What's the fastest spinning thing in the Universe?
Part of their "Extreme Universe" series, Daniel and Jorge make your head spin with all of the crazy spinning objects in the Universe.
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2020-12-15
46 min
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00:00:08 Speaker 1: Hey, Daniel, do you know what's weird about the universe? Everything all right, that's true, but I mean when I look at the planet, it kind of makes my head spin a little. Oh yeah, what makes your head spin? Because all the planets are spinning, you know, none of them are just sitting there. True, And they're also spinning around the Sun, right, which is also spinning around the galaxy. And our galaxy is spinning around other galaxies. It's like the whole universe is spinning around. Oh my gosh, now my head is also spinning. I am r Hammad, cartoonists and the creator of PhD Comics. I'm Daniel. I'm a particle physicist, but I don't have spin. Welcome to our podcast, Daniel and Jorge Explain the Universe, a production of I Heart Radio, a no Spin zone about the true facts of the universe. Everything that's crazy, everything that's amazing, everything that's fascinating, everything that makes you wonder. We dig deep into it and explore it and try to explain all of it to you. I like how you put a positive spin on the fact that we put no spin on science. It's just a facts around here. When we know something, we say we know it. When we don't know something, we are happy to say we are clueless. Well, do you think maybe the universe does need a little bit of spinning, you know, just if people feel a little bit more positive about it. It is pretty dark and dangerous out there. It is dark and dangerous. But I prefer to take a direct approach because then those moments when you do learn something amazing and true and incredible about the universe and really just sort of fills your heart with light to know something about the universe, that's that's a good way to spin it. But anyways, we like to talk about all the amazing things have pening out there in the cosmos, all of the crazy and all of the mind blowing objects that are out there. And we have a series of podcasts where we talk about the most extreme things in the universe. The best snowboarder in the universe? What how the snowboarding fitting? It's an extreme sport, man. No, we'd like to talk about all the extremes in the universe because they tell us something. We are interested in the limits. Why do stars only get up to a certain size? How hot can something get? What prevents something from getting bigger or hotter or faster, or spinning even more rapidly. There are lessons there about the limits of physics and about what is allowed in the universe and what is not allowed in the universe, because in the end, that's our goal to figure out what are the rules of this crazy, beautiful, bonkers universe, and the extremes help point the way. So we have episodes in the archive about the biggest thing in the universe, the hottest thing in the universe. I think we've also done the coldest thing in the universe, right, we have, we did the emptiest places in the universe, and we haven't done one about the fastest thing in the universe because that one's a little bit tricky because basically, the fastest thing in the universe is a photon. Is just the speed of light, right, Oh, that was a short podcast that was the mini warm up podcast to the real podcast today. But also because you know, the speed of something depends on the speed that you're measuring from, so you can make anything fast by just getting in a spaceship and zooming around. So the fastest thing in the universe not that easy to pin down, other than of course a photon. I guess My question is is a photon a thing? First of all? And those some other things move with the speed of light too. You know what what happens if you race them? Yes, Actually, gravitational waves move at the speed of light, and everything that is massless moves at the speed of light. So that includes gluons, for example, and photons. So if you had a race between photons and gluons, it would be an exact tie. All right, Well, so we can't fill a whole hour on the fastest thing, but we can talk about another fastest thing that happens in the universe. So to the other podcast, we'll be talking about what is the fastest spinning thing in the universe. I'm guessing most people saw this coming, probably because they read the title of the episode before they play. But yeah, we're we're spinning up an interesting story here today, and also because we made a hundred spin jokes before we told them the topic of the episode. But this, to me is a really fascinating question. The whole notion that things in the universe are spinning, and this is spinning this way, and that's spending that way, and why are things spinning anyway? And the whole question of angler momentum to me really fun and fundamental, and you learned something really interesting about sort of the way the universe works and the way space works from studying how things spin right, spinning it is, by itself kind of a weird thing, isn't it. It's like, if I'm spinning, am I really turning? Or are just my particles going around in a circle? Whoa, It's like a whole other teleportation question. Yeah, like are my particles actually like turning around or are they just moving around? I see, Yeah, this is an interesting question. I mean, you can imagine all of them moving in a circle but pointing in the same direction, like their internal acts not changing, or you can imagine them like a car moving around on a track, where they actually do change direction. If you stand in a circle and turn, then you know your molecules are held together by pretty tight bonds and so they're gonna be pulled to turn with you. So I think if you stand in turn, then you're more like a car going around the track. All of your molecules and particles are definitely turning with you. They're not like little gyroscopes, right, but their point particles can they have a direction they do have spin, right, These particles do have spin absolutely all right, Well, this is a fascinating question. What is the fastest spinning thing in the unerse And I'm guessing Daniel will be measuring that by revolutions per second or like or how dizzy they get? Yeah, I think revolutions per second is probably the best metric. But then it's also fun to calculate like the speed at the surface. You know, how fast how close to the speed of light is the surface of a neutron star moving, and this kind of stuff. Well, as usually, what we were wondering how many people out there had an opinion or a favorite as to what is the fastest spinning thing in the universe. So Daniel went out there and ask people on the internet this question. So thank you to everybody who participated. As usual, if you would like to take your turn and answer questions without Googling about a tough physics topic that we are going to unpack, please volunteer two questions at Daniel and Jorge dot com and the use of different search engine Daniel, or is googling now a universal verb? I'm working on a physics version of Google. Yeah, that just gives you the physics answer to everything. Time it says no, or we have no idea. By the way, by this book that these two podcasters wrote, that's all it does. It just links you to our book. There you go, perfect, let's make it happen. All right, Well, think about it for a second. As if you listening, if someone ask you what you thought is the fastest spinning thing in the universe, what would you say? Here's what people had to say. So I'm guessing that by spinning, it makes like actually spinning, not like a quantum spin. So I'm guessing it's probably some type of special star or maybe like a black hole, a neutron star, and I think that's the same thing as like a pulsar pulsar I think, or possibly even like a magneto, which I think maybe spins at a faster rate, or maybe just has a much larger magnetic field. I'm not sure unless we are including a particle's spin like it's spin up and spin down properties as a definition of a fast spin. But I don't think that's quite the angular momentum that we're familiar with. Probably a Tasmanian devil. No, it's probably a spinning neutron star or maybe a black hole that spins. Well, there's a pulsar, and above pulsar it's a magnetor so. Electrons spins pretty fast. I think X ray or gamma ray particles in real activistic teams shot from quasars. All right, I like the person who said the Tasmanian devil. I've obviously we've been watching physics cartoons. There's a lot of physics consulting going on in looney tunes. Let me tell you the whole time delay of the gravitational effect in the road Runner cartoons. Yeah, not sure, but I think the research center is called ACNE. Yeah, exactly. They are very generous with their funding, apparently. And now there's a lot of great answers in here, a lot of cool ideas, a lot of informed answers, but none of them are actually right. Wow, nobody could to grind and they went for the whole shi bank here. They went with pulsars and neutron stars. There pretty extreme things. Yeah, all the way down to a electrons and everything. Oh, nobody got it right. Nobody got it right. Zero points for all of you folks, But thank you for trying. Boy, this is a pretty negative website here. It doesn't give you any points. We will send you all an ACME company gift package. All right, well maybe three. A lot of people talked about particle spin, and so because it's so small, I think I would imagine that maybe it is the fastest spinning thing in the universe, right, I mean, it's it's almost like an abstract quantity. So could you say it's the fastest spinning thing in the universe. Yeah, it's really weird, actually, right. We talk about particles as having spin, and we know that there's spin is something closely related to angular momentum. Like if something is actually physically spinning, like it's moving around the nucleus of an atom, you can take that motion and you can convert it into particle spin. So it's like a real kind of anglar momentum. But we don't think it's an actual physical spin of an object, because an electron, as we think about, is a really time the particle maybe even just a point, and it doesn't actually make sense to think about that object as spinning. Like if you try to do the calculation, you say, well, how much energy is in the spin and what's the mass of the electron, And what can I assume about the radius to the electron if you put in what we know to be like the upper limit of the radius to the electron, like our measurement for the biggest an electron could be though you know it could be zero. And you crank all the numbers and you ask like how fast is the surface of the electron moving? You get a crazy number, it's like a hundred times the speed of light. Wow, what but that would be impossible. That would be impossible, which tells you something about your calculation is wrong. Like taking the energy of an electron spin and thinking about it as actual physical spin doesn't make sense. We don't think that this is a tiny little object that's actually spinning. It's a quantum spin. It's something weird, something different from actual physical spin. But it is related, like it's can you can't just say put it in that quantum box and say we don't understand it. Whatever, put a quantum in front of it. It's something connected to actual spin. You can take again real angular momentum and convert it into quantum spin and back again. So they're definitely connected, but we can't really say it's actual spin. Well, I do that all the time, tied Daniel with thinks I don't want to understand. I just put quantum in it, and I stick it in the box, you know, like my taxes or m Yeah. Yea deadline deadline, quantum deadlines plus our minus you know a year. Yeah, I got this in within the uncertainty right there, you go. I did, and I didn't turn it in. How about that? That's right, your contract is dead and alive at the same time. But I still get paid right in quantum dollars. But it is really fascinating, Like it's definitely something you can think about as a spin. These particles have a spin. It's definitely a quantity we connect with spinning things. But if we want to talk about what's the fastest spinning thing in the universe, I don't think it's really fair to say that a particle is something that is in the running for it because it's not physically spinning. But can you give it a value like a certain revolutions per second on an electron? Right, because you have the angular momentum and you know the mass of the electron, can you just divide that to get some kind of spinning velocity? Yeah? You can do that because you know, the angular kinetic energy is proportional to the moment of inertia and the number of revolutions per second. But the moment of inertia depends on the radius of the object, right, how much angular momentum there is depends on the distribution of stuff. This moment of inertia is like rotational mass, so it doesn't just depend on the mass and the object. That depends on where the mass of the object is, like is it all on the surface or all at the core? Sort of like how a figure skater, you know, when she moves her arms in closer, she spins faster and faster, even though she has the same mass. So the revolutions depend not just on the mass and on the energy, but also on like how that's distributed. And we just don't owe anything about how electron looks like inside. Is it really a point particle? Is it made of tiny vibrating strings? We just don't know, alright, So I guess the thing is that it just doesn't make sense to think of an electron as spinning, even though it has quantum spin, it's not actually like turning around. Yeah, So I think the physics referee, and this one is going to rule it out of bounds. For this competition. It's probably spinning in some crazy awesome way we just don't understand yet. It might take the cake and be the fastest spinning thing in the universe, but for the purposes of today's competition, it's been de cute. All right. Well, that's a bummer for particles there for Team Electron. I was trying to put a positive spin on it, Daniel, but um, you totally shut that down. I mean for particles, I know, and usually I'm pro particles, right, Like, that's sort of my job. I'm made of particles. I study particles. But in this case, I don't really think they qualified. Physicist are fickle alright, Well, um, let's talk about real things, like, you know, how fast is the Earth spinning? For example? I mean we I know that it's been once a day, but is that fast relative to other things in the universe. It's actually pretty fast, Like for our solar system, it's one of the faster spinning things. You know, Like the Sun, for example, rotates every twenty seven days. The Sun rotates. The Sun rotates, oh absolutely every month, yea once a month. The Sun completes a revolution, and you know the rest of the Solar system is basically just an extension of the Sun. Most of the stuff in the Solar system is the Sun, and everything is spinning. The whole thing is spinning, and most of its spinning in the same direction. Right. The planets move around the Sun the same direction the Sun spins because it all comes from the same original angle momentum of the huge blob of gas and dust that form the Solar system. So, yeah, the Sun is definitely rotating, but not that fast. Well, I guess it's weird to think of it like an explosion rotating, right, because that's what the Sun is. It's like a constant explosion, and so it's kind of weird to think of it as or like fire. You know, it's it's hard to think of fire spinning. Yeah, it is pretty cool. And you know, inside the Sun there's also all sorts of really complex conductions and currents and like streams of plasma that move around, and you know, the Sun's magnetic field flips every eleven years or so, probably because these streams of plasma are like swapping directions. And there's a whole podcast episode about that where we're doing the future about what's going on inside the Sun. But yeah, it's a really big, complex, spinning beast. So so what does that mean about the surface of the Sun. How fast is in moving? So the speed of the surface of the Sun is pretty fast, because the radius of the Sun is really large, right, So if something is rotating once every day or so, then the speed of the surface depends on how far you are from the center. And so the Sun is huge, and that means that it's moving at like sixty six thousand kilometers per day per day. Wow, that's close to what the Earth is moving, isn't it. Yeah, service of the Earth moves obviously, the circumference of the Earth twenty four miles per day. All right, so those are pretty fast. And what else in our solar system is spinning pretty fast? Well, surprisingly to me, Jupiter actually spends faster than the Earth. I was thinking the begger the object, maybe the slower it rotates, because the Sun rotates more slowly than the Earth. But Jupiter actually spins faster than the Earth. It does a revolution in ten hours. So wait, the like the core of it, or the whole thing, or just the clouds in the surface we can't really measure very well what's going on inside Jupiter. We think that there's differential rotation, like the internal core might be rotating at different speeds than the outer cloud cells, and this could be what's contributing to all that turbulence. But we can just look at stuff on the surface of Jupiter and watch it rotate. So like that red eye actually goes around once every ten hours, once every ten hours. Yeah, it is kind of like the iosaurin it's looking around keeping an eye on the Solar system. That's right. So if you're gonna sneak around, you've got about ten hours until the eye turns around and looks at you, so you can finish your plans. All right, let's get into other things that are spinning fast in the Solar System and into wider space. But first let's take a quick break, all right, Dannel, we're asking the question what is the fastest spinning thing in the universe, And there's a lot of spinning things in the universe. A lot of things are spinning around. They certainly are, and in our Solar system, Jupiter spins every ten hours, but it's not the champion in our Solar system. We have a lot of little objects out there, like past Pluto, around the size of Pluto, and some of them has been pretty fast. Like well, the king of the Solar System or queen, depending on the gender of this object, is the dwarf planet how maya. It's out in the Kuiper Belt. It's about the size of Pluto, and it spins around every four hours. Whoa, So I guess if you're standing on it, a day would be four hours, like every four hours the sun would set and rise. Yeah, exactly. And we don't know that much about it because it's really far away. It has this like dark red spot on its surface, so you can see it move around. But it's spinning, and you know that must have come from some like crazy collision with some other object to get it spinning so fast. Really, like maybe it was just standing there and then it got knocked or grazed by another thing and that said it to spin. Yeah, or it was spinning in some other way and then it got knocked into and some crazy collision and it came out with more spin. You know, Like a lot of the objects in the Solar System, like Uranus has weird spin and Venus has weird spin, and that can also be the result of collision from something else outside the Solar System. Wow, alright, so it's a super short day. But you know what about out further in space? What else do we know is spinning out there pretty fast? So the listeners were on the right track when they were thinking about pulsars and neutron stars, because these are objects that do spin pretty fast. And remember, a neutron star is when a star has collapsed, like it's mostly done with its life, and the core of it has collapsed into a very very dense object that's dense enough to like squish all of the protons and electrons together to make neutrons, but not so dense to overcome the pressure of the neutrons and compacted into a black hole. So it's sort of like a black hole that didn't quite make it into a black hole. This is a neutron star. This is a neutron star. And so they're all neutrons. They're very very dense, and because they've been compacted very very small, like it's a huge amount of stuff in a very very small space, they also gained a lot of spin, just like that figure skater you're pulling in all that angular momentum, but now you're radius is much much smaller, so you have to be moving faster to have the same angular momentum. So these things can spin really really fast. How fast are they spinning? Well, there's one variety of them called pulsars, and these guys shoot out a beam of light from their north and south poles, and so we can actually see them spin. That's how they were discovered. That this beam of lights of like washes over the Earth once every rotation, and so you might imagine, Okay, these things they've probably spin once a day, or once every hour or once every minute. But the fastest spinning pulsars spin like six or seven hundred times a second per second per second. Yeah, these are huge objects that are spinning hundreds of times a second right totally blowing away the Sun, Jupiter, the Earth, even our dwarf planet. Like, these things are really spinning. I can't even hit wrap my head around something. I mean, how big is this thing? How can something that large spin that fast? But did it just explode? Well, it's held together really tightly right by gravity. It's about sixteen kilometers in radius. So this one that's like the Queen of pulsars is about eighteen thousand light years from Earth. It's in the constellation Sagittarius. It has a radius of only about sixteen kilometers. Tiny, so these things are not big. Yeah, but it's spinning super duper fast. And if you do the calculation, like the surface of this thing is spinning at a quarter of the speed of light. Wow, that's crazy. How do is it something that massive and large spin that fast when it explode at some point or break apart. Well, there's a lot of things going on here, right. You have gravity pushing it down, and then you have rotational pressure preventing it from collapsing. Right. One of the things that prevents things from collapsing into black holes is rotational pressure. It's hard to get things to get smaller and more compact because they would have to spin even faster. So what we're looking at here is sort of a balance between all the forces at play. You have the pressure from the molecules not wanting to get squeezed down more. You have the rotational pressure, which makes it harder and harder for things to get smaller, But then you have gravity pushing down on it. So you know, that's why the Earth has not fallen into the Sun, right because our angular momentum protects us. That's why the galaxy is not fallen into the black hole at the center of the galaxy because of our angular momentum. And so as you get smaller and small, you have to spin faster and faster. So meaning if you stop these neutron stars or pulsars from spinning, they would collapse into a black hole. They might collapse new black hole. They would definitely get smaller. Yeah, something that's spinning is definitely bigger than something that's not spinning. Right, Well, that sounds pretty crazy, but there's even crazier spinning things. There's another one out there. This is neutron star, which has sort of the crown for the fastest spinning thing that we know about out there in outer space at least. And it's got some crazy name, and it's about thirty thousand light years from Earth and it's spinning at more than a thousand times a second twenty two hers. Wow. Yeah, it has a pretty cool name. It sounds like a science fiction name. E J one eight five that's right, not to be confused with a four. That's a totally lame. Neutron star to eight five is the one that wins the spinning contest. Yeah, it's incredible, and this thing is only ten kilometers wide, right, it's a tiny dot. It's amazing how much stuff is crammed into these tiny little areas and the incredible speeds they move at. And this surface is also spinning. It just about a quarter of the speed of light, but again, because it's smaller, that's a faster rotation speed. And these things are really dense, right, like it's about the mass of the sun. Maybe, yeah, exactly, they're both the mass of the Sun. But it's only ten kilometers wide, so like you know, a tea spoon of this stuff weighs like a billion tons. It's really pretty incredible, and it's not something that we understand very well, like what's going on inside a neutron star? What is the pressure? How do all these things squeeze together? And one of the reasons we don't understand it is because what's at work here is the strong force, like the force that holds protons together and neutrons together and the nucleus together. It's taken over because everything is so squeezed together, and we don't really understand how to do calculations with a strong force really nasty because it's so strong that any small change in your calculation means a big change in what happens. And so it's hard to describe. Like the internals of an entire neutron star, it's kind of hard to imagine, you know, something the size of you know, Los Angeles spinning a thousand times a second. Yeah, and their spin can change. Also, because they're a tiny bit unstable, sometimes when they're spinning, they get this glitch where like this like a quake on the crust of the neutron stars, things shift and then it might like compact a tiny little bit and then speed up, or if it quakes in a different direction, they can glitch and then slow down. It's pretty amazing. Wow, it's almost kind of like a surreal you know, like if you were standing next to it, your mind would just be blown. Yeah, exactly. And these things are hard to see. Also, we can see the ones that are pulsars that emit these beams of light along their magnetic axis, and obviously we see those beams, but if they don't shine in our direction, they're pretty hard to spot. Because these neutron stars are not undergoing fusion. They don't glow like our stars, right, so it's not clear exactly what you would see. I think it's just a big hot, lowing rock basically, So it'd be fascinating to actually see one up close. We've only ever really seen them because of their pulsar radiation. All right, Well, um, I feel like we can have a discussion of wild things in the universe without talking about black holes. Can black hole spin as well? Black holes definitely can spin. And one of the amazing things about black holes, of all the amazing things about black holes is how little you can know about them. Like two black holes that have the same amount of stuff in them, you can't tell them apart, Like there's no information about what went into the black hole that you can extract, and that includes information about like what order the stuff went in, or when it went in, how long ago went in. The only things you can know about a black hole are its mass and its spin and it's electric charge. So if you have two black holes that have like no electric charge and no spin and the same mass, there's nothing you can do to tell them apart. They're like as quip lent as two electrons to us. I mean, right, but if you were inside the black hole, could you tell the difference? That's an awesome question. If you were inside the black hole, then yes, you could tell the difference if things were thrown in after you or before you. Right, But if everything has been thrown in before you, it would be closer to the singularity than you would be, and so you wouldn't be able to probe any of that stuff. But you can tell if a black hole is spinning. So like, if you make a black hole by just dropping a bunch of bananas with no spin and make a black hole, that will look different than a black hole where you've like thrown the bananas in so they have angular momentum relative to the center of the black hole. You throw them sort of like a little bit to the side, so you get the thing spinning. And now I guess a question is what does it mean for a black hole to spin? Does it mean that the stuff inside of it is spinning? Or is it also sort of like a quantum quantity That doesn't really make sense. Man, I wish black holes did make sense. We have to use just the only theory we have, which is general relativity, to describe what we think is happening inside of black holes. We know that theory is limited. We know it breaks down when you get to the singularity, that you cannot describe what happens in infinite curvature. So we know this is wrong, but it's also sort of our best idea for what's happening. So in the universe without quantum effects and only general relativity, then yes, we think that the stuff inside the black hole is actually spinning, like orbiting around the center. Well, we think that there's a singularity at the heart of the black hole, and the singularity is a point, right, and so how can a point spin? Well, we think that a spinning black hole doesn't have a singularity that's a point. We think it's singularity is a ring. What what does that even mean, Daniel. It means that the place where the curvature goes infinite is not just one place in space because a point cannot spin, right, the singularity that's a point cannot have any angular momentum. However a circle can. So you have a singularity which is not a point but a perfect circle. Well, so that means that things are spinning around the ring or towards the ring. The ring is spinning itself is spinning because it has a radius and so it can spin, you see. But it could also mean the stuff between that ring and the surface of the black hole is also spinning, right like. It could be a swirling thing inside of the black hole, or it could just be things falling in right, Yeah, exactly, And it's very likely that if something is approaching the end of the black hole, it will be spinning because it's hard to otherwise. Like, if you're gonna fall into a black hole, you have two options. One is go straight to the heart of the singularity right exactly right on, or any other direction, And any other direction will mean you're falling in with some spin because you're not gonna be going straight at it, and so you're gonna be giving it like a little bit of torque. And so most likely things that fall into the black hole do give it some spin. So we think that most black holes are spinning. And if you look at the stuff around the black hole, the accretion disk, the stuff that has not yet fallen in, that's spinning, right's swirling around, gradually losing its Anglo momentum as it falls into the black hole. All right, So we can know the mass, the charge, and the spin of a black hole. So how do we measure the spin of a black hole? Because it's it's just a giant, you know, black ball. How can you tell if it's spinning or not? And how much? That's a great question because your first thought might be, well, a black hole is just a big gravitational object, and according to Newton, the force of gravity only depends on the mass of the thing, right, not on its spin. So you can't tell gravitationally if something is spinning. And since gravity is the only way to probe the spin of these things, how could you tell at all? Well, Newton wasn't right right. Newton's theory of gravity is not complete, and it fails, especially around black holes. There are more complicated effects here, and there are corrections to Newton's theory in Einstein's theory that do depend on the spin of the black hole. So the gravitational effect of an object depends not just on how much stuff is in it, but also on its energy density. Right, energy density, and one component of its energy density is its spin. So how much it's spinning changes its gravitational effects, right, I see, so kind of because mass is energy and spin is also energy. You can sort of maybe tell the difference between the two. Yeah, And there's one really awesome test case where they have a super big black hole. There's this black hole that's eighteen billion solar masses, so it's like one of the biggest black holes we know about, and it's being orbited by another black hole, a tiny little black hole that only has a hundred and fifty million solar masses right now on its own. This one would also be an awesome black hole, but in comparison to this monster black hole, it's pretty small. So the little one is orbiting the big one, right, and it's affected by the gravity of the big one. But because the big one is spinning, this causes a procession in the orbit of the smaller black hole. So the smaller black holes orbiting the bigger one, but it's orbit itself is spinning. It's like an ellipse, and the ellipse is moving around the bigger black hole, and that tells you something about the spin of the big black hole exactly. The procession of the orbit of the little one comes from the spin of the big black hole. And you can do these calculations. It's not trivial to think about, like Newton's laws, Einstein's calculations are much more complicated. But the spin of the big black hole affects how things move around it and affects the orbit of this little black hole. Interesting, and so that's how they were able to measure in this case that very precisely the spin of the big black hole. I see, so like a black hole that has mass would affect things differently around it than a black hole that has mass and spin exactly. And the way you probe that is by looking at the stuff around the black hole seeing the effect on that stuff. Usually is on the accretion disk. Sometimes it's on other big massive objects like a black hole, And so typically looking at the accretion disc you can tell how fast is this black hole spinning? Does that apply to other things? Of our Sun wasn't spinning, would our orbit be totally different? Yeah, if the Sun wasn't spinning, our orbit would be different. The Sun's gravitational energy is mostly due to its mass though, because it's not spinning that fast. But yeah, we would have settled into a different orbit that I don't think it's by a big number. But that's how you can tell how much a black hole is spinning, yes, exactly, and you could look at the accretion disc. So, for example, a black hole that's spinning in the same direction to see acretion disc, the acreation disc can actually get closer to the black hole than otherwise a black hole that's not spinning. The acreation disc can't get quite as close because remember the acreation disk sort of ends not at the edge of the black hole, but like a little bit further out. All right, that's a pretty impressive black hole to eighteen billion times the mass of our Sun. But surprisingly it's not the fastest spinning black hole. So let's dig into what is the fastest spinning black hole and whether or not that is actually the fastest spinning thing in the universe. But first, let's take a quick break. All right, Daniel, we are spinning black holes here, and my head is spinning a little just to think about a black hole spinning. I mean, how can a weird thing like a black hole spin? But it can, and you can measure it. And we're gonna talk about the fastest spinning black holder is because it's not this big one we just talked about. Yeah, and that big one is not actually even spinning that fast. And the reason is that it's huge. Like the radius of that black hole is like three hundred and sixty times the distance from the Earth to the Sun. It is this enormous. It's much much bigger than our entire solar system. And so even though the surface of that black hole is moving it like of the speed of light, it takes five million seconds to complete a spin. Wow, so the surface is going really fast, but it's actually not spinning that fast. Yeah, because it's so big. The surface is so far away from the center that even moving a of the speed of light, it takes a long time to complete one circumference. All right, So what is the fastest spinning black hole do we know? Or what is this fastest spinning black hole we know about? So there's another black hole that we think is spinning faster. It's another one of these big black holes that has two million solar masses. Remember that there are two categories of black holes. The ones that come from like stars that collapsed, and those tend to have you know, like ten to a hundred solar masses, and then there's just like a leap. There are no black holes in between that, and like the really big monster ones that the centers of galaxies that have millions and millions or even billions of solar masses. So this is one of those. It's two million solar mass is again pretty small compared to the monster we talked about, but a really very massive object. All right, So this one is near us? Is it in another galaxy? So this one is in another galaxy. It's at the center of another galaxy about fifty million light years away in the constellation formats, and it's called n g CT. And we can study the spin of this one by looking in detail at the accretion disc. So this acreation disc is like the stuff that's swirling around the black hole that's waiting to fall in. And can we actually see it or do we just kind of see it as a a star almost We don't have an image of it the way we have imaged another black hole in another galaxy. But what we can do is look at the radiation from it admits in the radio and an X rays, and all this hot gast that's surrounding the black hole sends us information according to how it's emitting radiation. So that's how we measured these things. By looking at the X ray spectrum at the center of those galaxies. Yeah, like I guess you. You see kind of lips and dips. It tells you how fast the black hole is spinning. Yeah, exactly. And you can get the radiation from mostly from the iron that's emitting inside this secretion disk, and it's really hot and it's smashing into itself, and so it has a lot of energy and it tends to emit in the X ray and that information comes all the way to our X ray telescopes and tells us about what's going on. And we can look at sort of like how close to the center of the black hole is this accretion disc getting. And if the black hole is spinning in the same direction as the accretion disc, then the stuff in the acreation disc can actually get closer and closer to the center of the black hole. Remember we talked once about how if a black hole starts spinning, it's event horizon actually shrinks, right, Because if you're converting sort of the energy of the black hole directly from mass and into spin, then the event horizon shrinks. And if you spin it actually fast enough, the event horizon collapses down and you can actually see the singularity on this thing, so we're not talking about that. We don't have any naked singularities that we're looking at. But if a black hole is spinning really really fast, then it's event horizon shrinks, and so they creation disc also gets closer and closer to the center of this thing. So how fast is it spinning? Do we know for sure? This one we think is spinning at eight of the maximum speed that a black hole can spin before it turns into a naked singularity. Wow, I imagine that's a lot. But do we have a number for that? I don't actually have a number for that. It depends a little bit on the mass of the object. But they think that there is this theoretical rate that black hole can't spin faster than this theoretical rate without losing its event horizon and revealing itself as a naked singularity. And this one's moving at eight four percent of that speed. So it's a real spinner. I see. We just have to imagine a ridiculous spinning rate that would strip away the event horizon of a black hole and then imagine that exactly of a big number is a big number. But I guess, you know, I just did not leave us hanging. Is it like millions of revolutions per second? Is it bill revolutions per second? What is there a rough estimate? Now, these things are not spinning that fast, right, It's a lot of energy. But these things are big, and so they're not spinning as fast as pulsars or neutron stars. So you know, the other black hole took five million seconds to spin. I did some calculations for you. You have to know something about the distribution of mass inside the black hole to actually figure it out, and of course we don't know that. But if you make some pretty dubious assumptions, you find if this one takes even longer to spin than the last one, even though the surface of it is actually moving closer to the speed of light. Oh, I see, these things are large, so they have a high speed at their surface. But again they are so big that they can't spin around very many times per second. Well, disappointed here, Daniel. I thought black holes were gonna beat out neutron stars and pulsars, but it sounds like not. No, they're more awesome and weird than neutron stars and pulsars, but they do not spin faster. But there is something else which is faster than both black holes and neutron stars. Yeah, so this is where we get to the winner of the spinning contest. And it's not pulsars, it's not neutron stars, and it's not black holes. It's actually pretty surprising. It's right here at home. It's engineers and how they spin, how they spend their safety protocols. Yeah, you know, it's hard to spend something that's really really big, Right, You're gonna take a planet and spin it really really fast. That's a lot of energy, and if you don't want it to tear itself apart, you have to really compact it to a dense object. So it's not actually that hard to make something that spends more than a thousand times a second. Right, every time you drive your car, if you have a gas car, you probably get it up two thousands of rpm, right, and that's spinning pretty fast, faster than a neutron star or pulsar. Well, you have to do the conversion because a neutron star spending a thousand times per second in your car probably you know, red lines at five or six thousand revolutions per minute, so your car is probably not spinning as fast as a new on star. But you know, there are jet engines out there that's been really really fast and those things spin at like rpm, and so that's approaching the speed of a neutron star. Wow. So I guess if you're in an airplane, then you're next to something spinning as fast as an adron star. Yeah, exactly. Those things are pretty awesome. But there's something of a race going on. There's folks trying to make things spinning as fast as they can. There are these physicists that build these tiny little objects, these nanoparticles, and then try to get them spinning. And there's been something of a race over the last ten twenty years to make nano particles and then spin them as fast as possible. Really, there's a race, yeah, like a contest for real. Or is it just kind of like bragging rights among physicists who can make something small spin as fast as possible. It's definitely bragging rights. There's no like X prize or anything that people are going for. It's like a lower case xpress. But if you read the papers over the last ten or fifteen years, they're all announcing the fastest spinning thing ever and then the number just keeps going up and up and up. So, for example, in two thousand thirteen is a paper announcaying the fastest spinning nanoparticle ever. And they took this tiny little thing they built, and they levitated it with a laser. Right, It's so light that just shining a laser on it will float it up. And then they spin it with another laser, a pulse laser that gives it like a little push every time it goes around. And this thing goes around six hundred million times a minute, what six hundred million times oh a minute? A minute? What ten million times a second? Ten million times a second exactly, So you know, every time you take a breath or whatever, this thing has done ten or twenty million last what are we trying to learn about? Are we trying to learn about the physics of spinning? Why are they doing this other than ragging? Right, that's not enough for you? That seems pretty awesome. I think they're trying to understand, you know, the materials, like how fast can you make this thing spin? How fast can you hold it to other? But I also think that it's just pure questioning. It's just pure like how fast can we do this, is there a maximum number? And so they're just pushing it and pushing it and you know that number ten million times per second. That and now they're up to three hundred billion revolutions per minute, so that would be five billion revolutions per second, which is pretty awesome. Five billion times each second. This thing goes around and it still holds together. It still holds together. Right, it's a it's made of silica, right, which is sort of like related to sand and glass, And it's amazing. But to make these things spin this fast, they have to be really really tiny. Interesting. There are these viral videos on YouTube where they people spin apples like they suspended in a jet of air and they spin it and it actually like explodes at some point because they can't hold together. Yeah, exactly, See physics works, right, That's exactly what happens. Maybe if you had dark matter apple right there, you could hold it together dark apple. Yeah, I just let it rot a little bit and make us messier. Explosion. But I guess, I guess. My question is like, at what point will it fall apart or explode these nanoparticles or never? Maybe because the atomic bond is so strong, we don't know. There are some theories that if you go fast enough, you could reach some quantum effects, like there are these virtual photons, these quantum fluctuations in the vacuum that might affect how this thing spins, and so you might reach some sort of limit. That's like probing quantum physics. But they don't really know it's it's really it's an area where the experiment is sort of pushing past with the theory can calculate like you're just trying to break the rules and see what happens. We're trying to break the rules exactly. Hey, that's what physics is all about, right, pushing the boundaries, understanding the universe, breaking things and taking notes and hopefully not destroy the Earth in the process. This is just take things apart, engineers put them back together. Well, in this case, it's the engineers doing the amazing stuff. I'm trying to spin it for the engineers. Yeah, and so for the record, these were folks that Perdue that have the currently the fastest spinning thing in the universe at five billion times per second. Alright, go boiler makers. All right, well, I guess maybe that we can crown out as the winner. The fastest spinning thing in the universe that we know about is man made in apparently Indiana exactly. Yeah, West Lafayette holds the record for the whole universe as far as we know. All right, they should put that on their brochures for visiting West Lafayette. Yeah, they'll get alien tourists stopping by just to see that. Right. Well, I guess that answers the question that is the fastest spinning thing in the universe that we know about? Right? I mean, we don't know of anything else out there. Could there be smaller particles out there spinning that we don't know about. There certainly could be, And it could be that strings are real that they are spinning. And it could also be that alien physicists have spun things even faster and hit these quantum limits. We just don't know. But as of today, this is the fastest spinning thing that we are aware of. All right. Well, hopefully that made everyone's head spin a little, if not think a little bit about the extremes of the universe and what happens when you push things to their limits. That's when we learned things when we push and push and break things and understand why they break, or why they don't break, or why they do something weird. Those are our opportunities to sort of pull on a thread of mystery and unravel something we didn't understand before, and that, in the end, is what our curiosity is all about. And just give a hammer to physicist and everything will look like yeah, exactly, especially a big ten billion dollar you'd spend faster than a black hole. That's the title of my next funding proposal. All right, well, we hope you enjoyed that. Thanks for joining us, See you next time. Thanks for listening, and remember that Daniel and Jorge explained. The Universe is a production of I Heart Radio. Or more podcast from my heart Radio. Visit the I heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.
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