0:19:22.480 --> 0:19:25.240 need stronger forces to resist it, and eventually it just 0:19:25.280 --> 0:19:27.520 gives up and becomes a black hole. And a neutron 0:19:27.560 --> 0:19:30.440 star is like the last line of defense against gravity. 0:19:30.440 --> 0:19:33.360 It's like the densest thing in the universe that's not 0:19:33.640 --> 0:19:35.840 a black hole, right, Like, if you squeeze it a 0:19:35.920 --> 0:19:38.040 little bit more, you would get a black hole. But 0:19:38.280 --> 0:19:40.679 if you stop squeezing it or adding more mass right 0:19:40.680 --> 0:19:42.680 before it turns into black hole, then that's what you get. 0:19:42.720 --> 0:19:44.800 You get a neutron star exactly. And so it's this 0:19:44.960 --> 0:19:49.000 object which has enough strength to resist the incredible mass 0:19:49.040 --> 0:19:51.840 and the incredible gravity that it does have, but if 0:19:51.880 --> 0:19:53.840 you added a little bit more, yeah, it would collapse 0:19:54.000 --> 0:19:56.120 into a black hole. And so it's really the perfect 0:19:56.119 --> 0:20:00.159 way to understand this balance between the strong fo and 0:20:00.200 --> 0:20:03.879 the quantum mechanics that's resistant collapse and the gravitational pressure 0:20:03.960 --> 0:20:06.840 that's squeezing down on it. So like how many plates 0:20:06.840 --> 0:20:08.600 of pasta would you have to throw in to turn 0:20:08.640 --> 0:20:12.280