Speaker 1: Hey or hey, do you have strong opinions about pasta?
Speaker 1: I mean, like in my pro pasta or antipasta. Yeah,
Speaker 1: but I want to dig a little deeper, like, do
Speaker 1: you have opinions about all of the varieties? Yeah? No,
Speaker 1: I love that there are so many kinds of pasta,
Speaker 1: the more of the tastier. So then in the opinion
Speaker 1: of an artist, what is the prettiest pasta there is?
Speaker 1: M I try not to judge pasta bytes looks, you know,
Speaker 1: that seems kind of rude, So I just go by taste. Well,
Speaker 1: to me, it all tastes the same. I mean, fundamentally,
Speaker 1: it's all made of the same stuff. Though my kids
Speaker 1: insist that some of them are tastier than others. I
Speaker 1: think it's your kids. In an entire country called Italy
Speaker 1: would argue the same thing. I mean, it's all made
Speaker 1: of dough, right, which in the end just made of
Speaker 1: like protons, neutrons and electrons. How can it taste different? Can?
Speaker 1: We'll probably get a lot of hate mail from Italians
Speaker 1: because you know your physicist, right, Like, each pasta has
Speaker 1: a different cross section and a different ratio of volume
Speaker 1: to surface area. Right. Welcome to the physics of pasta podcasting.
Speaker 1: That's right, we're all postic. I am Jorge. I'm a
Speaker 1: cartoonists and the co author of Frequently Asked Questions about
Speaker 1: the Universe. Hi, I'm Daniel. I'm a particle physicist and
Speaker 1: a professor at u C Irvine. And I seriously can't
Speaker 1: taste the difference between different kinds of pasta. And I'm
Speaker 1: sure there are a lot of Italians right now feeling
Speaker 1: kind of sorry for you. You can't see. It's like
Speaker 1: nuts being able to see colors. I mean, I don't
Speaker 1: even understand the chemistry of it. Right once it gets
Speaker 1: into your mouth, it's just sauce and noodle. What does
Speaker 1: it matter what the shape of the noodle was when
Speaker 1: it was on your plate. Explain it to me. What's
Speaker 1: the science of it? Are you and those people that
Speaker 1: just blends all their food into smoothies, you know, salmon, steak, rice,
Speaker 1: whatever it just said, it's all going to get digested.
Speaker 1: It might as will blended together. No, I'm a big
Speaker 1: fan of texture. I get that absolutely, But you know,
Speaker 1: in the end, the noodles they don't taste different. They're
Speaker 1: not different texture when they go into your mouth. Maybe
Speaker 1: I'm overcooking them. I don't know. Yeah, I think if
Speaker 1: you overcook them, it's kind a big giant globe. But
Speaker 1: you know, it's like the ratio between the volume and
Speaker 1: the surface area, you know, makes the sauces kind of
Speaker 1: coat the pasta a little differently. Right, taste makes makes
Speaker 1: to taste different, I guess. So it definitely makes it
Speaker 1: look different, and it gives my kids an excuse to
Speaker 1: refuse to eat something like my son will not eat
Speaker 1: or Ka and my daughter will not eat Farfalla. And
Speaker 1: I'm like, look, it's just postable sauce on it. What's
Speaker 1: the big deal. Wow, your kids are pretty picky there.
Speaker 1: Maybe I should just blend it into a smoothie before
Speaker 1: I serve it to them. There you go. You could
Speaker 1: blend it and then make your own pasta. We do
Speaker 1: make our own pasta. Actually, sometimes we start from scratch,
Speaker 1: We make the dough, we roll it out. It's pretty fun. Yeah,
Speaker 1: it's kind of I guess. It's kind of like bread, right,
Speaker 1: Like all breads are basically flour and water. But you
Speaker 1: know you're gonna have a whole range of different breads
Speaker 1: and they all taste different. Oh my gosh, don't get
Speaker 1: into bread with me. Bread have very different mixtures of
Speaker 1: flower and water. You've got your moist breads, You've got
Speaker 1: your drier breads. You've got breads with more fat or
Speaker 1: less fat. It's totally different ingredients. That's what makes different
Speaker 1: kind of bread delicious. It's the same ingredients, isn't it.
Speaker 1: With different proportions? Oh, different proportions you mean, like different
Speaker 1: proportions of surface area volume. Alright, good point, but anyway,
Speaker 1: welcome to our I guess Culinary podcast. Daniel and Jorge
Speaker 1: Explain the Universe, a production of I Heart Radio in
Speaker 1: which to total lon experts argue about pasta when we
Speaker 1: really should be talking about the deepest questions in the universe.
Speaker 1: What shape do fundamental objects take? How do they come
Speaker 1: together to make this incredible universe with all of its
Speaker 1: amazing and different shapes. How do we get baseballs and
Speaker 1: fish and clouds and far falla and rikieta and spaghetti
Speaker 1: and cappellini and all the incredible shapes that we find
Speaker 1: here on our planet and the insane things going on
Speaker 1: inside our planet and inside stars and inside neutron stars
Speaker 1: and inside black hole. We dig into all of it
Speaker 1: for you. We codd with the delicious sauce of explanations
Speaker 1: and banana jokes and serve it up to you. That's right.
Speaker 1: It is a big, beautiful and delicious universe full of
Speaker 1: oodles and noodles of interesting things to learn and discover
Speaker 1: and to figure out how it works. Because somehow we
Speaker 1: are able to discover how things work in this universe
Speaker 1: using science. Absolutely, we think that it's possible to sit
Speaker 1: here on the crust of our planet and to just
Speaker 1: use our minds and our eyeballs to explore what's going
Speaker 1: on deep within our planet in conditions we could never
Speaker 1: replicate in our laboratories, and also what's going on inside
Speaker 1: crazy things out there in the universe. These our minds
Speaker 1: to try to extrapolate from the situations we can explore
Speaker 1: from the laws we have discovered, and wonder if those
Speaker 1: ideas and understandings hold up under very extreme conditions. Yeah,
Speaker 1: because that is one way to do science, is to
Speaker 1: observe things, and especially observe the crazy and the wild
Speaker 1: and the extreme situations out there in the universe, because
Speaker 1: they do teach us a lot about what can happen
Speaker 1: in the universe, even if you don't see it in
Speaker 1: an everyday basis, because one of our goals in physics
Speaker 1: is not to have a special set of rules for
Speaker 1: every situation. We don't want the physics of laundry and
Speaker 1: the physics of pasta, and the physics of air and
Speaker 1: the physics of water weight. That sounds like a great podcast. Actually,
Speaker 1: maybe we should do more of those rather than amplitus
Speaker 1: the physics of laundry. Yeah, I'll listen to that might
Speaker 1: give me some pointers, you know, like what are the
Speaker 1: physics of taking out post stains out of your white shirt? Wow?
Speaker 1: Crossover episode with our culinary podcast series. Yeah, well, that's fascinating.
Speaker 1: You know. All the different applications of physics in different
Speaker 1: conditions are interesting how these things emerge. But physics, you know,
Speaker 1: in the end, is reductionists. We want to go down
Speaker 1: to the lowest level. We want to understand a general
Speaker 1: theory about the universe that applies everywhere that you could
Speaker 1: take to your laundry or pasta or neutron star and
Speaker 1: say I can start from these rules and I can
Speaker 1: understand what's going on here, and the way to test that,
Speaker 1: the way to make sure that the ideas you have
Speaker 1: are not just specific to your pasta stains or to
Speaker 1: the experiments you do in your laboratory, but our general
Speaker 1: is to test them under extreme conditions, to say what
Speaker 1: happens if I make this really really dense or really
Speaker 1: really hot where we go really really fast. So that's
Speaker 1: why the extreme conditions are the best places to learn
Speaker 1: where your rules break down and to get clues about
Speaker 1: how to make new rules about the universe. Yeah, we
Speaker 1: like to look at extremes here on the podcast, and
Speaker 1: we have a whole series of extreme things that we've
Speaker 1: looked at in the universe, like the brightest things in
Speaker 1: the universe or the hottest things in the universe, and
Speaker 1: it usually comes down to only a couple of candidates.
Speaker 1: One of them are neutron stars. Neutron stars are one
Speaker 1: of the most amazing laboratories for physics in the universe
Speaker 1: because it's one of the few places where all of
Speaker 1: the forces are important. And we talk a lot in
Speaker 1: this podcast about quantum field theory and understanding three of
Speaker 1: the forces electromagnetism, the weak force, and the strong force.
Speaker 1: But we don't have many situations where we can put
Speaker 1: those three forces up against gravity because gravity is so weak.
Speaker 1: It's only really in the heart of black coals that
Speaker 1: gravity dominates and takes over. But in the inside of
Speaker 1: neutron stars, we think that gravity is just about as
Speaker 1: strong as these other forces. So it's a great laboratory
Speaker 1: for understanding how gravity and these other forces talk to
Speaker 1: each other and play together or don't play together. Yeah,
Speaker 1: we've talked about neutron stars before, but we've never sort
Speaker 1: of dug deeper into them to find out what it's
Speaker 1: all made out of on the inside. So to be
Speaker 1: on the program, we'll be asking the question what is
Speaker 1: inside a neutron star? And what would Italians call it? Neutrinos? No,
Speaker 1: that's taken. I think I know what the answer to
Speaker 1: this question is, though, Daniel, what's inside a neutron star?
Speaker 1: Isn't it just neutrons? Done? Thanks for joining us, see
Speaker 1: you next time. I thought you were gonna say what's
Speaker 1: inside a neutron star? One neutron star? I mean, that's
Speaker 1: like the ingredients, right, It's like what is pasta made
Speaker 1: out of pasta? Is that what you're saying? Is that
Speaker 1: what physics has come down to, giving up? Giving up? Yes, exactly. No,
Speaker 1: of course neutrons are inside a new tron star. But
Speaker 1: what are they doing. Man, what's the conditions? How dense
Speaker 1: are they? They form weird objects and shapes when they're
Speaker 1: in that crazy conditions. Are they even really still neutrons?
Speaker 1: Or they squeezed down into some other weird kind of matter,
Speaker 1: maybe even a quirk gluon plasma. Wait wait, neutron stars
Speaker 1: might not be made out of neutrons. I smell some
Speaker 1: misnaming here exactly. That is the question of the podcast,
Speaker 1: Our neutron stars fundamentally misnamed? That seems to be the
Speaker 1: mission of the entire program here. You're just trying to
Speaker 1: undermine people's confidence in physics, man or physicists. Is their
Speaker 1: confidence in physics? I mean, think about all the technology
Speaker 1: you're using to make this podcast and to listen to
Speaker 1: this podcast. All of that is based on fundamental physics
Speaker 1: that we understood through basic research. So I think, on
Speaker 1: one hand, we've been doing a pretty good job of
Speaker 1: exploring the universe and learning how to manipulate it for
Speaker 1: our benefit. On the other hand, we definitely don't understand
Speaker 1: a lot about the universe, so there's a huge amount
Speaker 1: left to discover. Yeah, I know, physics, it's just a
Speaker 1: big confident game, right, That's right. Keep paying us, and
Speaker 1: we'll keep teaching you the secrets of the universe. Except
Speaker 1: in this confidence game, the secrets are true, or at
Speaker 1: least as true as you think they can be. But
Speaker 1: I think maybe what you're saying that the question is
Speaker 1: in this episode is actually more like what's it like
Speaker 1: inside a neutron star? What's it like? You know, like,
Speaker 1: what's going on inside a neutron star? Yeah? Exactly. We
Speaker 1: did an episode on what's it like inside the Earth?
Speaker 1: What we dug into the crust and talked about, you know,
Speaker 1: the different layers. You could have answered that question what's
Speaker 1: inside the Earth by saying Earth, but that's not as
Speaker 1: satisfactory and answer. So, yeah, we want to understand like
Speaker 1: are there layers? There is it one big soup of neutrons?
Speaker 1: You know? Are there different phases of matter as you
Speaker 1: get crazy hot and dense? What is going on inside
Speaker 1: a neutron star? Can you find pasta inside? And apparently
Speaker 1: the answer is yes, there is pasta inside of neutron stars.
Speaker 1: If Michael Bay could film a movie about journey to
Speaker 1: the center of a neutron star, what would he show
Speaker 1: you on the screen? You would have to bring in
Speaker 1: some Italian consultants, because apparently the answer is pasta. Pasta
Speaker 1: is everywhere turns out to be the fundamental building block
Speaker 1: of the universe. Well, it's usually were wondering how many
Speaker 1: people out there had thought about this question, what's going
Speaker 1: on inside of a neutron star? So Daniel went out
Speaker 1: there to the wilds of the internet to get people's opinions.
Speaker 1: And I'm eternally grateful to our volunteers who answer these
Speaker 1: random questions and give us a sense for what people
Speaker 1: know and what they might be curious to learn about.
Speaker 1: Thank you very much. And if you are out there
Speaker 1: listening and they've never been on the podcast, we would
Speaker 1: love to have your voice to add it to our library.
Speaker 1: So please write to us two questions at Daniel and
Speaker 1: Jorge dot com. It's free, it's easy, it's fun. So
Speaker 1: think about it for a second. What kind of pasta
Speaker 1: would you like to see inside of a neutron star?
Speaker 1: And what do you think it's doing. Here's what people
Speaker 1: had to say. I've heard you guys talk about this
Speaker 1: in the past. Um, I know, like there is a
Speaker 1: crust and then as you go down deeper towards the core,
Speaker 1: there's like I think they call it quantum spaghetti. And
Speaker 1: then at the very center, I've heard you guys talk
Speaker 1: about luans, and the neutrons are no longer associated, so
Speaker 1: it's just like the soup of quarks and gluons floating around. Well,
Speaker 1: I would say it's pretty tight. I wouldn't want to
Speaker 1: be in there. Actually, in neutron stars are made out
Speaker 1: of nutrons, and the core I would think is the
Speaker 1: densest part of a star. So I would say there's
Speaker 1: a lot of nutrons, really really packed with nutrons. I
Speaker 1: would imagine it's hot and bright and chaotic, and if
Speaker 1: it had a high enough mass and you were actually
Speaker 1: inside it, then you might be able to find out
Speaker 1: what's in a black hole. Oh boy, very hot, very dense,
Speaker 1: very angry. I wouldn't want to be inside of a
Speaker 1: neutron star. A neutron star, other than a black hole,
Speaker 1: is the densest known object in the universe. It is
Speaker 1: so dense, in fact, that it has high enough pressure
Speaker 1: to merge to push all of the electrons and the
Speaker 1: protons together to form neutrons. Fusion is over, but it
Speaker 1: is very hot, and it is emanating very high frequency
Speaker 1: black body radiation, and I know it must be spinning
Speaker 1: very fast due to the laws of the conservation of
Speaker 1: angular momentum. Well, it's very compressed, extreme pressure, lots of heat, radiation,
Speaker 1: extreme electromagnetic fields, dizzy and spinning and death. I can
Speaker 1: only imagine that being inside a neutron star is like
Speaker 1: being inside of a bag of popcorn that is being
Speaker 1: cooked in the microwave. Um. There's a lot of pressure,
Speaker 1: a lot of build up, it's hot, and there's no escape.
Speaker 1: It seems like a prison. All right. People aren't painting
Speaker 1: a very pleasant picture here of neutron stars. Yeah, but
Speaker 1: they're reaching for a lot of food analogies. You know,
Speaker 1: we've got soup, We've got spaghetti, we even got popcorn.
Speaker 1: I guess did you pull people right before lunch or something.
Speaker 1: I think there's a deep and unexplored connection between physics
Speaker 1: and food, you know. I think that's what we're discovering
Speaker 1: here today because physicists like to eat a lot of
Speaker 1: or is that just your personal perspective, Daniel. You know
Speaker 1: I'm not a big eater. I don't eat anything actually
Speaker 1: during the day. I only eat at night, So you know,
Speaker 1: I can do physics all day long on an empty stomach.
Speaker 1: But I think that people reach for these analogies because
Speaker 1: they're trying to explain something weird and unfamiliar in terms
Speaker 1: of something that's familiar. And in the end, that's what
Speaker 1: physics is, right. We explain the unknown in terms of
Speaker 1: the known. So when you see something weird and new,
Speaker 1: you try to say that reminds me of and then
Speaker 1: you look for something familiar around you, like whatever you're
Speaker 1: having for lunch. Yeah, and most people here seem to
Speaker 1: have an idea that neutron stars are really hot and
Speaker 1: dance and compressed. A lot of the answers were sort
Speaker 1: of sort of people describing a pretty intense environment inside
Speaker 1: of a neutron star. Yes, exactly, And that's what get
Speaker 1: physicists excited, right, because we think it's a situation unlike
Speaker 1: any other in the universe, one that's very hard, if
Speaker 1: not impossible, to read create in our laboratory, and yet
Speaker 1: there it sits out there, actually doing its thing. And
Speaker 1: if we could know what was going on inside those
Speaker 1: neutron stars, we would have the answers to lots of
Speaker 1: questions about crazy conditions that we're curious about. You know,
Speaker 1: what happens when you squeeze these particles really close to
Speaker 1: each other, because remember that at the heart of a
Speaker 1: neutron star, these things are dominated by the strong force
Speaker 1: battling it out with gravity, and these are two forces
Speaker 1: that we do not understand very well. Of all of
Speaker 1: the fundamental forces in the universe. We understand the weak
Speaker 1: force and electromagnetism the best. We understand the strong force
Speaker 1: and gravity the worst. And so to get to see
Speaker 1: them fight it out helps us understand both of them.
Speaker 1: The strong mystery. Break it down for the audience here,
Speaker 1: what is exactly a neutron star. So a neutron star
Speaker 1: is one of the most amazing and weird objects in
Speaker 1: the universe, and it's also left over from one of
Speaker 1: the most dramatic kinds of events we have in the universe,
Speaker 1: which is a supernova. So you know, you start with
Speaker 1: a normal star which burns, and they have the typical
Speaker 1: battle between pressure from gravity squeezing in and fusion and
Speaker 1: radiation pushing out, and it burns for millions or billions
Speaker 1: of years, depending on its size, and at some point
Speaker 1: the core of it gets so heavy because it's fused
Speaker 1: all of these lighter elements and heavier elements carbon neon, oxygen.
Speaker 1: You work your way up the periodic table. At some
Speaker 1: point the core gets so heavy that gravity wins and
Speaker 1: the thing collapses. You get this shock wave that rushes
Speaker 1: in towards the heart of the star and then bounces
Speaker 1: back and comes out, and you get a supernova, and
Speaker 1: that blows out most of the stuff from the star.
Speaker 1: You know, huge amount of energy comes out in neutrinos
Speaker 1: and in photons and then just massive the stuff of
Speaker 1: the star. But it leaves behind this very very dense core.
Speaker 1: And so that's what the neutron star is. It's the
Speaker 1: remnant of a supernova from a super giant star. Yeah,
Speaker 1: that's something that I think, I know we've talked about before,
Speaker 1: but it's still pretty cool because I don't think a
Speaker 1: lot of people suld have realized that a supernova. You know,
Speaker 1: we think that maybe it's like an explosion or something
Speaker 1: reacts and explodes, but it's actually like what happens when
Speaker 1: stars and suns collapse. It's actually like the collapse of
Speaker 1: a star, and it's that collapse that kind of causes
Speaker 1: the big explosion. Yeah, you have the supersonic shock wave
Speaker 1: of traveling inwards and then traveling outwards, right it bounces
Speaker 1: back and explodes, and so it's a lot like you know,
Speaker 1: the way a fusion bomb works where we talked about
Speaker 1: laser fusion recently on the podcast, where you have this
Speaker 1: symmetric implosion which creates very fast runaway fusion which then
Speaker 1: triggers an explosion, right, and so it's really a dramatic end.
Speaker 1: It's incredible also the time scales, because these stars burned
Speaker 1: for millions or billions of years happily in almost a
Speaker 1: steady state, and then the end comes very quickly. You know,
Speaker 1: you think of cosmic objects having long time scales. You
Speaker 1: should do everything slowly, but when it dies, it dies
Speaker 1: very quickly, and it leaves behind these little remnants, these
Speaker 1: neutron stars, and they're super small, you know. These things
Speaker 1: have a radius of like ten to twenty kilometers, you know,
Speaker 1: so again we're talking about astrophysical objects. You used to
Speaker 1: thinking about like millions of kilometers. These things are billions
Speaker 1: of light years away, but we're talking about things like
Speaker 1: the size of Manhattan or Los Angeles, and yet they're
Speaker 1: super massive, like they still have the mass of an
Speaker 1: entire sun, like our sun. So these things of a
Speaker 1: mass of like one to maybe three masses of our
Speaker 1: Sun compressed into a tiny little space. Yeah, that's how
Speaker 1: That's exactly why I feel when I visit Manhattan actually
Speaker 1: super dance and compressing and hot as well. But what's
Speaker 1: interesting too is that, first of all, not every star
Speaker 1: goes supernova, and not every supernova turns into a neutron star. Right,
Speaker 1: that's right. The final fate of the star is determined
Speaker 1: almost entirely by how massive it was when it was born.
Speaker 1: If it has a mass between like ten and twenty
Speaker 1: or twenty five times the mass of our Sun, then
Speaker 1: it will go supernova and then go neutron star. If
Speaker 1: it has more mass than that, it'll go supernova, but
Speaker 1: it'll leave a black hole at the center instead of
Speaker 1: a neutron star. So if you have enough mass, then
Speaker 1: you can overcome even the strength of the neutron star
Speaker 1: and collapse it even further to a black hole. So
Speaker 1: gravity wins there if you add more mass. If you don't,
Speaker 1: if you had less mass, like less than ten times
Speaker 1: the mass of the Sun, then you don't get a supernova,
Speaker 1: and you get what's going to happen to our Sun,
Speaker 1: which is is just gonna leave behind the original core,
Speaker 1: which would be a white dwarf. So then for a
Speaker 1: neutron star, you start with a regular star that's about
Speaker 1: ten to twenty five times the mass of our sun.
Speaker 1: He's supernova that most of it I guess blows out
Speaker 1: in the supernova, but some of it, like one to
Speaker 1: three masses of our Sun, stays in the middle in
Speaker 1: this super duper dense state that I guess had its
Speaker 1: origin when the star collapse, right exactly, So you take
Speaker 1: the core of the star and you squeeze it down
Speaker 1: to this tiny little dot, this neutron star. So it's
Speaker 1: like a white dwarf that's been compressed by a supernova.
Speaker 1: And it's fascinating to me because it's like the last
Speaker 1: step before a black hole. You know, gravity is a
Speaker 1: runaway effect. If you only had gravity and no other
Speaker 1: forces in the universe, everything would eventually just collapse to
Speaker 1: a black hole to be nothing to stop it, because
Speaker 1: gravity just pull stuff in and it gets dense here
Speaker 1: and denser, and the denser gets the stronger it is,
Speaker 1: and then the stronger it is, the denser gets etcetera, etcetera.
Speaker 1: So the way to avoid becoming a black hole is
Speaker 1: to have something pushed back against gravity. So a star
Speaker 1: doesn't collapse into a black hole while it's burning because
Speaker 1: the fusion provides pressure outwards. The Earth doesn't collapse into
Speaker 1: a black hole right now because all that dirt has
Speaker 1: structural integrity. As the mass gets stronger and stronger, you
Speaker 1: need stronger forces to resist it, and eventually it just
Speaker 1: gives up and becomes a black hole. And a neutron
Speaker 1: star is like the last line of defense against gravity.
Speaker 1: It's like the densest thing in the universe that's not
Speaker 1: a black hole, right, Like, if you squeeze it a
Speaker 1: little bit more, you would get a black hole. But
Speaker 1: if you stop squeezing it or adding more mass right
Speaker 1: before it turns into black hole, then that's what you get.
Speaker 1: You get a neutron star exactly. And so it's this
Speaker 1: object which has enough strength to resist the incredible mass
Speaker 1: and the incredible gravity that it does have, but if
Speaker 1: you added a little bit more, yeah, it would collapse
Speaker 1: into a black hole. And so it's really the perfect
Speaker 1: way to understand this balance between the strong fo and
Speaker 1: the quantum mechanics that's resistant collapse and the gravitational pressure
Speaker 1: that's squeezing down on it. So like how many plates
Speaker 1: of pasta would you have to throw in to turn
Speaker 1: a neutron star into a black hole. It's a great question.
Speaker 1: We don't know actually, what is the maximum mass of
Speaker 1: a neutron star. Biggest ones we've seen are like two
Speaker 1: and a half up to maybe three times the mass
Speaker 1: of the sun. There's some speculative observations for larger ones,
Speaker 1: but we think it's probably impossible to have anything much
Speaker 1: more than three times the mass of the Sun. Well,
Speaker 1: that was kind of my next question, which is, you know,
Speaker 1: have we actually seen these things or are they like
Speaker 1: sort of like black holes that were sort of theoretical
Speaker 1: for a long time. We have seen these things, so
Speaker 1: they are not easy to see. These things don't have
Speaker 1: fusion inside of them, so they're not glowing very very brightly.
Speaker 1: Most neutron stars are kind of dim, right, They just
Speaker 1: sit there and they're cooling gradually, though you know, they
Speaker 1: can get bigger if something else comes behind, like dumps
Speaker 1: a huge load of pasta on them. So they're hard
Speaker 1: to see unless they're like in a binary system. So
Speaker 1: for example, there's another star nearby and they're strong gravity
Speaker 1: is affecting that star. So if you see like a
Speaker 1: normal star and then nothing nearby it, then you can say, oh,
Speaker 1: there must be something there because of its gravity. You
Speaker 1: can argue about whether it's a black hole or a
Speaker 1: neutron star based on its mass. So it's one way
Speaker 1: to know that they are there. You can also see
Speaker 1: them directly if they are pulsars. So a neutron stars
Speaker 1: is heavy, heavy object. It's also spinning really really fast,
Speaker 1: right because remember, angular momentum is conserved. If you take
Speaker 1: an object which was big and spinning and compress it,
Speaker 1: it's still gonna be spinning, and now it's going to
Speaker 1: spin much much faster in order to have the same
Speaker 1: angular momentum. So sometimes these neutron stars spin super fast,
Speaker 1: and they also sometimes shoot out energy from their polls,
Speaker 1: and if there's a misalignment between where they're shooting energy
Speaker 1: out and the spin axis, then this beam that they
Speaker 1: shoot out sort of sweeps across the universe, and if
Speaker 1: it passes Earth, then we see it. And that's what
Speaker 1: a pulsar is. So some action of neutron stars we
Speaker 1: can see because they are pulsars and they're pointed right
Speaker 1: in the exact direction where we can see them. But
Speaker 1: most neutron stars we cannot observe directly, right, because we
Speaker 1: call them stars, but they're really not sort of shining
Speaker 1: in the bright night sky unless, like you said, they
Speaker 1: somehow have this spin and the somehows shooting a beam
Speaker 1: in a particular direction, which is what pulsars are. Yeah,
Speaker 1: you can argue about exactly what is a star and
Speaker 1: whether these count. You know, there's sort of the endpoint
Speaker 1: of the life of a star. You definitely wouldn't call
Speaker 1: a black hole a star, right, even though it's also
Speaker 1: the endpoint of the life of a star. So these
Speaker 1: things do emit some light, and so the one way
Speaker 1: to see them is if there are pulsars. Another way
Speaker 1: to see them is to see X rays from their surface.
Speaker 1: So they don't glow in the visible light, but sometimes
Speaker 1: X rays leak out of their surface. If there's like
Speaker 1: a crack in the surface of the neutron star or
Speaker 1: like a hot spot, it can emit some X rays.
Speaker 1: And we have X ray telescopes that are able to
Speaker 1: see those X rays see of photons from these distant stars,
Speaker 1: and that can help us see that a neutron star
Speaker 1: is there. So we think there's like a billion of
Speaker 1: these things floating out there. In our galaxy, but most
Speaker 1: of them are basically invisible to us. Yeah. I was
Speaker 1: gonna ask next whether we have a picture of a
Speaker 1: neutron star, but actually then I realized we don't really
Speaker 1: have a picture of anything outside of the Solar system, right, Like,
Speaker 1: we don't really have a full on picture of any
Speaker 1: star out there in the universe. We just know them
Speaker 1: as pinpoints. That's interesting. I mean, we certainly have a
Speaker 1: picture of them, right Even a pin point is a picture.
Speaker 1: It's light from the star. So yeah, I guess we
Speaker 1: do have some, you know, pictures of these stars, but
Speaker 1: not in a lot of great resolution, certainly not the
Speaker 1: way we can look at our own son, for example.
Speaker 1: But yeah, we don't have pictures of these neutron stars
Speaker 1: at all. In most of the cases, all we have
Speaker 1: is like a stream of X rays, so like a
Speaker 1: time series when we say, oh, we saw some X rays,
Speaker 1: Oh we didn't see anymore. Now we saw some more,
Speaker 1: because the entire neutron star doesn't admit X rays, just
Speaker 1: little cracks and hot spots on the surface, and so
Speaker 1: sometimes the hot spot will be like around the back
Speaker 1: of the neutron star, and sometimes will be on the
Speaker 1: front of the neutron star. So you can learn a
Speaker 1: lot about the neutron star from these X rays. Yeah,
Speaker 1: and maybe it'll let you see inside of him like
Speaker 1: regular X rays. And so let's get into more amazing
Speaker 1: facts about neutron stars and also talk about what could
Speaker 1: be going on inside of him. But first let's take
Speaker 1: a quick break. We're talking about neutron stars and what's
Speaker 1: going on inside of them. I'm guessing it's non neutral things.
Speaker 1: If we have a whole episode about them, Well, there's
Speaker 1: definitely a lot of neutrons inside there. It's hard to imagine,
Speaker 1: like and to really conceptualize what this stuff is that's
Speaker 1: inside a neutron star because you've taken normal matter and
Speaker 1: you've squeezed it down to incredible densities. You know, this stuff,
Speaker 1: whatever it is, is a hundred trillion times denser than
Speaker 1: anything we have on Earth. You know, you think you
Speaker 1: ate a heavy lunch, that's nothing compared to like a
Speaker 1: spoonful of neutron star. Yeah, Like, how much is a
Speaker 1: spoonful of a neutron star weight? Well, here on Earth
Speaker 1: they would weigh three billion tons just one table spoon
Speaker 1: of neutron star material. Of course, if you had it
Speaker 1: here on Earth, it would explode because it's under great pressure.
Speaker 1: But you know, just to sort of like conceptualize how
Speaker 1: dense it is when it's in its location, it's a
Speaker 1: crazy amount of mass. It would explode in your mouth.
Speaker 1: I guess like a flavor explosion, like a flavor explosion exactly.
Speaker 1: They should have like a summer drink called Neutron Star,
Speaker 1: you know, added to our online store. I was thinking
Speaker 1: like a seven eleven crossover episode. You know, you mean
Speaker 1: like an icy kind of like a slushy. Yeah, a
Speaker 1: Neutron Star slurpy. You know. My daughter went in to
Speaker 1: get a slurpy recently and she came back with one.
Speaker 1: I said what flavor is it? And she said blue?
Speaker 1: And I was like, blue is not a flavor and
Speaker 1: she said, well, the guy asked me what flavor I
Speaker 1: wanted and I said blue, and this is what he
Speaker 1: gave me. That's thought. She was going to say, all
Speaker 1: of them, don't know what you're supposed to do mixing
Speaker 1: them all up. I don't know. Then we'll get gray,
Speaker 1: won't you. Nobody wants to get a gray slushy, and
Speaker 1: I think it comes out chocolate chocolate color. That sounds delicious.
Speaker 1: Maybe it's like neutron star chocolate. But anyways, back to
Speaker 1: neutron stars, I guess the question is what would it
Speaker 1: look like if I'm sitting in front of a neutron star.
Speaker 1: I know we want to get into it, but like
Speaker 1: if I was sitting outside of it and it's like,
Speaker 1: you know, a few light year or a half of
Speaker 1: a U from a neutron star, what would I be seen?
Speaker 1: So if you're close enough to you know, this thing
Speaker 1: is hot, so it's going to miss some light and
Speaker 1: you're also gonna see hot spots from its surface. But
Speaker 1: one thing about a neutron star is that the gravity
Speaker 1: is so strong and near the neutron star that it
Speaker 1: distorts the space around it, sort of the way a
Speaker 1: black hole does. We're used to thinking about this for
Speaker 1: black holes. You know that if you're in front of
Speaker 1: a black hole, you're looking at the event horizon. You're
Speaker 1: not only seeing the part of the event horizon that's
Speaker 1: on your side of it. You can also see around
Speaker 1: the back of the black hole because photons emitted near
Speaker 1: there would be bent by the curvature of ace and
Speaker 1: come to your eyeballs. The same thing is true around
Speaker 1: neutron stars because they are so incredibly dense. Right, the
Speaker 1: gravitational field at the surface of a neutron star is
Speaker 1: two hundred billion times stronger than the gravitational forces on
Speaker 1: the surface of the Earth. So if you're looking at
Speaker 1: a neutron star, you can not only see the front
Speaker 1: of it, you can also see the back of it
Speaker 1: at the same time. So if you're on a neutron star,
Speaker 1: you would wait two hundred billion times more than you
Speaker 1: do now. Yeah, so start working out so I can
Speaker 1: I can stand up, is that what you mean? Or
Speaker 1: so I can lose weight so you can survive. Man,
Speaker 1: that thing would tear you to shreds. Not only is
Speaker 1: the force of gravity very very strong, but it varies
Speaker 1: very quickly, you know, and so you get tidal forces.
Speaker 1: The difference between the gravitational force on your head and
Speaker 1: on your shoulders would be very strong enough to rip
Speaker 1: your head off of your shoulders. So I wouldn't recommend
Speaker 1: a trip to a neutron star. Would there be a
Speaker 1: spectification point like in a black hole? Yeah, well, before
Speaker 1: you got to the surface of the neutron star, you
Speaker 1: would be torn apart because the title forces would be
Speaker 1: very very strong. Remember, this thing only has the mass
Speaker 1: of the Sun right so far away. It has the
Speaker 1: same gravitational force as the Sun, but you can get
Speaker 1: much much closer to all of that mass because it's
Speaker 1: compressed down to just like you know, ten or twenty kilometers,
Speaker 1: whereas our Sun is huge. So if you're on the
Speaker 1: surface of our Sun, you're very far away from the
Speaker 1: gravitational center of mass, whereas if you're in the surface
Speaker 1: of the neutron star, you're only ten kilometers from an
Speaker 1: entire star's worth of mass. That's why the gravitational forces
Speaker 1: are so much stronger for the same amount of mass,
Speaker 1: because you can get closer to it. So you and
Speaker 1: the spaghetti head for lunch would turn into spaghetti exactly.
Speaker 1: You would be postified. Right. Well, I guess the big
Speaker 1: good question now is why is it even called the
Speaker 1: neutron star? Like is it full of neutrons basically? And
Speaker 1: how did a regular sun, which is what it was
Speaker 1: before it's supernova and collapse into a neutron star is
Speaker 1: made out of all kinds of stuff, right, like iron
Speaker 1: and all kinds of complex elements and electrons and protons,
Speaker 1: But now it seems to have collapsed into something that
Speaker 1: you now call a neutron star. So is that everything
Speaker 1: just turned into neutrons or what? Yeah, everything turns into neutrons. Right.
Speaker 1: You have your atom which has neutrons, protons, and electrons
Speaker 1: in it, right, Well, what happens if you squeeze that
Speaker 1: down really really far, if you really push a bunch
Speaker 1: of that stuff together, Well, if you get the electron
Speaker 1: and the proton close enough to each other, well, you know,
Speaker 1: they have opposite charges and so they actually kind of
Speaker 1: like to hang out together. So if you squeeze them
Speaker 1: down enough, the proton captures the electron, the electron gets
Speaker 1: like eaten by the proton, and that converts it into
Speaker 1: a neutron. It's exactly the opposite process of neutron decay
Speaker 1: that we talked about recently on the podcast, where a
Speaker 1: neutron turns into a proton and electron. This is the
Speaker 1: reverse process. So you put enough energy into it, you
Speaker 1: can reverse basically anything that happens in the universe. And
Speaker 1: so this is what happens. If you squeeze down matter,
Speaker 1: all the protons and electrons emerge and become neutrons. So
Speaker 1: usually electrons and protons are attracted to each other, but
Speaker 1: they don't get together and merge. Right, what's keeping them apart? Well,
Speaker 1: what's keeping them apart usually is that the electron is
Speaker 1: in a stable state, just the way, for example, the
Speaker 1: Earth is in a stable state around the Sun. The
Speaker 1: Earth and the Sun attract each other. There's gravity there. Right,
Speaker 1: Why doesn't the Earth collapse into the Sun. Because it
Speaker 1: has enough energy to resist that, right, it can stay
Speaker 1: in a stable orbit. And so you shouldn't be thinking
Speaker 1: about electrons as orbiting protons. But they have enough energy,
Speaker 1: they have a minimum energy in their stable solution to
Speaker 1: avoid collapsing into the proton. And so here you're overcoming that, right,
Speaker 1: you are like squeezing the electron down. You're applying external pressure.
Speaker 1: And so that's why an electron doesn't collapse into the proton,
Speaker 1: because it has enough energy to avoid it. But that's
Speaker 1: if it's by itself. If you squeeze on if you
Speaker 1: push on it from the outside, if you can find
Speaker 1: it to a location the size of the proton, then
Speaker 1: it gets captured by the proton. And then what happens
Speaker 1: The proton eats the electron. Right, Because the proton is
Speaker 1: made out of three quarks and a neutron is made
Speaker 1: out of three quarks. So then does the electron just
Speaker 1: sort of like flip one of the corks or or something. Yeah,
Speaker 1: that's exactly what happens. Remember, a proton is two up
Speaker 1: corks and a down and a neutron is two down
Speaker 1: corks and an up. So what happens when an electron
Speaker 1: is captured is that you're converting one of those up
Speaker 1: corks into a down cork, and so that converts the
Speaker 1: proton into a neutron. There's also one more step because
Speaker 1: you can't just delete electrons from the universe, so you
Speaker 1: also need to create an electron neutrino. Interesting, So it's
Speaker 1: like the proton eats the electrons and then then they
Speaker 1: become neutral. And then what happens to all of these neutrinos,
Speaker 1: It just gets spit out into space. Yeah, they get
Speaker 1: spit out into space because neutrinos mostly see stuff in
Speaker 1: the universe as transparent, right, they hardly interact with anything.
Speaker 1: They can go through a light year of lead without interacting,
Speaker 1: and so mostly they just get shot out while it's collapsing. Remember,
Speaker 1: supernova is the process that produces these neutron stars. Emit
Speaker 1: most of their energy via neutrinos, right, something like of
Speaker 1: the energy of a supernova is not emitted visually, not
Speaker 1: in the optical, not via photo tons at all, but
Speaker 1: via new trinos. And so this is part of the
Speaker 1: process that creates all of those neutrinos when the supernova happens. Yeah,
Speaker 1: supernovas are known to be silent, but deadly silent and invisible.
Speaker 1: Supernovas are incredible because you can see them in with
Speaker 1: a naked eye, right, that's how bright they are. All
Speaker 1: of a sudden, a star becomes as bright as the
Speaker 1: entire galaxy. And that's just the visible light we're talking about.
Speaker 1: It turns out there's a hundred times more energy in
Speaker 1: the new trinos. But a whole fun podcast episode about
Speaker 1: how supernovas can be seen first in new trinos with
Speaker 1: our new trino telescopes. And so this is part of
Speaker 1: the process. Creating those neutron stars means making neutrons, which
Speaker 1: also requires you to make the new trinos because you've
Speaker 1: got to balance the books of particle physics in the end. Right,
Speaker 1: So they're calling neutron stars, but actually not all of
Speaker 1: it inside our neutrons, and so maybe can maybe step
Speaker 1: us through a little bit, like asked, the supernova is collapsing,
Speaker 1: and as things are getting squeezed together, like what's happening
Speaker 1: to all those atoms of the bigger elements. They're just
Speaker 1: getting broken up and squeezed together or they just explode.
Speaker 1: What's going on? So some of them get broken up,
Speaker 1: and depends on where they end up. So we'll learn
Speaker 1: about it as we step through the layers of the
Speaker 1: neutron star. But near the outside of the neutron star,
Speaker 1: for example, the atoms don't get broken up. You get
Speaker 1: atomic nuclei still, for example, so the outer crust of
Speaker 1: a neutron star is atomic nuclei. You can have helium there,
Speaker 1: you can have carbon, you can have oxygen, this kind
Speaker 1: of stuff. It's only as you get deeper in that
Speaker 1: these nuclei get squished together so far that the separation
Speaker 1: between the nuclei breakdown, and then you just get like
Speaker 1: a sea of neutrons, or maybe a sea of corks,
Speaker 1: or maybe even weirder stuff. And so you can't really
Speaker 1: think about it as like lead or iron or carbon
Speaker 1: anymore because it's gotten broken up into its constituent bits
Speaker 1: that's at the very center. But you're saying that the
Speaker 1: crust of a neutron star you could get you just
Speaker 1: have regular stuff. Then, yeah, at the crust you just
Speaker 1: have regular stuff, like you might be able to like
Speaker 1: stand on it maybe or is it all sort of
Speaker 1: like in a liquid or gas form. So there is
Speaker 1: an atmosphere of a neutron star. Actually there's like a
Speaker 1: gaseous atmosphere, but it's micrometers thick, like micrometers. So this
Speaker 1: thing is like ten kilometers or fifteen kilometers wide, and
Speaker 1: it has an atmosphere and that's like micrometers of gas
Speaker 1: just above the surface. And then the surface itself is hard,
Speaker 1: it's like brittle, it's like a crunchy, right, and it's
Speaker 1: made of atomic nuclei. So these are things that used
Speaker 1: to be part of the star, carbon, oxygen, nitrogen, whatever,
Speaker 1: and now it's crystallized into this like lattice on the
Speaker 1: outside of the star, which is very very smooth because
Speaker 1: the gravity is so strong that you basically can't form
Speaker 1: any hills. So they think that like the maximum elevation
Speaker 1: on the surface of a neutron star might be like
Speaker 1: one millimeter, or gravity like pulls it back down. So
Speaker 1: if you're standing next to a neutron star. What you
Speaker 1: would see is a basically a big, shiny smooth ball, right,
Speaker 1: made out of some of these heavier elements, almost perfectly
Speaker 1: shiny smooth ball. Really incredible how spherical this thing will be,
Speaker 1: But there will be some exceptions because the crust is brittle.
Speaker 1: The crust can crack, right, it's under incredible pressure gravity
Speaker 1: squeezing it down, and sometimes you get like a little
Speaker 1: bit of a weakness, and so you can get like
Speaker 1: a star quake because you've got a crack in this
Speaker 1: crust and things like a just a little bit, and
Speaker 1: that's when, for example, X rays can leak out. So
Speaker 1: the reason you get X rays is from these hotspots,
Speaker 1: which can cause these little neutron star quakes on the surface.
Speaker 1: But what if it's spinning, wouldn't it also kind of
Speaker 1: give it a weird shape, right, It is spinning, and
Speaker 1: so that changes it from a spherical a little bit, right,
Speaker 1: But it's also very very compact gravitationally, how far something
Speaker 1: goes from sphericals a balance between how fast it's spinning
Speaker 1: and also how strong the gravity is. So we've never
Speaker 1: seen one of these things. But you're right, it wouldn't
Speaker 1: be perfectly spherical, though it still would be very very smooth.
Speaker 1: All right, So I'm standing on top of a neutron star.
Speaker 1: I wait, two hundred billion times more than I normally do.
Speaker 1: And so I take a pick ax and I cracked
Speaker 1: the surface. What do I see inside? So you gotta
Speaker 1: dig a little bit wet. So inside the neutron star
Speaker 1: is a little bit more crust. You've got to dig
Speaker 1: a little bit into it before you get to sort
Speaker 1: of like the next layer. And we're not sure, of course,
Speaker 1: about any of this. A lot of this is speculation.
Speaker 1: These are models that we've developed based on our calculations
Speaker 1: from our understanding of the strong force and gravity, etcetera.
Speaker 1: But we think that this outer crust is like three
Speaker 1: hundred to five hundred meters thick. Once you penetrate through
Speaker 1: the crust, then these elements are no longer able to
Speaker 1: hold onto themselves, right, They're squeezed together by pressure, and
Speaker 1: so you get this like soup of neutrons that we
Speaker 1: think are just sort of like floating around there where
Speaker 1: the atoms themselves are getting broken up, so they're no
Speaker 1: longer really like have their identity as an element. I see,
Speaker 1: so on the shell you still had the heavier elements
Speaker 1: like lead and carbon, but then now they're being squeezed
Speaker 1: together so much they what they like, they just break
Speaker 1: apart the nuclei or they merged together. They do both.
Speaker 1: They sort of varies. As you go in near the
Speaker 1: outer layers of this part. They first merged together because
Speaker 1: they're getting squeezed together, and so you have weird fusion happening.
Speaker 1: You have like weird heavy elements that couldn't exist in
Speaker 1: other situations, you know, that wouldn't be stable out there
Speaker 1: on their own in the universe. But under this crazy pressure,
Speaker 1: we think you can form like ridiculously heavy elements, you know,
Speaker 1: things with huge numbers of neutrons on them. As you
Speaker 1: go further and further in, things become more and more
Speaker 1: neutron e Right. It's not pure neutrons. You still have
Speaker 1: some protons and some electrons. Not every single proton and
Speaker 1: electron has been converted into a neutron. But as you
Speaker 1: go inwards you have like a higher and higher fraction
Speaker 1: of neutrons m Because I guess as you squeeze this
Speaker 1: stuff together, that's what it all ends up as, right,
Speaker 1: just play neutrons because all of the electrons, and the
Speaker 1: protons eat each other exactly, and we think that overall
Speaker 1: there's gonna be a charge balance. So there is a
Speaker 1: proton for every electron, and so you squeeze it hard
Speaker 1: enough and they'll find each other eventually. But so as
Speaker 1: you go deeper and deeper, and you get like a
Speaker 1: higher and higher fraction of neutrons, and then what happens
Speaker 1: as you go in deeper. As we go in deeper
Speaker 1: is where the real mystery is, right, and so you
Speaker 1: have this inner core where we don't really know what's
Speaker 1: going on, Like we think maybe there's some super fluid
Speaker 1: neutron matter there, Like we think that maybe under these
Speaker 1: conditions and neutrons just like slide around past each other
Speaker 1: and have all this weird chemistry. This is a lot
Speaker 1: of where the question marks are. You might wonder, like, well,
Speaker 1: why is it a question mark? Can't we just take
Speaker 1: the laws of physics that we have gravity and the
Speaker 1: strong force and do the calculations and say what does
Speaker 1: it predict? It's not always so easy, right to say
Speaker 1: I know what the laws are, what's going to happen.
Speaker 1: We can't even do that for lots of situations. You know,
Speaker 1: if you just gave me quantum mechanics and a baseball
Speaker 1: and said, here's ten to the twenty nine particles, what
Speaker 1: do they do next? It would be very very hard
Speaker 1: for me to come up with like parabolic motion. It's
Speaker 1: not easy always to go from the underlying laws to
Speaker 1: predicting what's going to happen on the macroscopic scale, and
Speaker 1: especially when things are very very strong, when the forces
Speaker 1: are very powerful. Here you have gravity, which is unusually
Speaker 1: powerful because it's so dense, and you have this strong
Speaker 1: force doing its thing with very short distances. These things
Speaker 1: are exchanging incredible numbers of gluons. So we just don't
Speaker 1: know how to do that calculation. Even if the laws
Speaker 1: that we have, the ideas that we have about what's
Speaker 1: fundamentally guiding it are true, we don't know how to
Speaker 1: take those and predict in great detail what's going on inside.
Speaker 1: It just gets too crazy. It just gets too crazy er.
Speaker 1: It's too many things to keep track of. So we've tried,
Speaker 1: and we have a few ideas. People make approximations this
Speaker 1: way or approximations that way to say maybe it's like this,
Speaker 1: or maybe this equation will work. But everybody's reaching past
Speaker 1: the edge of what they really know. So there's a
Speaker 1: bunch of speculative ideas and they're all really different, and
Speaker 1: they're all totally different from each other, and so we'd
Speaker 1: love to see it. We'd love to understand what's going
Speaker 1: on there, because it would tell us, oh, this idea
Speaker 1: is correct, or actually, none of your ideas are correct,
Speaker 1: and something totally weird and unexpected happens. So that's what
Speaker 1: we're trying to do. Unfortunately, of course, we can't see
Speaker 1: the inside of the neutron star. We have to just
Speaker 1: try to guess what's going on based on what we
Speaker 1: can see from outside. All right, well, let's get to
Speaker 1: the core of this mystery and think about what exciting
Speaker 1: and maybe delicious things could be inside at the core
Speaker 1: of neutron stars. But first let's take another quick break.
Speaker 1: All right, we're talking about neutron stars and what is
Speaker 1: inside of him, and I'm sort of getting the picture, Daniel, Dad,
Speaker 1: inside of a neutron star are not necessarily neutrons. There
Speaker 1: seems to be a lot of other stuff. They should
Speaker 1: be called mostly neutron stars. Neutron star, yeah, or neutrinas stars. Well,
Speaker 1: all the neutrinos have left the building. Right, they took
Speaker 1: their little weak forces and they ran away. I see
Speaker 1: there are no Italians in the room anymore. You're free
Speaker 1: to make whatever pasta you want. All the rules are
Speaker 1: out the window. How a d is the inside of
Speaker 1: a neutron star? So we correct the heart surface of
Speaker 1: a neutron star. We dug in a little bit. When
Speaker 1: you get this soup of electrons, the neutrons maybe like
Speaker 1: super deeper heavy atoms, but eventually those break down as
Speaker 1: you go deeper and deeper into the neutron start to
Speaker 1: you get basically just neutrons, right, like a sea of neutrons.
Speaker 1: But then what happens as you go even further in,
Speaker 1: So we don't know what those neutrons do, and that's
Speaker 1: fundamentally the question, Like if you have a bunch of
Speaker 1: neutrons and you squeeze them into these incredibly dense situations,
Speaker 1: what do they do? Do they form a super fluid
Speaker 1: or do they do something else? Something weird? But you're
Speaker 1: still calling them neutrons because like, inside of a neutrons
Speaker 1: are three quarks. But so you're saying at this point,
Speaker 1: like each triplet of quarks is still held together. They're
Speaker 1: just interacting with other triplets of neutrons, or have the
Speaker 1: corks sort of even broken out of that. That's one
Speaker 1: of the options, right, Do the neutrons stay together and
Speaker 1: form weird shapes, weird emergence structures, or do they break down?
Speaker 1: And really we should be talking about cork matter, you know,
Speaker 1: and cork gluon plasmas. That's one of the options that's
Speaker 1: on the table. But to me, it's a great example
Speaker 1: of some of the deepest mysteries at the heart of
Speaker 1: our understanding of the universe, you know, like what emerges.
Speaker 1: You can take the basic rules of physics, and incredible
Speaker 1: structures emerge, you know, atoms and ice cream and galaxies,
Speaker 1: all these things sort of emerge from the underlying complexity.
Speaker 1: And it's exciting to see a situation where we just
Speaker 1: don't know what will emerge. You put the neutrons in
Speaker 1: this situation, maybe they'll just be a crazy, chaotic soup,
Speaker 1: but maybe new structures will form, right, And so people
Speaker 1: have exciting ideas for what kind of weird structures might
Speaker 1: form from neutrons in these configurations, right, because, as you said,
Speaker 1: I think at this point it's so crazy and so dance.
Speaker 1: There's only two forces involved. The gravity that's keeping them
Speaker 1: all in and keeping them attracted to each other, and
Speaker 1: also the strong force, which is what bringing in the
Speaker 1: courts together, help holding the courts together, or what does
Speaker 1: this strong force do? Does a strong force repel? Also
Speaker 1: here it just attracts, right. The strong force is really
Speaker 1: really weird and has a very strange behavior with distance,
Speaker 1: but under short distance and will attract quarks and gluons
Speaker 1: to each other. And we think of protons and neutrons
Speaker 1: as sort of like balanced in the strong force, that
Speaker 1: all the quarks are bound together into this state that
Speaker 1: has overall no strong charge, no color. But that's not
Speaker 1: really true. If you get close up enough to a proton.
Speaker 1: If you get close up enough to a proton, then
Speaker 1: you'll be like closer to part of it then to
Speaker 1: the backside of it, and so you'll still feel a
Speaker 1: little bit of that effective color, right, And so if
Speaker 1: you get close up enough to a proton with your corks,
Speaker 1: then your corks will start talking to the quarks inside
Speaker 1: that proton. And that's for example, why a nucleus holds together.
Speaker 1: Remember a nucleus is filled with protons and neutrons, is
Speaker 1: only positive electric charges there, Why doesn't it blow apart
Speaker 1: Because the quarks inside the protons and neutrons are talking
Speaker 1: to each other. They're making it sticky. And so inside
Speaker 1: a neutron star, the strong forces pulling these things together
Speaker 1: the same way gravity is. Right, So you have all
Speaker 1: these neutrons, then these triplets of corks held together by gravity,
Speaker 1: and you're saying that they can sort of form matter
Speaker 1: like they can you know, arrange themselves in special, maybe
Speaker 1: delicious ways. Yeah, well, we don't know for sure, but
Speaker 1: we have done supercomputer studies where we simulate these things.
Speaker 1: We put in the laws of nature and we just
Speaker 1: see sort of what happens, and interesting stuff does seem
Speaker 1: to emerge. After like two hundred and fifty computer years
Speaker 1: of calculations, they see these weird blobs form, and so
Speaker 1: as things get denser, they form these sort of semi
Speaker 1: spherical blobs of matter where things sort of like clumped
Speaker 1: together into these huge blobs of neutrons with a few
Speaker 1: protons mixed in. And so they called these things Nioki
Speaker 1: might be Italian, you know, potato blobs that people enjoy
Speaker 1: eating for lunch. I guess it's sort of like if
Speaker 1: you take a whole bunch of carbon and atoms, loose atoms,
Speaker 1: and you squeeze them together enough at some point they'll
Speaker 1: sort of form into a diamond or some sort of shape. Right.
Speaker 1: That's kind of what's happening here, is that you're taking
Speaker 1: these neutrons and you're squeezing them so much they kind
Speaker 1: of lock into these shapes. Yeah, and so instead of
Speaker 1: having like a sleet ocean where everything is just mixed together,
Speaker 1: they form a blobs of a certain size. Right, They
Speaker 1: like distinguished themselves say, oh, we'd like to have this
Speaker 1: many neutrons into a blob with a few protons mixed
Speaker 1: in would have the same thing over there. So instead
Speaker 1: of being like totally indeterminate, they seem to want to
Speaker 1: form these structures. Right. And if you squeeze even further
Speaker 1: than these blobs form these long rods. They like come
Speaker 1: together to make these long rods, which looks sort of
Speaker 1: like spaghetti. Well, I mean, they could look like a
Speaker 1: lot of things, bread sticks, steel bars, but we're we're
Speaker 1: you're you're staying with the pasta analogy. They sort of
Speaker 1: look like spaghetti. I didn't name any of these things.
Speaker 1: I'm just enjoying saying them but yeah, they could have
Speaker 1: called them, you know, twizzlers or bread sticks or whatever.
Speaker 1: But they look sort of like spaghetti, and they form
Speaker 1: these long rods. They're parallel, right. Don't think of spaghetti
Speaker 1: like a big mess on your plate. Think of spaghetti
Speaker 1: sort of the way it comes in the package from
Speaker 1: the store. They're all these rods in parallel with each other.
Speaker 1: So they call this nuclear pasta, right, right, And so
Speaker 1: they kept going, and all the other shapes that neutrons
Speaker 1: can form have sort of a pasta analogy. Right. Yeah,
Speaker 1: you keep going, you keep squeezing this stuff down, and
Speaker 1: they think, or they predict from these calculations that the
Speaker 1: spaghetti will merge together to form sheets. So then you
Speaker 1: have nuclear lasagna, these like layers of this weird kind
Speaker 1: of matter that's mostly neutrons with a few protons in it.
Speaker 1: And it's very very strong stuff. In their calculations, this
Speaker 1: stuff has incredible strength. It's like very hard to break
Speaker 1: it apart. It might be some of the strongest stuff
Speaker 1: in the universe. You mean, these lasagna sheets of neutrons,
Speaker 1: and these Lasagna sheets of neutrons, they're not just like
Speaker 1: forming and then breaking up and then reforming it's not
Speaker 1: like a crazy gas or a plasma. Right. These things
Speaker 1: are like very very strong sheets of a weird kind
Speaker 1: of matter. Right. It's not like a solid or liquid
Speaker 1: or exactly like a crystal made out of almost all neutrons. Right,
Speaker 1: it's not like a regular lattice of atoms like the
Speaker 1: way we think of like a piece of steel. Right.
Speaker 1: And you're saying some of those strongest stuff in universe
Speaker 1: because it's it's basically surviving these intense and crazy pressures
Speaker 1: inside of the neutron star. But I guess if you
Speaker 1: took it out of the neutron star, which is blow up, Yeah,
Speaker 1: it would probably blow up. We don't know, right, Maybe
Speaker 1: it's strong enough it will hold itself together. Right, Because,
Speaker 1: for example, diamonds are formed under very crazy conditions, but
Speaker 1: then they're stable, so you pull them out from the
Speaker 1: heart of the Earth where they were made, they don't explode.
Speaker 1: So maybe nuclear pasta doesn't explode. We just don't know.
Speaker 1: But if you keep squeezing this stuff together, you squeeze
Speaker 1: the Lasagna sheets together, it forms this thing called anti spaghetti,
Speaker 1: which is like a blob of matter with holes in it,
Speaker 1: like long, thin spaghetti holes sort of like drilled through it. Wait,
Speaker 1: what kind of like pant pasta like Swiss cheese. More
Speaker 1: like Swiss cheese, Yeah, than penna pasta, right, more like
Speaker 1: parmiers Maybe should say parmesan or what's in the Italian
Speaker 1: cheese with holds in it. But those holes are bubbles
Speaker 1: right here. We're talking about holes that are like long tubes.
Speaker 1: So it's like wormholes through a block of parmesan. It's
Speaker 1: more like a clump of bucatinia then perhaps, yeah, like
Speaker 1: a clumb of bukatina. Any They called it anti spaghetti
Speaker 1: because it's like take the spaghetti state and flip it
Speaker 1: so that everything that was matter is now a hole
Speaker 1: and everything that was a whole is now matter. So
Speaker 1: if you add spaghetti and anti spaghetti together, you get,
Speaker 1: you know, like a complete block of matter. You get
Speaker 1: anti pasta. You annihilate your stomach, and that's not even
Speaker 1: like the core of the neutron star. Like if you
Speaker 1: go further in then things start to even this pasta
Speaker 1: can't survive. Yeah, so they think that this pasta is
Speaker 1: maybe like a layer that's like a hundred meters thick,
Speaker 1: and as you go even deeper, you know, we're in
Speaker 1: a huge question mark territory. But some people speculate that
Speaker 1: you might get a quark gluon plasma or something else,
Speaker 1: this stuff called cork matter, or as you suggested earlier,
Speaker 1: you no longer really can think about this stuff in
Speaker 1: terms of neutrons and protons anymore, because everything is just
Speaker 1: interacting with everything else. If it's a high enough energy,
Speaker 1: if the high enough temperature, that doesn't really matter that
Speaker 1: you used to call vs three quarks and neutron and
Speaker 1: those three quarks of proton. Now they're all talking to
Speaker 1: each other, so it's just like a big sea of
Speaker 1: quarks and gluons. I thought at the center you would
Speaker 1: find Daniel going, how this taste the same? That's all
Speaker 1: the same stuff. I bet a bite of nuclear lasagna
Speaker 1: and nuclear anti spaghetti tastes just about the same. The
Speaker 1: pats on how the I guess quark glulon sauce coats
Speaker 1: the shapes now. But I think what you're saying is
Speaker 1: that you get to a point where it doesn't make
Speaker 1: sense to call things uh neutron, because like the separation
Speaker 1: between a triple of quarks and a triple of corks
Speaker 1: here is sort of gone. Like you basically crack open
Speaker 1: those neutrons and it's just a soup of of the
Speaker 1: what's inside. Yeah, and that's the possibility, right. It might
Speaker 1: be that the conditions are intense enough to create that,
Speaker 1: but we're not sure, right, it might be that instead,
Speaker 1: other things happen. So there are other possibilities on the list.
Speaker 1: Some people think you might form weird, strange kinds of
Speaker 1: matter inside things like hyperon matter or kaon matter. These
Speaker 1: are other versions of nucleons. But instead of having just
Speaker 1: up quirks and down quirks, now you have strange quirks
Speaker 1: as well, just ing And then I guess you can
Speaker 1: break things down further because corks are fundamental particles in
Speaker 1: the universe, right, or could you maybe squeeze them down
Speaker 1: to like just pure energy. Well, we don't know the
Speaker 1: corks are fundamental, right, They are as fundamental as we
Speaker 1: have discovered. We don't know that there's anything inside of cork,
Speaker 1: but we have lots of hints that suggests that they
Speaker 1: shouldn't be fundamental. They are all these unexplained patterns among
Speaker 1: the corks, the kind of patterns you see when they're
Speaker 1: made out of something smaller, something more fundamental, like we
Speaker 1: saw patterns in the periodic table. Those were clues that
Speaker 1: atoms were actually made of smaller building blocks you could
Speaker 1: arrange in lots of different ways. We see similar patterns
Speaker 1: in the corks that suggests that they should probably be
Speaker 1: made of something smaller, but we've never seen it. So
Speaker 1: it's possible that the heart of neutron stars, you go
Speaker 1: beyond cork gluon plasma, and you can even go inside
Speaker 1: the corks, and maybe the things inside corks break open
Speaker 1: and talk to each other. We just don't know, all right,
Speaker 1: So then, uh, I guess what's inside when nintron star?
Speaker 1: The answer is we're not quite sure. I mean, defly
Speaker 1: you had neutrons there, but maybe at the core you
Speaker 1: get to something that is not even neutrons, or maybe
Speaker 1: even quarts, is what you're saying. Yeah, we just don't know.
Speaker 1: It's a big question mark, and lots of different calculations
Speaker 1: lead to different predictions, which is confusing and also exciting
Speaker 1: because it means that we can learn something about the universe. Unfortunately,
Speaker 1: we can't see the inside of neutron stars directly. Right
Speaker 1: Even if you were near a neutron star, how would
Speaker 1: you see what's going on inside it. We have the
Speaker 1: same question with our own star. We don't really understand
Speaker 1: all the plasmac currens inside the Sun and why it
Speaker 1: creates this magnetic field which flips every eleven years because
Speaker 1: we can't go inside it. We can only look at
Speaker 1: it from the outside. Well, these are even dimmer objects
Speaker 1: much further away, so they're even harder to study. But
Speaker 1: you know, we can use our X ray telescopes to
Speaker 1: look for these photons from these cracks on the surface
Speaker 1: of the neutron star, and those can give us a
Speaker 1: lot of clues. They tell us something about the mass
Speaker 1: and the radius of the neutron star, and we think
Speaker 1: that knowing the mass and radius the neutron star will
Speaker 1: help us try to figure out what's going on at
Speaker 1: the core of it. Because you're building this neutron star
Speaker 1: out of different kinds of stuff, So one idea for
Speaker 1: what's of the heart of a neutron star will give
Speaker 1: you different predictions for the masses and the radio you
Speaker 1: see than another idea. M I guess the problem is that,
Speaker 1: like in our son, the one we have here, we
Speaker 1: can sort of look in using our equations because things
Speaker 1: aren't that extreme yet, Like the regular laws of physics
Speaker 1: still work. But you know, with a neutron star, you
Speaker 1: start of getting up to that point where things start
Speaker 1: to get a little crazy, right, Like you're sort of
Speaker 1: starting to get into black hole territory where you don't
Speaker 1: even know if your loss of physics are the same. Yeah,
Speaker 1: we don't know if these hold. And you know, one
Speaker 1: of the guiding equations of these things is called the
Speaker 1: Tulman open hyber Molcov equation, which is the thing that
Speaker 1: constrains the structure of a spherically symmetric object that's homogeneous.
Speaker 1: It's all one kind of material which is in gravitational equilibrium.
Speaker 1: So that's like the simplest model we have for a
Speaker 1: neutron star, and it makes all sorts of predictions. And
Speaker 1: some of those predictions are, for example, that there's a
Speaker 1: connection between the mass and the radius of a neutron
Speaker 1: star that if you fix the mass of it, that
Speaker 1: also determines the radius. But when we look out into
Speaker 1: the universe, does neutron stars don't seem to be following
Speaker 1: that rule, Like we see some neutron stars that are
Speaker 1: twenty five kilometers hy that have the mass of one
Speaker 1: point four times the mass of the Sun and other
Speaker 1: ones that are the massive two point one times the
Speaker 1: mass of the Sun at the same radius, so they
Speaker 1: break these rules, which, as you say, suggest that these
Speaker 1: rules aren't complete, right, that something about what's going on
Speaker 1: inside the neutron star is different from what we imagine,
Speaker 1: from what our rules can currently predict, Which might mean
Speaker 1: that it's like a new complex way that these rules
Speaker 1: interact and new structures emerge. Or it might mean that
Speaker 1: there is some new physics, something else going on, a
Speaker 1: new force, something inside corks, something weird we haven't even imagined,
Speaker 1: but I guess on like a black hole, like it
Speaker 1: is maybe possible for us to one day get to
Speaker 1: a neutron star and maybe actually sort of like touch
Speaker 1: it and maybe even send probes into it. Do you
Speaker 1: think it certainly is possible? Right? We can't even land
Speaker 1: probes on the surface of Venus right now that lasts
Speaker 1: more than like nineties seconds without getting crushed, And Venus
Speaker 1: is the like, you know, a day on the beach
Speaker 1: compared to the surface of a neutron star. But yeah,
Speaker 1: you know, if you have a lot of faith in
Speaker 1: our engineers and our pasta engineers, our pasta engineers maybe
Speaker 1: they can imagine a way to drill into a neutron
Speaker 1: star and see it. Yeah, it's not technically forbidden, it's
Speaker 1: just very very difficult. Yeah, and they are out there,
Speaker 1: and neutron stars just like black holes, and they have
Speaker 1: lots of interesting secrets inside of them, right they do.
Speaker 1: If we could know today what's going on inside a
Speaker 1: neutron star, it would tell us so much about gravity
Speaker 1: and the strong force, and also just like what our
Speaker 1: universe can do. Remember that the part of the universe
Speaker 1: we experience, this liquid, the solid, the gases, is just
Speaker 1: a tiny, tiny slice of what the universe is capable of.
Speaker 1: We don't really observe most of what the universe can do.
Speaker 1: So I would love to let the universe show its colors,
Speaker 1: you know, like go crazy in the kitchen universe, make
Speaker 1: us some weird pasta. I want to see what you
Speaker 1: can cook up. Yeah, it's almost like they're kind of
Speaker 1: little lab experiments, right, or like they're like little labs,
Speaker 1: Like you want to know what happens when you crushed
Speaker 1: two quarts together. You know, that's what's happening inside of
Speaker 1: a neutron star. So if you want to know what
Speaker 1: happens go observe neutron stars. Yea, go observe neutron stars exactly.
Speaker 1: I wish we could. But it's wonderful that these experiments
Speaker 1: are happening, right Like, we can't create these things ourselves,
Speaker 1: but it's fantastic that the universe has arranged for them
Speaker 1: to happen so that we can study them. Unfortunately, they're
Speaker 1: very difficult to approach and very very far away, so
Speaker 1: there are some stumbling blocks there. But maybe one day
Speaker 1: we'll be able to visit them, or we'll just get
Speaker 1: more clever about observing them from the outside and using
Speaker 1: that information to infer what's going on inside. Maybe it
Speaker 1: will be the Italians to do it, since there are
Speaker 1: the experts that's right, Maybe to be so offended by
Speaker 1: these models of anti spaghetti that they will be motivated
Speaker 1: to figure this out. And then your kids will be like, no,
Speaker 1: I don't like that kind of pusta, not for me, thanks.
Speaker 1: I want blue pasta. I want all the pastas squished together.
Speaker 1: Next to you going to tell me that different colors
Speaker 1: of pasta change the flavor, Well, depen's how they get
Speaker 1: their color, but they do change. Do you really want
Speaker 1: to spend another hour talking about this. Have you never
Speaker 1: had squitting pasta or vegetable pasta? All right, that's a
Speaker 1: topic for our spinoff pasta podcast. Daniel and Jorge argue
Speaker 1: about food. Daniel and Jorge eat the Universe. Well, I
Speaker 1: hope you enjoyed that discussion, and it's certainly made me
Speaker 1: a little bit hungry. I need to go have lunch now,
Speaker 1: So thanks for joining us, see you next time. Thanks
Speaker 1: for listening, and remember that Daniel and Jorge explained. The
Speaker 1: Universe is a production of I Heart Radio. For more
Speaker 1: podcast from my heart Radio, visit the i heart Radio app,
Speaker 1: Apple Podcasts, or wherever you listen to your favorite shows. Yeah,