A mind-expanding tour of the cosmos with Neil deGrasse Tyson and Robert Krulwich

that's welcome the Oh deGrasse Tyson alright alright so want to inflate him so everything we see in the universe the Stars the planets the galaxies the plants the rocks the power of us everything you say it's near the front of this book is is what you call the product of a remarkable asymmetry of matter over antimatter what did you mean by that oh can I just say something about your introduction woman if I may you man so I'm I'm impressed by your persistent scepticism of all things I say reporters hosta you can never really believe you have to check and verify hmm okay I guess I had to you just get you you're right every time though so far I mean how can I possibly just come up with that unless it was correct what that a building kicks off by the second you're ridiculous but do we may built the building did you think well I have a wonderful idea what it's all we got a half a foot Charles maybe we'll get a second on the celestial clock okay I don't think so yeah no I'm sure it was not on purpose it just is as so much of the universe is so profound a symmetry so you just went right into the stuff hi there yeah well okay uh just a quick note yeah that this title astrophysics for people in a hurry I've had people joke with me about it say Oh was Astro physics for dummies already taken you know and I just wanted to make it clear that first yes it was taken but but there's nothing I don't think there's anything quote dumbed down about the astrophysics in this book it's all sort of curated legitimate full up astrophysics in an attempt to sort of grant the reader a degree of fluency in modern astrophysics like the next morning at the water cooler you could just be talking about yeah and like there are things in here I had never heard of really and you and you get around I get around yeah you got around so I'm going to be checked but so I in the in the early universe the temperature was very hot and above certain thresholds of temperature what happens is matter no longer stays as matter it can freely move back and forth between itself and energy and we have the recipe for this it comes from e equals mc-squared we all know that equation it's the formal conversion recipe for matter and energy and the C squared is the speed of light square is a huge number a little bit of mass times that huge number gives you a lot of energy we don't experience in our lives equals MC squared because the energy in which we're immersed is not high enough to enable matter to go back and forth between energy and itself that's why it took so long to discover equals MC squared and to come to terms and to come to understand it but it is a profound equation that manifests from the beginning of time all the way to the future of the universe but not in our life experience alright so and also let me preface it by saying in one of the opening pages of the book is what you call it the rubric no the episode what's the beginning no no I don't you know the publishers have a word for the maze that has a thing on it yeah well it since that's the dedication for all those that's the dedication or you want to read it okay I mean for all those who are too busy to read fat books yet nonetheless seek a conduit to the cosmos yeah yeah but that's not what I was looking for you look it up the teenagers beyond two pages beyond yeah contents yeah preface preface okay oh yes the universe is under no obligation to make sense to you that's it signed by you the scores can make that clear so the universe is under no obligation to make sense to any of us so I will be saying things and you'll say that doesn't make sense just remember what I just said okay okay what we've learned is that the universe is what we measure it to be not what we want it to be not what feels good not what only has to make sense to our five senses our five biological senses forged in the plains of Africa you know a million years ago a half a million years ago I would whatever what's the latest the biologists tell us is those senses to prevent us from getting eaten by a lion are very different from what you need to grasp the universe and so this is why mathematics is so potent because it takes us out of our senses and enables us to still probe the reality of what the universe is so here's what goes on if matter and energy can go back and forth this is how that works I have a blob of energy and it decides that it wants to become matter and it does so all this energy becomes matter but I mean it decides it goes and then it thinks what could I like to be today it happens spontaneously and it depends on what the temperature is oh okay cool what's it we get it's hot and then it gets yeah so if it if the temperature drops too low then it's not going to happen energy will stay energy and whatever matter was around at that time we'll stay matter so watch what happens we now have high enough energy that if you converted up this pocket of energy into mass equals MC squared you get enough mass to create particles out of it okay so get a very low take electron for example that's very low mass among atomic subatomic particles so you can ask how much energy does it take to make an electron write that number down if you don't have that much energy around you your energy will never become a particle whoever okay so in the early universe there was so much energy every particle could be made so watch what happens you have a pocket of energy it becomes mass the only way we know that can happen is if if it becomes a particle and an antiparticle pair matter and antimatter antimatter is the opposite of the first thing yes in every measurable way huh okay so the opposite of an electron is a positron it looks just like an electron but among other things it has the opposite charge of an electron positron okay every particle has an antiparticle there's a neutron have an anti Neutron yes there's a proton have an antiproton yes and so you might say well what's the opposite charge of a neutron because the neutron has no charge the neutron is made of it's made of quarks that have fractional charges that cancel each other to get zero net charge on the neutron so an anti neutron has all those same quarks but the antimatter version of those quarks on the inside what will happen if these two kiss if you take matter and antimatter and put them together they annihilate and become pure energy and the matter disappears entirely let me delete something over oh no not even a little not a light a photon something yes yes so you take the particles matter antimatter identical particles other except that they were matter antennae bring them together they disappear and that matter becomes energy and all that's left is energy right in that pocket right there that happens all the time in the center of the Sun it happened everywhere in the early universe now here's the rug you have all these photons of light oh by the way I have a photon joke can I tell it tell the thoughts okay [Laughter] vote on checks into a hotel it's not a bar oh well it can't be racy because the families are the family I got it okay I got I got this vote on checks into a hotel the bellhop hat comes up and says do you have any luggage and the photon says no I'm traveling light and if the bellhop were here tonight he'd left a big fat lab yes yes yeah in the end so when I say pocket of energy let's just simply refer to photons because they carry energy all right so a photon turns into matter it's a matter antimatter pair matter antimatter come together they make a photon it's symmetric okay okay so basic that mean that if every matter part met every antimatter part they all would going to be left with just light yes there would be no matter in the universe only light oh okay so now as in let there be light yes except there's nothing else after that so sort of a very short store let there be light and we're done yeah yeah yeah take that light of Genesis and start over yeah yeah yeah yeah that would be a very short Genesis right there so so you have all this energy in the form of photons becoming mattering back and forth and there it goes as the temperature of the universe dropped you reach a point where you can no longer make particles with the energy you have but you have all these matter and antimatter particle pairs that eventually find one another and annihilate and make a photon but we're still cooling the universe so according to our known laws of physics in the cooling universe every matter and antimatter particle pair would have annihilated made of photon the photon would have cooled and no more matter would have been made and we would have had an entire universe of just light but it is not the universe we occupy we can start up like a band you know no no I just I'm saying we apparently are the exception yes yes so mysteriously we call it symmetry breaking just because we don't that's what if what happened we're just describing what happened not that we fully understand why it happened one out of basically a million of these reactions one out of a million the photon did not make a matter/antimatter pair it just made a matter particle it was the you're trying to find out why yeah and I'm just saying it is that okay so one out of about a million makes a matter particle without the antimatter counterpart so now the dance card the dance hall has nine hundred and ninety nine thousand partners that can pair out of nine hundred and ninety nine nine thousand yes well not that one 999 here and is one left over so everybody else becomes light and that one has no antimatter particle two mates with and it is frozen out of the universe and has become all the matter that we know and see today so everything that we are a profound asymmetry on the early universe we are the stuff that didn't get a date correct doesn't that strike you as an extremely fragile interpretation of all but there is I mean it's like being around by the skinny skinny skin if your chin each unique you whatever that thing is except in the concept of multiverse we have many many universes all the laws of physics don't have to be the same in each universe so there could be plenty of universes wherever the dance card was full and they just have light in them and you are not in that universe saying that it was just a chance of Curren oh well you are in the universe I'm worried about the other ones I'm just interested that our universe the one that we know and live in is such a fragile arrangement originally not well it doesn't have to be it may be but it doesn't have to be and it is unlikely to be and can I give an obscure example that will settle this yeah okay okay line up a thousand people and give them a coin and everybody's had flip the coin and about half will get tails half will get it if you got tails sit down that's 500 left approximately mm-hmm have them flip half get heads have it 250 of you sit down never let go to it do it again go from 215 to 125 to 60 to 30 15 to 8 to 4 to 2 to 1 okay in this experiments not it's not an unthinkable experiment mm-hmm this person who survived this exercise flipped heads 10 consecutive times now here's what journalists do they go up to that person and they say how do you feel well I knew I had felt that heads energy halfway through and I and I was feeling it and I did they ask anyone else that they felt up that heads energy no they only interviewed that guy you come well I'm not done all right so that person says boy I was lucky to flip heads ten consecutive times well every time essentially every time you do this experiment somebody's going to flip heads ten consecutive times so you want to say oh this is a special universe in which that happened no no because of the the nature of this the fact you can have a thousand experiments happening all the time there's going to be one where somebody flips head head ten consecutive times every time you do this experiment that does not make it special just because somebody flips heads take ten consecutive times every time you do the experiment so you're in a universe where this weird thing happens at the beginning and you want to feel all feel all heads energy about it and I'm saying in a multiverse that could be 999 universes where that did not happen and you're the one that did and you want special credit for it I'm not giving it to you alright let me move on to another thought in the second sort of section of this book I this is something I hadn't really occurred to me I mean once it'll write the book I don't know I know it doesn't I just meant the next thing I noticed that one you stand a book up yeah yeah yeah I do then is that allowed well if you didn't know it you all get like a free book tonight did you know this okay everybody excuse me just to be clear I signed every one of your books okay and those are the the books that are part of that series if you look on that page that you're signed there six or seven cities there I'm going to be each in each one of those cities giving one talk and all those books are signed and I'm not signing any other books but those so it's a limited edition yeah basically that's right if you open your book and you're Nate your signature hissing sure he's not in there and you're the lonely one you go up and start speaking of universes up there there was a time when people believed that the heavens up there were the province of God and whatever was going on in there was unknowable and it would be basically sinful to find out you point out that that with gravity well whether you just briefly Newton comes along and then everything changes yeah yes so you look up and the planets are going forward against the background stars and then backwards and we call it there's a word for that retrograde and they do a loop-the-loop and nobody understands it and the fact that no one understands it it's presented as evidence in some bits of scholarship as evidence for the divinity of the heavens because that is the handiwork of God and we are mortal and God is immortal and omniscient and so we can't possibly know the mind of God so you just content just in your ignorance watching planet there was some attempts at this with the geocentric epicycles and all this but this was it was well accepted that you'll never understand Newton comes along writes down equations of motion equations of gravity and kind of on a dare he invents integral and differential calculus then he turned 26 this is why Isaac Newton is my man did it just to make that clear okay among many reasons but so he writes down these equations and he can now demonstrate full knowledge of how why and where and what the planets are doing and so potent was his new theory of gravity that it worked for moons of Jupiter orbiting Jupiter not just planets orbiting the Sun and this was the first indication maybe this is not just a local truth that maybe it applies across the universe and this was a little bit of heresy bought by some that in fact Newton was accused by some say Isaac you've left nothing for God to do and that's simultaneously a dig at him but also quite a compliment that he can actually understand the mind of God well that's what guys read this is where it got interesting then you went off I mean everybody knows that gravity is apparently is ubiquitous and universal but then you wouldn't asked about chemistry and physics constants and and kindly thought about that before is it is the chemistry of the Sun and the chemistry of the earth and the chemistry of the furthest thing you can think of are the laws about bonds and pairings and so the other thing are the same everywhere without exception it was not obvious there's not there's no tablet in the sky that required that the laws of physics we discover on Earth's surface would apply elsewhere if they were different on earth than on the moon and on a Sun and I suppose we could deal with that but what a remarkable fact that it is the same well wait a second like you've seen that thing on on Jupiter that's the one that never quits you're the big red thing the big yeah we call it the Red Spot on Jupiter we call it Jupiter's red spot okay because that's how we roll that thing is BOTS on the Sun sunspots big feet we have any geologists or chemists in the audience geologists but but can you be jealous of this fact because you guys name stuff that nobody knows what the hell you're talking about okay and you know we're talking it's suspicious to you that a storm there could go on for 350 years without a break and we never have storms that go on for 350 years without a break we don't even have storms that go on for like six weeks without a break so first of all these storms are when we have storms it's in our atmosphere mmm let's gas yeah we rotate once a day and so that rotation creates a what we call a Coriolis force which moving air air that moves from one latitude to another actually has its direction deflected because of this Coriolis force and this is why storms rotate in one direction counterclockwise in the Northern Hemisphere and clockwise in the southern hemisphere just a quick aside I I was channel surfing one day waiting for a movie to come on at the top of the hour had 15 minutes I hit a football game and they just ended the game at a tie and they just started overtime that's about right let me just watch this how bad could it be after the necessary exchange of possession it became sudden-death overtime and then one of the teams Cincinnati Bengals got within 50 yards and they kicked a field goal and the ball rotated up it hits the left upright who love the goalpost and went in and I said who wait a minute and I said which stadium is this what's the latitude and I looked at the orientation of the stadium I did a calculation and then I tweeted and I said they though the overtime winning field goal by the Cincinnati Bengals was likely aided by a 1/3 of an inch deflection to the right imparted by Earth's rotation look even lost in my people I'm at the local sports channel that and and so the point is if if if you were going north south at all in the northern hemisphere you will deflect to the right no matter what you're doing ok that's that's why you have a low-pressure system and I'm a ball of gas below it if it's low pressure there and I'm air I'm going to head for the low pressure that's how this works it's low pressure that means it's higher pressure out here so all the pressure is going to send me in that direction but I'm crossing lines of latitude and so Earth's rotation will deflect me to the right now but how about air that's above it it says I see a low pressure system let me go to it so goes to it and it deflects to the right so all this air deflects to the right but it's still trying to get to the center of the low-pressure system but it can't because it keeps that getting deflected and all this deflection becomes this cyclonic energy that turns into a storm and that is how you get hurricanes tornadoes it's what he called it cyclones psyche ok ok so we're back at cupid if yes we are know what so this happens in the gasps yeah all right the Coriolis force is heightened if you spin faster ok and so what is Jupiter it's a hundred times bigger than Earth more than that ten four thousand times bigger than Earth it's like weather to ten it's ten times across cubed so it's a thousand times bigger than Earth it's mostly gas and it rotates once in about ten hours you want to talk about ferocious Coriolis forces we have storms that last weeks here hurricanes that pick up and they get weeks on this little speck we call earth that has this much atmosphere on it go to a planet that rotates twice as fast is ten times as wide a thousand times the volume and is mostly gas and you're complaining that it lasted 300 years you are really good all right let me I'll grant you that the speed of light is universal obviously angular momentum comes of eternity sure what about a big chapter just gonna be clear he's coming from a chapter called on earth as it is in the heavens why you see can you spontaneously levitate and hover above the ground in a lotus position like like Michael Keaton in Birdman can let me know the beginning of Birdman his underpants forget the underpants just the levitation this for such that your first thought when you think of someone in a lotus position Michael Keaton in that movie yeah ok yeah uh yeah so so it's just there's certain things you just can't do because they're prevented by all known laws of physics you cannot spontaneously set yourself into motion unless you push off of something else or you lose some kind of mass that was within you so rockets when they take off their ejecting mass out the other side okay Wow so do you saw Birdman did you just leap up to museums it can't do that can't do that no there are movies where I'm prepared to suspend my disbelief yes like just for as an example I was asked about the movie guardians of the galaxy and they asked me well the ships that are going through space they make noise and clearly you would does that upset you because in space where there is no air no one can hear you scream but no one can hear you explode either nor will you hear engines or anything and so they said does that upset you and I said I bought into the idea that this movie has a talking raccoon that shoots artillery from heavy weaponry off its shoulder if I can accept that I'm good with whatever else they deliver in the film so I have the capacity to accept movie magic and what would happen if someone served you a hot cocoa with whipped cream and you see no whipped cream in evidence oh oh don't get me started okay oh wait wait let me finish about let me hating right so all the levites all the people are levitating that it's some kind of an illusion that they're not telling you about okay period here you okay now then but if you really want to levitate if this is really important to you i-i-i tried to calculate how many cans of beans this would require then you got to kind of hold it in yeah right then let loose suddenly suddenly and in principle for the duration of the thrust you can levitate briefly but this would argue against the lotus position because there would be an opening so suddenly that there'd be too much too soon too fast and therefore no rise oh yeah you wouldn't like you wouldn't well you could stay there if it just kept yeah coming that right so it's not impossible to hold a lotus position it's just unlikely you're doing it for these other ways that are described I said yes the cocoa cocoa oh yeah so I had to do it was it was an incident in Pasadena California I was there I don't drink much coffee I don't have a relationship with caffeine but every now and then I'll be delighted to have a nice cup of hot cocoa and I went to one of these coffee houses you know with the chalkboard out front and so I had you know the kind I'm talking about there's all over Brooklyn you trip on the chalkboards in Brooklyn so so I'm in the I ordered hot chocolate and I ordered it with whipped cream of course right and it comes to the table and there's no whipped cream and I said I ordered this with whipped cream this is all we put it on and I said well where is it oh he said it's sunk to the bottom I then said either the laws of physics that apply everywhere in the universe are suspended in your coffee shop or you didn't put whipped cream on my hot cocoa and he looked indignant really now to his credit rather than continue to argue with me he intended to prove me wrong well he went into the kitchen brought out the the whipped cream scooped it up popped it in my and my hot cocoa and it bobbed once and floated atop and there it was did your virus which we might owe a horse whipped cream hats the float because first of all before was whipped cream it was cream okay and old-timers remember what is cream do in unhomogenized milk it floats to the top and you skim off the cream leaving behind skim milk okay this is how that looks now you take that heavy cream and then whip it putting air into it it is not going to sink on any no liquid devised by man okay all right so so here's my point the lesson there is yes I'm I'm a fan of the edict if an argument last more than five minutes then both sides are wrong if that applies maybe 85 percent of the time it's a good it's a good rule it's a good tenant to is to carry with you now watch this how science works one researcher comes up with a result and that is not the truth no no a scientific emergent truth is not the result of any one experiment what has to happen is somebody else has to verify it preferably a competitor preferably someone who doesn't want you to be correct such as my waiter he went out to prove me wrong and got the same result that I had declared we can call that the beginnings of an emergent truth about whipped cream now we need someone to do it in Asia and in Europe and and and and then you get a trend and you can do then declare that a consensus of observation and experiments has emerged in the scientific community whipped cream floats on hot chocolate and that waiter today is getting a PhD ah let me go on to to a question that came up later in the book just how boy D is the void of space like so it looks pretty empty out there between galaxies just a lot of black you know it seems anyway if you step into intergalactic space by the way what might happen to you you die yeah ship but you might see stuff and this is the list well I don't I had never heard anything Worf galaxies run away stars faint blue she's hot cause that you let me just ask about some of them what is a dwarf galaxy it's a little galaxy well that I figure didn't we go through this already our words mean what they say haven't got but we're past that already wait what there are galaxies that you see the ones the Magellan saw smudges in the sky those are huge things No well we're dwarf galaxies those are let's go oh yeah oh oh yeah they're like a hundredth the size of our galaxy so how many dwarf they far outnumber big galaxies they do yes so maybe we shouldn't be calling them dwarfs because they're the common size galaxies we should just be called Giants perhaps I asked and they call them regular with the worthy right that's how that works right what is the difference how many stars are in a galaxy galaxy our galaxy has several hundred billion stars and in a dwarf galaxy um at most a billion but more typically hundreds of millions these are small numbers compared to full-up red blooded galaxies so tinier dwarf galaxies and we tend to find them in the vicinity of big galaxies but you know what happens you know they orbit the big galaxies but the orbits are not stable and they do a death spiral in they get eaten by the larger galaxies and we have a term for that it's called galactic cannibalism in fact there are stars there streams of stars that we see in our own galaxy that have the same trajectory as one another through the stellar system that is the Milky Way so they they relate and you follow it and it comes back out and back in again and so this is evidence that this was once a fleshie but dwarfee galaxies that we ate ripped apart and now the stars are just trying to have some last bastions of a memory of what they once were because they're getting stretched apart but what we call the tidal forces of our galaxy is that does the Milky Way have dwarfs yeah just I mean has the flow so the first science essay I ever wrote was called the galaxies and the Seven Dwarfs because at the time the Milky Way had seven dwarf galaxies in orbit found it and then what dwarf galaxies are very small they're hard to detect and since then we've discovered you know couple dozen more so it might be up above 22,000 - ARF galaxies in our vicinity basically nearby so the point getting back to the void is you look out on the void you say there's nothing there well what are you invoking to declare that it's a void is it your eyes well let's bring in a telescope or using visible light is that a visible light telescope bring in an x-ray telescope an infrared telescope bring in the spate of senses that science has developed that transcend the five native senses we have through our human physiology and that power enables us to decode the universe not as our senses receive them but as our detectors there is an amazing chapter of kotas or in the back where you find out how human beings finally sensed what they couldn't see that there is a rainbow of color that we all can see which are waves of different lengths they go eat a cue from whatever it's get beaded bow Roy be viv so whatever they get Roy beat it Roy had Roy we had to repeat after me Roy wrought red Boise Biff wrought red on yellow green Biff blue indigo indigo the violent violent you got it but it's weird I just a quick thing roses are red violets are violet right is it me who came up with violence or blue with that we have a name for that color that was a desperate poet looking for a rhyme I think don't be violating laws of physics just to make the rhyme okay I was gonna send out Mark Twain's edik that I love what is it first get your facts straight then distort them at your leisure the log let me just finish this button and I've been command I know I'm sorry um at the end there's this this moment where somebody has to figure out that that there might be something redder than red or somehow more than violet now we only have eyes but this particular person used a thermometer what was brilliant it was brilliant brilliant okay so Isaac Newton is the first to understand that white light is composed of colors he takes white light puts it through a prism and he gets ROYGBIV actually the indigo he had a mystical fascination with the number seven so he wanted to lay down seven colors with indigo it's just really blue violet all right okay but any I will give him his indigo cuz he did all that stuff before he turned 26 so if you invent calculus just on a dare we give it to you all right we'll give you him to go if you need to have indigo so he's got the colors and then he took those colors merged them back together and he got white light out the other side that's some freaky stuff that's just freaky yeah that red orange yellow green blue violet equals white okay so we're good there William Herschel comes around later and says I wonder just to even ask this question I wonder if the different colors of light have different temperatures so he laid down the spectrum with sunlight prism and he put a thermometer in each color and then he had it an eighth thermometer I don't know if he used one and did the experiment eight seven times but yet another thermometer did he used as a control thermometer you put that over to the side where there are no colors and that would presumably just measure the room temperature mmm-hmm so he knows enough to even think that this is an interesting exercise and he's got a control thermometer and he just puts it over to the side of the read out of sight and then he watches the two thermometers and the control thermometer goes through the roof yes it does and he's looking at it and he says something must be coming through this the prism that I cannot see and he describes this as light unfit for vision he discovers infrared light with that experiment and then another guy slip which the human eye cannot see it's like if you if you go to the hardware store and get an infrared bulb you turn it on and it looks red you're seeing the red light that is also emitted from this infrared bulb and the heat that you feel your eye cannot see that's all the infrared that you're buying when you pay money for that bulb and then some other guy put a piece of paper on the other side of violet and it turned dark and he photographed a photographic paper and he found that it responds it's responded in the way you would normally respond by putting photographic paper in front of visible light so he concludes that was somebody else somebody else yes right and says there's something beyond the light there's something less than the red infrared something beyond the violet and thus was discovered ultra violet light and so to pose the question in the first place was a stroke of brilliance to then trust your measurements on a level where you then declare you have made that discovery is a whole other thing it's okay yeah it's yeah here's the thing about this book I just because I miss all this what just so people get a sense of the history yeah a history of puzzlement and the history of discovery rolled up into one I'm not going to ask anything else because it's time for questions and answers but I would have so just you know what else is in here there's something there's dark matter which is this mysterious thing that's out there which with dark matter is everywhere okay the dark energy one of the questions yes is why are so many heavenly bodies round is there anything in the universe that's perfectly round what's going on between planets where why is there still debris coming in when the earth is seem to have scooped up everything after 4.6 billion rotations something at the end called the Copernican principle all of it is really but never mind you just let will turn on the light here's what we're going to ask you if you can to just raise a hand I'll choose you and then wow you are then quechua smash I'll choose you and then you just stand up and ask and I'll repeat the question so people in the streaming part of the world can hear this okay the question is the universe is 14 something something billion years old we've now seen stars stars galaxies galaxies that are 13 billion years old and somehow that might suggest that the the universe is expanding and that there is more and more universe all the time well first of all the universe is expanding and there is more and more observable universe all the time the universe at its edge is expanding at one light-year per year that's how that works and so in a billion years the edge is not going to be 14 billion light years away at least 15 billion light years away so we got that okay so now galaxies 13 billion light years away we are seeing light emitted by that galaxy and that light has been traveling for 13 billion years okay yes that galaxy emitted its light when the universe was 10 percent its current age and in fact was much smaller than it is today now you said the current paradigm is 14 billion year age of the universe you said that with a little bit of oh you'll come up with something different later the proper way to say that is that is the current measurements of the age of the universe that's how that works okay paradigm is we came into our lexicon in a big way in the 1970s with a book written by the science philosopher Thomas Kuhn what's it there's a dangerous woman in here who is this joker speaks so dangerously remember what happened to the guy who put the didn't put the cream in the coffee so this book the structure of scientific revolutions sort of introduced paradigm as a as a as a way that scientists sort of gather around a paradigm and they all sort of accepted although then something different happens and better data comes along that we all gather around a different paradigm that happened basically until the dawn of the age of modern science which I date from Galileo and and bacon Francis Bacon where when you experimentally measure something to be true and it's verified that is a truth that does not later turn out to be false period it's not how science works it's not like oh this is now definitely false now let's all crowd around this you would be left with that impression having read that book but the book got that very wrong for the age of modern science before then sure because people have thought stuff up and then and call themselves scientists and that was with philosophers and you turn out to be profoundly wrong when somebody else thought up something better and then everybody's wrong when we finally started taking data it's all about the data okay so everything you described is just perfectly fine yes it founds galaxies the next telescope the James Webb Space Telescope is tuned to live in that regime to find galaxies being born in the early universe so to be a whole lot more data coming back from the early universe when that telescope gets launched lands at its observing point and gets turned on so there's nothing you said that's odd or weird that is the universe we live in no you don't get to you don't get to a lot of people oh he's no he's verifying that I let off with the universe is under no obligation to make sense to you yes yeah okay how about upstairs is there anybody up here I can well you're not upstairs but I'll mr. cat they asked you yeah okay well in a second just yell next time green cat first yes I think you'd have a great game a plaid cat oh wow okay thank you I don't think sinful is the word it's just uh it's it's clear that's maybe the word okay question there's people there's he heard something he talked about God on CBS television and he's had he's like thinking about near-death experiences and he wonders whether these deep mysteries are interesting to you okay so one of the things we know from research in psychology as well as just practical matters in the conducting of scientific experiments is that one of the lowest forms of evidence you could possibly invoke is eyewitness testimony which is odd because it's one of the highest forms of evidence in the court of law which disturbs me greatly mm-hmm so if you cut if you come from a lab to a science conference and say this is true we say how do you know this because I saw it that's really the end of your talk and you just leave and then we say come back when you have a chart recorder or you have to just give me something that does not have to flow through your senses because your senses is some of the worst data taking devices that exist and science did not achieve maturity modern science does not receive maturity until we had instruments that either extended our senses or replace them and Galileo is not an accident that we have modern science as I've described it experiment verification this these tactics these methods and tools began with Galileo and Francis Bacon and Galilei was around 1600 that was the invention in that period of the microscope and the telescope so it's not an accident that all this sort of came together at that time so now we have people who are in the act of dying and they come back from life and they report on mental experiences and that's intriguing it's intriguing but because it is in the realm of eyewitness testimony you can establish it perhaps as a personal truth but it will take more than that to establish it as an objective truth and an objective truth is the kind of truths that science discovers and it's the kind of truth that is true whether or not you believe in it okay it exists outside of your culture your religion your political affiliation personal truths if I may consider that would be okay Jesus is your Savior that's your personal truth you cannot convince someone else that Jesus is their Savior in an objective way you have to persuade them you have to persuade them and some with in some cases by war right look at the wars that have been fought between religions that did not agree about who was their respective saviors so so I'm sure we hello I walked on water made you unblind turned got created loaves and fishes out of nothing that would be a maze I think we would like investigate that and we would sit we would say whoa let yes we would we would so it would be an amazing thing and then if we if we cannot account for that for by any other known laws of physics and it's only happening with you that we see we'd wonder if you were like alien or something first right but no it would be so easy to demonstrate divinity if in fact you had the power you wanted to display but getting back to the gentleman's point so part of this issue is what does it mean to be dead okay it used to be did you fog a mirror that was held up in front of you while you were laying there on your bed all right and if you didn't fog the mirror you were judged to be dead they would put you in a coffin and in some parts that it is told there's a string that they put into the coffin as they buried you and they put it over a tree branch and connected to a bell if you woke up you would pull the string and you that's where you get the term dead ringer okay you would pull the string and you come rescue me because you buried a living person okay so then it was you dead because your heart stops well we know why our heart beats its electrochemical so you do poke the heart beats again we got that one okay well is it when you're brain dead well you can be brain dead but your heart is still beating and if we can keep you alive are you dead yet well no cuz your heart still beating is your brain functioning no okay I can tell you this that if you're dead long enough so your brain is deprived oxygen and then you we bring you back you're not talking about seeing any lights because you're brain dead okay so plus this often happens to someone who is deathly ill to begin with and where are they they're in a hospital and if they go into cardiac arrest or something critical they take you from your hospital bed to an operating table and what is sitting above an operating table lights bright lights okay and so if you say oh I was dead and I came back and I saw lights we maybe it's not all the cases but it's many of the cases okay now do skeptics who tried to do an experiment they're people who say they left their body hmm and they thought we got some of those Montesquiou so here's what they did when was Montesquieu he got rear-ended by some guy in a horse fell off flew up into the air looked down at himself in agony watched his wife wait we're in collisions in the air Montaigne Montaigne sorry Montaigne not till they have rear-end collisions in the air well you ride a horse with a guy behind you is riding two fans like a cab situation okay I didn't know that okay okay so I didn't know that well I loved stopping you mid rear-end collision little horses where was I so so there was an experiment so there's some descriptions that are part of this near-death experience a literature where they come above and they see themselves down there on the bed okay so what they decided to do is for people who are about to die they would write a message facing upwards to the ceiling above the bed and suspend it there so if a person goes above their bed and looks down they'd be able to read the message so they rejoin their body they what they should then tell us what message they saw that's never happen no that's enough now now I have a cousin who when her father died was alone with him in the room and he's in an open casket and she's otherwise completely rational okay I'm not saying this a crazy person - completely what she's a real estate agent so okay thanks for itself okay among other town okay so she's in there she tells me of a conversation she had with her dead father and I said was it in your mind no he sat up and spoke to her I said what was the conversation and she said well he asked he said don't worry about him he's in a better place this sort of thing so this is her eyewitness testimony I'm not going to say it's wrong I'm just saying it's not scientifically useful that's all I'm really saying here okay I told her next time this happens ask these questions and not those questions okay don't say are you happy did you how you know saying are you wearing clothes okay where are you where did you get your clothes what temperature is it are you just asked questions like this is this is an amazing scientific experiment you could be performing so so that's my lesson to all of you didn't find yourself in that situation okay kind of a dead person sits up and starts talking to me oh my god but my iphone is coming out I'm getting charged for quarters I'm I'm going to be all up in that as an experiment okay all right up in the balcony whoever that was yes yeah question is can you help us understand a multi-dimensional universe what would be the dimensions we are unaware of any dimension higher than the three that we're familiar with or the actual four that we're embedded in we live in a four-dimensional world and that might sound a little flaky freaky but consider the following fact you have never met someone at a place unless it was also at a time and you have never met someone at a time unless it was also at a place that requires four mentions of nama what about in a dream this is the dream happening inside your head yes I don't know when so the only point is we know intuitively that we need four dimensions to localize someone to meet up with them especially well only two dimensions if you don't have tall buildings you have 12 buildings you need the third dimension so you don't say I'll meet you at the 20th floor of you know on 721 Park Avenue what time okay this is a full four dimensions going on there so just somewhat a convention we live in a four-dimensional world for that reason okay it may be that these four dimensions are manifest to us but that in fact we are embedded in higher than in a higher dimensional space and strength theorists on the frontier of this exercise are hypothesizing at least ten dimensions to account for everything we see in the universe even if we do not directly measure those dimensions themselves now with your permission may I go on a dimensional journey with you man might take you on a journey a dimensional Odyssey honestly are you ready yes okay are you ready to get ready for this okay so I'm at my desk and the desk is a surface okay and I start putting pages down on the desk of tiling them on the desk and then I run out of room I have exhausted to two dimensions of the surface of my desk we have ways of accommodating this problem and so we have page organizers that go upwards so now when I don't have any more surface area of the desk I can enter a third dimension and put pages there if you are an ant embedded in this two-dimensional world of the surface of my desk and you fill up the desk with these sheets of paper the ant will say there is no more room and I say yes there is watch me and I take a piece of paper off the desk put it in the page organizer and according to the ant that's embedded into two dimensions that page disappeared it disappeared into a dimension that ant does not have access to what a brilliant invention this is you can put practically an unlimited number of pages but far more pages above the desk than on the desk so access to a third dimension is an extraordinarily useful storage device for a two-dimensional creature does the ant trust you that what it cannot see is nevertheless there I have to then talk to it about this extra dimension and then it will have to just trust you yes because watch what happens next I now have my three-dimensional room and I'm filling it with boxes now I've run out of space to put the boxes but now an alien four dimensional alien looks at us and says I got this just move it into the fourth dimension what are you talking about and the alien comes in reaches in takes one of the boxes and then the Box disappears disappears it went into a fourth dimension and this was captured in the film Monsters Inc did you guys see the film these are monsters that work in a door Factory and they make these doors and they open the door and it is the door of the kids bedroom or their closet and they've step through and they're in the kid's closet and then they scare the kid because that's their job they're monsters okay this doorway is a portal through the fourth dimension and then back to the third so imagine a new storage system we just go to Home Depot and buy a door and that door is your portal to a fourth dimension you open the door put your boxes close the door you look on the other side of the door there's nothing there so this is what's going on when you have access to higher dimensions wait don't you have to then talk to somebody as far as you know if you're a scientist and you need data what you have is something that you had it's gone and now a voice says I've got this yeah if that what data it was a voice from the fourth dimension I'm going to listen to it so does everything I'm not going to say no you're a lie i if if there's a voice coming out of the fourth dimension and makes one of my boxes disappear I'm thinking it's got more power than I do and more knowledge of the space-time continuum so I'm going with it does that mean that in order for scientists to credit another dimension with reality with real existence it will need a testifier from beyond so you need a dimension plus a dimension dimension voice demand a dimension a dimensionless voice yeah that comes from another from another place now there are things that happen in quantum physics that kind of defy our sensibilities like particles pop in and out of existence they don't they defy any rational attempt to understand it particles can be entangled with one another a particle can be here and there's a barrier and it can spontaneously show up on the other side of the barrier at faster than the speed of light all of this is just mysterious let me ask you suppose you have a sphere and I live in a 2-dimensional world and you take this hollow sphere so it's a shell and you pass that sphere through my two-dimensional universe how will I describe that I will say this point just appeared out of nowhere oops now it's a circle a small circle and that circle is getting bigger by the moment oh my gosh well if we study maximum size now that circle is just shrinking it's shrinking up now it's a point now the whole thing disappeared this will be completely freaky to a two dimensional being but it makes complete sense if you live in three dimensions and you passed a sphere through my universe so who is to say that some of the mysterious things we are describing accurately but don't otherwise make sense make sense in a higher dimension and these are just the manifestations of higher dimensional phenomena in our world and that's an aspect of what these higher dimensional physicists are trying to establish at this point I want to totally blow their minds if I can oh if I may but you got to stay with me on this okay we'll all Upper East Siders so you got this you ready okay these are not all Upper East so haha era suspiciously um Upper East Side people littering the room okay but you got to stay with me okay a point has no dimensions there's no height width depth so it has zero dimensions a line has one dimension length okay a square has two dimensions so the height and width a cube has three dimensions height width depth we got this now follow me a line is one dimensional but it's bounded by two zero dimensional things those are the points one dimension bounded by two zero dimensional points a square is two dimensions bounded by four one-dimensional sides a cube is three dimensions bounded by six two-dimensional sides so in other words the dimensions of your sides are going up your line is bound by zero dimensional points your square is bound by two-dimensional lines I mean by by um by one-dimensional sides the cube is bound by two dimensional squares okay so we going up to four six two points four sides of a square six sides of a cube and each side is one dimension less they're squares on the sides of a cube they're lines on the side of a square they're dots on the sides of a line let's go up to a four dimensional cube a four-dimensional cube has eight sides a regular cube has six sides we're going up by two a four dimensional cube has eight sides and each of those sides is a three dimensional cube one dimension down from itself in the same way each side of a three-dimensional cube is a two-dimensional square so when you get to four dimensions the sides are three dimensional surfaces and you can take this all the way up and our brains can't picture what we call a hypercube in some circles a tesseract we can't picture a volume bounded by three-dimensional cubes what does it even mean this is because we evolved in the plains of Africa just not wanting to get eaten by a lion our neuro synapses are ill-equipped to do to do the distance on this and this is why we invent mathematics that can take us there well the mathematics can help us imagine it but if we want to credit it with reality then you have to design an experiment that somehow touches your own world yes yes so you can invent something that you can't see if it has testable consequences in ways that you can see that's perfectly allowed not a problem oh and by the way there's some people that say you cannot prove a negative some people like coming after so you generally won't hear a scientist say that it's others like philosophers and people who like criticizing scientists but who are not scientist so that you can't prove a neck we kind of do that all the time okay but we don't use the word proof we demonstrate without any further discussion that the negative is true okay so here's an example there's a cave there is there a bear in the cave I don't know I'm not going in to find out okay I'm going to set up cameras and see if a bear comes out okay so I set up the cameras all throughout summer no bear goes in and out but then I okay then I take down the camera maybe a bear went in there to hibernate so here's what you do you set up powder outside of the cave something that will record a footprint and you just monitor this month after month after month after month do it for 12 months look up in the charts how often a bear has to eat and how long would take a bear to die for not eating if the period of time you waited is long enough so that there are no footprints you conclude that there is no bear in that cave I just demonstrated a negative sufficient enough for me to no longer pose that question and go on to another problem but if you were so distracted that it's not a formal proof of a negative then you could just keep sitting there wondering while the rest of us decode the nature of the universe we have a for the last bear in the cave but I guess let's see oh by the way maybe the cave is not a closed cave he might have a rear but wait have a back door yeah okay that's possible I suppose that's possible so then the assumption that there's no bear in the cave would be wrong but I'm or the cave could have a cave and that cave could have another cave you see there is just so much to worry about right and so you will sit there you'll sit there arrested by your own capacity to doubt an experimental reality yes well like I said the recipes that we keep making discovery well we need we have time for one more question and that person at the very end underneath the exit sign hands prominently raised not the one waving it that the woman in the yellow shirts still with their hand up and wondering if I'm looking at her yellow looking back and what's not a yellow shirt that's it it's a horizontal striped shirt oh okay really oh oh repeat it but this was an art major or something I'm right I guess yeah if you had one last question to answer this evening what would that question be uh so you you you misunderstand me uh oh that wasn't your question what good what can I at least answer that no okay oh you're in your career as a scientist if there is one question that you wish to address before you go to the great cave with the bear or wait forever for the bear to come out and stay there what would that science question be or do you like your previous question better uh yeah okay so I'm going to give an answer but then I want your permission to give you a kind of a cop-out answer I'll give both a full answer and then a cop-out answer that my full answer is I wonder if in fact the human intellect is sufficient to actually decode the full operations of this universe in which we live and it's not specifically an Astrophysical question it's just more we are intelligent species because we defined ourselves that way we don't have the benefit of another species to compare ourselves with against whom we might fail miserably and so when we compare ourselves to chimps we sit up righteously and say we have poetry and the Hubble telescope and philosophy and the trim just stacks banette stacks boxes to reach a banana yet there's only 1% difference in our DNA but then you'll say what a difference that 1% makes and I would say maybe that 1% DNA difference corresponds with an equally small difference in the intelligence between a chimp and humans and you say I can't believe that no no well imagine some other species that visits us that's 1% along on that same scale smarter than us consider the smartest chimp does what our toddlers can do and there's no way you will explain to a chimp all of dinner ready at 6:30 if you pick up some sub juice on the way home that the simplest human thoughts are inconceivable to a chimp and their talents are about what our toddlers can do so let's get back to this 1% smarter alien that we've discovered corresponding this analogy we now say what would we look like to them well they would roll Stephen Hawking forward after combing the human species and they'd say this one is slightly smarter than the rest because he can do astrophysics calculations in his head like little Timmy over here but who just came home from preschool Oh Timmy you just composed three sonnets isn't that cute let's put it up on the refrigerator door oh you just derived the fundamental law of calculus isn't that kid put it up on the refrigerator their simplest thoughts would transcend our deepest thoughts and maybe they to them it is obvious what dark matter is and dark energy maybe to them particles popping in and out of existence is a trivial exercise in their understanding of the multi-dimensional space-time continuum and we are here groping at the sides of a wall not knowing how tall wide or deep it is because we have the limits of the human physiology evolved off the plains of Africa just to try to understand the entire universe so I lose sleep on that question each night so that's my way did you almost say at the beginning of that answers that you are wondering we may be something of a mysterion that you you you're not sure I'm not sure the world is so the universe is so complicated that it may be more complicated than we can ever that no that's the hubristic way to say it it's not how I said it okay how did you say it again we might not be smart enough okay not your Brist 'ok if you're hubristic you would say we are smart but the universe is just really complicated that's not what I said well I said we might not be smart enough to figure out a universe that could be trivial to the brain of a more intelligent species okay so check your hubris at the door otherwise you're you will not bask in the cosmic perspective that so much of this discussion brings upon us so may I now give you my cop-out answer my cop-out answer is I think often about the questions we do not yet know to ask because discoveries yet to come but when they arrive will put us in a new Vista a new place to stand enabling us to see questions undreamt of and unimaginable when I again lay awake at night I ponder what kinds of questions lay beyond our reach because the questions that we even know how to pose they're there those are not even interesting to me anymore because we knew how to ask the question I want to know the question that is beyond everyone's reach and by definition I can't because we haven't gotten there yet but that doesn't mean I shouldn't dream of that frontier and that sounded like a coda to me I gotta say I could hear the orchestra playing yeah huh can man offer a better coda yes and then we'll let you go but I we've been here long sorry we went long try not to ever forget that the history of this exercise this beautiful exercise where we find out where we fit in this great unfolding of cosmic events and phenomenon that the larger grows the area of knowledge the bigger that area grows just to remember so - grows our perimeter of ignorance it may be that as much as we think we know as much as we know we know as much as the more things that we ultimately learn for all we know we could be steeped in the center of infinite ignorant which then provides job security forever for scientists sorry Robert Chloe you're right you

Channel: 92nd Street Y

Views: 1,354,287

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Keywords: 92Y, 92nd Street Y, Neil deGrasse Tyson, Robert Krulwich, cosmos, science, physics

Id: AyAK3QBnMGQ

Length: 82min 42sec (4962 seconds)

Published: Wed May 10 2017