Neil deGrasse Tyson & Matt O’Dowd Discuss Their Favorite Scientific Discoveries

surely they've asked this but no one's told me should we Google [Music] it this is Star Talk Neil degrass Tyson you're a personal astrophysicist today we're going to do cosmic queries and this time my special guest is friend and colleague Matt odow Matt how you doing man great new how you feeling all right been too long been too long exciting and of course we got Chuck Nice Chuck B what happening Matt good to see you Chuck there's no Cosmic queries without you reading the questions no there is there is there truly is but I appreciate that so let me catch up our audience to who the few of them who might not know who you are uh so first you're a professor and science Communicator so in the same business in that part of your life and you have a PhD in astronomy and astrophysics from University of Melbourne oh did I pronounce that right melbs as we say no I'm not going there no no that's too intimate I'm just youil University of Mel Melbourne Melbourne Australia that's right and you're into all the stuff that I like most about the universe uh extragalactic astrophysics everything that's happening beyond the Milky Way quazars active Galactic nuclei these are badass galaxies that have super massive black holes in their core right just into that you're also associate professor at the City University of New York at Leman College exactly up across the street from my former High School oh the Bronx High School of Science is on one side of the street Leman college is on the other separated by field an athletic field oh they had to keep you guys apart there some kind of beef between no chance of my people taking over the athletic field BRS High School of Science is not that kind of place oh that's hilarious uh and you're also Affiliated here in our department of astrophysics as a research associate but uh I think most people who know you know you as host of the PBS uh it's a YouTube uh program SpaceTime EXA oh my gosh what a following that has we busted through three million subscribers 3 million just the other day oh congratulations thought congratulations I think YouTube gives you a little momento for that we got we got it at 1 million the the the gold button yes which by the way it does nothing when you push it well least know you know a lot of times I was going say yeah every time you pushed it somebody's computer exploded in their face all right so so tell let's compare notes because we're both in the same business if you will so uh you brand yourself as a science communicator but but not a science teacher so how would you divide those two tasks well I I do teach and communicate so I see the division yeah how I teach a nice astronomy class each semester at with the textbook text and homework exam slideshow Top Quiz exactly yeah which is really fun I mean you don't get quite the intimate contact when you're staring at a camera and pretending it's your audience right right you have to pretend there's a human on the other side of the glass right yeah unless you see humans at all times no matter where you go that's a different diagnosis even when you're alone you see a human yeah there's this there's this point in in the like 10 seasons of SpaceTime where you can kind of tell where I started to do that a friend who's like an improv Champion gave me this advice just imagine it's someone you know and I became so much more natural as soon as I was doing that I talking to this yeah just imagining that it's my mom or you know my girlfriend or whatever right so what you saying the early episodes you were a little stiff you were like delivering information rather than hanging out with the person in the the camera I was thinking exactly what my hands were doing and it was uncanny valy oh don't don't go back to those anyway but yes to get back to your question ignore his first nine Seasons exactly yeah this was just last week actually uhuh uh but but no talking to real students and having the the interaction in real time is great so I I you know I teach classes and you get feedback yeah it's a very if if you say something that befuddles them they'll look befuddled and there's such a you can get away with more when you're talking to the camera because there's no immediate accountability right in the classroom there's accountability every single lecture so when I first started you know proper Professor lecturing my my mood at any time was completely based on how the last lecture had gone like if I flubbed the lecture I would feel like crap until the next lecture and if it was amazing then I would be on top of the world a feedback exactly oh yeah oh yeah yeah yeah yeah but but it's also you know the the like the stakes are high because if you don't get it right this class the next class they'll be lost from the beginning right so like you're building this you leave them behind edifice of knowledge and you have to do it right right and how do you know that they're just not sitting there glazed over receiving all the information and not really processing well if they're glazed over that's a hint and so then you have to you have to know that they're glazed over part part of your social skills is to be able to read that to some extent and you know one trick is there's always a few kids who are so into it that you can be totally teaching to them and everyone else suck UPS always sitting in the front they bring an apple every class yeah just kiss is all day long so and if you're one of those thank you thank you so much so which astronomy how much math is in that intro astronomy class wow this one is not much okay because it's you know it's a at cuni you got to take a science class City University in New York yeah exactly uh so you got to take a science class and so there are there are people with all sorts of trajectories who don't have a lot of math otherwise so I've I've paired it back semester after semester until now we have like if I teach them a core mathematical concept they they come out with one big intuition um and for this class it's like the the nature of proportionality and you know so understanding why these equations are what they are without having to solve too many of them yeah because there are people who think astronomies is looking at pretty pictures that's how the Press delivers images from the James web telescope from Hubble and no behind closed doors we got to figure this stuff out it ain't Instagram you know what I mean it's like Instagram for science it was shocking when I discovered that that it wasn't just taking pictures through telescope so uh just today just today uh my assistant brought to my attention some paper mail not email wow paper snail mail snail mail and it's right here this is two letters one from a 10-year-old and one from an 8-year-old wow look at that see that see that wow at that W those are real right and I handwritten letters and this I know this is Cosmic queries yes but I I don't think they're patreon members well could they don't have a job most likely I'll read them only because I know that they probably unemployed but I will tell you this much um let's see one is from Dexter and the other is from Abby and Dexter and Abby I'm gonna let you know uh you owe us $5 and the moment you get a job you need to join patreon and send us our money okay because you have cut the line and you have displaced many people who take their hard-earned cash and send it to us so that they may inquire of Dr Tyson the wonders of the universe but you think cuz you 10 years old and cute that we just going to do whatever you well I got news for you you need to get a job I think they got the point you think they got the point at some point there I morphed into talking to my own children get a job you will not just lay around this house you're five years old exactly you know you pick one from each okay all right here we go all right let's go with um let's go with Dexter okay who's coming from Middletown Maryland and he says Dear Mr Tyson or should I say Dear Mr tyon okay I'm not gonna do that if he's watching he's going to be like Chuck you know what you're a real a-hole he's going say shuck deeper than that I'm I'm like damn Mr Tyson I don't know what his problem is anyway he says Dear Mr Tyson my name is Dexter I'm 10 years old and I have a few questions if you have time to answer them we'll only take one of them okay we'll only take one and by the way let me just say to Dexter your handwriting is impeccable and it's cursive it's incursive nobody yeah he's a 10-year-old incursive okay what planet is he from do you see this Matt look at what what planet what planet is right I didn't know they Tau kids to write anymore to write at all let just be emojis row after row all right okay uh pick one you demand um I'm going to say I I want to pick because many of them are personally okay here's where I'm I'm going to pick the last question he asked because he asked a lot of great questions I want to read them all but here's the last one uh it's the fourth he says finally why do you want to die by jumping into a black hole I mean it sounds awful what would it feel like what could you actually learn oh yeah so he might have heard something I said at some other time about this it's not that I want to die by falling into a black hole is that if I'm going to die and I could pick I would pick the black hole okay instead of getting hit by a bus or laying up from some disase right if if if somebody say you going to die tomorrow pick I'm picking a black hole right okay because how many people get to tell you what happens while they're falling into a black hole I I'd be the first person sharing that information that's true wait who would you tell well so whoever's listening that's the problem with the black hole I need like a like a you know a tin cans string a long cord that comes out so my my my signals will get red shifted as I get closer to the black you a black hole man right so my signal I'm dubious you don't think I could pull this off so so I would send signals as I descended but those signals would get shifted by the gravity difference between where I am and where you are receiving my signals so we'd have to figure out a way to make that work but I would be I would be broadcasting the entire time until the title forces ripped me apart right now it would first rip me apart at my midsection you can calculate that right when the tital forces exceed the molecular forces that hold together your flesh now if I'm broken at my midsection I probably am still alive yes CU all my organs you know my my vital organs are they're yeah they're up here and my brain so I'll probably stay alive fine but intestines will be hanging out you're also a little thinner because of the yeah I didn't get there yet I didn't get there yet so the intestines will but you don't need your intestines your going to have a meal in the black hole exactly right okay so the intestines will spill out but my heart lungs you know all right but then my other those two other parts would snap into that be become four pieces right and then eight and at some point it's just my head okay all right and then after that my head splits so he says how would that feel it would hurt what do you think but also as Matt made sure I included here I'm being funneled down into a narrower and narrower Channel Through SpaceTime so not only am I being stretched head to toe I'm being ex being extruded through the fabric of space toothpaste like toothpaste through a tube right and we have a word for this uh you should be impressed with the English language for how many words we have for how to die and one of them is spaghettified I get spaghettification oh that's the most delicious way to dye spaghettification yeah anyhow yes it would hurt and I would be I would be stretched apart so what would we learn Matt is there something to learn if I get close to a black hole that you can't figure out theoretic first up so my favorite type of black hole is the super massive type okay the type not just the massive massive they're a little smaller than the super duper massive but bigger than the inter anyway those ones are so big like they can be the size of our solar system you don't get spaghettified until you're deep in the interior so you can cross the Event Horizon I'd be able to talk about it totally fine totally fine I mean you still get the the red shift so you those weits you might have to wait the entire age of the universe to get your message crawl out of that black hole but you would you would witness it yourself and and you would know you'd be able to tell yourself the story about what's inside a black hole so once I'm inside the black hole I'm alive cuz I'm not spaghettified yet the superm Falling Towards towards the singularity Singularity and I would be enlightened to myself to yourself what would happen but that's about it yeah oh man and that but that wouldn't that but you know you got to die some way that would be almost worse because you know you would have all this knowledge of the only person who's ever seen a black hole and you wouldn't be able to tell anybody yeah depends how selfish you are really me for me I'd rather tell people but if it's just me yeah it's good to know still good to know hello start talk averse Neil degrass Tyson here your host of the Star Talk podcast I'm here to announce that we just opened a brand new channel on YouTube called Star Talk Plus and that's where we're going to bring all kinds of innovative content that doesn't quite fit on our Flagship Channel but they will involve experiments in what we create what your reaction might be to what we create and it's going to be our Skunk Works as it were to borrow a term from Aerospace so I look forward to sharing all of this new content with you and check it out if you have a chance all so Chuck what do you got Abby there what do you have oh this is Abby and she's eight years old she says firstly what has been your favorite Discovery so far and what do you predict they will discover in in the future ooh all right Matt let's go to you wow my favorite Discovery yeah not not of mine because those are yes of yours crappy I thought I thought you know historically oh no no your favorite this is a personal letter handwritten wow i' I found some pretty cool gravitational lenses that uh that's geeky that are pretty awesome yeah so uh I mean you know at this point what what did the does it so a gravitational lens would be a a mass mass in the universe that sits between you and something behind it and the light from behind it got lensed what makes one lens better than another okay so by the way I'm old enough to remember the very first lens discovered that's how old I am wow yeah we we were we were losing our yeah oh sorry this is she's an eight-year-old child old kid sorry it's a grown-up show right yeah so we think of we we think of the universe as you know the light comes to us it follows St lines and wherever you see a star or a Galaxy or whatever that's where it is it's not the case Okay the the universe is wibbly wobbly so there's gravity everywhere that that that that makes this space like this stretchy Fabric and so light travels by these you know slightly Wiggly paths but sometimes if there's a big Mass like a Galaxy lined up then the the light can travel multiple paths from some distant object like one of these giant black holes to us and so instead of seeing one we can see many four many images of that one that one object yeah so why why do you have a favorite one what they they all sound like they look the same after a while there are some that are just you would you would call them golden lenses because just everything lined up they are more photogenic everything's lined up so perfectly that we just see amazing stuff like we we you know there's this the the one of the very was it the first one the Einstein cross yeah yeah early that was early yeah yeah that that one's really cool because the lens is really close to us and so everything that's happening happens much more quickly so we see the quazar flickering really quickly as the stars in that lens move around and we just H we can we can do really cool stuff we can we can essentially map that distant Black Hole by looking at how the thing flickers and you know how we first discovered that it was an actual so lens we have two images of a quazar initially there's just two different quazars right until someone discovered that A variation in one quazar was the same was was repeated exactly the in the other quazar but with a time delay oh look at that okay so it meant the two path lengths were different and it was like whoa and everything that changed matched that's really cool one yeah so it was the same object yeah yeah and we we we freaked out in a in a joyous way yeah that's how old I am back in my day we said the first we discovered Earth in the first planet first we thought it was a copycat quaz off playing Simon says we did we thought these could be like binary quazars yeah yeah there was a whole lot of first thought about it right cuz no one seen a landens why would you that's not your first thought Einstein knew that his theory predicted these lenses general relativity but he didn't think he would ever be seen right because it was such a small effect same with gravitational waves you know then we built some pretty good telescopes yeah better than he imagined so what's the second part of that question what's your favorite discover is what do you think they'll discover in the future yeah yeah give us your best prediction one thing that you can do with gravitational lenses I'm on the bandwagon today with this whole time delay thing so you see one one change and you see the other change this lets you measure the distances to these galaxies to the quazar and that's one of the hardest things to do in astronomy as I'm sure you know like you know we discover that the universe is expanding by looking at um at these fluctuating stars in Andromeda and more distant and now we use Supernova explosions to try to get the distances to more distant galaxies but and all of this showed us for one thing that the universe is expanding if we if we track the the size of the universe looking back through Cosmic time we see that it's expanding we also see that that expansion is accelerating Dark Energy okay that's what the Supernova showed us um but in order to so we have no idea what dark energy is but if we have a way to track the rate of expansion over Cosmic time to the greatest distances then we can see if dark energy is the thing that fits into Einstein's equations in the in the kind of most simple way the way that Einstein actually wrote it himself the So-Cal Cosmo constant or if dark energy is changing over time okay in which case it could be something really crazy so we can use these time delays to figure out what the hell dark energy is and this is I would say one of you're you're you're giving all this hypothetical we might see it could be the kid wants to know what your prediction is my prediction is that this is that that what dark energy is is one of the biggest unsolved questions and one that we really have a hope of finding so knowing what dark energy is I'm going to say it could Happ okay that's that that's a prediction we will find out next year five years 10 years 20 years one of those one of those yeah I mean that's the thing with science you just don't know you don't know which experiments are going to pan out yeah yeah all right all right all right so Chuck yeah let's get straight to the cosmic quer all right patreon Edition and for for the not the freeloading C freeling do the real patreon okay we're g find out that that that Dexter and Abby like had to go to therapy after your after listening to your no those guys are guys those guys are the best eight and 10 years old and listening to this show yeah I mean that's impressive enough you know that's that's outstanding and one of them said their favorite show their favorite variant of this is is explainers yeah I mean that's that kid is pretty Advanced uh way to shame all the other kids out [Music] there I like that all right what this is Kylie Ron uh ronning Kylie ronning dear Neil Matt and Chuck I have been waiting for this moment for so long thank you for reading my question I'm wondering if you think it is possible that there is no such thing as the smallest particle and that we can zoom in on matter infinitely the Big Rip Theory assumes that there is a finite end to the universe's ability to stretch out why do we assume this and what if this assumption is wrong man man look at that that's so easy I'm going to let Matt take that one okay I'm I don't want to I is beneath me exactly yeah Matt no this keeps me awake at night this this whole idea of of is there you know an end to scale like is there so you know we we have this idea that there is a sort of smallest measurable distance the the plank length right so we can't do experiments that can prove space distances down Bel so plank length remind me that's the distance over which light travels in a plank time now I'm call that's 0. I'm call them BS I'm sorry I mean first of all that is fathomable like you cannot conceive of that space that's why it's the plank length that's this yeah but but you know you can imagine all right so you have this this ruler and you you you break it down it's a it's a meter ruler okay break it down to a centimeter okay now it's made up of millimeters break the millimeters down blah blah blah you can go all the way down why is it that you have to stop being able to break it down into smaller at a plank length at a plank length you know there's no more rulers why and and it's not I don't think it's understood honestly I think we don't know what the dimension is understood or you don't think you understand it and the I are different things yeah I definitely don't understand it and I think there are others who have better ideas but it's certainly not known right it's certainly not so there is an i and it so so the the limit the limit comes from these these combinations of these fundamental constants like the speed of light the plank constant the the gravitational constant and when you put them together in certain ways you see including things like the Heisenberg uncertainty principle you see that it is unmeasurable at this scale but there's there's no other reason besides the value those constants it's unmeasurable well before then it's just unmeasurable in principle principle yeah you ain't measuring you ain't coming near that with your with your school ruler I have a protractor so it has to work so anyway so so so what happens when you try to subdivide even smaller then okay so maybe the Big Rip is a hypothetical thing what so at what point is anyone declaring that space cannot stretch so the big I mean so the the idea if the space is is space infinitely stretchable the the idea of the plank length doesn't preclude that so you could take whatever smaller than the plank length and make it bigger than the plank length and then it's measurable but it doesn't after you stretch space to shreds and so if the dominant theory of you know what happened at the Big Bang is Right which is inflation so the so the idea that the Universe multiplied its size by a factor of 10 like 60 times then you know that's pretty stretchy and and so so if it could do that then the current pretty gentle rate of expansion isn't going to be a problem using past evidence if if inflation is Right which right you know some smart folks believe okay well it's more fun to think we're all going to end in a tear in the fabric of space and time right and they're just going to get fat and Bloated keep getting stretched out until we can't stretch I mean forever forever forever just continuously stretching wow that's a great question way to go way to go with the question there nice very good this is Jeremy corello he says hello Dr odow Dr Tyson Lord nice this is Jeremy from Austin Texas considering all moving objects in the universe are causing gravitational waves as proposed by Einstein's general theory of relativity can we mathematically accumulate all of the outward momentum from gravitational waves from the inner portion of the universe and use that to help justify the acceleration that we're seeing in the expansion of the universe Visa Dark Energy everything from the beginning of the universe has always been pushing outward and every bit of gravitational wave energy would be accelerating that expansion by the way love the show okay that's a hell of a that's a mouthful of question right there L man so it sounds like they're they're wondering since everything makes gravitational waves however small that these go out into the universe and form this this this pressure that we measure as the dark energy yeah uh I mean I haven't heard this idea and I need to think about it more you know a couple of nitpicks is that you know the normal way we think about the universe is not as it having a center and an exterior so we don't have it's not pushing out into anything it's you know by it's either according to the standard general relativity it's either infinite and expanding or it's this kind of closed volume that doesn't have an exterior so there's no there's no middle of the universe there's definitely no middle of the universe to to to push out to push out so so you can't think of it as like a cake rising in a pan you you could try but I don't think you'd get to the right answer if you did if you did okay just eat the cake and call call it a day okay just draw your sorrows in the cake itself you know that said could you could gravitational waves do this for some of the what the universe actually let's ask it differently what is happening to all those gravitational waves oh yeah they because we measured it it washed over us we know that it's happening the black holes collided we had the waves so then where what happens to them they they SL right so they slowly dissipate right as they so they get weaker and weaker but then they especially in an expanding universe even more they get red shifted Etc but they they so they become part of what we call the gravitational wave background oh okay so so there's this very I forgot about that right on so it's it's everywhere the ones we've detected are relatively nearby big gravitational waves but black holes have been merging since the beginning of time close to there's a background d a background little wiggle wiggle wiggle can we talk about this cuz this is the first I have ever heard I knew about it I forgot to connect do background forg to connect the dot gravitational wave background the the coolest Observatory ever in I'm not going to say built because it wasn't built but invented is looking for it conceived which is the Pulsar timing array which is just the most awesome thing in the world this is not using pulsars across the Galaxy carefully timing them and watching waves move through your line of sight changing the pulse rate that you had so carefully measured exactly and that way you can track gravitational waves going bump in the night even if they don't come across gy size gravitational this is Galaxy size gravitation okay so now I'm going to be honest because you lost me let's go back you're take tracking what the spin of the Pulsar or what what the spin of the Pulsar pulsars are these Exquisite Cosmic clocks they're the the cuse of of dead stars that weren't quite massive enough to make black holes but they they spin rapidly precisely and very precise and and so when and they also shoot out these beams of of of particles that that sweep by the Earth and so we see this okay right faster um and so we see these across the G that's right if they were simply spinning you wouldn't you wouldn't be able to do it you would have to have something spinning off of them for you to see the difference in in fact it's more than that so it's not just particles and energy being spew out the pole of the axis the the spewing part is actually tipped relative to that gotcha so as it spins on its axis right the this other pole swings by that's a better gauge that's a better gauge of the spin like Earth's magnetic pole doesn't align with our spin pole if we had one of these it would spin around every day you'd see this beam this makes this makes great sense great great okay so keep going yeah so so some cases like a thousand times a second yeah and and so we see just slight variations in the in the in the the that are correlated across the Galaxy so a little lag here that becomes a little lag here that becomes a little lag here and we can reconstruct we can reconstruct these way at the speed of light God right exactly and so recently there was this the first you know tentative but still pretty intriguing detection of the gravitational wave background and how how big it is and so you know could the could that gravitational wave background be dark energy uh I don't that was the question that's basically the question the answer is I don't know I I surely they've asked this but no one's told me should we Google it that's awesome well there you go we don't know we don't know okay Jeremy what a great question that was uh enlightening all right that that was my Pulsar joke see all right never mind lightning I get it okay never mind yeah you had to actually explain that didn't you seriously when you got to explain them they're not working that's all there is to it ain't a joke have you ever wanted one of your questions on the universe answered we all have questions about the universe black holes to quazars quantum entanglement wormholes there is no end to the depths of cosmic curiosity well the entry level of patreon on membership with Star Talk gets you just that I think it starts at $5 a month you have access to the question line that reaches our Cosmic query programming and not only that we produce a special Cosmic queries installment just for patreon members if you weren't the director of the Hayden planetarium what do you think you would be doing what okay but this have to be another Universe it wouldn't happen in this universe okay I'd be I'd be a a a songwriter for Broadway musicals o so that's the entry level and the perks ascend from there uh there's a level in fact where we send you a an autographed copy of one of my latest books uh right now it's Star Messenger Cosmic perspectives on civilization and it's signed with my fancy fountain pen with purple ink so I invite you to just check the link below and all of that money goes to our ability to experiment with new ways of bringing the universe down to earth so thank you for those who have already joined and we welcome others to participate in this Grand Adventure of what it is to bring the universe down to earth as always keep looking up all right this is Town poem uh uh hello world this is Jesse from West vir Virginia is there any correlation between the increasing amount of space being compressed in the interior black holes and the increasing amount of space stretched by the expanding Universe uh kind of the same but here's the difference could radiation and dark matter be thought of as counterparts since radiation is a wavelength without mass and dark matter is a mass without wavelength what since radiation is produced by matter interacting with radiation could dark matter be produced by matter interacting with mass oo damn these people are where these people coming from where are they coming from that's like three questions in a row where they're just like like yo man I'm going make sure you went to school on this like I got to make sure that your degree is legit here's a question so there was a paper on the first idea that was that was pretty recent um a paper a research paper published by scientist so all right so now the first paper was in the 60s and it was by a Russian physicist named gliner and and he had this notion that there could be this coupling between the interior of the black hole and cosmological scales right and and so gler was a sort of Forgotten genius um and it it sort of got you know got got forgotten but there was a recent paper that sort of tried to resurrect it and to argue that this coupling between the interior of the black hole and the cosmological scale by what mechanism I don't know uh would lead to This Global negative pressure and negative pressure is what you need to accelerate the expansion of the universe and I crazily I actually read these papers but I don't remember why I strongly objected to them which I but I do remember objecting to them like I don't think there was a a meaningful mechanism to have that communication between the scales right interior of a black just asserting it as a plausible no there there was like there was like a loose interpretation of general relativity that I I thought was unjustified so I thought there was a a slightly crappy interpretation of of gr say crap yeah it's crap yeah like it felt like you know looking at the from one college to another your work is crap yeah I just I didn't buy it I didn't buy it we did an episode we did an episode on this actually of space time isn't that the whole uh you know that's the whole um Crux of science that's the whole point is for you guys to hate on each other's work just you wor you're worse than rappers to be honest scientists are worse than rappers just you think you think you so you think you good you think you sol you solve this you think you solved this how about this your work is crap scientific method yeah exactly that's pretty cool though so Chuck we only have a couple of minutes so maybe we can like speed up our answers and we can okay all right here we go this is Gina Martin she says hello smarty pants I was wondering since space is expanding what is filling in the gaps is matter being created to fill and expand our universe volume I've heard space compared to a balloon is expanding with dots on the surface you know the old balloon right but a balloon is only able to expand if something is put inside of it so what exactly is inside of our universe that's making it expand so I I love it these people are like taking all the examples like you know the Rubber seet and the balloon and all of that and they're just like yo man what's the deal like what's inside I don't know I think it's possible to extend the metaphor too far oh and that might What's Happening Here you too far you go Gina Gina you're the problem you're the problem you're the problem Gina you went too far you went tooo far well I can say because I'm old I'm the senior member here yeah back in my day right well we knew the universe was expanding we didn't know whether one day recollapse Okay okay right plus there was no direct evidence for the Big Bang okay cuz that's how old I am okay at the time Fred Hoy said I I get it we we live in an expanding universe but I don't like the big bang fact he named it the big bang pejoratively oh and then it's it stuck look at that okay wow said we you want a big bang you C an attitude about it a big bang right and then it's stuck so he hypothesized like Obamacare now we own it so the problem was if we're expanding how do you keep the universe approximately looking the same at all times right if you're expanding okay okay so he said hydrogen molecules are being hatched into the expanding vacuum and those molecules then create clouds and then form new generations of stars wow so if that were true you'd be able to see new galaxies being born today today or at any time right but we didn't right all galaxies are approximately the same age ah so this it's it's a steady creation of matter he just hypothesized that right right right and but people said people said to him uh how is it that you can just assume matter is popping in out of no out of nothing that's crazy and he said is it any crazier than you popping the universe into existence out of nothing and that shut everybody up right he was a smart guy he was still wrong he was still wrong still wrong but he knew had to shut people up yeah no but I'm I'm just saying in the day this idea that matter is being created in the vacuum vacuum expanding vacuum this is this is like how how much can you stretch space thing and and the answer is maybe infinitely but there's also no interior to the Ballo in the case of right our universe there's no analogist inor right so there you go wow that's uh wow that's pretty cool man all right this is couple more questions and we can even speed up our answers go okay this is euklid a liche h who says his name is uid uid okay I'm afraid based on those other four questions Lich is the last name Aloha Dr Tyson Dr D and Sir nice it's Lord nice thank you um Lord is is just in case you didn't know uh uid here from the Big Island I tried asking this question before not sure if you missed if I missed the deadline there's no dude relax there's no deadlines okay you're okay all right here we go could there have been big he's from Hawai he's from Hawaii right the big island where we have our big telescopes there you go could there have been much more massive clouds of ghast and dust in the early Universe with strong enough gravity to cause super massive black holes to form rather quickly so that's your deal man I feel like I feel like I feel mildly qualified for once the answer is yes okay so there there is a big mystery especially with jwst the James web Space Telescope we're seeing these quazar in the early universe that are powered by these black holes that are just too big okay these things had to grow and they had to grow by either eating gas or by merging little black holes into bigger ones and so the ones we see back there that are a billion times the mass of the Sun there's no way that in our current understanding they could have grown that pig and so a lot of people have been asking how how did they start did was there some crazy mechanism by which they could just gobble up all the gas super quickly was there a did they all these black holes form near each other and then fall together or mhm did super massive black holes spontaneously form or at least if not super massive the one tier below it which is intermediate Mass black hole so there there are ways to collapse clouds of gas directly into black holes normally what happens when you have a giant cloud of gas is it starts to collapse but then it fragments it breaks apart and and it forms Stars right in the early Universe the gas was let's say more pure the thing that makes gas fragment today is that it's it's polluted it's polluted by enriched enr all right oh look at that we're made of that Stu I'm saying enr okay he's talking about oxygen carbon so all this stuff so all the other no is it noi super no super no and those elements cause these classs to cool down too quickly which causes them to fragment but in the old Universe it was just hydrogen helium none of these elements had been made because there had been no stars to make them right and so the clouds cool down very slowly which means they could hold together as they collapsed not one GI exactly and when you get when you get wow a it's like if it's a million solar masses the size of our by the way this is not shorter as it should be well cut cut the uh so the answer is there some people think so some people think these these things could have formed by the way that's fascinating yeah slip in one last one one last one okay 30 second answer 30 second answer okay this is Bogart derer okay I think buar derer hello Professor I'm hailing from Belgium could you please describe plank second by plank second on a Quantum scale what happens the moment a black hole Event Horizon is created so he wants you to step by step give us the breakdown of the Event Horizon in the next 30 in the next 30 seconds which I mean measured by plank seconds can I talk that fast so so black holes these days are created by a collapsing cores of dead massive stars um and the first thing that happens is that that the Supernova occurs which results when the the the core collapses into a neutron star most of the stuff gets flung off the neutron star if it's big enough will will shrink the bigger it is the smaller it ends up but at some point a virtual Event Horizon forms in the core and it doesn't really exist but it it grows and and if the if the black hole if the neutron St isn't too big then it the VT the virtual vent Horizon doesn't quite reach the surface and it's a neutron star but if it if it is big enough then as the as the neutron star shrinks the virtual Event Horizon expands when they meet each other it becomes a black hole okay the the escape velocity of the surface becomes the speed of light and in that instance everything goes dark whoa that is pretty damn dope I so that's cool so the Event Horizon is actually born within and then expands out well the Earth has a virtual Event Horizon also it's about 1 cm in diameter at the core and it's not real it's just how you much you would have to crush the Earth down to get down to that about the size of a plum I did the math on that if Earth were a black hole I've been telling people it's a centimeter holy crap I have to contact a lot of students that's wrong maybe that's a really tiny Plum I think I think it's I think it's 9 mm but is it is it diameter or radius oh so two of those so 2 cm is a little closer to a plum have you been telling them that's the diameter I think it's the I think it's the diameter you've been telling them it's the diameter oh no it's the SWAT Shield radius yeah no I get it so no you're right it's the radius it's the radius so two of those gets you 2 cmet that's about like that yeah small plum about an inch less inch yeah about inch yeah I was getting a plum look at that that's pretty cool man yeah so I I I I that well that that's still a cool thing to think about is that yeah that's just mindblowing yeah so every object has its own virtual event you within that you're a black hole black hole you ain't coming out exactly so yeah are there any okay cuz I know you need a certain mass in order to actually achieve black holism okay but uh density density not yeah right so uh yeah cuz the mass itself has to go down to a certain density to create that but are there any localized black holes that you know like we have clusters do we have black hole clusters like yes yes crazily we do the the at the center of our galaxy and so this has been hypothesize for a long time because we think that because black holes tend to be a bit denser they just as as you know dense materials fall to the bottom of you know whatever material they they slowly trickled into the center of our galaxy and over the the billions of years the the inner core of our galaxy the black holes should have ended up in the center okay so you can do these dynamical calculations that show that but there were recent observations with I think it was the Newar x-ray uh observ is it N St that saw them so it it took these x-ray images of the core of our gy and saw these bright spots too many of them and so there we do expect there to be this swarm of black holes in the core of our galaxy damn like thousands of them that's amazing yeah avoid the galactic avoid avoid avoid avoid DET guys this was great thanks for enlightening us absolute pleasure I'm sorry you enlightened us not guys thanks for enlightening us Matt thank you for Enlighten for enlightening us you really made us laugh but I'm reminded that with the power of math and knowledge of the laws of physics that we're not limited by just what you can see we're only limited by what you can think which brings the question is there a limit to how far the mind can go in the universe how far beyond where we can physically travel can our mind take us that's the real future of science wow you just came up with that on yourself right then okay this has been Star Talk Cosmic qu's edition of course all about the universe until next time keep looking [Music] out

Channel: StarTalk

Views: 454,270

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, science communication, black hole, spaghettification, supermassive black hole, gravitational lens, pulsars, The Einstein Cross, quasars, dark energy, infinite universe, Planck length, spacetime, Grab Bag, Science Podcast, JWST, early universe, event horizon, virtual event horizon

Id: kZPkHkorS9E

Length: 50min 0sec (3000 seconds)

Published: Thu Apr 04 2024