SciShow Tangents - Black Holes

Episode Date: September 1, 2020

Does the Tangents crew know anything about black holes? Not really. But when has that ever stopped us? Let’s get theoretical! Follow us on Twitter @SciShowTangents, where we’ll tweet out topics f...or upcoming episodes and you can ask the science couch questions! While you're at it, check out the Tangents crew on Twitter: Stefan: @itsmestefanchin Ceri: @ceriley Sam: @slamschultz Hank: @hankgreenIf you want to learn more about any of our main topics, check out these links: [Truth or Fail]Gravastarhttps://www.universetoday.com/24299/types-of-stars/https://web.archive.org/web/20061213095149/http://www.lanl.gov/news/releases/archive/02-035.shtmlBlanethttps://www.sciencealert.com/we-have-ploonets-we-have-moonmoons-now-hold-onto-your-hats-for-blanetshttps://arxiv.org/abs/2007.15198Massteroidhttps://www.space.com/51-asteroids-formation-discovery-and-exploration.htmlhttps://solarsystem.nasa.gov/basics/primer/ [Fact Off]Stealing energy from black holehttp://large.stanford.edu/courses/2011/ph240/nagasawa2/https://www.sciencealert.com/an-experiment-has-just-demonstrated-how-energy-could-be-extracted-from-a-black-holehttps://www.gla.ac.uk/news/headline_727690_en.htmlhttps://www.youtube.com/watch?time_continue=73&v=ES2VxhRAkUM&feature=emb_titlehttps://science.howstuffworks.com/dictionary/astronomy-terms/black-hole.htm#:~:text=The%20Schwarzschild%20black%20hole%20is,singularity%20and%20an%20event%20horizon.&text=The%20Kerr%20black%20hole%2C%20which,it%20was%20formed%20was%20rotating.https://www.quora.com/What-is-an-ergospherehttps://www.howmusicworks.org/103/Sound-and-Music/Amplitude-and-Frequency#:~:text=There%20are%20two%20main%20properties,how%20loud%20the%20sound%20is.&text=A%20frequency%20of%201%20Hz%20means%20one%20wave%20cycle%20per%20second.[Ask the Science Couch]White holeshttps://www.space.com/white-holes.htmlhttps://www.discovermagazine.com/the-sciences/white-holes-do-black-holes-have-mirror-imageshttps://www.youtube.com/watch?v=Y1HqOEbq2L4https://www.youtube.com/watch?v=S4aqGI1mSqo [Butt One More Thing]Carl Sagan BHAhttps://www.engadget.com/2014-02-26-when-carl-sagan-sued-apple-twice.html#:~:text=In%20the%20wake%20of%20Sagan's,first%20place%20is%20beyond%20comical. 

Transcript
Discussion (0)
Starting point is 00:00:00 Hello and welcome to SciShow Tangents, the lightly competitive knowledge showcase starring some of the geniuses that make the YouTube series SciShow happen. This week, as always, I'm joined by Stefan Chin. I'm back, as always. What was your first car? Ooh, a 1992 Oldsmobile Regency Elite. That's a dope car. Yeah, I chopped the muffler off so that it had a nice growl to it.
Starting point is 00:00:39 So nice. I bet you did. Stefan, what's your tagline? Hot dog sandwich. Ooh, delish. Sam Schultz is here with us today as well. Hello. What's your tagline, Sam?
Starting point is 00:00:51 Just a head full of old beans. Sorry that your beans have gotten so old. Sari Riley is with us here today as well. What do you think of the name Beth? I think it's fine. I've never known any Beths in my life. Sari, what's your tagline? Porkapalooza.
Starting point is 00:01:05 Ooh, gosh. Sign me up. And I'm Hank Green, and my tagline is panic now, now, now. Every week here on SciShow Tangents, we get together to try to one-up amaze and delight each other with science facts. We're playing for glory.
Starting point is 00:01:20 We're also keeping score and awarding sandbox from week to week. We do everything we can to stay on topic, but sometimes we're bad at that. So if the rest of the team deems your tangent unworthy, they'll force you to give up one of your sandbox. So tangent with care. And now, as always, we introduce this week's topic with the traditional science poem this week from Stefan. If you're a big enough star who's getting quite old, the first thing to do is just to explode. Overcoming all the forces, you'll head for collapse, becoming the smallest space with the largest mass. No light can escape,
Starting point is 00:01:52 so you're invisible to me, though I can still see the effect of your singularity. But anything that tries to visit, tries to jump inside, doesn't make it far because it gets spaghettified. Now I find this quite sad because you're singularly alone, unless you happen to come across another black hole. You begin to orbit each other, going round and round, becoming ever closer as your fates become bound. And as the merger approaches, your bodies
Starting point is 00:02:16 accelerate, warping time and space, making gravitational waves, which will travel across the universe, slightly distorting space, for a billion years until they reach a very specific place. Passing through the planet Earth, the message is received, confirming a thing predicted by some dude in 1916. And while it's worth celebrating all the ways our knowledge does extend,
Starting point is 00:02:37 when we raised our glasses, I just toasted the fact that you'd found a friend. Oh, my God. The topic for the day is black holes. Any old kind of black hole. Siri, you're going to tell us what a black hole is here, but I'm going to start out with it by positing something. Black holes, I feel like, aren't as special as we make them sound. I get the impression that people think that they're this like a hole in space that stuff gets sucked into, but they're just an object that has gravity like any other object. Yeah.
Starting point is 00:03:08 They're basically a neutron star, but big enough that light can't get out. And like that creates interesting phenomena. It's like a good experimental location. But if you have a planet orbiting a black hole, I was recently asked what would happen if the sun suddenly turned into a black hole. And I was like, well, we would just sit here and freeze you know like we keep orbiting as normal the problem would be that it wouldn't be creating light anymore which would end life on earth i mean they are definitely not unique there's a lot of them but they do seem special like they're not just a
Starting point is 00:03:40 neutron star like they're so much smaller. Infinite density, Hank. That's crazy. Is it infinite density? It's not infinite density. It seems like when you do the math, and I am not an astrophysicist, then you start getting into infinite numbers when it comes to black holes.
Starting point is 00:03:57 So they're like the most extreme math and butt up against things that feel impossible because if you plot them on a math coordinate that doesn't look like a normal X, Y coordinate, you can argue that a black hole could be a wormhole to another dimension. And I think that's why people think they're cool because of how they're an edge case.
Starting point is 00:04:18 I always sort of assumed that like, that was all just sort of talk. Not math. But if it's math, and if there's like an infinite dense point and like our equations break down, okay. They're very, they're cool. Black holes are cool. In my research on black holes,
Starting point is 00:04:34 my one day worth of I'm becoming an expert on black holes, it seems like the word infinite is used in a lot of cases. So it is pushing against the boundaries of mathematical equations. So like, for example, if you tried to like throw a ball into a black hole, not that we're close enough to any black holes to even try this, to us as observers at our point in the space-time continuum, the ball would sit on the event horizon forever because there's something to do with like the infinite future and infinite past of that ball being in that place in space time before falling into the black hole. Time and space, man.
Starting point is 00:05:11 It's not cool what they do to us with time and space. It's not cool that something traveling at the speed of light experiences no passage of time. I'm not into that. That doesn't seem right to me. I don't want that. It's less sad-ish. I mean, if you're the person who's on the edge of the black hole, it's still
Starting point is 00:05:29 sad because you're going to die, but it's less sad because I guess theoretically you watched the entire history of the future of the universe play out. You should have done the fact off. You seem like you understand what you're talking about. I watched a lot of videos to write this poem. Oh, boy. Have we ever studied a black hole in any way except theoretically?
Starting point is 00:05:50 Like, do we have any? How? Well, we just recently took a really good picture of one, remember? Oh, yeah. But do we have like any measurements or anything from up there? That's how we know black holes exist is by measuring areas of space where we're like, what's going on there? And then we're like, space time is weird.
Starting point is 00:06:06 And then they're weird and consistent ways, I think. And so physicists and astronomers are like, let's classify all these weird measurements as black hole. Okay. Sarah, you have anything more to say about black holes? So besides not knowing anything about them, that's a lie, but like me personally, I know relatively little compared to astrophysicists
Starting point is 00:06:25 who actually model them with equations. We also don't really know the exact moment where black hole became an astrophysics term. It seems like it was somewhere in the 1960s where a physicist and the attributions vary. So I don't want to say any particular name, referenced a celestial object that was like the black hole of Calcutta, which was a name for a prison, I think, or like a punishment cell. And then it was first used in print by the journalist Anne Ewing in 1964. And the popularization of it is generally credited to a physicist named john wheeler who used it in a lecture in like 1967 1968 but really people just started calling them black holes and there was never like a seminal paper where we were like the black hole that i've discovered
Starting point is 00:07:18 my feeling about ultimately whether it's the black hole of calcutta, I feel more like it's just like, it was a black hole. Yeah, it's pretty apt. So they called it that. All right, everybody. We gotta keep moving. It's time for Truth or Fail. One of our panelists has prepared three science facts
Starting point is 00:07:38 for our education and enjoyment, but only one of them is real. And the rest of us have to decide by deduction or wild guess which is the true fact. And if we do, we get a sandbook. If not, and we get tricked, then Sari will get the sandbook.
Starting point is 00:07:51 Sari, what are your three facts? Around some supermassive black holes, there's a bunch of dust and gas and other junk swirling around and gradually getting sucked in sometimes. According to a 2019 paper that was uploaded to the preprint service archive and submitted to the Astrophysical Journal for peer review, there may be a special kind of object that forms in this muck. What is it? star. Basically, a different kind of star that doesn't follow the same pattern as main sequence
Starting point is 00:08:25 stars, where the fusion reactions and the gravitational pull from the black hole are what they're pushing it outward. So they can have a not quite spherical shape, but are relatively stable near the black hole. Number two, a planet, which is a mushed together black hole planet, which is basically a small exoplanet that forms when the dust and gas around a black hole stick together because of electrostatic forces and stabilize, kind of like how we think planets form in accretion disks around protostars, like in our solar system.
Starting point is 00:08:55 Or number three, a masteroid or a massive asteroid, which are basically asteroids that gain mass so quickly, it's almost violent. And instead of getting pulled toward the black hole, they get knocked on a trajectory to fly away, basically like the gravitational slingshot maneuver used by certain spacecraft to adjust speed in orbit. So in the slurry around a black hole,
Starting point is 00:09:18 we think one of these things will exist. A gravistar is a gravitational vacuum star. A planet, which is a gravitational vacuum star, a planet, which is a black hole planet that's held together by electrostatic forces, or a masteroid. This is a massive asteroid
Starting point is 00:09:37 that we think would get ejected out from the area around the black hole. Oh my God. Does anybody think that Sari would make up Blanet if it weren't real? Like, would you think that she'd be like, I think I'm going to say Blanet in this episode.
Starting point is 00:09:56 I think the key is to find the one she couldn't make up and then to work backwards from there. I'm not sure it's Blanet. That seems make-up-able to me. It seems completely likely that there would be some kind of way for just some stuff to collect that'd be big enough to be planet-sized. But I mean, I don't know what it's like.
Starting point is 00:10:13 You got a lot of tidal forces, though. That's ripping you apart. And also, she said it was held together by electrostatic force rather than gravity, which is just like, what? How does that mean? Like, I hope that it's real so that she can explain that to me.
Starting point is 00:10:26 Or if you want to, you could do that right now. Oh, no, I can't do that right now. I feel like that is just what I read on a website as far as a force that starts collecting dust particles together. I guess gravity would be involved at some point in the mass gaining of any of these objects. But when you initially have very, very tiny dust, then its electrostatic forces are more at play before it gets big enough to have significant gravity.
Starting point is 00:10:56 Gravastar sounds super real to me. That's the worst portmanteau of all of them. So I feel like that's the real one because it is the least fun one, kind of. Do you just mean that it's like just a gravity star? Yeah. It's not like a proper portmanteau really. It doesn't add up like it doesn't hold together as much as the other two. I think Sarah used her
Starting point is 00:11:16 mind too good to make up the other two. Are you going with gravistar? I think I gotta go with gravistar. I don't understand what any of them are. Yeah. I feel the same way and I'm excited to learn more about any of these things. Masteroid feels exactly like a villain
Starting point is 00:11:31 that Mega Man would fight. I'm going to go with Blanet. I don't think that that's right, but I'm beyond... I'm past caring. You just want to say Blanet as many times as you can. Apparently.
Starting point is 00:11:45 I also know nothing about any of these, but I feel like I've heard all of these names as things. I just don't know what they're related to. But I'll go with Mastroid. I like this villain idea. Sarah's got two points no matter what. Now it is time for you to go vote at twitter.com slash SciShow Tangents and follow us
Starting point is 00:12:01 while you're there. But also, I just love seeing how this turns out. It's one of my favorite parts of the week. All right, Sari, who is it? Who is the portmanteau?
Starting point is 00:12:11 The real portmanteau is Blanet. Yes! Whoa! I can't believe it. Yeah, it was really hard to come up with
Starting point is 00:12:19 other portmanteaus that were on the level of Blanet because I told it to Sylvia, my partner, and she just laughed for like a minute.
Starting point is 00:12:25 And I was like, I gotta distract them with other answers. Blandit was a name made up by a team led by Keiichi Wada of Kagoshima University in Japan. And basically what they did was a bunch of math to calculate what the dust might look like around supermassive black holes and specifically low luminosity ones. So not a really bright one like a quasar, but like a
Starting point is 00:12:51 dimmer one. And at sufficient distances from a point called, they called the snow line, which I guess is where it's cold enough to freeze. Then they hypothesized that exoplanets could form from all that junk floating around in a similar manner to accretion disks around a protostar. But maybe even more favorably because of the way that stuff moves around and swirls around black holes, that could make it even more favorable that chunks will mush together and form a planet or a planet, to be more specific. So there might be lots of these things. Yeah, but we haven't observed any and we don't know even like vaguely how we would begin to observe them because they'd be so close to a black hole. Sort of like Hank was saying with
Starting point is 00:13:38 if the sun turned into a black hole, the earth would just be orbiting and freezing. So it'd be sort of like that, probably a non-habitable planet unless it was some extremophile form of life. I'm here to read a science fiction story about life on a planet. And I want someone to think hard about how that would be possible, but it does not seem possible.
Starting point is 00:13:59 But like black holes are really big and there's a lot of dust around them. So there's probably not like one planet around a black hole. There's probably like millions. Their argument against planets or like why there wouldn't be infinite planets is sort of similar. Like instead of it collecting and sticking together, the clumps would crash into each other and explode each other apart. So there's too much energy and stuff happening to form a nice stable happy planet there's like
Starting point is 00:14:26 death by planets because they're all crashing into each other yeah i guess i sort of imagine it would follow a similar process as like the formation of the solar system like you'd have to find sort of stable orbits yeah but that sounds like it would be more complicated in such a large system but i don't know why do i know what's a do I know? What's a gravistar, Sari? So a gravistar is an object hypothesized in astrophysics. And from my best understanding, it is like an alternative to black hole theory. So like many scientific things, the idea of black holes, because we've taken pictures of one and we've observed it many times with mathematical observations, but there are other ways to explain
Starting point is 00:15:07 that particular mathematical anomaly is my best understanding of it. And one of these alternative theories that I don't think many people are behind are called gravistars, which has similar measurements outside of the event horizon, which is like the ring around a black hole,
Starting point is 00:15:26 but a slightly different measurement inside. And I think that it hasn't been formally disproved. And so there may be some scientists out there that are still like, this thing is not a black hole. It's a gravistar instead. And then Masteroids is just something I made up because I was trying to come up with a portmanteau as good as planets.
Starting point is 00:15:44 That was the one I was the most confident I had heard before. Dang it. I know. I looked up list of space words and then tried to take the parts of supermassive black hole and squish them together.
Starting point is 00:15:57 So it was either mastroids or asterhole. And I thought that mastroids sounded more convincingly like an astronomer would do it. Next up, we're going to take a short break and then it will be time for the Fact Off. Welcome back, everybody. Sandbuck totals.
Starting point is 00:16:30 Sari has two after truth or fail. Stefan has one from the poem. I have one from getting it right. And Sam's coming in the back with nothing. But he can redeem himself because it's time for the fact off. Two panelists have brought in science facts to present to the others in an attempt to blow their minds. And each of the presentees have a Sambuck to award to the fact that they like the most. And we are going to
Starting point is 00:16:51 decide who goes first. Will it be me or will it be Sam with a trivia question that will be read to me by someone. In April 2019, the Event Horizon Telescope captured the first image of a black hole by linking telescopes from around the world to act as one Earth-sized virtual telescope. How many telescopes worked together to capture that image?
Starting point is 00:17:14 Oh, Hank knows probably. I don't know. Oh, okay, good. I'm glad you think I know just because I said it in a SciShow once. Well, it seems like the kind of thing you'd remember. Hmm, 43. Oh, wow the kind of thing you'd remember. 43. Oh, wow. I was going to go first. Sam says
Starting point is 00:17:29 43. I will say 12. The answer is 8. Alright. They could have taken a way better picture with 43 though. And that means that I think that I guess I will go first.
Starting point is 00:17:47 And I'm going to tell you guys about black holes. For this phenomenon that I don't know if you've heard about. When a galaxy and another galaxy love each other very much, they merge. And as they do, the black holes at their center also merge, causing them to grow bigger. And also to do all that lovely stuff that Stefan talked about in the science poem. And at the center of almost every galaxy is a super massive black hole formed by these various collisions of smaller galaxies over the course of the life of the universe. And they sink to the galaxy's center. And that's what happens. They're always at the center because they migrate toward the place that is the most dense spot. So supermassive black holes in galaxies are terrifying. Just the words supermassive black hole is pretty scary.
Starting point is 00:18:44 are where they are supposed to be chilling out in the middle of the galaxy if you don't want to get inside of it just don't go there except when they actually aren't where they're supposed to be and they're instead roving through the galaxy so in 2017 a group of astronomers studying a galaxy eight billion light years away so we are you know relatively safe with the hubble space telescope found a supermassive black hole that had just made a run for it. It had dashed out of the center of its galaxy and was already 35,000 light years away from the center. And it was still moving at a speed of about 1300 miles per second. And it weighed as much as a billion suns. So how do you get something that weighs as much as a billion suns moving at 1,300 miles per second? The researchers estimated that it would require the energy equivalent of 100 million supernovas. So how did that happen? Oh, if you need that much energy,
Starting point is 00:19:43 what you need to do apparently is mix the wrong black holes together. When two galaxies combine their respective black holes, we'll start to circle each other around each other and then they'll send out these gravitational waves. But if you mix a larger black hole with a smaller one, or if one is rotating faster than the other one, you end up with stronger gravitational waves in one direction than in the other. And when the black holes finally collapse onto each other to make one larger black hole, the energy from that merger will cause the new black hole to recoil away from the stronger set of gravitational waves,
Starting point is 00:20:21 which launches it out of the center of the galaxy. gravitational waves, which launches it out of the center of the galaxy. This is at least right now the best hypothesis that astronomers have for why a black hole might be getting slung out from the center of the galaxy. It's a prediction they've been exploring and looking for examples of for a while. This seems to be a rare thing, but we have seen it happen more than once. But the 2017 example that I talked about in the beginning here was the largest yet found. So are most black holes just so similar that this doesn't happen very much, or how are they finding
Starting point is 00:20:52 each other? Well, one, I think that eventually they settle back down to the center of the galaxy again. So like, various gravitational interactions will eventually cause it to sort of like drift back down to the bottom of the well. So it's not like completely escaping the galaxy.
Starting point is 00:21:08 It's just like taking a stroll and busting some heads. Yeah. And so it's just there might be to some extent it might be that like time has passed and so galaxy collisions don't happen that often. And then the other thing is that it does seem
Starting point is 00:21:24 like a lot of these black holes are fairly similar in properties. That's lucky. I don't think, it probably isn't lucky. Probably has something to do with the nature of the universe. That's mathematically lucky. You found my secret. That's how I talk about anything physics-y.
Starting point is 00:21:42 I add mathematically in front of the words that I'm saying. Yeah, yeah, yeah, yeah. Sam, is it your turn? Okay, here I go. In 1969, theoretical physicist Roger Penrose proposed a process called the Penrose Process, through which an advanced space-faring society
Starting point is 00:21:59 could extract energy from a black hole, which I will try to summarize using my terrible brain. But first, a few quick definitions. So I think this is true, but we haven't mentioned it yet. There are rotating and non-rotating black holes. Is that the case? Yes.
Starting point is 00:22:15 Okay. So a non-rotating black hole only has the event horizon, which is like the opening of it. And then the singularity, which is like where the star collapsed into, like the point the star collapsed into. But if the star was spinning, then it makes a rotating black hole when it collapses. And rotating black holes have something called the ergosphere,
Starting point is 00:22:36 which is an area around the event horizon where like space and time are all distorted and screwed up. And that's like what you see in movies like Interstellar, the weird like, whew, whew, whew. So the thing about the Ergosphere is that unlike the Aventurisers, something could theoretically escape from it if it had the ability to give itself a boost to kick it out of the black hole's like,
Starting point is 00:22:57 orbit-y kind of thing. And in escaping from it, the escaping object would effectively steal some of the black hole's rotational power, like slingshotting it out and escaping with more energy than it went in with. So the Penrose process would basically be a system where like little machines or something were dropped into the ergosphere, shoot themselves out with like a rocket booster, be collected, and then have the extra energy harnessed.
Starting point is 00:23:21 And the prediction is that the object would come out with 20 percent more energy than it entered with but a problem with this kind of stuff is that there's no way to figure out if they're right or not because we can't go to a black hole and start dropping stuff and it's going to shoot itself out so we have to figure out ways on earth to replicate theories like this so in 1971 a physicist came up with an experiment using light waves and a rotating metal cylinder to try this out. But the cylinder would need to rotate a billion times a second for it to work. So then we couldn't figure out how to do it until 2020 when a research group at the University of Glasgow came up with a way to test the theory using sound waves, which have a lower frequency and are easier
Starting point is 00:24:01 slash possible to even work with. So they built like this big evil scientist looking ring of speakers that produce what they call a twisted sound wave that imitates light in a black hole. And they shot the sound waves at a foam disc that was spinning faster and faster as they were shooting the sound at it. And they recorded the result. And what they found was that as the speed of the spinning disc increased, the amplitude of the spinning disc increased the amplitude
Starting point is 00:24:25 of the sound passing through it got lower and lower until it matched the spin of the disc and which point it hit zero amplitude and then as the disc went faster it passed zero amplitude and became a negative version of itself and shot out the other side and what they found was that it was audible as it passed out the other side but that it was that it was audible as it passed out the other side, but that it was also 30% louder as it passed out the other side. So it was stealing the rotational power of the spinning foam disc. And they think that this is like the first step in proving
Starting point is 00:24:57 that this is a possible thing to do, even though it's with sound instead of light. So that's my thing. Oh wait, I have the sound too. You want to hear the sound? Oh sure. Oh yeah. Whoa. It sounds exactly as expected. Yeah, that was the most Doctor Who sound I've ever heard. It was more Doctor Who than Doctor Who. So there's a video that explains it way better
Starting point is 00:25:21 than I did with cool sound and it shows like the whole thing working yeah as it gets lower that's the speed that's the disc spinning up and lowering the sound as it matches the sound and then like pushing the sound waves i guess as it comes out the other side making them faster if if we can use black holes to create energy well i guess we can't use the sound waves to create energy because we had to make the sound waves and that probably took energy i think the key is having something big huge in space that we didn't have in that we can't use the sound waves to create energy because we had to make the sound waves and that probably took energy. I think the key is having something big, huge in space that we don't have to power. Yeah, it's not creating energy, right? It's like stealing energy. Yes, and it would slow down the black hole a little bit every time you did it, too. But like a little bit.
Starting point is 00:25:58 But like a little bit, yeah. But if you were an infinite race of space-dwelling super beings, then eventually that would be a problem, I suppose. You'd just go from galaxy to galaxy, sucking up and depleting every black hole. Yeah, yeah. That's what the people who live on the planets are doing. And they're slowly going to stop their black hole. That's what the science fiction story is about.
Starting point is 00:26:20 Yeah, instead of having a fossil fuel shortage or something, it's black hole. We're running out of black hole, guys. Yeah, and the scientists are like, I think that we're running out of black hole. And the people are like, that sounds impossible. Yeah, we're fine. Okay, so now you, Sarah and Stefan, you have to decide which fact you like the most. Do you like colliding galaxies with mismatched central supermassive black holes can propel their new combined black hole away and have it wander
Starting point is 00:26:49 around the galaxy for a little while? Or Sam, with scientists modeling matter escaping a black hole using sound waves and spinning foam as evidence in favor of an old theory proposing that we could use black holes to generate energy. Three, two, one. Hank? Oh, phew. You know, honestly, I'm surprised I got one. Sam, that was so cool. I have, well, I read it for so, so long yesterday,
Starting point is 00:27:14 trying to figure out what the hell it was talking about. And if I'm wrong, tell me on Twitter, please. And now it's time to Ask the Science Couch, where we've got a listener question for our virtual couch of finely honed scientific minds. It's from at Jake E.T. Kennedy who says, could there be some sort of
Starting point is 00:27:31 opposite to a black hole? Like if it was an outie instead of an innie. So what we like, I mean, there's two ways I can imagine this. Either you have like a bunch of antiparticles
Starting point is 00:27:42 that have like collected and so you actually have like an antimatter black hole oh or i guess that's it because like like zero density is like all over the place we have lots of areas of zero density and it's not particularly interesting we need negative density so i don't understand antimatter at all no i did not look into it but you can tell me if it fits into the explanation i did look up about how general relativity so the thing that einstein was like ah general relativity these laws help govern our universe says that anything that happens forwards can theoretically happen in reverse and this is true for both space and time,
Starting point is 00:28:26 even though we've mostly observed time just going forwards rather than happening in reverse. But according to the math, it can happen backwards. And may yet. Who knows? We could all just start rewinding someday. Yeah. Physics is weird. I don't understand it. But based on that principle, that anything that happens forwards can theoretically happen in reverse, black holes sucking stuff into their singularity can theoretically have an opposite called a white hole that are expelling matter out of the singularity past the event horizon. And it would be a white hole instead of a black hole because instead of sucking in all the light so it just looks black
Starting point is 00:29:06 it's so bright because it's just vomiting rainbows or like everything. Does the white hole also have infinite density? Yes. So it's like infinite density but in reverse. No. Would it last a long time
Starting point is 00:29:22 or just be like an instantaneous infinitely bright blast of light? There are many reasons why this is so hypothetical that many scientists don't think it even can happen. So the second law of thermodynamics is that entropy across the universe must increase. And so that's like the idea that like if I have a bookshelf and I have a bunch of books on it and they're all ordered, there is one state in which they are ordered. But if I knock them on the ground in a pile, then they're disordered. And there are lots of different ways that they can be disordered.
Starting point is 00:29:52 And that's increasing entropy. I think the concept of a white hole is that, and this is where I don't get it exactly because my visual of this is a vacuum cleaner spewing in reverse. because my visual of this is a vacuum cleaner spewing in reverse, but inserting things into the universe would be decreasing entropy. And so a white hole would theoretically break that second law. And it could be possible if net entropy across the universe was still increasing, but then it was decreasing in one little burst in a white hole. So basically, I used all those words to say that if this hypothetical thing happened, scientists think it would be very short, like a short burst of things coming out and then collapsing back in on itself to form a black hole, which is entropically favorable. There's a group of scientists that think that the Big Bang could have approximated a white hole because it was just like a bunch of stuff all at once.
Starting point is 00:30:49 So, Sari, is every, just like, let me know if every black hole creates a universe. Just let me know, right? Just like, send me an email when you work that one out or just a text, that'd be great. Is every black hole poking through and making an entire universe of its own somewhere else where,
Starting point is 00:31:09 just because like, you know, ultimately they say this universe is infinite, but I want this to be an infinite universe of universes. That's what I want. Is that too much to ask? And I want to orbit one. I want to orbit a universe on a planet. I want my own private planet.
Starting point is 00:31:27 Thank you, Jake, for your question. If you want to ask the science couch your questions, you can follow us on Twitter at SciShowTangents. We will tweet out topics for upcoming episodes every week. Thank you to at Acer Gray, at NG Jenkins, and everybody else who tweeted us your questions this episode. I like how he put NG Jenkins like he is not Nick, our co-worker.
Starting point is 00:31:48 Gotta keep an air of mystery, you know? Sam Buck final scores. Sari and I have tied for the lead. Sam and Stefan come in second with one point each. And that means very little for the final scores, but Sari and Stefan are now tied. Sam is three
Starting point is 00:32:04 points behind them, and I am five points behind sam so maybe i don't know maybe i have a chance if you like this show and you want to help us out you can do that very easily you can leave us a review in places where you listen that helps us know what you like about the show and also we like read them and then we think that's nice i feel good about making this thing that i that i like doing i'm glad and it makes me happy. Second, you can tweet out your favorite moment from the episode so we can laugh along with you. And finally, if you want to show your love
Starting point is 00:32:31 for SciShow Tangents, just tell people about us. Thank you for joining us. I've been Hank Green. I've been Sari Reilly. I've been Stefan Chin. And I've been Sam Schultz. SciShow Tangents is a co-production of Complexly and the wonderful team of WNYC Studios. It's created by all of us and produced by Caitlin Hoffmeister and Sam Schultz,
Starting point is 00:32:48 who also edits a lot of these episodes along with Hiroko Matsushima. Our social media organizer is Paola Garcia-Brieto. Our editorial assistant is Deboki Chakravarti. Our sound design is by Joseph Tuna-Medish. And we couldn't make any of this without our patrons on Patreon. Thank you. And remember, the mind is not a vessel to be filled, but a fire to be lighted.
Starting point is 00:33:22 But one more thing. For a lot of people, Carl Sagan was the astronomer and science communicator who taught us, not me, but us, about all things space, including black holes. But for Apple in the 90s, Carl Sagan was the codename for their upcoming product, the Power Mac 7100. the Power Mac 7100. And when Sagan asked them to stop using his name, Apple complied, but they changed the code name to BHA, or Butthead Astronomer. They disrespected the Sagan. Oh, my God.
Starting point is 00:33:59 We need to get off this ecosystem. Those, that's it. That's the last straw. It's one of the rudest things I've ever heard in my life.

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