StarTalk Podcast: Cosmic Queries – Black Hole Survival Guide

[Music] this is Star Talk Cosmic queries Edition which has become a fan favorite like Chuck we're doing these like all the time yes people like them very much people like them and even though you don't know how to pronounce anybody's name who asks questions I think that's why people like it they're like wow I now know my Alias I now I have't I have an also known as you know oh yeah there it is well so on this episode it's going to be about black holes again you can't do too many black holes and we go to our our black hole person I'm so glad we have her uh and it's Jan 11 Jan and welcome back to Star Talk hey great to see you guys very excellent and you're a professor up at Barnard and Columbia and so you're a neighbor of ours on the upper west side from the American Museum of Natural History and you're cosmologist and also author and we just caught up with you thanks for fitting us into your busy media schedule um you've got another black hole book I remember your you have two other black hole black hole Blues was one of black hole Blues is was from 2016 after the ligo detection of the Collision of black holes right and then you had a book before that how black holes got their spots no How the Universe got it SP Universe got it spots okay that's just so reference and that's actually just about the shape of SpaceTime and whether or not the universe is infinite you heard that Chuck it's just about the shape of SpaceTime it's only about that that's that was her first book you know it had to be about something simple you know yeah I think the subtitle is is the universe infinite or just really big oh no that that was a paper I wrote actually that's notle I'm going with just really big it's hard to wrap your head around infinite right so uh this one um is so who who's the publisher you got to give a shout out to the publisher oh this is knop who's been my publisher for the duration love them no yeah yeah kop will do write by you if they like you yeah awesome Dan Frank my editor is wonderful there so we've we've done a lot of really creative projects and Dan really keeps me on like you know keeps me on track yeah yeah so if the book does well they said okay when's the next book coming right he's paying his rent off of you just make that so so tell me tell me about this book so this book uh so when I was writing black hole Blues I I set out to write a certain no no no no we TR Janna we trained you it's the black hole Blues Chuck give me your version black hole Blues yeah okay now that was perfect black hole Blues no it's the black hole Blues I don't quite have your I don't have that Chuck's got a good Chuck's got it better than I I like let hear again Chuck black hole Blues yeah oh that's the one you want I like I like Janice though it sounds like it sounds like the blues as played on a ukulele you know this is the vessel this is the vessel I got okay so I you know I I love it I really have to clip those recordings of you guys saying the title because it's like my favorite thing your DJ voices but so I when I when I was writing that book that turned into real a story about the The Climb that turned into a story about um the pilgrimage of trying to detect something so incredibly difficult and so a lot of this idea of writing about black holes actually didn't happen in that book so much so this one black hole Survival Guide is just all black holes all the time it's uh you know it's not historical it's not about particular characters it's very much the the character in the book is the black hole and the astronaut trying to explore it so it's very short and also oh damn I wish I had one of my copies it's tiny it's so cute it's like this big it's a little guide you can put it in your back pocket okay so so so you can carry it with you when you confront the black hole and it's not much of a right a luggage issue and I also had an artist friend of mine do the illustrations and she did 23 original paintings Leah howerin for it and they're just beautiful so it's really this book feels very much like a little object but just to be clear you have access to artists because you are active with the Pioneer works over in Brooklyn which is this this remarkably creative juxtoposition of science and art just give me like a fast 30 seconds on that yes so Pioneer works is a new Cultural Center it was founded by the artist Dustin Yellen and Gabriel Florence is a founding artistic director and they're very art focused because they're both artists and um and then I just we all kind of fell in love and I started doing science there and that was always kind of the vision that it would be all things in culture and I'm a very big believer that science is part of culture so something I just believe very strongly you don't have to package it hide it and something else for it to be part of culture and so we've been doing these events like last night I spoke to sadar mukari the Polster prize winning researcher and Doctor um about covid to you know a very small because because of covid very modest audience with masks on and socially distan but um but that's the kind of stuff that that we do is is yeah excellent so you have access to artists that's great they're just an Arms Reach of you to have one to illustrate your book yeah I mean the idea is really that there's friction that just happens naturally we don't prescribe it we never try to force people to talk to each other it just is what happens naturally because we're all under the same roof see I want artist in Arms Reach all I have is Chuck and I say Chuck I need a joke here give me one Chuck I need 23 jokes for my next book we should probably have a comedic Department that's what we need he should I I also paint so but I mean you know yeah well not fine art more like the Sherwin Williams kind but it's cool you paint the walls yeah I paint walls you're a painter I paint houses yeah so I is you're trying to keep the astronaut alive in your storytelling here yeah it doesn't always end that well for my astronaut oh okay yeah but it's sort of I mean a it's funny I was talking to a friend of mine as I started to write the book and and it's a lot of dispelling misconceptions about black holes so people think for instance black holes are these dense objects and if you go up to the event horizon of a black hole and you uh you'll knock on some very dense matter or something like that but a black hole actually is nothing there's nothing there why why it's a hole it's it's lit you go up to the event horizon and you actually shouldn't really notice you could float right across and not not really realize the danger you're in the Peril you're in because it's empty SpaceTime and so there's a lot of um kind of trying to dispel this idea of sort of the cartoon Notions of what black holes are well that's good because that's the natural progression I think first people have to know black holes exist then they know some basic properties of it and now you're taking us to the next level of the nuances of black holes yeah I mean it's some pretty fun stuff too things that you know occur in research and then you realize oh people don't actually think about this the black holes are are dark on the outside but they can be bright on the inside I mean that's just sort of one of now that's but okay so well maybe I should I'm not gonna ask my question no you should I love it CH all right so with that no no if Chuck doesn't want to ask his question you should just believe him cuz he says stuff that does not get filtered and he wants to filter this let him filter it I can't filter myself no no I I I just don't know if I'm going to steal somebody's Thunder but when you talk about a a hole being bright inside if light cannot Escape is there a particular distance that light would come that light would transmit from the epicenter is there just a radiation the light is coming in from behind you basically ah so then it's the light coming in never the light going out that's right the light could never come back can never come back at you in fact so the light is always Falling Towards yeah wow do you know how when you combine all the colors you get bright white right that's how you get bright white light so if you imagine all the light paint yeah right if you do with light not paint with paint you get black yeah you know Chuck's are resident painter so the light falls in from the Galaxy behind you and it gets really concentrated at you so that when you're falling inside the black hole towards your demise this light gets concentrated you actually would see like a bright light like like the near-death experience light I'm repeating myself but I always call this it's like a total death experience you got this bright white light right before and then like it's all over yeah so so and so tell me about remind us all about spaghettification because I love describing it did you coin that phrase Neil no no no I did not coin it but I was sort of a visible astrophysicist using the term that gave it sort of social currency MH at a time when others didn't have that access to social currency I think it it's traceable to Sir Martin Reese or actually he's Lord that was it it is it's Lord Reese Lord Lord Reese so I think he I think he he also invented a peanut butter cup but go ahead Reese's that's a different one yeah so so I think he came up with it but when I started writing about it I had books and I was on and so people associate it with me but I love the word and I'm happy to keep using it I'm pretty sure it came from him yeah but I have somebody since you're going to go ahead and and talk about spaghettification there's a question that I might as well just give you since you're going to do it well let's start it off then let's if it goes there yeah let's do it so Chuck give me some Cosmic queries all right sure let's let's start it off with um you know uh first of all all of these are from patreon so all of our Pat this is the benefit of being a patreon patron you uh you know you get priority you know so uh Tony Baker says is there a way to prevent spaghettification and travel into a black hole Yeah okay well I would advise you fall into as big a black hole as possible that's the first step because it's kind of I I liken it to standing on a basketball where you really notice the difference in the position of your two feet on the basketball whereas if you stand on the earth which is the same shape you hardly notice the curvature so it surprises people but it's actually safer to fall into a bigger black hole and you would transition across the Event Horizon it would be completely empty uh there'd be no stuff there and you'd be fine for a little while and the bigger the black hole the long the longer you'll survive right but once you cross the Event Horizon you are forced to continue to fall towards the center and we talked about this with the Nobel Prize um announcement just a couple weeks ago that the singularity from your point of view because space and time are relative from your point of view what somebody on the outside considers the center of this sphere of this black hole for you is actually in your future it is a point in time and you are inevitably going to hit that Singularity there is nothing you can do to avoid it you can prolong you could try to go on some crazy orbit and prolong your life but it's coming it's it's as inevitable as a moment in time um and so so once you're near the singularity then you're really experiencing just such extreme curvature that you're you're almost like a disruption in the SpaceTime your energy and your mass are disrupting the SpaceTime it creates almost like a storm is kind of what you have to imagine but you're being squeezed because everything's trying to focus you towards the singularities you're also being elongated because if one part of your body is Falling Towards a singularity it notices that it's coming sooner than your head let's say so you begin to get what Neil has described as spaghettification you begin to get spaghettified and you also get pulverized from the SpaceTime so so basically you're Fayed and it's it's not great have a nice day right it's not great so you're you know obviously your leg I mean nobody describes it better than Neil but your ligatures break you become Torn to Pieces and eventually you are just your atoms and your Quantum bits and then J you're saying Singularity is inevitable no matter the size of the black hole it's just that with a larger black hole you'll delay it a few minutes more into your future you might even get a year out of it if you go into a super massive black hole wow so I think the numbers are if you fall in a straight line in the sun you know if the sun wore a black hole it would be about six kilometers across you'd get across that without too much pain and you'd have just a micros seconds I mean it'd be very fast before you hit the singularity but if you go into a super massive black hole you know which is a billion times or 50 billion times the mass of the Sun you can you can hope for a little longer wow so so I got a quick question okay yes so I'm trying to imagine how to beat the spaghettification wp okay so suppose as I'm falling because what you're saying tital forces will stretch you suppose I I tumble really fast that way there's not one sort of make yourself as small as possible it make himself as small as possible and then I spin I tumble so then there's not to just sort of one um Forest separating my feet from my head because I'm always swapping them out right will that help eventually you will no matter how small you try to make yourself you will be large compared to the tidal forces eventually it's just inevitable and that's like the basketball example right that eventually you will start to notice no matter how small you if you're a tiny tiny ant on the basketball you might not notice it's curved right so if you just make yourself smaller relative to the black hole you're doing okay you're going to do better that way but eventually if you make something small enough even the ant realizes it's on a curved surface and so the curvature is so extreme you also have to remember you have mass and energy so you have a a an effect on SpaceTime as well and at those extreme curvatures your effect on SpaceTime also goes up so you create a kind of a storm I mean it's absolutely inevitable that you will be shredded and flayed into your Quantum bits but but that's you know that's the story that terrifies people because physics is all about predicting the future or reconstructing the past or knowing the world and what the singularity suggests is at that point we no no longer know things about the world so I had I had neglected to fully embrace the fact that my body contains Mass which has its own relationship to the to the structure of SpaceTime so it's actually an interaction between my mass and the mass of the black hole it's actually a question that people ask a lot so suppose your two astronauts Chuck and Neil are in a space station in a safe orbit around a black hole and you can find a safe orbit very close to a black hole and you can find a nice stable safe orbit you don't get sucked in unless you do something silly I'm let you know we call that orbit Earth stay on Earth just are in orbit I'm in orbit around a black hole right now so I'm just saying I'm staying you are we're in orbit around Sagittarius A star four million times the mass of the Sun we're very safe orbit but so so so Chuck let's say you have a change of heart you go you explore the black hole everyone knows that or not everyone knows but this is one of the well-known things is that as Chuck gets closer and closer closer to the event horizon to kneel back on the space station Chuck it's going to look like you're Frozen there like you never really crossed the Event Horizon and if you imagine like the last light signal that you try to send as you're crossing the Horizon it gets stuck at the Event Horizon because you'd have to travel faster than the speed of light to Escape right so your signals stop coming and you appear as though you've just Frozen there but what people fail to take into account is the massive Chuck and if I take into account the mass of Chuck it will actually the Event Horizon will bubble around him in a finite time according to Neil now Neil might have already had his clones replace him and you know hundreds of years have passed thousands of years it could take a very long time depending on how small you are but eventually that event horizon will bubble around you take you in shake away any imperfections so that it restores itself to a perfect pristine featureless black hole and in a finite time according to Neil and his descendants you will have cross the Event Horizon wow right so it's it's it's at some point you do see the entry at some point for the reason she gave yeah so look at so Jenna I I I have more inquiry about that but we got to take a quick break so when we come back more Cosmic queries with Jan 11 uh of course we're talking about black holes start talk Cosmic quaries NE de grass Tyson here Chuck Nice hey hey you're always there for me thank you Chuck always Jan 11 you're like you're our black hole correspondent I love it I love it I miss I miss doing this in person okay yeah yeah that that day will come for sure so I remember Janet in the 1970s uh there was a a science writer for the New York Times named Walter Sullivan and he wrote a book called Frozen star and it was inspired by the fact that time Rel the relative time between someone falling into a black hole and someone safely at a distance the the person at a safe distance would report that that person slow gets slower and slower and slower and then just freezes there Y and just before the break what you said was no that's not really how that plays out yeah it is it is surprising that if you C take the most extreme example of two black holes you might think well I'll never see them merge because the time dilation as each one make one much bigger than the other even as each one you know as the small one approaches Event Horizon of the other you would think it would take an infinite time from our point of view for them to merge but that's because we're only considering the SpaceTime of one black hole and in reality it's a different SpaceTime when you have two black holes and they will you will actually see in the simulations um which are very accurate using relativity that the event Horizons get totally deformed the whole event Horizons bubble around each other and these two black holes absorb each other and then they they do something which we call the ring down which is they shed away all those imperfections and gravitational waves not to be confused with the ho down not be confused with the ho down the black hole ho down the black hole down the ring down so they it rings down literally creating waves in the shape of SpaceTime which we record a sound you know we we literally record the ringing drum and play it back to to our that's what ligo does and um you hear the ring down you hear it shedding away imp perfe and at the end of the day it just goes quiet and it's this featureless perfect black hole wow wow that is that's fascinated okay so chuck chuck we got through the first question exactly this is Cosmic queries let's keep going give me some more all right uh this is Andrew Stope stop stop Stope okay whatever um Andrew says hello Dr Tyson Dr Levan and Dr comedy oh nice nice and then he says first off Chuck uh if you pronounce my name correctly I'll immediately double my patreon membership well guess what you should have read that first I should have read that first I should have read that first how do you how do you spell the last name okay it's St a u p e so I say Stope Stope Stope Stope I'm going for Stope I'm going for Stope so I bet I I bet there's a sh sound of Stope something like oh that's good that's a good detail that's very that's very yish yeah sh stupid no hoing no stoping all right so he says so sorry patreon I uh I I I missed he just haveed his donations he just have I know that's a shame I I just lost us half of damn Chuck we take that out of your paycheck says hey my question is this if the Multiverse which God it's everybody wants black holes to be part of the Multiverse but he says if the Multiverse is indeed true and there are other universes down the road so to speak do you think that massive black holes in our universe could bump into or enter into another Universe since they are creating such a deep ho in space time I love that hole in space time what's up can we jet between the Multiverse through black hole portals well um it's a complicated question but there there is h a real intuition that goes back a long way that the singularity inside a black hole kind of sounds like the singularity of a big bang and in fact formally mathematically I can sew them together so you imagine you know you sew together pieces that don't fit together it's a mess it doesn't work but I can actually smoothly take a black hole go into the interior and smoothly sew it onto what we call a white hole which is basically a big bang right so that when you enter the singularity instead of it actually being a true Singularity you actually get blown out into a big bang right and that then that that that's where the whole Multiverse thing comes together so well with that that's where the Multiverse comes in yeah yeah so the white hole is the birth of some other Universe on the other side un so all your Quantum particles and all your information could get blown out into a new universe and get recycled and then there's new black holes and maybe your material even becomes part wait wait does that mean this universe is wait wait wait wait does that mean this universe loses information well obviously that's okay so that's extremely contentious so that would mean that this universe you see Chuck we have scientists we have fights they have fights now at ding ding ding in this corner okay what is the contention Jan so so well there's there's two things one thing just to point out which is just kind of cool is that the black hole let's say it's the mass of the sun it's about six kilometers across it's tiny black holes are small that's that's the cool thing about them that's it's the size of the Event Horizon that you're giving there right that's the size of the shadow cast and really that's what we really mean by a black hole anything that goes on the interior is so defended we're so defended from it by the Event Horizon because no information can come out that to some extent we don't care that much about the interior because all black holes are the same because of the Event Horizon I can't know that Chuck's the one who fell in by looking at the black hole because that would suggest the Event Horizon was leaking information and it can't so so there's one thing to note is that first of all the black hole could be six kilometers across on the outside but as big as a Universe on the inside so that's pretty staggering they're bigger on the inside than outside right so it's like Doctor Who's Tardis you know um you go into your little booth and it's like um so so the black hole can be arbitrarily large inside that six kilometer surface which is crazy and then your question about information is absolutely the most profound question on in theoretical physics right now is what happens to the information that goes into a black hole now it's fine because and the reason why it's so important is because information is what physics is all about right it's about can I track the information and and is the information conserved because if information simply disappears from the universe then we then we don't have a knowable universe then we don't have laws of physics that make sense to us so it seems like no big deal and in fact a lot of people who started to think about this didn't realize what a big deal it was well the idea of information going into another universe is even okay because it still exists but is that is that information really going into another Universe if black holes evaporate that's the problem exactly Chuck such a good student of astrophysics look at you um exactly so when Stephen Hawking comes along in the 70s and says oh I found this really weird trick that when I add quantum mechanics around a black hole allows a black hole to steal energy basically from nothing from nothingness and and create what's called Hawking radiation and we could talk about how the Hawking radiation happens because it's actually pretty cool but if you believe his thesis everybody does nobody disputes it black holes will slowly evaporate away and eventually the whole of that Horizon is yanked up it's gone and the singularity is exposed if it exists and all this information seems to have disappeared from the from from the universe in a way that's really pathological that suggests that oh now we're not protected by the Event Horizon anymore and we've lost predictability of facts of the world so quantum mechanics people went crazy how that's that means that the whole world's unknowable that there's no that physics doesn't make sense that the laws are paradoxical um and so it it it stirred a war that went on for 50 years what happened to that information where does it go and what's the resolution of this Paradox so it is called the information loss Paradox oh my God that is I thought freaking trippy that is absolutely trippy very it's really can we talk about how it steals energy oh wait and it's bigger on the inside just to just to round that out yeah yeah that's the beautiful thing about SpaceTime like Janna I I thought and I this is what I've been saying maybe I don't have it right that the Hawking radiation which which preed digitat matter out of the gravitational field all right that if you inventor the Hawking particles they would be a onetoone match with every particle that the black hole had ever eaten in life right so so that's that's the hope so exactly so people said look here's how you're going to resolve this problem the Hawking radiation's actually going to encode information about the interior but let's talk about why that's so incredibly hard because the radiation is not coming from the interior and to some extent the radiation has nothing to do with what fell in so let's say Chuck Falls in wow and your descendants want to deconstruct in the Hawking radiation of that evaporating black hole the information about what happened to Chuck before he hit the singularity like what his last moments were like and they want to reconstruct it it from the Hawking radiation which is what you're saying maybe it contains all of those all of that information but if you look at how Hawking radiation is generated it has nothing to do with Chuck literally because of Heisenberg uncertainty principle you know the wait a minute ho ho ho wait a minute wait a second Chuck get your principal straight I you know you're not a principal person no man come on okay all right so of all your principles you're not Heisenberg uncertain principles all right all right here's the deal right we got to stop for a second because I gotta I gotta understand something here I gotta understand something all right yeah okay all right so here's the deal what you're saying is everything that is Chuck goes into the black hole so yeah as you want to reconstr recreate or reconstruct the circumstance or anything about me that before I'm in there but now that I'm in there okay what comes out which would be the Hawking radiation and the evaporation of the black hole that's what's coming out but what's coming out is really nothing to do with it's not a representation it's not coming out it's not it's not a representation of me it's material izing as opposed to exiting and so since it's materializing as opposed to exiting then what comes out is not necessarily related to me that went in it's even worse than that the radi oh sorry the radiation God you got me you got me I'm like oh damn the the radiation was never inside the black coal ever that's what I'm saying what's happening it doesn't come out so what happens is there are these little Quantum fluctuations that happen in empty space that are allowed because of uncertainty because uncertainty says you cannot precisely say a particle is there precisely infinitely precisely you also cannot say it's not there okay so is that the uncertainty principle that you were talking the unty principle so that that creates the possibility that particles just kind of create so so it's popping out of thin air oh wait there's no air in out of it's thin air thin space thin space thin empty space and what happens is the black hole so they have to come in pairs because if you think about empty space it you know it h it has to be also just completely Bland and featureless so I can't have an electron appearing right because it has charge and it has Spin and it has all these properties it has to come with a pair that cancels its charge and it's neutralizes it completely we we call it neutralizing all its quantum numbers so it has to come in pairs and then it can go in and out of the vacuum and just creates a kind of quantum froth that we never notice that paired particle is antimatter just to be clear right it would be an antimatter particle but you could also have it with two photons or two two bundles of Light which the photon is its own antiparticle right oh my God so the electron has a positron so the electron and the positron can be created and then disappear light can be created any any particle that exists in the universe has these fluctuations that we don't notice it's happening in this room it's just very very very low level we don't notice it but the black hole what it does is it steals one of the partners doesn't matter which one it steals one of the pair and then the other one can't go back to nothing because it's not neutralized by its pair it's just sits there so suddenly this particle em leaves and comes out of what seems like thin air thin empty space and that's the Hawking radiation so it never originated inside the black hole it was stolen so therefore you saying wait however go ahead wait wait wait wait wait wait wait oh my God this is insane okay it's insane insane that's why Hawking was so famous because it was like insane Jan yeah Jan so let me make things nice okay I can't have Chuck lose a brain gasket here because I need him for other shows okay you said early at the beginning that the event horizon is not some wall it's just space moves smoothly through and across the Event Horizon you said that correct okay yes now the curved SpaceTime shape is made by the black hole correct yep so every place that feels this curvature is basically part of the footprint of this black hole on the fabric of space and time yeah so if I'm going to make a Hawking particle pair outside of the Event Horizon from the gravit ation energy of the black hole itself M why won't you allow me to say I am using the black hole identity to make this happen I will allow you to say that but the only identity the only feature from outside the black hole this is why the whole featureless aspect is so profound the only feature you can know about the black hole from outside because of the Event Horizon is its mass its electric charge and its spin if it spins like the Earth and those are the only three things you can know about the black hole so any other information is uded by The Event Horizon all right so so so you will reflect in the radiation the mass the spin and the charge but you won't reflect that Chuck fell in that he screamed you know somebody's name okay so I can I can Rec that's gone I can reconstruct his particles perhaps n you can't reconstruct even his Quantum no features about his quantum numbers are knowable wait wait you're telling me Chuck has has 80 gazillion um neutrons made of quarks now coming out the other side will I get that same number of quarks that make neutrons so the the hope is okay so so if you just look at Hawkings original calculation he said no you won't and that's what initiated the whole crisis so wait a minute wait a minute minute Quantum theorist said that's not possible so so the deal this if if if what Neil just asked is the case and you're saying no right then are we saying that there's a that there's a theft of information is there a loss of information that's that's what Hawking suggested and then there became this big fight so I would say right now if you talk to people like Lenny suskin who has a great book um called black hole Wars where he talks about trying to make the universe safe from stepen Hawking you know they would say they figured out a way to encode the information the Hawking radiation so so I would say right now the Hawking um eventually kind of started to say okay maybe you Quantum guys are on to something and maybe there's a sneaky sneaky way the the black hole emits information but it's no mean feet and one of the craziest suggestions for how the black hole allows information to escape is to say that there are wormholes that connect the interior of the black hole to the exterior of the black hole so the Hawking radiation which never came from inside the black hole is actually the the same particle as lived in Chuck's body and it was navigated by a wormhole to the outside so it basically tunnels out oh tunnels out so it sounds like Janet it sounds like they had the same reaction that Chuck did said guys we got to fix this we can't we can't live with this phenomenon let's make something up let's pull something out of our ass let's pull a pull a wormhole out of our ass so that we don't have to blow our own gasket that's exactly what happened but it's actually had really successful ideas so then you it gets even worse because if you imagine all of these wormholes entangling every single one of truck's particles with a particle on the outside that means that Neil you you or your descendants Could reconstruct from fire what happened to Chuck what he said what his last moments were like but what also happen we know we know what I said here's what I said that's what I said oh yeah we don't need we don't need wormholes to know that you right it's still fun to hear so so the wormholes what they end up doing is they create like stitching Quantum stitching so imagine like embroidery so imagine I embroider an image of a black hole it's really made up of tons of stitches and when I look closely I realize that there is no black hole there it's just made up of tons of stitches and that's actually one of the ideas that's coming out that's most radical is that the black hole is made by these Quantum entangled wormholes that that is what Event Horizon is it is like cross-hatched Quantum phenomena and if I could see closely on the quantum level I would realize the black hole emerges as an illusion out of quantum mechanics and that might be true for all of gravity that it's actually it's actually something that is fundamentally uh lery and really is just a Quantum phenomenon that we didn't recognize all this because they didn't want to lose information what what's what what sore losers they are it's we got we got to take another break uh when we come back more Star Talk Cosmic queries stuff you never knew you didn't know about black holes when we return start talk Cosmic Aquarius the final segment maybe Ever After Janna tells us what happens if we fall into a black fall Jan 11 you got a book coming out uh titled black hole Survival Guide yeah but everything you've said in the show thus far tells us none of us will survive so it's really the black hole death guide is sounds like I don't want to I don't want to you know spoiler alert but yeah the odds are not the odds are not great Chuck we've been through two questions we gotta give me just and and Janet let's see if we can go into a sound bite mode here okay Chuck keep them coming all right here we go more patreon questions go here we go this is Paul love he says Chuck you're welcome for the easy to pronounce name people totally people are in on it now man all right here we go my question is about singularities is the concept of a singularity something that might actually exist at the center of black holes or are they verbal descriptions of a mathematical error representing where our understanding of gravity breaks down oh I'd love is that where God is dividing by zero that's the another way to say that wow um I I agree with the latter part which stated as a question I think most of us suspect that the singularity is general relativity signaling its breakdown it's telling us I'm no longer predicting the laws of physics well here and it's telling us that we have to look for something Beyond general relativity to understand the singularity and that's even what Roger penro says in his 1965 paper that won him the Nobel Prize he says the singularity is inevitable in the mathematics of Relativity but it's not inevitable in reality how do we ever observe if we can never see beyond the Event Horizon right you might not care a lot of people and that's another thing Pen Rose talked about was what he called um you know kind of cosmic censorship that that that any terrible things like singularities would' be projected by The Event Horizon they would be hidden by The Event Horizon which is another reason why Hawking radiation was so bad because it says eventually EV vent Horizon is yanked up and there you are stuck confronting this terrible thing that happened in the interior way it's only terrible because we have found the limits of general relativity right if you right you calling it terrible because we're not smart enough yet to figure out what's actually going on so that doesn't make it terrible that makes it exhilarating that's right it is exhilarating because that's exactly what the new direction is the new direction is oh well when we understand quantum gravity The Singularity will go away but how do you understand Quantum gravities you bang your head against these questions and that's exactly why Hawking radiation has been so fruitful it's been so provocative because by banging your head against this incredibly uh confusing suggestion that the black hole evaporated it's forced people to make discoveries about quantum gravity excellent all right next one Chuck keep coming this is Cameron Bishop he says how can light orbit black holes if photons are massless is it more accurate to say that black holes bends the path of the light like a silly straw and if so does that mean that light eventually carries on to its destination um all of that is quite right so in Newtonian thinking before for SpaceTime thinking the the photon has no mass and would have absolutely gravity would have absolutely no effect on it as a consequence um but we know two things are true one is that when we start to talk about SpaceTime that what we really mean by the shape of space time are the paths that things follow like I can prove to you that the Earth curves SpaceTime by throwing a golf ball across the room because it's not going to travel on a straight line and the curve it takes is measuring the curvature of SpaceTime right and so yeah yes the path of the light is bent and you can bend the path of light into a full circle there's a particular location around a black hole where you could stand what would be hard to to stay there you'd have to be firing jetpacks but light from your face would reflect you know if you were shining a light off the back of your head and come back around again on a perfect circle and you'd see your you could watch your back so the path of the light is definitely bent but also in relativity it's not just Mass it's anything with energy that's affected by gravity okay CH I think I have to disagree with you on something okay uh and you tell me I think you I think Newtonian gravity also bends light because the strength of the gravitational field that you're moving in in Newtonian gravity does not care what your mass is the mass divides out and the the reason why I think this is really relevant is when Einstein did his famous well when Edington did the famous 1919 experiment M during another pandemic by the way going on yes the um the Spanish Flu the Spanish Flu he wanted to see whether during a total solar eclipse which is the only way you can see Paths of light moving past the sun otherwise it blots out it's the sun is too bright okay so he found that the path of light was bent however that alone did not demonstrate relativity it had to bend by the amount Einstein relativity would have predicted which is twice the value that Newtonian gravity would have predicted yeah I that's absolutely true I totally so you know what I'm gonna do I'm I'm gonna take both your words for this no so so no that's absolutely true and it is just to talk about the Edington Eclipse because it was such a wonderful moment in in history so here's this total eclipse it's it's it's uh I think it's May 29 1919 it's 6 months after World War I ends the Europe is devastated you have this British astronomer trying to prove a German physicist's work which was unbelievable at the time so it was just it was almost like a a political gesture in a subtle way he was a pacifist Edington and so he goes to this small island Principe off Africa for this Eclipse they're in cloud cover totality only lasts for a few minutes eventually the clouds break and they do this um incredibly monumental measurement and what they measured is the star cluster hiades which was technically behind the sun they could see it because the path of the light emanating from Hades was bent their way and Neil you're of course absolutely right they did have a newtonium prediction that that because this is part of the equivalence principle that right exactly that we all fall along the same path you know the feather and the hammer on the moon falling at the same rate that that's that's what you're referring to really and so we did know that there would be some effect from T mechanics but it was twice by the way the the hammer and feather on the moon is a little deceptive because first it was all faked no because we never went to the moon we never went to the moon no no no people are thinking that that only happens on the moon but the point of that experiment was they're in a in in a vacuum and so in a vacuum a hammer and a feather fall at exactly the same rate right and but there happens to also be a vacuum on the moon so people are thinking go to the the moon to do this experiment no do it in an evacuated chamber you can get that to happen on Earth as long as you get rid of the air interference not the equivalent principle is very profound actually the idea that that you know we all fall like if I throw a car and I throw a golfball I can throw them on the same path one just requires more energy to do so but they should follow along the same path yeah and and AR which which blew out Aristotle's statement that uh heavy Things Fall faster than light things in proportion to how massive they are that's he just clearly never did that experiment right because he would know yeah yeah Chuck give me some more questions all right here we go this is Stephen spotted horse and Stephen says I simply want to know if everything was gone all matter in the universe is nonexistent but just one simple super massive black hole was at one end of the observable universe and say a planet at the other end of that same observable universe and both objects are not moving in space would the black hole eventually grasp the planet and pull it to its death or is there simply too much space for the gravity to take hold um there all all things being equal we would in principle anything that could would eventually fall into a black hole we in principle will very likely fall into Sagittarius AAR after it merges with Andromeda and becomes a new bigger black hole um but the universe is expanding and so the stretching I got I got a clue in Chuck Chuck yeah Jana casually implied correctly that our galaxy is going to collide with the Andromeda galaxy and that Collision which will look like a train Leck we each have super massive black holes in our Center and they will merge continue Jen So eventually like if you out the train wreck yeah I did I know I just Breeze over there so the whole solar system will start to orbit together it's unlikely that the sun would be disrupted we'll stay together with the solar system if the sun's still alive which it won't have much time after that and we'll orbit this new bigger black hole but but in the in the example phrased in the question you have two things at opposite ends of the observable universe the universe is expanding and so it's a competition between the universe trying to get these things to go apart and the gravitational attraction and presumably at that large scale the expansion win out yeah expansion will win out you have to be really like you know this this this Woody Allen line and you know like you live in Brooklyn Brooklyn is not expanding like he didn't want to do his homework because he was upset about the universe expanding so you know Brooklyn is not expanding and the reason it's not is because the local gravitational effect of the earth is much more significant than the expansion made of the universe but as you get to larger and larger scales the expansion eventually takes over so the Galaxy stays together we will fall with Andromeda we will fall into the center of the black hole if the expansion picks up it could tear the Galaxy apart if it picks up and we don't really know in the far future if it just gets if it just mounts and mounts and mounts there will come a point where the expansion will tear apart the Galaxy and Brooklyn will be expanding that'll be the Big Rip it's just there's just no there's there's just no good news here I mean there's just none there's just no good news well damn J just bum in a tough year for us all I don't know like you way here's here speaking of that though here's the greatest thing if you people if you're bummed out about 2020 if you if you're looking at covid and you're looking at everything that we're going through call Janice and she will make you feel worse so so you can say this ain't so bad we're going through right now it's not so bad an election some Supreme Court nominee um well you know the interesting thing is universes can be like ecosystems so if there is a Multiverse out there if there's an infinite Multiverse out there everything and if this isn't necessarily follow but and if everything that can happen will happen an infinite number of times we're going to have this conversation somewhere else in the Multiverse so you know there'll be somebody who's almost chuck chuck not the evil chuck with a goatee but he already has a goatee right you know Neil will like you know will be slight we'll all be slightly different but we'll be having this conversation somewhere else all right well Janna good luck with your tiny book look for it on new stands or certainly on the internet so cute I'm so bummed I didn't bring a copy with me it's Survival Guide uh Janna always good to have you always fond to talk to you guys miss you guys a lot Neil degrass Tyson as always bidding us all to keep looking [Music] up

Channel: StarTalk

Views: 202,398

Keywords: startalk, star talk, startalk radio, neil degrasse tyson, neil tyson, science, space, astrophysics, astronomy, podcast, space podcast, science podcast, astronomy podcast, niel degrasse tyson, physics, janna levin, black hole survival guide, black hole explained, black holes, chuck nice

Id: E_whdaP1xxM

Length: 50min 13sec (3013 seconds)

Published: Thu Nov 19 2020