Spacetime with Neil deGrasse Tyson | StarTalk Full Episode

this is Startalk this is Startalk and I'm your host Neil deGrasse Tyson your personal astrophysicist I serve as director of New York City's Hayden Planetarium right here in New York City and today's edition is the fan-favorite cosmic queries I've got with me Godfrey Don Chima hey Godfrey it's happened welcome back thank you for having me banshee my Nigerian and team ah yes it's Maya Tokyo its own I had total don't you all there's plenty can I tell you something was that the Japanese pronunciations are the same as African pronunciations so today's topic yes I is what is it it's it's space-time space-time very nice I like space-time and here we go so my best friends live in the fabric of space-time there it is all right listen I haven't seen any of these and it called from our social media okay here we go mm-hmm okay Kyle yokum's spelled with C but it's still pronounced Kyle from Tennessee when I've heard that name before is he one of our patreon PE is your patreon patron oh yes I so he bought his way to the top of this list oh yeah he's not he's not planned I mean you got a lot of space time I put money in that huh I got a lot of money in that space no it's better if you supports the show their perks you get you do right on up the ladder and this is just one of them but there's others yeah great I think he deserves it he's always at the top Yocum I love that last name Yocum okay ready yeah remind me some Yocum if Isaac Newton were alive again today which of our more read not be able to hold my pee Yeah right it would be kind of nice yeah we gripping him like a fanboy and I would totally yeah yeah would you like touch his wig did they well yeah I would touch his wig probably no no I wouldn't touch why why you get me to say that I would go but you make him out to be no baby no no nothing come on some thug that knows about please like no I'm not touching his wig okay okay sir Angela Davis came forward into the present kitchen can I touch your fro no that's true she was slap you silly she would slap us oh okay even today right if Isaac Newton were alive again today which of our more recent understandings about the universe do you think he might find most exciting if you were to get to work with him on a particular project of your choice what would that be and why he was so brilliant I would just I would present all the world's problems to him no matter whether or not they were in physics and just to get his brilliant mind to apply to it really I just I've read his writings and you can't the hair stands up on the back I don't have hair there but if I had hair it would stand up on the back of my neck because he was so plugged in to the operations of nature he had an understanding he had a sensitivity to what we knew and did not know and where the frontier was to ask questions there's a whole section of one of his books one of his books optics wrote in seventh written in 1704 understood uh yeah they talk differently out there I don't know I'm just so you learn how to read you know yeah so the language was a little more classical yeah for English you know at the time yeah not quite Shakespeare right that was a hundred years earlier but it's transitioning even the writing with independence to be able Divya penmanship is different and even the printed words are different right some words are capitalized and others are not I do that in my Twitter stream by the way I capitalize certain nouns okay I want to bring attention to like the V's would be like use although that's different so that would add about that would be the use would be like these he's like you admit at CES or whatever in Roman times with the yeah yeah annoying what are you was fully developed as a letter it took somebody to go put a butt on it the evolution of language yeah so I would I would learn how to communicate with him that wouldn't be too hard because he's still speaking English okay and so we speaking recognizable English so so I would just show them all the problems we have a famine issue we got this issue but the problem is and I've gone through this mental exercise many times you sit him down yeah okay and he hears some car noises outside said what's that I said it's a car and he says what's a car oh it's a horse-drawn carriage without the horse so then he says well what draws it and I said Oh an engine and so what's an engine well it uses fuel well what's fuel well it's gasoline well what's gasoline well it's fossilized ancient dead extinct what's extinct oh you did none of these ideas existed in his day Wow but he'd be annoying what I liked that I ate your old kid yeah was asking questions I would be like she shut up Isaac Jesus law of inertia I push him huh every most everybody in motion right every man I feel is in mosted I I'd say we use chemical energy okay he says what is chemical energy what is energy because energy was not a fully developed idea in his day that would take another hundred years right so so conversation would be really but he's a quick study so I think okay human afternoon he just kept asking you questions oh no I mean it would be like what what is that what what is that and they'd both walking God he will emerge like the most brilliant person got it once he got it he said Trump what is trauma yeah our top scientists they'll figure it out with many laboratories in the world so I think he would be very intrigued by Einstein's relativity general theory because those were extensions of his theories of his laws of motion and gravity Einstein's relativity are extensions so I said special theory of relativity is the continuation of Newton's laws of motion and Einstein's general theory of relativity is the continuation of Newton's laws of gravity so he would he would be intrigued how his ideas failed and then Isaac and and my goodness yeah you got it right these ideas failed and and Einstein's picked up to take two regimes that he never even dreamt up do you think that Isaac Newton would be a hater who would be like this yo oh man is they say yo you know the stuff you were talking about well this guy took it to the next level nothing could be like math get that dude you know and I I don't you know they hate a little bit said that he wouldn't say it that way I'm sorry had to be something at this dude that do even like dot slow like this I can't believe he actually took my theories that roughly on him took my publishing nothing ruffian yeah what up ruffian he was in dispute with with Leibnitz who's a German philosopher right mathematician who they could there's a contention between the two who invented calculus oh by the way Newton is not even best known for having invented calculus that's how brilliant he was that's how brilliant just like react yes calculus was basically on a dare my friend said why do the planets orbit the Sun any in this shape and not this ellipse and not some other shape yes I don't know I'll get back to you I'll get back here get back it comes back in a month later here's why how did you figure it out I had to invent integral and differential calculus I answer your question I couldn't pass Isaac um I guess I invented something that you couldn't learn I armed for him to see that to see that if he was Z um Einstein's whatever you call it I mean no but he would feel like a failure though he wouldn't know because he was the foundation of it all there was no Industrial Revolution without the intellectual muscle of Isaac Newton so no no the man was never any so you said you talked about that German philosopher siren cutting you off and they they they dispute each I say disputed and it's clear they came up with it independently of one another around the same time that's just like Einstein around the time Bohr's and all those guys Madame cute they were all hanging out everybody's to get each other right in fact if Einsteins Berg Heisenberg Eichenberg sigh yeah so Werner von Heisenberg oh is that all this is what I have one more time on in there but what a vital thing I can just put in a vault I think it's just - Brad yeah suddenly you need it apart what happens at the beginning holds water and bomb whatever any of those mean you know what my name my name is in German is Gottfried Godfrey oh yeah okay I like God for it it means gods get the peace got feet oh really what yeah okay this is know that digital the Neil deGrasse Tyson at nine no night night I but they had I thought they because I know when I read I actually went read Walter Isaacson's biography on China huh and so one of many great biographies written everything of Steve Jobs yeah amazing no I I saw that picture they all took it was Boers um Heisenberg all all those guy hitters Adam Curie pr2 all of I think they all long outweigh Johanna and they discovered the modern physics yeah birth of quantum mechanics unbelievers of relativity I believe yeah they're all haters a little bit I don't know I hate it on you know it is it's friendly competition that's true that's true that's just all it okay next all right what that was awesome right to comply warring football teams don't really hate one another really know I on the field maybe afterwards did happen to be issue or yeah they're having a beer we talked about I don't know cowboy guys okay here we go our next one Steve Latham Facebook Steve Staffordshire England if the shape of the universe is hyperbolic or hyperbolic hyperbolic thank you hyperbolic paraboloid then why doesn't the universe expand evenly thanks he says as far as we know the universe is expanding evenly uniformly is the right word so wherever you are you will measure the same expansion rate of the universe okay no matter what and so that would mean it's expanding uniformly and so yeah I don't I don't know why he thinks there's a problem there it's a sheep well the two-dimensional version is a sheet we all pull on the edge of the sea we all start pulling right okay and dots on the sheet will all start moving away from one another all at a uniform rate and so that's how we measure this we see this so ya know when it's not a problem you think that it was just a bad question there are no bad question Arnold okay alright but is this a serious question no no people do do they do serious homework for volatile boyd wow it's nice that sounds like a problem likely your bladder yeah no no no it's appointment fix that right up hyperbolic paraboloid do you have hyperbolic paraboloids we got a new sound so you it sounded like an auditory auditory no more hyperbolic rambling okay here we go next one is this fill SAS a our fast it might be fill SAS I don't mean to pronounce mispronounces last name fill sounds from Georgia USA alright if we decided to launch a manned exploration spacecraft how long would it take for it to explore the entire galaxy and how could we prep prep it for such an undertaking yeah it depends on how fast you're going let's go to the speed of light okay okay now if they managed to go the speed of light they won't age but we will so at the speed of light it would take 100,000 years to cross the galaxy so we're all dead and none of us will remember that we ever launched you anywhere so that's a Tau beat of light speed of light to suffice speed of light yeah okay so now let me reshape the question a little bit because there's an interesting there's a fascinating Avenue that comes out of this it turns out that if you created a robot that could use resources on the planet and lands on to replicate itself uh-huh so to make two robots and then send one robot off to another planet right okay let's say sweet robots send off to one stays yeah so then they then make two robots okay and if you keep this up you can populate the galaxy over and at what we call an evolution a lifetime so over much less than the age of a star so over hundreds of thousands millions of years you can significantly populate the galaxy right and this led to what was at the time known as the Fermi paradox because any alien who could do that would have done that by now and easily have populated the entire galaxy in the time the universe has been around right so he asked where are they now right I'll come they're not among us so I have two responses one of them is maybe we are they oh like that or the one I just say all the time because it's like it's a cheap and easy crackit our species so maybe they did come and take a look and conclude there's no sign of intelligent life on earth that's so mean no that's for these dummies we're out I know we're out we're out yeah go to China Mao we out two minutes left on this segment okay both okay how many physicists does it take to change a lightbulb that's a quantity Hornet Facebook how many physicists how many physicists does it take to change a light bulb yes since it's physicists arm who invented the LED right going forward the physicist will never have to change the light bulb it will burn longer than their lifespan boom next forget little smart little a question blow so just a bit over so two Nobel Prizes ago or one Nobel Prize ago the Nobel Prize in Physics was to a team of physicists who invented the blue light-emitting diode we had had a green we had the red okay okay we never didn't have a blue now that we have the blue we have RGB you can make any color at all using LEDs and the fact blue open the tire lighting market that's why you go you can't even get a light bulb that you need to change yeah oh yeah in a hardware store right am i right you're right you're right oh that's it so again how many physicists does it take they were clever enough to remove the meaning of the question itself oh man I love that this cosmic way of destroying that dude is awesome hunter whatever your name is if you're slick with your little joke know your lesson we are we going 21 okay okay okay okay go I'll get the space/time have limit or is it infinite if we're on a spaceship going faster than light would we stop eventually because we reach the edge and there is no more space nor time this is guy is a psycho EXO Instagram from France Cyril tor friends whoa well there's no time to answer the second okay you'll have to wait until the next segment of cosmic queries on Startalk we'll see in a moment we're back on Startalk I got Godfrey here is a free man Jimo what rose it was last night I'm sorry that's why I'm Godfrey Godfrey just Godfrey and she mother said she Vincenzo but I know I'm Ben Gunn remember 900 billion galaxies is it man chimo excellent now that good with names but I'm good with mathematical calculation on Timothy I got Oh funny I got a med team on munching all dead men you African right same thing said what you're they're ready so we we let lose a cliffhanger there cliffhanger yeah I want to know was there an edge to the universe yeah just kept traveling so so here's the thing we do not know how big the actual universe is there is the size of the universe we see and like from the edge of that universe has been traveling for 13.8 billion years to reach us now of course over that time the universe has expanded the actual universe is bigger than that today it's bigger than that but you have to ask beyond that horizon is there more universe to be found we can only assume yes but we don't know for sure but it's that isn't that just and it could be infinite and here's why I say it let me tell you I say because infinity makes people uncomfortable yet you know the biblical version of infinity is eternity right all right there's me a new car there's a word eternity no it's a it's a fragrance there more science words they get there yeah the event horizon yeah once you get close yeah you you are any people learn and grow that second immortal like immortal thing is not a cosmic word unity yes no to me yes so and they want it big because there's also infinite decimal but nobody's in somebody's name on anything that infinitesimally yeah yeah nobody's name on that site so so the infinite decimal so you go out there and we don't know we say infinity because we don't have any reason to give any other value what I'm going to say is 138 billion light years across we have no reason to we'll just say you have to say if no reason to assign one number versus another so we just say infinite until till we have better reason that to say infinite cuz you can't go over there you can't you do everything from Earth you can't maybe one day you'll be such a Luddite now you're trying to go to Mars man we've been to Mars oh yeah anytime yeah not a person our robotic emissaries have yeah okay you got your robot over there okay there is a little GI Joe whatever over there that's right you got a saying but you can't we can stay over Joe that's a smart thing that astronomers say and all you guys say because I would say it to a goal it's infinite man not what I say everything only because I can't justify giving any other value to it and we so we just say this infinite until we have a better saving your own ass by saying that no cream you like yo it's infinite then if you said listen it's 138 billion then they can't wait to go you lied oh no me no because I didn't say it is infinite I said we have no reason to think it isn't okay that's different oh I like a little Elvis thing you just did to me today that is a nice simple is no infinite don't forget baby I'm doin it well next question as are you I'll give it over sin and God read it isn't it right you kind of cosmic says what I like it's kind of close well that's how I feel Haitian a little causeway I would home it mama I want another except I what everything could be speaking Japanese I gave the other store hey Neil deGrasse Tyson there's only about a universe I want to rule is it big or is it small like you're still expanding like my belly not my belly in physics we call that the accretion disk recreation disk I love that are we ready yeah let's do it next question I think this is this is guy David Hamilton I think this is one of the toughest things to wrap my head around when we talk about space curving or warping are we talking about something permeating everything we see that bends and warps yes so what is it made of and does that mean on some level space isn't truly a vacuum he's from mayagüez Puerto Rico alga where's my Polly phone yes testicle bond on seagull but the world's largest radio telescope until two months ago was in Puerto Rico what what part RC bo odyssey boo that's a great evening good evening but you're not gonna ask who's got it now who's got the biggest good who has it now where's it at China what so if he's going to talk to us and we need the most sensitive radio telescope Chinese are gonna hear the aliens first so the Chinese right here 4head that's right first of all it's aliens here Chinese then I don't know China Chinese is hard Oh perfectly how an estate house oh it looks a bit like whoa let's go back to Puerto Rico oh I'm just saying I'm trying to learn Chinese it stopped it's hard if married it's the hardest language ever even though more people know that language than any else you know what I'm saying so how hard could it be yeah there's a video yes of a guy speaking English gibberish oh yeah and it is it is mind-blowing so it is what English sounds like to a non-native speaker I love that so how is it you know dates it's like I should understand this but not really nothing makes any sense at all there's no accent you don't hear usually if there's an accent ah it was but you can't understand them it is it it is a perfect American accent but nothing is coming out nothing meaningful is coming out at sea speaking trunk yes so it's up to control that's a key speakers rap with no real run/walk did I answer the question yes you did answer the question was the question I got the question oh it was he said that that it's about the space curving Olin carbonate curve become known I didn't answer the question no so space so the idea that space is curved is hard for us to see because we're embedded in the space right so of course it's hard to see in the same way it's hard to know that earth is round because we're kind of in a sense embedded in the surface of that curve and we are small relative to it if we step out of the dimensionality and look back yeah there's the round earth that's what we did when we went to the moon there's the rounder you step out of the surface of the earth if we step out of the dimensionality of our universe you would see all the curvature manifested by all the mass and the total curvature represented in the universe itself so it's all a matter of your your point of view it's like a crappy relationship you have to step out of it and say what the hell was I doing with and sometimes unit activation you don't even know Tilly's when you're in distance right you think it's normal until you don't just right right exactly no right that we did that was great do it okay we're moving on right here we go this is Lucas Meza Nova Instagram from Colombia or Libya oh yeah whatever all the knuckle it said not Colombia Oromia no I got it I know how to pronounce Onoda he said it right there trying to make sure he's like it's grow colombiana Colombia some theories say that our universe is a 3d hologram of another universe with more dimensions how would this affect space-time is there a proof of this no there's no proof but there's a very cogent argument to support it and so the idea is that the surface of an event horizon is the complete record of anything that ever have pet having passed through it so that it is the sort of the ghost of all things and so you can ask have we passed through some other event horizon the horizon of the universe can be thought of as kind of like an event horizon of the universe itself and so if that's the case then we could be shadows to a higher dimension on the edge of the event horizon that they observe and so it's been called a holographic printer status yeah it's been suggested that that we might as the Carrows yes so that means this is very platonic Plato imagined a world where you're in a cave and there's a campfire and all you can do is look in the adjacent wall and you see shadows your own shadow and the shadows of others so if you only see the shadows and that is your reality then look at how much you're missing when someone else comes in and say wait a minute there's a campfire there and there people with clothing on and there's always but all you see and know is that wall that is your entire existence so could it be that everything we see and think is real is just a projection of a much more textured higher dimensional reality and in fact we are we are blind deaf and dumb to it all interesting yeah fantastic fantastic yeah there's another one that was good you answered it it's amazing but Ricardo Montalban would be much gonna be proud buyers everyone smile only if you only if you have couldn't see a letter yes okay down the Montalban it's awesome you have you pull out the Montalbano turning back to Boston in a plan yeah the plane the cosmic hover over there oh there you ready go this guy is an interesting last name Jeff sauce teresh star sauce Trek it might because it's like I think it's polish sauce Tareq I don't know he's from Bethlehem Pennsylvania gotcha is there anywhere in the universe where you can find is really yes no matter what follows in that question the answer is probably yes okay is there universes large it's old yo and stuff happens in the universe where you can find a zero state of energy perhaps where even the cosmic background radiation does not permeate man these questions are some Malibu so that would be ology that would be as absolute zero we as far as we know the vacuum of space is a seething ocean of what we call virtual particles that are that are predicted by quantum physics and quantum physics has been right in every other way it's ever made a prediction so we have high confidence that what it's saying is true but as long as you have particles even in the vacuum there's going to be an energy level there and you never actually get to perfect zero energy because of the quantum and so the quantum prevents it we would need some higher theory of understanding of the universe that might enclose quantum physics that will enable us to get to places that our current understanding does not but right now there's no way to get to a perfect zero energy because every state even the zero energy state has a probability of having real energy quantum physics requires it hmm yeah yeah your quantum physics to quantum physics oh it's at the end of the day yet invisible math man is this will you get this from Invisible Man this man that can describe invisible things that's what I met what the math itself is not invisible guys like are you getting it that is no I'm not accessible man not accepting I you know like all invisible now absolutely call you because you don't understand it doesn't mean it's not there I call it's invisible to me because I don't want to see it okay cuz you look the other way great that's like because I decided to say far is the foamer I thought yeah we observe weird stuff happening in the lab and for people who hate math this must freak them out so we have scientists of the day saying who lets attach math to this to make it easy so we can bring bring some understanding law so the mathematics of quantum physics six is an extraordinary achievement of the human mind that's yeah yeah that's another brain that you did something I don't have that no but maybe you did and you it still has to be found we think that I could bring that out I can get good the part of physics I think mathematic and all always get better no I think they're not we can become great at anything we can always become better at you're naturally good at math I don't think I think it's a natural knack it is there's people I knew in grade school like some good some guys I knew and girls that would just do they'd even study they'd even study I had to use the teachers example and flip the page over to do look at the examples answer in the back of my friends were just certain guy they were just naturally good at it you know that come naturally good at bad I I spent a lot of time at home reading books what's your man yeah I mean I'm naturally good cuz I mean I'm naturally curious and I happen to apply that curiosity to math and therefore got higher grades and math then you did what were you doing when you went home after school I was confused so I just kept watching cartoons man you know to me and this stuff that you were reading you're probably reading I was rereading reticle stuff about mathematically in math I was reading naturally have an inclination for that because you would naturally get it from that I had what is a reality in childhood that I'd never left me that's what I want I watch comedies man I so do I love my mom comedy - you're funny guy I continued my funniness in that way comedian you funny guy but astrophysicist because you're amazing at math and invisible man because you see the invisibility okay you made your case are you ready now what's the next question yeah Nicholas Lambert Facebook why is dark matter presumed to exist when modified Newtonian dynamics is able to account for most of the missing mass have businesses forgotten the principle of Occam's razor Occam's razor comes up sorrow comes razor when we come back to Startalk we'll see in a moment welcome back to Startalk I got Godfrey here yo really comedian twit tweeting at Godfrey comedian yes excellent excellent Instagram and I'm scum cut yeah you gotta come comedian i'm comedian godfrey Instagram oh so what someone else was Godfrey comedian Instagram I I did that and I don't know how to get into that I didn't I've messed myself up okay I didn't know I don't know how to get into that old account so I had to go comedian God for I'm stupid all right median Godfrey Instagram yeah I get Instagram but I'm not yet live on it I'm gonna be I got a whole lot of stuff I wanna put I'm sure you're not worried about me I'm putting you on my Instagram though all right and go we got questions here someone asked about yes dark matter and modified Newtonian gravity as a solution at Occam's razor Occam's razor there was I I think was Earl of Occam okay British fellow I think he was British who uttered the following words multiplicity ought not be posited without simplicity okay which is what he means is I think I got that quote right what he means is if you have an explanation for something it's long and complicated right and someone else has a really simple explanation yeah the simplest explanation is probably the correct one gotcha that's all okay so for example let's take a Pepsi before we understood epilepsy there you are writhing on the ground and so people had an argument for it well the creator of the universe yeah in the judeo-christian tradition has a nemesis called the devil and that devil has occupied the body of this particular person because of the things this person is done okay or the brain is misfiring in its neural synapses okay so this this is what we're contending with right right so there you have it so in the movie The Exorcist off like this is the 21st century I'd the 20th century I think we got this one yeah all right so the notion there is there's a modify Newton's equations of gravity then you don't need to posit dark matter to explain things in the universe and it would mean that our understanding of gravity was flawed in this way where when we corrected it we wouldn't need to invoke this magical mystical thing called dark matter and so it turns out you can modify Newton's laws of gravity to explain some of the places where dark matter was otherwise invoked there are other places where it fails completely and we have no way around that we don't with the modifying you can't modify Newton's gravity in the same way to account for it and so that's why we all haven't jumped on the bandwagon adding terms to Newton's equations of gravity that's why awesome awesome let me keep going okay like that one hope for it here we go Adrian gray Marcin from California California we currently can go we can cleat levels are we curly can only go forward in time with regards to black hole trick nology given technologies for acknowledging well given what little we know about dark matter and dark energy being our physics opposite do you think our future insights and education on all things dark will grant the option to move backwards in time ooh All Things duh yeah all right and black hole technical technical is black hole trick knowledge in technology okay so it turns out if you you can warp the fabric of space and time by the way I have been told this I have not double-checked the math these are people whose math in other cases I trust implicitly so that there's a configuration of curved space-time where if you go around a black hole in a particular trajectory and come back around another one you can actually go back in your own space-time and so effectively go backwards in time okay but it's still a little bit mysterious to me okay I got people who do this I'm not the one who does it right okay as a colleague of mine J Richard got the third well actually I'm co-author on in a book that was just released I Princeton University Press what's the title welcome to the universe yeah yeah an Astrophysical tour just add in local bookstore near you I'm gonna get it so no so in there he talks about these solutions to Einstein's equations where you go back in time but they're involved very exotic trajectories the point is the bigger point of the question is we've got dark matter we don't know anything about it dark energy we don't know anything about it and who knows what else we don't know anything about right that's kind of the fun part of not known about something not even knowing that you don't know about something right okay so with all of this could it be that once all of that to figure it out we can have access to the past I can't rule that out I will not rule that out almost everything we've discovered that came about from profound ignorance has transformed civilization think about the discovery of electricity whoo what it has done yes it's the probably the greatest thing to ever happen to civilization I can't even imagine cannot have matches it I can't even imagine not plugging stuff plugging stuff in flicking a switch it is a switch right don't know how it works don't care it's there it's not even and we've made it into something that's not even only about light movies and movies just and ever every everything ok so this is harnessing something that previously we ran away from or didn't understand so so I look forward to a future where dark matter and dark energy come to be understood but then that only puts us in a new place to stand possibly observing new unknowns that today are yet to be dreamt of all right I like that maybe access to our past network lurks among those on the day I like that next ride there we go I like this so I think gonzo know Gonzalo Martin face book from Chile land of the stars Derby gonzalo Martine yes Martine how you know you know him I say Marty he said Martin Martin this did Marty you're in South America Arden I didn't want to be American thanks Martin monotheism sorry this is land of the stars he said land of the start my yacht all the data that went into my PhD thesis was obtained in the Andes Mountains of Chile Wow deep settle to low low inter-american Observatory Oh outside of the town of La Sirena fantastic if you think that yeah I'm not either try status it was my I say specific office fun times to go and that's you notice you doesn't matter yes I can't do that I can't even think you do the whole universe thing smooth like do you do your tile your book got welcome to the universe so you don't say like might look no no no yeah none okay the dusty if sound won't travel through space how does the sound of celestial bodies whoa whoa wait it sound won't travel through space how does the sound of celestial bodies can be listened to yeah whoo I guess they Jesus said no um that's because we are not consistent with our vocabulary we are we play loosey-goosey with our words okay so when we say let's listen for aliens who are send us radio waves it means we're pulling out a radio telescope trying to detect electromagnetic waves light sent by them from another place in the galaxy that has now trapped and this signal has traveled through the vacuum of space we can then turn that electromagnetic signal into sound if you want but that doesn't mean they're making sounds they're making electromagnetic energy and so you know we have the unfortunate word radio because radio became not only the name for the light ways it became the name of the object that brought you radio waves turned into sounds so we hear we hear the word radio and we think sound the astrophysicist hears the word radio waves and we think radio wave light so so we've been sloppy I feel I feel bad sloppy no sound moves through space in the vacuum of space period okay period so even if we say that we're listening sound with sound wave sound can't travel through sound needs a medium to vibrate right to transmit itself from one place to another that's right so so like for example let's say a comedy club you need a a particular building for sound to travel right is that how microphones work I don't know what you're talking about I thought I had it what sound needs a medium to travel through air is a medium it strikes through the air your vibrates okay so what did you just say I just got confused I said air propagates sound right okay but light does not need a medium to propagate through one of the great discoveries of the 20th century this is not necessary it can travel through the vacuum of space which is why this the sign on every broadcast door that says on the air on air right there on space okay the radio waves don't need air ah the neat it is technically on the air but air is not carrying it if you're in the moon it could still you could still broadcast your TV and radio and and there's no air you have to say on the vacuum of space watching okay I guess I was confused no that's just a weird thing but yeah a weird thing okay but in comedy club you sneak it goes to the microphone it comes it gets converted into electrical signals comes out two speakers right people hear you directly through the air other people hear you through the speakers through the air okay yeah there it is oh we got to lightning round oh if we built the time machine what's the best way to long time isn't it the same as Earth years ooh if you have access to your time line there is no logging of time because time is a permanent fixture in your life okay damn it how would you explain same way when you're looking at a map yeah you're not logging distance because the whole map is just right there boom you just see New York to California it's just all there right not logging distance from New York to California while you're looking at a map any more than you would need to log time looking at your entire timeline of your life oh it theater Smith how would you explain space-time to a non-scientist or anatomist who is generally bad but fascinated by physics I would say sir that if there's a sir yes wasn't what's-his-name Oh Theater Smith you have never been at a place unless it was at a time and you've never been at a time unless you are at a place recognizing that fact you will understand that space and time are forever intertwined with one another you've never said I'll meet you 10 o'clock tomorrow where I'll meet you the corner of Hollywood and Vine when we know intuitively that space and time are conjoined even if you don't think actively about it space and time were always together like beans and rice oh it just took Einstein to show us hey it's a fundamental property of the cosmos Wow let's do it okay we're in the known universe this is I'm sorry ah this is uh this is a Kyle Sakia sake oh we're in the known universe would you experience extreme time dilation near the surface of a black hole you time will go so slowly for you that the entire future history of the universe unfolds before your eyes that is perhaps the most serious time dilation that exists so avoid black holes in fact I'm going outside one more kiss Chris couples oh here we go Lord couple dat Lord couple's Twitter could gravitational bleeding from other dimensions be what we call dark matter that is my favorite explanation for what dark matter could be but I'm told I've had this conversation with folks it's unlikely only because it would have to bleed in a higher dimension out of the other universe and if you bleed in a higher dimension it drops off much faster than one over R squared gravity gravity drops off as one over R squared it would drop off as one over R cubed so that means to feel it in another universe had to be really really really really strong in the adjacent universe for while it's dropping off as one over the distance cube for you to feel it in the adjacent universe if that were the case then Dark Matter would just be ordinary matter harassing matter in our universe the ordinary matter in a parallel universe harassing us rationals I'd have no other way to account for that - collecting but it's notice harassing with harassing okay it's either it's bothering yes I got my planet I got my star I got my gravity in a day now there's more gravity I got a mess with I'm aware it's coming from what it's about why you messing with me I guess with why you mess with me question of faith if I'm harassing me matter find you if I give ya copy we gotta call this we got it we got to land this plane you awesome jockeys thanks for being on Startalk thank you I'm back again glad you slipped us in your schedule you're on your way to California why don't I light a couch got some gigs there you'll talk about in another time another time right but add another space time that's too cool fantastic there you go I'm Neil deGrasse Tyson this has been Startalk and as always I bid you to keep looking up this is Startalk [Music] you [Music]

Channel: StarTalk

Views: 524,203

Rating: 4.876018 out of 5

Keywords: StarTalk, Star Talk, Neil deGrasse Tyson, Godfrey, spacetime, universe, black holes, Fermi paradox, quantum physics, quantum mechanics, extraterrestrial life, time travel, gravitational bleeding, dark matter, dark energy, Isaac Newton, Albert Einstein, theory of relativity, Occam’s razor, Newtonian physics

Id: c2jknvagrmw

Length: 46min 44sec (2804 seconds)

Published: Mon Jul 17 2017