How does degeneracy pressure work? What kinds of particles exist below the level of neutrons? Can they hold up a star against gravity? I discuss these questions and more in today’s Ask a Spaceman!
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EPISODE TRANSCRIPTION (AUTO-GENERATED)
I want you to know that I do have standards when it comes to this show. Don't get me wrong. It is very, very minimal standards. And it's basically, I have a set of notes. So, yeah. I was developing another show. I had planned this episode to be totally devoted to the idea of quantum entanglement. And it was going to be awesome because it's a really, really cool concept with lots of intricate physics. But as I was prepping it, as I was reading, as I was taking my notes, it just... I wasn't liking the metaphors. I wasn't like the direction I was going in. I couldn't come up with any good jokes, even bad ones, especially bad ones. And I decided to pause it. And I decided to put it off. Maybe next month, maybe six months, maybe like 10 years from now. I don't know when I'm going to get back to it, when I'm going to feel happy with the subject of quantum entanglement. So I thought, instead, I'd just do something fun and lighthearted and easy, like, I don't know, QuarkStars. And I guess when it comes to the world of Ask a Spaceman, QuarkStars qualify as fun and lighthearted entertainment.
Well, it turns out as I was digging into the world of quark stars and figuring out and I really want to explain it to you. You know, the cool physics is happening with quark stars. Halfway through that topic, I found myself talking about entanglement. And here we are. I need to mention Entanglement in order to get across what I need to talk about with QuarkStars, whatever the heck those are. But I don't want to actually dig into the topic of Entanglement because I got entangled in it in a very bad way. And I want something better for all of us. So what I'm going to do, and that's the reason I'm kind of prefacing this episode with this discussion, is I'm going to allude... I'm going to wink and nod to entanglement where it figures in, but I'm not going to go into detail. I'm going to save that. So just put a placeholder. Say when I, when I say the word entanglement, I want you to ring a little mental bell and say, okay, I may not fully understand how that works. We're going to get there later.
I would have preferred it the other way around, but this is life. And I don't want to go into detail because who would want to spoil an entire episode on Entanglement? I've got to have some reason to bring you guys back every other week. I need some sort of hook where you'll just think you're done. We're never done with complete knowledge of time and space, but I have to convince you every single time. I need to talk about entanglement because I need to talk about degeneracy pressure. I've mentioned and I've spoken about degeneracy pressure before. We've met it. We've met it in white dwarves. We've met it in magnetars and neutron stars. We met it recently in metallic hydrogen. And while I've talked about it at a very surface level, we never got into the real nitty gritty dirt under your fingernails, hearty meal satisfaction detail that I think you deserve. So I'm going to start there with degeneracy pressure. Entanglement works in in a very cool way. And then we'll go on to quark stars.
So to get this story started, before we build up to quirk stars, whatever the heck a quirk is, I want you to think of two particles. Completely, 100% identical twins. You cannot tell them apart. They look the same. They talk the same. They smell the same. They act the same. They are identical. You can't tell. To help yourself out... To keep them distinguished, these two identical twins, you're going to give them labels, just little name tags. Nothing associated with the property of the particle itself, because there's twins, you can't tell them apart, but just totally random and artificial name tags that you're going to stick on them. Say one you're going to call Adrian, and the other you're going to call Enrico. Just two names out of a hat. Now, these two particles, because they're identical, they're a little bit mischievous. They like to play games. Sometimes when you're not looking, they'll swap name tags. And this frustrates you to no end because you would like to keep track of which one is Adrian and which one is Enrico.
And every time you turn around, they get together and they swap name tags. And then you're not exactly 100% sure if you're looking at Adrian or you're looking at Enrico. So to mitigate this, to try to stop them, you're going to keep them separate. You're going to keep them in separate rooms. If they're in the same room, they're going to be on opposite side of the dinner table. They're not going to get close to each other. And as long as you can keep them apart, you can keep track of each individual particle. As it moves around, they might have their own trajectories and positions and velocities, whatever particles do when they're up to no good. You're going to keep track of them. And as long as they're separated, you are confident that Adrian is Adrian and Enrico is Enrico. But if that situation happens, let's say, you know, you get a little lazy, something comes up at work, you're home late, whatever. And you've come home to find Enrico and Adrian very close to each other in the same room.
How do you know that? They've switched labels or not. How do you know which particle you're looking at? This situation, the definition of close might mean they're entangled. That if they're in an entangled state, they have an opportunity to switch labels. And you're not exactly sure which label goes on which particle. That happens in the entangled state. So how do you know you don't? They're identical. That's like the definition of identical. You can't tell them apart without these artificial labels. So that's the definition of identical. And when they're close, not only are they identical, they're indistinguishable. That's a very, very subtle thing, the difference between identical and indistinguishable, but we need to make that distinction. When they're far apart, they're identical, but you can tell which is which because you know there's no chance that they've swapped labels. Once they have the opportunity to swap labels, they become indistinguishable. You really don't know. Which one is Adrian? Which one is Enrico? Let's say these particles are like electrons or protons, even atoms.
Particles, tiny little particles, are ruled by quantum mechanics. And in quantum mechanics, we need to summarize every property of a particle so that we can keep track of how it might evolve when it's moving around or interacting or doing physics stuff. The summary, the list of everything associated with a particle, The label you might give it isn't necessarily a name, but it's called a state. When I say the state of a particle, I mean a list of its mass, its charge, its spin, its energy level. Everything that I can associate with that particle goes in a big list, and I call that list a state. When there are two identical particles next to each other in a tiny box, we have a little bit of a mathematical conundrum. When they are close to each other, when they are indistinguishable, when they can swap labels at any time, they are in an entangled state. And in quantum mechanics, it's not just good enough to describe each individual particle separately because they're entangled, because they're a little bit mixed together because I don't know which one I'm talking to at any given moment.
I need to create, I need to write a state. I really need to write a mathematical description of the combined states of the two particles. Come on. So one mathematical description that describes both particles simultaneously in the box. If I want to do any kind of physics and quantum mechanics, that's what I have to do. Now, it turns out that that mathematical description that we use to describe those combined particles can only take one of two possible forms. There's only two ways we can write down a mathematical description in quantum mechanics to describe these two indistinguishable particles. In one form of the equations, one way of writing the equations down of this combined indistinguishable state, when the two particles swap places, nothing changes. In the other form, the way the mathematics are written, the actual equations that we would write down, when the two particles swap places, a minus sign pops out in front. In the first case where you swap particle positions, when they swap labels or swap positions and nothing changes, that's called symmetric.
And if they swap places and in the mathematics and a minus sign pops up, it's called anti-symmetric. Just to be clear, that minus sign that pops up in the mathematics, it's not like a minus sign appears in space or the particles have negative charge or negative mass or negative anything. It's a minus sign in the mathematics and the mathematics only. It appears in the math. It doesn't appear like to your eyeballs. And I hope that makes sense. What I'm trying to get across is we need to separate the physics of what's happening, the physical reality of these two particles being close to each other, with our mathematical description of it. And in the mathematical description of two particles to a set of twins in a box where we can't tell them apart, if they swap positions... If Adrian is on the left and Enrico is on the right, and then I turn around and Enrico is on the left and Adrian is on the right, if the math that I use to describe their state doesn't change, then they're symmetric. And if it does change, if a little minus sign pops out, it's anti-symmetric.
Now, it turns out that particles in the universe must either be of the first kind, symmetric, or the second kind, anti-symmetric. If they're the first kind, if they're a certain kind of particle and they just happen to be symmetric, when they swap places, nothing changes. And if it happens to be an anti-symmetric kind of particle, when they swap places, the mathematics gets an extra minus sign. What does this have to do with anything? Don't worry, we're almost there. You remember particle spin? If not, check out the old episode. It's a great one. It's a fundamental property of particles. Like if you have a particle, it has mass, it has charge. It also has this property that we'll just call spin, even though that's kind of a horrible name. Different particles have different masses, they have different charges, and they have different spins. Some particles have spin that we call half or three halves or five halves. Other kinds of particles have spins of zero or one or two. You can either have a spin of a half or one or one half or two, you know, on and on and on.
It turns out that if you happen to be spin zero or spin one or spin two, then you are a symmetric particle. That means if you swap places with one of your friends, nothing changes in the mathematics. And it turns out if you're spin half or three halves or five halves, you're the second kind. You're anti-symmetric. That means if you swap places with one of your friends, a little minus sign pops out in the mathematics. Where'd that come from? Who asked for that? It is just how the universe kind of works. We give a name. to particles that are symmetric, that are spin 0, 1, 2, or 3. We call these bosons. And the half-spin, the half, three-halves, five-half-halves that are antispectric, we call them fermions. So here we go. This is the big bow to put on this particle present. If Adrian and Enrico, you've put these little labels on these two particles, And you want to know, like, hey, I wonder if they're symmetric or antisymmetric. I wonder if they're fermions or they're bosons. Well, you put their little label on and you let them swap places.
If nothing changes, then they must be bosons. They must be spin one or spin two or spin zero. And if a minus sign pops up in the mathematics, they must be fermions. They must have spin half, three halves, five halves. Okay, so what? Well, here's the juicy bit. The juicy bit is you need to go to patreon.com slash pmsutter to learn how you can support this show. Your contributions, your monthly contributions, whether it's a dollar or five dollars, any amount of dollars, even fractions of a dollar, half dollar or whole dollar, it doesn't matter. Fermion dollar, boson dollar, it doesn't matter. You can keep this show going. I greatly appreciate it. It's your contributions that keep this show alive. Go to patreon.com slash pmsutter. Now here's the real juicy bit. Let's say, let's say, go ahead and say Adrian and Enrico are fermions. They're half spin. They're antisymmetric. They're fermions. And they have the exact same state. They really are identical and indistinguishable. They have the same charge.
They have the same spin. They have the same mass. They have the same energy value. Everything about these two particles is identical. Adrian and Enrico. And they're fermions. If they swap places... If I put them in a little box and they flip around, by the quantum rules of fermions, a little minus sign pops out in the mathematics that describes their combined state. But for us, just looking at it with our eyeballs... The two situations must be identical because the particles are twins. Enrico on the left and Adrian on the right looks exactly the same as Adrian on the left and Enrico on the right. Because that's by definition. They're identical. There's absolutely no way I can tell one particle from the other. Nothing at all distinguishes them. So by just looking at it, if I flip them around, that situation looks exactly the same. But... In the mathematics, it's not the same. A little minus sign pops out. Something is wrong. Something doesn't add up. How can a state or a combination of states, a mathematical description, be a negative of itself? In one view...
The particles flipped around look exactly the same. I don't know which one's Adrian, which one's Rico. But the mathematics says, no, it's totally different. There's a minus sign. Like the mathematical description is off. The only number that is equal to its own negative is zero. The only way to resolve this situation where from one point of view, the particles are absolutely identical, have the exact same state. But from the mathematical point of view, no, there's something different happens when they swap places. Is that this situation can't happen. that Adrian and Enrico can't. It's impossible for them to have the same state. If these particles are fermions, if they have spin half, then there are rules that apply to them. This particular rule is called the Pauli Exclusion Principle, named after the guy who figured it out, Wolfgang Pauli. Two fermions cannot occupy the exact same state because the mathematics won't allow it. The rules of the universe... cast down upon us have said, hey, if you have spin half or three halves or five halves, you are not allowed to have the exact same state, the same charge, the same mass, the same energy level, everything the same as any of your friends.
Just not allowed. something about Adrian and Rico have to be different. They're not allowed to be indistinguishable. They're not allowed to be identical. They're not allowed to have the exact same state. They're just not allowed because a little minus sign. You don't always blame a minus sign. A minus sign pops up in the mathematics. They are not allowed to have the same state. Something has to be different. Maybe one is spin up and the other is spin down. Maybe they have to sit at different energy levels. It doesn't matter what's different about them. Something's got to give. Something has to be different. They cannot be the same. They cannot have the exact same state. To get to this point where no two fermions can share the same state. I said a lot. It turns out. It turns out this. It turns out that. It just so happens that this is the way the universe works. When we were first uncovering quantum mechanics in the early 20th century, these rules just appeared to be basic facts about the way the universe works.
We discovered them through experimentation, but they were just kind of shoehorned into quantum mechanics. Like, hey, we'll just make a list of everything that nature is telling us. We have no idea what's going on. But hey, we're going to call these kind of particles fermions. They can't share the same state. They're antisymmetric, et cetera, et cetera. We're just going to write it down. Back in the day, you could win a Nobel Prize for just doing that. Those, man, those were the good old days where you could just list things that you don't understand and not only write a paper, you could get the highest honor in physics. But, you know, that ship has sailed. You got to do harder stuff nowadays. The cool thing is that we do have a source for understanding where these fundamental rules come from. They don't just pop out out of nowhere. It's when you combine special relativity with quantum mechanics, you can develop some theorems. That's right, theorems, not theories. These are theorems. These are mathematical proofs.
that connect the spin of a particle to the properties of its symmetry, whether it's symmetric or anti-symmetric, whether it gets to share the same state with one of its friends or whether it doesn't. That comes from a very cool connection, very deep, a very mathematical connection happening. It's a rule of special relativity. It turns out it has something to do with special relativity applied to the case of quantum mechanical systems give you these things. That's kind of hard to talk about, so I'm just going to stick with it there. If you'd like to learn more about that very deep and fundamental connection, feel free to ask. So what does this give us? We have fermions like electrons, protons, neutrons, and quarks that can't occupy the same state. What? Who cares? Who cares? Well, atoms care. This is how you can get electrons in different energy levels orbiting a nucleus, surrounding a nucleus, I should say, which gives you, I don't know, all of chemistry. It's due to these rules, due to these symmetric rules, the exclusion principle.
This gives you, let's say, the behavior of metals. Kind of important. Gives you metallic hydrogen, which we talked about. And it gives you degenerate stars. Degenerate stars are stars, dead stars, that are held up by the rules of quantum mechanics itself. Most stars are not supported by degeneracy pressure. They're supported by just normal pressure. They're just super hot. They're a gas. And gravity wants to squeeze it in, but because it's so hot, the gas says, no, I resist you. I'm going to try to blow up in those two forces, the explosive outward expansion and the contraction of gravity, balance each other out, and boom, you get a star. If you take a gas of fermion, say you take a whole bunch of electrons. And cool it down. Get rid of its temperature. Ice it down. What if you brought it all the way down to absolute zero? Which you can't, but let's play pretend. You would expect, you would expect, if you took this cloud of electrons and cooled it down to absolute zero, it would scrunch way tight together.
But... You will be surprised. There is still a source of pressure because not all electrons can cram into the zero temperature, zero energy state. Only one electron will reach the zero temperature, zero energy state. And once it's there, it's like, hey, guys, I'm full. I already took it. It's mine. I'm in the ground state. I'm in the low energy state at zero degrees temperature. And none of you can come in. All other electrons, because they can't share that state, they're not allowed in. There's only one of them. They have to go into higher energy levels. So they will still have energy. A gas of fermions at absolute zero will still have energy because of this exclusion principle. And that energy translates into a degeneracy pressure. You can cool this ball of electrons, this ball of fermions down to absolute zero, and you can try squeezing on them and they'll resist because they've got nowhere to go. They're like, no, I can't go down to the ground and say, I don't care how hard you're pushing me, man.
I cannot go down there. It's already full. Can't you see? I'm going to have a certain amount of energy. like I mentioned in the episode with metallic hydrogen, there's another way to understand this or another, another way to approach this, I should say. And that's through the Heisenberg uncertainty principle where you cannot measure the position and the velocity of a particle with equal precision. You have to give up something. You can imagine, you can look at it through this lens, where you're trying to squeeze down electrons into a very, very, very, very, very tiny state. You know, small, compact volume. Say, no, I want you to go in this tiny little box, little electron. But the more you pin down its position, the more you know about its position, it means the less you know about its momentum, the less you know about its speed. So if you try to cram down an electron into a very tiny box, it's going to vibrate like crazy. It's going to have really, really high ridiculous velocity due to the fact that you're trying to cram down its position.
So it's going to bounce around a lot. It's going to fight you. It's going to be a pressure. It's going to be hard to do. When electrons support a star against collapse, we call it a white dwarf. And that's about the mass of the sun compressed into, say, the size of the Earth. This degeneracy pressure of a white dwarf was first worked out. It was discovered by supermanian Chandrasekhar, who is an awesome guy in physics and astronomy history. An amazing story. I'd love to tell this story sometime. Just ask. And if you can't write it down, just say, hey, that Indian physicist that figured out white dwarfs, happy to go into it. Chandrasekhar figured out how a star could support itself with degeneracy pressure, basically discovered white dwarfs before we knew what a white dwarf was, but figured out that there is a limit when it comes to electrons. Degeneracy pressure is super strong, but it can be overwhelmed. You can force the electrons into a different state. Chandrasekhar didn't really know what would happen if you took a white dwarf and overwhelmed it.
If it has a mass greater than 40% more than the mass of the sun, gravity will be too strong. It will overwhelm the degeneracy pressure. He wasn't exactly sure what would happen. We do know what happens now. When you take something like a white dwarf and squeeze on it so much that the degeneracy pressure of electrons overwhelm it. What we realize can happen is that you can take a proton, shove an electron inside of it, and turn it into a neutron. And so if you have a star made of a mixture, a nice healthy mixture, protons, neutrons, and electrons, if the gravity gets too strong, then the electrons, they're still fighting with degeneracy pressure. But due to the increased gravity, they'll find themselves being shoved into protons instead, turning them into neutrons. And you basically can convert an entire star into a giant ball of neutrons, just neutrons. Once you have that, the neutrons can support themselves again against further collapse by degeneracy pressure because neutrons are fermions.
They're in the same camp. They have the exact same quantum rules applied to them. So you can overwhelm electron degeneracy pressure and boom, get a neutron star. The neutrons are much more massive than the electrons, so they can be squeezed even tighter together. That's why you get these amazing creatures called neutron stars and magnetars, where you take two or three suns worth of material and cram it down into the size of a city or a neighborhood. That's how impressive these things are. But neutron stars, neutron degeneracy pressure, it can be overwhelming too. We're not exactly sure how massive a neutron star can get before the degeneracy pressure is overwhelmed in that case. Somewhere around two or three times the mass of the sun. It's much harder to figure out. Much, much, much, much harder to figure out because nuclear physics is kind of hard. And also gravity is strong enough inside of a neutron star that we need to understand general relativity. Basically, we don't fully understand what's going on inside neutron stars.
It's just super hard. And unless we crack one open, it's going to be kind of hard to figure it out observationally. We can only see them from the outside. We don't have any here on Earth. Kind of a sticky problem. So it's a good question to ask. Okay, if I overwhelm electron degeneracy pressure, I get a neutron star. What happens when I overwhelm neutron degeneracy pressure? Right now, we don't think there's any lower level. There's no other sources of pressure support. There's no other crazy exotic physics. Gravity just crushes everything to infinity and we get a black hole. Of course, like I talked about at length when it came to black holes, we know that the singularity doesn't exist, but we do know that black holes, the astrophysical objects exist. Black holes are there. We know that something happens in the singularity to prevent the formation of an infinite point of density because that's not a thing. But is there anything in between? Is there anything in between a neutron star and a black hole? Well, if you crack open an atom under high pressure, you get a bunch of electrons, you get a white dwarf.
Crack open that, you get, you know, push it down even further, you get converted into a neutron star. If you crack open neutrons under high pressure, you get a bunch of quarks. Yeah, quarks. Welcome back to the wonderful world of particle physics jargon, which I'm sure you've missed here on Ask a Spaceman. But you keep asking questions, and we need to dip our toes in the particle physics world with all its wonderful and Byzantine and horrible, I lied about the wonderful part, jargon that comes with particle physics. So it's really your fault that I'm here, and I'm totally blaming you. Very super quick version is electrons are just electrons. Protons and neutrons, however, are actually bags of smaller particles that we call quarks. Each proton and neutron is made up of three quarks all glued together with the strong force. There are six kinds of quarks called up, down, top, bottom, strange, and charm. If you have up, up, down mixed together, you get a proton. If you have down, down, up, you get a neutron.
You get various other combinations. You get various other kinds of heavy particles. One of the things that makes studying these so difficult is that quarks have an interesting property to be explored if you so desire. That they are confined to form groups like protons and neutrons. They can't exist on their own. You'll never see just one quark by itself. It will only ever be bound together with other quarks to make heavier particles. So no matter how much they'd like to be free and isolated, they'd always be forced to be in pairs or triplets or higher groups. So to get to the question, do quark stars exist? Is it possible to make a quark star, something between a neutron star and a black hole, that's supported by quark degeneracy pressure? Well, in order to figure out, we need to play some games of physics. In the game of physics, We follow the mathematics to make predictions and figure out what the observable consequences might be. We go hunting in the universe to look for a particular signature for evidence of a particular mathematical theory.
Or you can play it in reverse. You can find stuff in the universe that we can't explain and you can cook up an explanation for it. So let's follow game number one. What do we predict? If we're going to pretend that quark stars exist, what might they look like? Well, it's kind of hard to say. Neutron stars are hard to understand, but at least they're neutrons. I mean, come on, everybody has a neutron. Quarks are a whole new level of difficulty. We can't study individual ones in the lab, which sucks. And the math is super hard, which really sucks. We do know that to pop out some quarks out of a neutron, it requires incredible pressures and temperatures. And that if you tried to make a star out of, say, a mixture of the normal, familiar up-and-down quarks, like the ones a neutron is made out of, it would be very unstable. If it was exposed to space, it would just boil away, basically. But there are some possible pathways that if you're trying to scrunch down a neutron star, and it starts popping out quarks all over the place, and they start combining together in interesting combinations, that some of them might be converted into strange quarks, this...
one branch of the quark family tree and they might be a little bit more well-behaved like you can maybe kind of sort of construct a large object like a star and expose it to the vacuum of space and it might survive if it is possible if nature is even capable of manufacturing quark stars it must be very rare because there's only a thin window between a neutron star in an all-out black hole all-out gravitational collapse catastrophe. There's a transition from white dwarfs to neutron stars. And right now we think there's just the smooth transition. Like if you're too strong for a neutron star, boom, you're going to make black holes. We know neutron stars exist and we know black holes, the astrophysical objects exist. There's like not a lot of wiggle room to make a quark star. Well, what about a different approach? Maybe you could stuff a quark star core inside of a neutron star shell like an M&M. Except it's a Q&N. And it might be okay. It might live. Perhaps. Maybe all neutron stars really have quark cores.
And that is so hard to say. due to the extreme conditions in the cores. Well, then that's fine. We just need to rename it. That's just a renaming exercise. Instead of neutron stars, they're really quark neutron stars, and just call it a day. That's a big fat maybe, that maybe neutron stars, the cores, are so exotic that they really have quark cores. Say that 10 times fast, I dare you. That's super hypothetical, though, because like I've mentioned, we don't fully understand the material properties of quarks. We don't understand the strong nuclear force very, very well. It's hideously complex. We don't understand the interiors of neutron stars. Full stop. We don't know what's going on on the inside. So maybe they have quark cores. Maybe they don't. Either way, if they exist, whether quark stars exist inside of neutron stars or as their own independent object, it's very hard to tell a quark star from a neutron star. From the outside, they're both dense. They're both small. They're both super hot.
It's hard to tell if you just look at a neutron star or something weirder. So what about game number two? Is there anything out there in the universe that we can't explain that's just begging for an explanation? And wouldn't you know it, quark stars are just going to fit the bill. Well, there is a gap, right? There is a gap between the maximum neutron star mass, about two-ish times the mass of the sun, and the smallest black hole that we've ever seen, about three, a little over three times the mass of the sun. Maybe there's a nice snug little fit for quark stars right there. A little bit, I'll put it right there. A little bit, no one will even notice. Maybe. But it could be an observational bias, like it's easier to find big black holes. Maybe there are two, two and a half solar mass black holes floating around out there. They're just hard to spot. Possibly sometimes we see some explosions that look like supernova or regular nova, but seem a little off kilter. You know, the elements seem wrong.
The maximum brightness is a little bit off. The time it takes to cool down is a little bit off. Maybe it's what's called a quark nova. Yeah. We might be witnessing a transition from a neutron star to a quark star, and that releases a bunch of energy? Maybe, or could we just don't understand the finer details of supernovas? There are some neutron stars that might be a little bit too small and a little too dense to fit our current understanding of the strong force and how neutrons behave under high pressures. That could fit the bill as a quark star. Like, oh yeah, that's a candidate. Well, it could be due to the fact that we don't really understand, you know, neutron stars. So there's a lot of mystery around quark stars. Theoretically, it's hard to make progress because, you know, we don't understand quark physics and neutron physics, strong force physics very, very well. And it's hard to support observationally because all the candidates that you could point to could also reasonably be just other things.
So overall, do quark stars exist? I'm going to give it a weak maybe. A week, maybe. It's possible it hasn't been ruled out. There's no equation that's popped up saying, nope, nope, not in this universe, fellas. And there aren't a lot of observational hooks. A lot of things we can point to and say, you know what, that's really good Canada for a core star. We can't do that. We certainly don't understand many things about our universe. That's a given. But none of the mysteries really fit the bill for what a quark star would look like. There doesn't seem to be a lot of room for them. So they may end up as theoretical possibilities, but it's just that nature doesn't manufacture them. And you know what? That's just how physics works. Thank you so much for listening. And yes, I did change up my intros. Let me know how you like it. I can go back to the old way. I mean, you're the audience. You're in the driver's seat. If you like the old way of opening the show, let me know. If you like the new way of me just doing cold opens, going right into it, let me know too.
Go to AskASpaceman.com. There's submission form so you can tell me what you think. Thank you so much to AtWigabo. Not exactly sure how to say that, but you know who you are. On Twitter, for asking what's a quark star and its properties. At Shamanic Pistol. Also on Twitter, what's up with quark stars and strange matter. And Larry B. on YouTube asking, do quark stars exist? Big thanks to my top Patreon contributors this month. Justin G., Matthew K., Kevin O., Justin R., Chrissy, and Helga B. It is your contributions that keep this show on the air. Go to patreon.com slash pmstar to learn more. And before I go... Before I go, this is very cool. There is a new AstroTour available to northern Chile, to the Atacama Desert, the driest, some of the darkest skies in the world. I'm leading a very small select group. It's going to be a small tour, just no more than a couple dozen people. You need to go to astrotours.co, astrotours.co. to sign up, make your deposit for the Atacama Desert. We'll figure out the rest of the money later.
It's going to be amazing. It's like every night dedicated to some seriously hardcore stargazing. You need to go. You also need to go to spaceradioshow.com. That show is live and well, and you get to talk to me on the air every single week. It is just so much fun. There's a lot of cool stuff going on. Go to AskASpaceman.com. You'll see links for everything else. If you can't make a Patreon donation, I really appreciate telling your friends about it, telling people about mentioning it on social media, going to iTunes, giving a review, preferably a four or five star review. I'd really appreciate that. Whatever you can do to help keep this show going and growing, I am in your debt. And I try to service that debt by telling you about all the crazy stuff in the universe. Thank you so much. And I will see you next time. Keep those questions coming to hashtag Ask a Spaceman on Twitter and Facebook. Follow me on Twitter and Facebook. My name is at Paul Matt Sutter. Going to AskASpaceman.com. And I'll see you next time for more complete knowledge of time and space.
