Lawrence Krauss speaks at LogiCal-LA conference, Feb, 2018, v2

our our partner main speaker for today the one and only Lawrence Krauss he's the director of origins project Arizona State University Foundation professor at ASU School of Earth and space exploration his talk is called rivers in the dark exploring hidden wonders in the sky and things that go bump in the night as a kid there was a ravine next to his house they used to build little tents and they would hide there his favorite chocolate is a KitKat bar he prefers a shower I asked what what he would name his boat and I thought it'd be something fun like you know gone vision terrible but he said boat I think is actually way better and the question he would ask which is a legit one are the laws of physics unique please welcome Lawrence Krauss thank you it's good it's good to be here it's always good to be introduced by George I never know what will happen so let's see um well yeah we couldn't get this line back up there not me um this is a quote we hope you've all heard from Blake William Blake and it I've been thinking a lot about it lately because I I get asked to give a lot of talks lately and um and I I just was in fact with David he was here on a trip to - David Thiessen on a trip there Amazon with with Richard Dawkins and I prepare to talk which I've adapted for tonight about about the Milky Way but the point is that what is amazing about science and I guess this is what I want to begin with is this and there's my origins project is this notion here that I put up he can me in the end the abstract that they asked me but the wondrous science as opposed to religion is that we can follow nature beyond the evidence of our senses in an open-minded fashion where preconceptions disappear and anywhere you start you whether it's a grain of sand a speck in the night sky if you follow the evidence nature provides you find amazing things so I picked I picked the galaxy today but I've just I made a decision that I know I'm speaking I think I'm just agreed to speak its icon again in October and these things and what I'm gonna do was something I used to do when I was a kid when I worked at a Science Museum but I'm gonna next time and I'd be happy to it now but I already have these slides set up but but um I think what I'm gonna ask the audience to do is pick three things they like from that they see in their natural world and and then I'll just do a lecture following them as far as we can to the forefront of modern science because it'd be more interesting for me because then I don't know where I'm going and maybe more interesting for people but I picked the galaxy now so if you're coming to psych on you can think of something absurd to make it more difficult for me to do son and and and it'll keep me alert but any case for people how many of us see damn lights early how many people you are from LA here live in LA don't have to applaud it's not worth applauding okay for those of you I want to show you stars just watch this for a while and take a drink [Music] sorry for the waitresses worn out places worn out faces these are real shots actually races doing nowhere going nowhere their tears are feeling glasses no expression no expression my head I wanna drown my soul no - no okay I've heard enough um that goes on for another couple of minutes but um this is a particularly pretty shot of the Milky Way galaxy and when I was thinking about talking about the galaxy I also thought since I was with Richard and Richard does this so I'm gonna do it for a little bit he reads from his own books and but he does it in an English accent I can't do that but um but it reminded me of the fact that that which is true whether you live in Los Angeles or any any city of something I wrote a long time ago in a book I wrote called Adam and so I'll read it here for a second in the great cities of the world we've detach ourselves from night if you're a city dweller who doesn't believe this travel at least 100 miles the countryside go to the highest hill and stare at the sky it's not the same sky at all that you see here in this city in the city the stars overhead can glitter like lights on a distant rooftop and the sky begins beyond the horizon on a clear night in the mountains you become part of the sky the Stars reach out and touch you and suddenly you feel the embrace of the galaxy that's what you can see here and and when we were traveling in the Amazon in the dark I thought it would be a particularly appropriate time to talk about that because in fact another I remembered something I'd written about South America which is and and the rest of the world even today the mercy peoples of Ethiopia associate the annual flooding of the Omo River with the helical heliacal setting of the stars in the famous Southern Cross and then there's villagers in the Andes today take this connection to logical extreme the Milky Way and this is prickly worthwhile seeing here because it's a river actually in Peru right where we were in the n DS they take the Milky Way is viewed as a celestial extension of the vilcanota river which is a river actually that goes up to to Machu Picchu where where we were also visiting circulating waters from the heaven to the earth so ferment for not just for this was true for the Incas they had the same view that the river would be connected to the Milky Way galaxy and you can see it's not such a bad notion when you when you look and you really see what the night sky looked like to those people not today but that's the that's the sort of religious view that's the Milky Way as seen as for the first people who tried to think about how the world worked and what I want to do now is take that simple beautiful view that you get from Earth and take it as far as science has taken it in a variety of ways and show you some things that I think are interesting about the galaxy so that's what I'm gonna do in the next couple of hours okay this is the galaxy and and as I often asked at this point to see whose have hangovers and stuff from whatever you were doing last night this is not our galaxy why okay we were in it okay good mostly good okay well you're in it yeah most most of us are in it not the Republican Party Bible series but the okay so but with the reason I show you this is the Andromeda galaxy and we'll maybe take a look at it later it's the nearest large galaxy to our own but it's very similar on it says we it's a spiral galaxy and the thing about our galaxy is that is that we can't see most of it if you live in the southern hemisphere like my wife who's in the back used to when she lived in Australia you can see much more of our galaxy that's much more much prettier night sky in the southern hemisphere because most of our galaxy is visible but it's still most of it is invisible because of dust so if we want to see galaxies we look out and we see this one that's about two million light-years away and it is almost a clone of the of the Milky Way galaxy and it is also by the way just out of interest heading right towards us and about approximately a hundred kilometers per second about 60 miles per second it's heading towards us so if you work it out in about five billion years it will collide with the Milky Way Galaxy and and that won't be terrifying in fact the night sky won't change much at all this will get bigger and they'll get more beautiful in the night sky it'll look that big when it went before it gets to us but the galaxy is mostly empty space so actually when the two galaxies collide but almost nothing will hit anything else it'll just merge together and form a galaxy that's no longer a spiral galaxy it'll be a big round or elliptical galaxy but the night sky for any beings that are on that or will still look more or less the same to be a lot of stars out there and it'll just be a very different night sky but we the fact that we can't we have been able to see our own galaxy until very recently it's kind of interesting because how do we know was a spiral galaxy we used to say it was and so I and there's another video I thought I'd show which I found and it's interesting it's not that old but it's still out of date so I want to show it but nevertheless it gives you a sense of the scale of our galaxy so it starts with somewhere maybe Chicago I don't know where it just was last night and then it's some and then and then there's the earth on the moon but it's going to take you out to see the galaxy to give a sense of how big it is so the earth is now disappeared into the distance almost and you're beginning to see Mars and the Sun and you're travelling ever faster here of course is asteroid belt obviously someone's you already know you and then Jupiter so we're still in our solar system we haven't even left the safety of the cocoon that our Sun provides which is a large magnetic field and solar wind that really protects us from cosmic rays coming from the rest of the galaxy the interesting thing is that humans have met have launched their Saturn have already launched devices that can go out beyond here when this film was made that we hadn't actually launched Voyager and others and others had like like new horizon hidden which now sees Pluto hadn't been hadn't yet visited the planets so these were images from telescopes and what you imagine Pluto Uranus and Neptune looked like but we're still within even after traveling all this time we're still within the cocoon of our our galaxy and many of the outer planets have have ring was just like Saturn Santa's rings are not unique in any way in fact they're quite common and James Clerk Maxwell by the way was the first one to explain that you know you know high school thesis he did so but now leaving the solar system and we're beginning to look back I think that's the Sun back there as we as you can see it the Sun is still the brightest up in the sky we haven't even got gotten yet anywhere else but already at this point it's moving so fast that you're beginning to see what these this artist at the time imagined the outskirts of our gallant the stars in our galaxy would look like if you're moving away from the disk of our galaxy it's not not a very accurate picture but it's okay but you can see the fact that our galaxy is of course not static and rotates maybe you get there when this is far faster rotation than real time because the galaxy rotates and orbits are at the outer stars orbit around the inside of the galaxy once every two hundred million years so our Sun which is about five billion years old has orbit around the galaxy about 50 times which is interesting because it means that the stars we now see of course were at another time and the other edge of the galaxy that the locum a Janu I which of course early all early civilizations did and and and that the Christian Church did because they said the the stars were in violet that the the heavens were created and static are not static at all they're they they move and the fact that the Sun has gone around the galaxy 50 times is quite significant when when we get to things that I'll talk about later so that was the picture of the galaxy of these people had because we've never had a picture of our own spiral Gaussian and you're all supposed to be skeptics so you should be skeptical if we're living here and we see a bunch of star we see if you look out at the night sky see stars in all directions so how do we know that we're in that we're in a in a in a spiral galaxy well it turned out in 1992 about we were finally able to get a picture of our galaxy which hopefully I'll forget hopefully here we go this is the very first picture of our galaxy as seen from the earth and this is the first picture because most of our galaxies obscured by dust so you can't see it in visible light from the surface the earth but the cosmic microwave background or Explorer satellite which was meant to look at microwave radiation from the Big Bang also looked at infrared radiation and microwaves which could not propagate through the surface of the earth and actually looked out at the galaxies at from where we are and you see this is we do live in a spiral galaxy this is our galaxy we're looking we live in the edge and we're looking inward it's an amazing picture was one of a number picture this didn't win the Nobel Prize but several other pictures this satellite took did win the Nobel Prize so we do know we live in a sprog are just kind of interesting why do we live in a sprawling gosh that was a big mystery and it was sort of solved by classical dynamics you can show in physics that if you take a bunch of gas and have it collapse it'll if there's an instability to forming a disk great so there you go the problem is its unstable and the galaxy is 12 billion years old except in Texas but but in the rest civilized world it's it's 12 billion years old and so the the galaxy should not be a disk after more than about 500 600 million years it since unstable and this was a this was a problem it's a problem that got solved by an accidental discovery of other things that I want to talk about this is by the way it produced a nicer prettier image of that by embedding it in the stars you can see so that's the image that the Kobe proofs that you can then get posters up but that's our galaxy so and we your let you live in the first generation of humanity that's ever had a picture of a galaxy she's already a neat time to be alive but the modern era began with several other accidental discoveries and but let me point out that that we live in a time that's particularly interesting not just because it's the first time we've seen you can see our galaxy but it's the first time we've known that our galaxy isn't everything isn't the universe my mother was born in 1921 she's still alive and when she was born and when she was in fact probably first started school the conventional wisdom of scientists and everything else was that our galaxy was it the Milky Way was the universe there was one galaxy surrounded by eternal empty static space that was a conventional scientific wisdom less than a single human lifetime ago this is this is Edwin Hubble and some of you who heard me tell this joke but I'll tell it again anyway in case there are any lawyers in the audience what is what no one wants to admit their lawyer okay well anyway he this is Edwin Hubble who began life as a lawyer and then became an astronomer so there's hope for lawyers and I'm not going to talk about talk about the big discovery that he made that the universe is expanding that that I've talked about that before probably many people in this group but the important thing that he also did was this is the Mount Wilson telescope in 1925 there's a first large telescope he was able to look out and for the first time see that these fuzzy things called nebulae which is Latin for fuzzy language literally were not star systems in our galaxy he was the first one to discover there were other galaxies 19:25 and telephone we didn't know of anything but our galaxy one galaxy now we know in the observable universe there are a hundred billion galaxies in a single human lifetime think how that's changed our picture universe it's hard to imagine anything changing more than that our picture of the universe has changed tremendously in the lifetime of all of you even the youngest people in the audience now to study our galaxy and other galaxies we use these this is it from from Phoenix near where I work these are two Cowboys on the plane and and and one is looking at the other and says I love link hearing that lonesome whale or the train whistle as the magnitude of the frequency the wave changes due to the Doppler effect and and so you all know that when a train whistle comes towards you sounds higher when it goes away it sounds lower and the same is true for different reasons for light and we can use that to study those other galaxies which we can see so much easier we live at the edge of our galaxy we can't look in except with microwaves and infrared because there's dust but because we're the edge we can look up and see all those other galaxies like the Andromeda galaxy and when we look at them we use the fact that when that that when an object is moving with a sofa star emits light of a certain frequency when it's moving away from it as many of you know they'll like it's stretched just like sound weights do but for a very different reason and we call it red shifted because red light is that is the stretched is the longest wavelength visible light and then we're moving towards us we look blue light so if we're looking at a galaxy and it happens to be oriented correctly to us by chance we can actually see its motion by looking at the the the blue shifted light in the direction of objects moving towards us that part of the galaxy it's moving towards us and the red shift the light away and we can actually measure its rotation this will come back and be interesting so so I hope you'll be asking to me so I don't really care about the rest see now we can use this to weigh the universe and and but particularly we can weigh our galaxy and that was a serendipitous discovery that actually solved this problem about why our galaxy exists this is I took this on a picture on the I love n myself if it's a it's a island off sweden swedish isle they used to be a danish island but sweden is like the sort of us of the Scandinavians imperialist it sort of takes over everything in and and so it took over this island this is a guy who doesn't have the tip of his nose so some of you know he asked me tako brah hey he was a he was he was the last were almost the last person to see a star explode in our galaxy and at that time it's a big deal because the emperor gave him an island to because of that discovery and and he built an observatory and he was a real creepy feudal lord a really interesting fellow he had kept pet reindeer and a cat and a pet dwarf and and and and on a chain and and and he was a very weird man he built his Observatory which I visited it's usually closed but on the island and the interesting thing is he would he looked up and did and for 20 years with noble tradition he worked on his back he no one laughed at that joke and I'm thinking anyway um he looked up and he just recorded the positions the planets on the sky and the amazing thing is he did it he did it 10 times better than anyone had ever done it before in all of history which is amazing any time you can prove things by factor 10 is just remarkable and yeah I think since it's late an afternoon I want to make this interactive so I'll ask you a question when are you go our went to the observatory it's actually underground it's it's built a below ground why if anyone gets in I'll be amazed but I just wonder doc David might be might know what was that light pollution no this was the days before light pollution this is when you can see this is when you could look up and see the sky at night it's close close wind but wind is very good wind is the key point really you keeps you away from the wind but the point is this was before the invention of the telescope telescope hadn't been invented so he would heat the way he measured the positions of planets this guy was with sextants and things like that so what you wanted to do was get below ground so they wouldn't move so that's why his thing is like in a crater it's really kind of interesting to see the telescope at me hadn't been invented so he discovered something interesting well actually he just didn't discover anything except he took a lot of data which is the basis of science most of Sciences data taken then he got kicked off the island because he was a creepy fruit feudal lord and a new emperor came in and he moved to Prague there's a nicer city anyway and then he got a hapless assistant May Johannes Kepler who was the exact opposite of him and I could go into long stories about Kepler but I won't I'm probably already talking too long but he did what we all do to our assistants he gave them the data and said figure it out and and and and Kepler spent 20 years trying to figure out it amazingly discovered laws of the motion of the planets that allowed Isaac Newton to become famous so what Kepler discovered truly he would never have been if it hadn't been for Kepler so this is what Kepler discovered a regularity this is the velocity of planets around the Sun and I took this data from a from a high school or university introductory astronomy textbook and I would have fudged the data if I had to but I didn't have to it's fit perfectly by curve and the curve it's fit by and this is what Kepler discovered all of Kepler's laws can be codified in a single equation the square of the velocity of planets around the Sun falls off as one over the distance from the Sun now that that may not sound profound or useful but it it is because what happened is that Newton said aha if I develop a theory of gravity if I say gravity looks like you all learned in high school goes like one over R squared I can prove that planets will go around the Sun with a velocity it depends on one over the square one one over R so velocity squared goes as 1 over R velocity goes as one of the square root of R but more importantly I can find the constant of proportionality it's the strength of gravity times the mass of the Sun and this was a first of all it explained the motion of planets and he used the same thing to look at the motion of the earth and an apple on the earth and to show that this there was a single law of gravity that applied to apples falling in the earth the moon going around the earth and the earth going around the Sun and all the planets going around the Sun and and that the fact that the whole cosmos could be understood in that way was profoundly important we just saw in fact that the the burning of witches in earlier picture today and it's been said and you know I don't know if this is some historians have argued that Newton's development of the universal law of gravity was partly responsible for the ending of the burning of because it showed that as was pointed out that physical effects have physical causes that you can't don't need to blame supernatural things or for what happens and you don't need to blame witches for bad things happening so the fact that the whole cosmos could be comprehended by a single law may have indeed been one of the key factors in making the world a better place okay that's interesting okay but that when I see when you see this this is interesting because when I used to what many years ago when I was at first when I got my PhD and I was a postdoc at Harvard I I i was writing scientific papers and i learned something very important which is if you're writing a scientific paper the most important thing you can do is come up with a sexy title it's true for books but it's true for scientific papers because there's so many papers written every day that if you want to get people to read it you got to come up with a title that will get people to read it now this is relevant because see Newton didn't know the strength of gravity so he couldn't determine the mass the Sun he didn't couldn't determine the mass of the earth either because you could use this for the moon whose lawsuit we know and the distance to the moon so you can measure the mass the earth the first person to measure the strength of gravity was guy named Cavendish 100 years after Newton and its interesting way but I won't go into it again here but Cavendish when I looked at his paper it was called it wasn't called on measuring the strength of gravity it was called weighing the earth which is because he realized if he was the first person to measure the strength of gravity he was the first person to know the mass of the earth and he was but the neat thing is you can do it we can use it to weigh the mass of the Sun because we have this great these great measurements of the planets around the Sun so here's the law a prediction of Newton and if you put this curve off the Sun it be more massive and you push it down it's less massive here's his prediction and so by fitting the data we know the mass of the Sun that's how we know the mass of the Sun we weigh the Sun by measuring the speed of the planets around the Sun and the fit is so good that in principle you could measure the mass of the Sun this way to one part in a million but we can't why yeah I'm gonna make it really tough no no that elliptical is it's you're right they're not quite circular but that that's not the reason and you don't get a prize if you like George did if you answer these questions when it sits well it's may surprise you but the reason we can't is that gravity is the course of the weakest force in nature and it's the worst measured force in nature because it's so weak so we don't know the strength of gravity to one part in a million and therefore our limits on a build the ability to measure the sun's mass and all other masses is due to the fact we only know the accuracy the strength of gravity to about one part in a hundred thousand even after all these years because gravity is so weak so we're limited by understanding the fundamental forces but still one part in a hundred thousand is not bad for the Sun so we do this and we do the next thing that science is always that's really important about science and that is if it works it's like Hollywood if it works copy it and keep copying at Halloween 23 whatever happens spider-man 18 or just do the same movie over again which it seems to be the new thing you know okay so this this again is it Andromeda galaxies but just to the if this were our galaxy we'd be be sure here here in the edge and I told you that the Sun goes around the galaxy once every two hundred million years the Sun is moving as you are moving and we are moving at this instant at 220 kilometers per second about a hundred and probably about a hundred and sixty miles per second around the galaxy we're barreling we don't notice it because we're moving in a uniform speed but so the Sun is moving so the point is look we know the distance from the Sun from the center of the galaxy it's about 30,000 light years we know its speed around the galaxy and we're at the edge of the galaxy so we can weigh the whole galaxy that way and we do it there's the galaxy we're going around so we do it boom here's one number the Sun about 220 kilometers per second unknown distance this is using something called parsecs but doesn't really matter what that single number allows us to measure the mass of the galaxy and we do it we make that measurement and we get it we jump up and down with joy as you are doing now I can see because we get that the mass of the galaxy is a hundred million stars a hundred billion stars forgive me a hundred million stars and what the reason we're excited about that is if you ask if you count the number of stars in the galaxy it's roughly a hundred billion so it works which is always nice but we can do better let's look at objects that are further away from the center of the galaxy then our Sun is and try and do what we did for our Sun and do a better job and measure the mass of the galaxy more accurately and this is what we started to do and the first person to really start to do this was a one who was a wonderful woman named Vera Rubin with an astronomer who was she had wanted to go to Princeton to do her PhD but Princeton didn't allow women in in the 1960s so she did a night school in Washington and was a wonderful astronomer and a wonderful humanoid anywhere well and and she started to measure things and when you can look what happens it's if you if you've got this result in an undergraduate physics laboratory we fail you because it's supposed to follow this curve and we look at objects like globular clusters of the Large Magellanic Clouds satellite galaxies out to up to 10 times the distance from the center of the galaxy that we are and instead of fault you know the galaxy ends where we are we're at the edge instead of falling off like it's supposed to according to law of gravity it remains constant and she was the first one along with other collaborators in Australia and other places to show something really weird the velocity of rotation of our galaxy remains constant even as you go out to ten times the distance from the Sun in galaxies now there's two possible explanations it's either the date is wrong and it's astrophysics so that's likely but it isn't or gravity doesn't work anymore or since the velocity of objects goes as the strength of gravity times the mass enclosed in that region over R if remains constant that means the mass as you go out to ever larger regions must increase as radius so that masiva radius is a constant so that means up to ten times the distance from the center of the galaxy there must be ten times more mass out there than there is here but we're at the edge of the galaxy so 90% of the mass of our galaxy must not shine and physicists with their linguistic perspicacity call that dark matter now when you see something like this that is so anomalous as a skeptic you should again be skeptical this is one measurement which seems to be ridiculous it says that most of the mass of our galaxy doesn't reside in stars or anything hot gas or anything so this happily this isn't medicine so we can look at many samples and do real science and we can we and we look at another galaxy and it's rotation curve and it's constant we look at every galaxy iral galaxy we can see and here are some galaxies whose we can measure the density of stars in those galaxies we can measure determine therefore if the mass of the galaxy is only in the stars what the rotation curve of those galaxies should look like and it doesn't fall off it's constant every single galaxy we see is a constant flat rotation curve that's what tells us that galaxies from all galaxies must be dominated by dark matter and in fact a big sphere of dark matter 90% of the mass of the universe is invisible but that solves a problem it turns out not only is it true but it solved that long-standing problem it turns out if you embed a disk of gas in a spherical amount of matter you have a big sphere of matter and it remains spherical then that disk will be stable so the reason we have a spiral galaxy is precisely because we are embedded in a halo of dark matter now why doesn't the dark matter collapse to form a disc like the rest of stuff it won't do that if it can't emit light because the way.you collapses by emitting energy but if it doesn't emit light that it doesn't interact with electromagnetic radiation and that we think means it's made of new types of elementary power gurgles and what we think the dark matter that dominates the galaxy is is a new type of elementary particle and we are trying to find it one of the reasons I got into cosmology is a particle physicist is that well first of all I wanna know how the universe would end which seemed like a good idea at the time but also because by looking at trying to find this dark matter we might learn about the fundamental structure of the universe because if the dark matter is not made of planets or stars if it's made of new type of elementary particle it's not just out there it's it's going through this room it's going right through your bodies right now is you not off during this lecture and that means we can build experiments underground to look for it and we're doing that that's what we've been doing for the last thirty years we haven't found it yet but if we do we'll discover the nature of the dominant stuff in the universe now it turns out not only does it dominate our galaxy not only does it allow the shape of the galaxy to be what it is but it allows the galaxy to exist if dark matter hadn't been there we can show in the entire history of the universe there would have not have been enough time for normal matter to collapse to form stars and we we know that by building artificial universes on a computer so here is it you can sort of see this blue blob here and it's too much light but you should be able to see what happens as this region expands this is a simulation and I'm going to show you a numerical simulation involving dark matter that doesn't interact electromagnetically and it was gonna and it's so simulation about I think six billion particles of dark matter this is expanding as the universe expands this is a small region about the size of our galaxy and what you can see is things light up when the dark matter becomes dense enough normal matter falls in and you can show that the the stars will form so dark matter has begun to collapse and stars to begin to form and you can see eventually the dark matter and these simulations will this is e when it goes to zero is today will eventually form something that looks like our galaxy this is a simulation and it's only been possible in the last 15 years with supercomputers to simulate this many particles but we now know we can actually make something look like our galaxy and our galaxy can only a form because the dark matter collapsed first we would not be here if it weren't for dark matter so we've already learned in some sense why we're here if you want to ask that which is because dark matters here we learned it by an accident but thinking about our galaxy but our galaxy isn't the only galaxy in the universe okay here is it here's a simulation of a whole region of the universe about a hundred million light years across and we again can simulate this with with supercomputers and you can see very quickly because of gravity dark matter begins to collapse in a time normal matter doesn't collapse so quickly because it has pressure because it interacts with light and and the pressure of light stops it collapsing but dark matter can collapse quicker because it doesn't interact with light and what you what we discovered and this was only again since I was a graduate student we predicted that there should be large filamentary structures these are hundreds of millions of light years across that galaxies should fall visible galaxies should fall in the regions where dark matter is densest and we should see a honeycomb of galaxies that's a prediction okay now we again we never were able to observe that until recently but here's a here's a video from one of the most recent observational projects looking this is the actual universe we're finally able to measure the distance to galaxies and this is a simulation this is on a simulation and some measurement I think about two million galaxies in our neighborhood and we're gonna move through it this is the real universe it's not a simulation and the real universe looks just like this inhalation but if you can move faster this be like each of these things is a galaxy and the interesting thing is this is not this is not just painted on this is not just artificial these are the exact spots where these galaxies are this is our region of the universe until about 15 years ago we could never map the universe even in our local region now we know where we are where our neighbors are and if we and while we'll never be able to have spacecraft that can't reverse these kind of distances we can do it in our minds and we can do it having discovered where they are if we could this is what our region of the universe would look like and the galaxies aren't randomly located they are on filaments and large scales giving us further confidence that this universe of dark matter is what the universe really is and it's the first bit of real evidence that confirms something that that that we should all realize is that as we are completely insignificant that everything we see is completely insignificant in a cosmic sense because while the Stars are here the dominant stuff in the universe is dark matter it's responsible for our existence and you could get rid of us and everything we see in that beautiful night sky above that river that river of the Milky Way and the universe would be essentially the same we are just cosmic bystanders you know in a sea of dark matter and it turns out dark energy which I won't even talk about today we are so much for universe made for us it's clearly we are just lucky bystanders and we should enjoy it okay this is the universe we see this is the hot one of my favorite Hubble Space Telescope pictures the Hubble Deep Field every dot in this image is a galaxy except for that one that's a star but so and you can the the the the the faintest galaxies here are about 12 billion light-years away from us all but 90% of the way back to the beginning of the universe so the light from these all these galaxies is interesting to think about whenever you look at an image like this it should inspire kind of amazing thoughts because these galaxies so this light left two faint galaxies light left that galaxy ten billion years ago our Sun is five billion year four-and-a-half billion years old that means it left before our Sun and Earth and an entire solar system formed but more interestingly our Sun will last about 10 billion years most main-sequence stars like our Sun will last 10 billion years that means most of the stars in this picture don't exist anymore they're gone they burnt out and any civilizations that existed around those stars and had skeptics conferences they're gone too and we'll never know about it and that's what's going to happen here everything that matters to you everything that matters to each of us is important to us but the universe not only doesn't care about it in a in a time in a cosmic time that seemed like a wing to the line everything that we've ever accomplished as a species will be forgotten because we'll because the earth and everything around will go now maybe we'll be smart enough to leave the earth we'll see but quite likely our sons gonna burn out and in the long run everything we cherish will be gone so enjoy it while you can okay going back to our galaxy that's that picture we can see in from the southern hemisphere it's beautiful but well let me go back to that actually that picture so here are the stars you can see now one of the big questions that humans had eventually once they began to allow themselves to think more about a universe in which they might not be the center was okay the earth exists does life exists elsewhere in the universe it's one of those pressing questions today it's been about it's been a question question of any everyone every child has asked that question look up at the night sky are we alone in the universe it's terrifying to think that we might be alone for some people it's not it's comforting because that makes him seem like the universe was created for them and and and in fact the Catholic Church burned people regularly who suggested early on that maybe the earth wasn't the solar system and the Sun wasn't all there was that there were other planets and the question is are there other planets and could there be life this is a question that may be answered in the lifetime of some of the people in this room and again I would never have thought in my lifetime that we'd be able to even get as far as we have because so let's say if we want to look at a planet around a star so this is a planet around a distant star well you can see it's it's it's cult in the star but that's if you're close by if you actually look at what the what the earth say would look like if you were far away then we can sort of move away from it and see what the actual earth would look like if you are far away from the star and of course it would be totally obscured by the star and the star that's if you're close to the Sun but if you're far enough away from the Sun if you're on a distant planet looking around for life in our solar system this is what you see and so it seems impossible that you could ever after you look at planets what is amazing is that we can and again I'm not I'm not an experimentalist because half because I wouldn't have thought we could ever do this so there here's here's a here's a planet going around a star and what happens is the planet gets bright when it's behind the star because it reflects the light and then it when it goes in front of the star it reduces for a second the brightness of star and then it's bright again because it reflects the light from the star until it goes behind the star and it gets dark now this is this of course is far over over scale this is what you'd expect to see but this effect it would be less than less than 1% in the brightness of the star but astronomers weren't daunted and so among other things we beam a there they're stupid or they they they're good and in this case they were good this is the Kepler telescope which was sent out to look at a region of this of the galaxy a small region the galaxy right here and just stare at those stars every single day and measure thee and measure the brightness of those stars every single eight again this could not have been done when I was a graduate student it could have not have been done when I was a junior faculty member because we needed C CDs we needed objects that allow us to measure and digitize the position of millions of stars and look at them every night and compare digitally because humans could never do that themselves and what what of course the Kepler satellite is discovered and it's a little dark was here is over two thousand planets around nearby stars and what you can't see is that most of the planets are inside the orb of mercury here although here of the plant set of planets this is not all of them this is just some set mercury would be out here and the reason for that is that well why is it why is that I'm gonna ask again because I want to keep people awake anyone got an idea exactly right if the if the if you got Jupiter or you got a planet that's orbiting once every twenty years in order to see that effect and and and replicate it enough that you can test and get rid of the noise you have to measure it for over 100 years we have been able to do that so what you look for is planets that are going around their stars work very quickly well how do can they do that because they're close by moreover not just they're close by that most stars in our galaxy are smaller than our Sun and so the planets can be closer in and what we've discovered is what's amazing is not only does almost every star have a solar system around it something that many of us thought was true 40 years ago because of physics arguments we now know it but their solar systems we never thought were possible we all thought we thought we're typical it's always reasonable to assume your typical we have rocky planets inside gas giants on the outside what we discovered is everything it exists exists stuff we thought was impossible there are solar systems with gastrea it's inside how can that be well we now realize they can move I never thought they could they would because of the effect of other planets we've discovered lots of planets and in fact around small scars including around the nearest star to our own box myth Centauri we discovered planets that may be in what's called the habitable zone which means there's liquid water maybe and we know when we're trying to look for life we know we're like drunks who leave a bar and and and lose their keys where do you look you look under the lamppost so why not because it's there it's the only place you can see it right so when we think of life in the universe light lots of different life can exist I mean you talk about Star Trek and Star Trek has been good to me so you know mostly actors in Star Trek had most of aliens had two arms and two legs because most of the actors do but but but we have no idea what the spectrum of life can exist in universe what systems we've discovered extremophiles here on earth that can live in regions of a boiling water acid all sorts of regions that we never thought were possible but we do know that life arose here on earth because there was liquid water organic materials and sunlight so we say let's take a first pass and assume if we're looking for life elsewhere in the universe will look for liquid water organic materials and sunlight and all of those things exist and so we now know that there are many many many many planets including potentially around the nearest star Rome four light-years away that may have liquid water which is one of the reasons why I guess I'm excited I'm part of a program a very science fiction like program called breakthrough starshot that's funded by russian billionaire and me and stephen hawking and a few other people are about 20 of us are in this planning committee to try and create a spacecraft to go to the nearest star in a human lifetime at 20% the speed of light we do that because a spacecraft is one gram because you're never gonna send humans there and forget whatever Elon Musk may think he was gonna do it's not gonna happen but we did it using light a light sail we shot we're gonna have a sail and we're gonna have lasers pointed at it if it works and accelerated up in two minutes to 20% of the speed of light and then five you in in there for twenty years it'll get there it's ten years of Rd twenty years to get there I'm gonna put a little camera on it and take a picture of that planet and maybe you know see a water world and it may be green all sorts of neat things and then it'll take five years for that picture to come back 35 years that's why I work out every day I want to be there then but what we're we may not need to do that with with advanced telescopes and there are planet terrestrial planet finder telescopes we may believe the image plants and look for things like oxygen free oxygen didn't exist on earth life created the oxygen that's on earth it's very important if the oxygen was there at the beginning life never would have formed because oxygen is a poison if oxidizes and all the organic materials on earth would have been oxidized of oxygen it had been there it's not so if you look at a planet you can and you can visualize its atmosphere and see it then maybe if you can look for oxygen spectral lines of oxygen and that's a good sign that maybe life so stay tuned we may find out in this decade or the next decade about life elsewhere in the universe and that may be well would that be a profound change I don't know but it would be profound for me okay now well back to our galaxy oh yeah I remember what I want to do we're getting near the end oh good okay I'll be about an hour or so um he told me that we wanted me to go at least an hour so I have to okay so this is our galaxy and what you notice of course is the center of our galaxy a dense region the center of our galaxy I want to now to take you on a voyage to the center of our galaxy here so let's let's do it [Music] the fact that we can actually visualize scars near the center of our galaxy is amazing these each time looking at regions that have been amplified with telescopes and when we look at the center of the galaxy we can actually if we measure it over 30 years measure the motion of those stars in the center of the galaxy and what we discovered is something remarkable so let me look at this in a different way now I want to show you the years we did it and by we had only me okay but watch this this is over 1992 to about 2006 so we saw that's and this is repeated so you can see it now why do we care about the motionless stars in the Senate galaxies because if we focus in this is what we see we see or they orbit and we can use the law of kepler and the law of Newton and way whatever this star is moving around and this star and in fact we don't have to just do this star we can look at all of these things so let me just show you another video where you connect we've actually labeled the stars I think this is a video there we go and we look at not just one star but many stars and you can see they swing by something that isn't shining it's not a Sun they're in the center of that ellipse like there is for the solar system this is a hand-drawn star in case you wondered the Stars don't look like that um they're all orbiting around something dark and we can we can measure the mass of that thing by using exactly the same principles that I told you for measuring the mass of Sun because if it works copy it and what we discovered whatever is here has a mass of 2 million solar masses and this region is so small that the only way you can put 2 million solar masses in a region that small is if it's a black hole and so we've discovered we've now actually seen the object's orbit a 2 million solar mass black hole in our galaxy and it's amazing to me that we can actually visualize this and that astronomers can measure over decades carefully enough the motion of stars to see that there's a two million solar mass black hole nerve center Bhargavi it turns out we discovered that there are black holes in the center of almost every galaxy in fact our galaxy is anomalous in Andromeda there's a black hole of two billion solar masses and one of the big open questions in in this kind of astronomy is the chicken egg question which came first black holes or the galaxies because maybe you had to have gas collapsed and form a massive black hole around which other gas could collapse or maybe stars would form and combine together and collide and collapse into black holes that would merge this is an open question we don't know the answer which came first there are two ways we're looking for the answer one is to build the James Webb Space Telescope the next generation Space Telescope which will be launched in 2019 because it will be able to look back to the first galaxies that ever formed and look for black holes in those galaxies to see whether which formed first so it'll look what we call first light it will look at the first stars that turned on we think around a time around 300 million years into them into the Big Bang the first stars would have formed and that's one of the many things that James Webb Space Telescope will do but the other is to try and see if there are other black holes in our galaxy and I want to I want to serve getting near the end by telling you about again just thinking about our galaxy taking you to the most amazing discoveries that we've made and some of the most amazing ideas I know I mean where you'll see you can decide if you like it did that just go off for a reason well there it is so this is the LIGO Observatory this is in Hanford Washington in an in in a plane of I guess close to eastern Washington there's an identical one of these in Livingston Louisiana and this is a gravitational wave Observatory this is that this was designed to measure something which once again I would have never thought we'd ever be able to measure Einstein told us that that matter curves space and therefore when I do this I'm curving space but I'm moving around so I'm producing a disturbance in space and you can calculate that that disturbance will ripple outward at a speed equal to the speed of light just like when electrons jiggle in an atom they produce light electromagnetic waves that travel the speed of light general relativity tells us that when I do this I produce a gravitational wave a ripple in space that moves out there ripples in space going through all the time but you can't see them because gravity is so weak but right now this room is full of gravitational waves and it's causing the size of this room to change when a gravitational waves comes by the room gets a little smaller in that direction and a little bigger in that direction again for some of you who drank too much last night you probably noticing that right now but but but that it's there but you can say well could we ever see gravitational waves and say let's look well the intensity of gravitational waves gets bigger if you have more violent motion of matter what more violent motion of matter could you have them the collision of two massive black holes if they exist in our galaxy two solar mass black holes so this detector was built to try and look for that if you come back to it instead of me okay and well all you do is if a gravitational wave comes by here comes down this to this arm which is four kilometers long and this is four kilometers long this arm will get smaller and that one will get bigger with the frequency equal to the frequency of the gravitational wave they'll oscillate okay so that's all you have to do what's easy but the challenge is amazing because it turns out we can calculate what you'd have to do to be able to see the collision of two black holes in our galaxy or or in a nearby galaxy of two solar mass black holes and and the requirements is amazing to measure two solar mass black holes colliding you'd have to be able to measure the change in length of this four kilometer long tunnel by an amount equal to one one thousandth the size of a proton and you laugh and you should because no one would ever know science fiction writer would ever dream of suggesting to do that but that's what these guys decided they could do I thought they were crazy because if a truck hits a pothole here it produces a bigger signal okay if the wind blows it produces a bigger signal now and you also have to be able to make the measurement which is very complicated because you what you'd weigh to do is run lasers back and forth but that's one of the reasons there are two of them because there's noise in this all the time but there's noise in Livingston Louisiana detector all the time but at the speed of light if a gravitational wave comes through here it takes 8 milliseconds to get down to Livingston Louisiana so what you look is that is a signal in both detectors and you look for the exactly the same signal 8 milliseconds later and in September 15th 2015 an amazing thing happened the detector had just come online it had just been improved after 15 years of being developed and Ray Weiss who recent was one of the three people who won the Nobel Prize this discovery said ok it's it's we got the right sensitivity let's do an engineering run we won't take data ok the graduate students being graduate students happily didn't listen to him they turned on the detector and one hour later they discovered the signal from two black holes colliding 1.3 billion light-years away now think of that for a moment that meant the signal it was just a 2/10 of a second bursts as I'll show you in a second that signal was traveling for 1.3 billion years if they turned on the detector an hour later they would have missed it it's amazing how lucky it was and it was a beautiful signal and this is this is what it would look like if you could see it because the black holes are so massive this is a black hole of 36 times the mass of Sun this is a black hole of 29 times the mass of Sun and they Bend space around them so as they move around if you look through them the stars behind them get lens and this is what you'd see now this is slowed down there really going around each other 200 times a second 30 times the mass of Sun 200 times a second it's hard to believe that can happen in nature but they do but watch what happens when they coalesce you'll see rip in space watch carefully here we go see the space ripple that's now this is an artist's rendering this is not what but that was the emission of gravitational waves now there's two things I want to say that make this amazing one is and I need a mathematically literate person to but you're all mathematically literate so we had a 36 solar mass black hole at a twenty nine solar mass black hole combined together 36 and 29 combined together they form a black hole of mass what no no it's 136 and 25 we need mathematically of 29 math 65 who said 65 was the first person you wrong because in fact they form a black ball of mass 62 times the mass of the Sun why because three solar masses of energy were emitted in gravitational waves now you should if you didn't sigh then let me put it in context the Sun which is burning a hundred billions hydrogen bombs every second for ten billion years in its lifetime will convert less than one percent of its mass into energy in two-tenths of a second in that instant that collision produced three solar masses of energy in gravitational waves meaning in that two-tenths of a second that object was emitting more energy in gravitational waves than all the rest of the stars in the visible universe combined are emitting an energy isn't that amazing now if you weren't amazed by that try this sometimes stars collapse and don't form black holes sometimes they form objects called neutron stars when it starts tars explode they what happens is they collapse the inside of the star collapses until finally it becomes so dense that it becomes one gigantic atomic nucleus a neutron star a neutron star is that basically the mass of the more than the mass of the earth a fraction of the mass of Sun you know that whose size is the size of Manhattan all that material is compressed into an atomic nucleus saw the density of an atomic nucleus but then nuclear forces take over and it can't compress anymore and that produces a shockwave that blows the rest of the star out a supernova explosion but the neutron star that's left over weighs billions of tons for each cubic centimeter of material and most many many stars and their life as neutron stars and what's amazing is it turns out for some reason that it still amazes me even when a star explodes sometimes the nearby star around it that's orbiting around it survives and then it explodes and it turns out most neutron stars are in binary systems so neutron stars are dense and massive not quite as dense in massive as black holes but we figured that if the if the gravitational wave detector can detect colliding black holes it might detect colliding neutron stars and in February of this year LIGO was operational and another detector called Virgo and they detected the collision of two neutron stars but what's neat is with a black hole there's nothing there but gravity it's a hole in space and the only thing that's produced is gravitational waves but if you have a neutron star you have stuff so when those objects are organized or orbiting each other and colliding sure they produce lots of repetition ways but they produce a lot of other stuff and Virgo and LIGO were able to tell the rest of these astronomical community hey we just discovered a gravitational wave from two colliding neutron stars and every telescope in the world of every type was turned to that region visible light ultraviolet x-rays gamma rays it's the first time that 70% of the astronomers in the world all looked at the same thing because they were alerted by by LIGO and Virgo and and this is serve again an artist's rendering of what happened but so the here's the here the two neutron stars colliding and the first thing you're gonna see a gravitational waves emitted that's it what these sort of kind of that's what so and there's the sound of the gravitational waves it's actually in that in the audio frequency but then you produces incredible bursts of gamma rays and then afterwards this incredible burst of x-rays and then Ultra of all I didn't visit a light and we could predict that using laws of physics what we thought would happen now what's amazing to me is we have confirmed something that should make all of you how many people are wearing something gold right now some of you okay good some of you excellent and it's valuable to you okay well where does gold come from it's been a big mystery from the stars but no it doesn't because as some of you heard for me before and I talk about the history stars when stars burn they make helium and then carbon and the nitrogen and oxygen iron I mean silica oxide and silicon and then iron but they stopped burning when they form iron they can't cuz iron is the most tightly bound nucleus in nature stars can't burn fuel higher heavier than iron but gold is where could it come from we imagined that maybe it might come from a place with where the matter was very dense and there were lots of neutrons neutron star collisions maybe the gold came from there when we if you can go back to the image when we when we were actually able to measure over the period of the next month radioactive elements forming and decaying producing x-rays and observed that in that collision one solar mass of gold was formed but that means not only were we right but it means think about it it means if you're wearing gold then the atoms in your ring or whatever you're wearing had to come from the collision of two neutron stars the densest objects other than black holes in the universe and then make their way to you I mean isn't that amazing I mean it really is it's worth applause because and it's all comes it all comes from just thinking about our galaxy so I think I'm exhausted you there okay you know there's the gold of course and and then we're washing the Olympics now I I actually thought of this first because it's kind of interesting that it's you know I try and connect this to culture in a way it's kind of amazing so the Incas were destroyed because we wanted gold okay Gold has been a geopolitical driver and throughout human history and it amazes me so that this central aspect of our of our culture that's caused civilizations to be exterminated is an accident of a remnant of sava of a the most amazing esoteric collision in the universe and how it's affected our culture so how the way we behave is an accidental remnant of these amazing obscure esoteric things in the universe okay that's what happens when you think about our galaxy just looking at the rivers in the sky and the shirt was pretty to imagine for these for these primitive civilizations that the that the Milky Way was a river in the sky it was a beautiful story but like everything else with science does that religion hasn't been able to do and never can do is take that beautiful story and make it better and follow it wherever it takes you to discover things you never would have dreamed of and that's the beauty of science thank you Lawrence Krauss ladies and gentlemen [Applause] I'm sure there's no questions so we can know we have time for a bunch of questions so hands up who wants first questions questions right here we could put a logo in orbit or on the moon could we detect earthquakes instantaneously on earth no um you it's easier to detect earthquakes on Earth by being on earth but LIGO but earthquakes anything that happens on earth would be undetectable by logo but but what we want to do I don't know I'm playing with this now what we want to do is actually put not lie go in space but we want to put a gravitational wave detector that's much bigger LIGO is four kilometers long we want to put a gravitational wave detector the first one we want to build in space it's four million kilometers long now how can we do that well in space you don't need a tube you just mean mirrors at either end so you if you're very careful you can you can hook up mirrors at either end and what we've discovered in a pilot mission that was just setup is we can actually keep them at a distance where we can actually in principle do that and if we do that we may be able to detect a whole different type of gravitational waves from a whole different set of objects and not in the next generation or the next generation but by the 22nd century we may be able to detect gravitational waves from the Big Bang and then we will be observing the beginning of the universe so stay tuned some of you next question I heard about The Shard that came through the solar system a while ago oh yeah refined the orbit from that or anything well ya know recently it was kind of the first I think was the first we know what happens but it was the first direct observation of an of a extra solar system visitor not a not a being but but it was actually a an asteroid which came zipping through the social system and had a bigger than escape velocity from the solar system probably produced in the explosion of a star or solar system and it was and so we can actually see that it's escape velocity was bigger in the Sun we can measure it over a few weeks come zipping through and so we now know that something we knew before we now we know observationally we are visited by by visitors namely asteroids from throughout the rest of the galaxy that could be important because coming to the biology again life originated on earth about as early as the laws of physics allowed within 500 million years to fold the oldest fossils are discovered in Australia in a few other places now that's really short time the life couldn't have survived formed earlier because there was bombardment on the earth by other asteroids that would have vaporized any oceans but Jupiter ate them all or it kicked him out and over the over about two or three hundred million years the bombardment by asteroids went down and the earth became quiescent and could have oceans and within a few hundred million years of those oceans forming the oldest false fossils formed now that means one of two things either life is just easy to form in which case is ubiquitous everywhere in the universe which would be great or perhaps did life didn't form on earth maybe it arrived on earth and Francis Crick was the first person suggest something called panspermia which was when the idea that maybe because we now learn that organic molecules exist in space the basis of amino acids are observed in our in our in our solar system and can survive potentially interplanetary and maybe interstellar voyages so maybe complex organic materials from deceased life-form arrived on a host asteroid and polluted the earth allowing life to form we don't know but it's certainly a possibility and so the fact that we now see these things coming in happily didn't it hit the earth but some of them do and some of them well if we wait long enough there'll be an extraterrestrial extra solar system asteroid that will hit the earth and and and do great damage but so it's really an interesting object to see because it and it may answer these questions as well well we will discover that a bunch of ways one by looking for life elsewhere in our galaxy I'll answer worse near the back regarding the dark matter and how ninety percent of the known matter or at least the unknown matter in the universe would be not emitting any type of visible or spectra of light in any way would it be possible that those the material that is causing all that gravitational attraction be particles of which we know hardly if at all interact with known matters such as neutrinos or Higgs particles well it's a very good question the Higgs particle interacts strongly with matter sand and with light so it's in a way but well it would it would Higgs particles also are not stable they they actually decay in a fraction of a second but neutrinos are great candidates for dark matter they were the first candidates for dark matter because there are 10,000 billions neutrinos going through your body every second right now coming from the Sun and you don't notice them they're the perfect candidates for dark matter and in 1980 I remember when I was at when I was a graduate student a discovery was made that said hey these neutrinos we think have exactly the right mass to be dark matter and it was wrong and then we built simulations of a universe that would look like a universe dominated by neutrinos and we discovered it didn't look like our universe so neutrinos are the perfect candidate for dark matter but they're not so we we look at objects that are like neutrinos heavier versions of neutrinos and it turns out every fundamental theory in physics right now that goes beyond what's called the standard model predicts particles that have those properties and that's why we're actually doing a contest we're building detectors underground I'm happy to say many of which I proposed years and years ago underground to look for dark matter but we might also create it at the Large Hadron Collider which is also looking for physics beyond the standard model so we don't know who will discover dark matter first whether it will create the laboratory you know in a microcosm of but of the Big Bang or whether we'll look at the ones that come from the Big Bang or maybe we're just wrong which is also exciting it more exciting usually to be wrong just like when Vera Rubin got the wrong answer there was much more exciting than if she just who they'll care if we got that mass of the galaxy to five decimal places but what no by being wrong we discovered dark matter so being wrong is really neat there's a Bob novella from the skeptics good you give me a quick overview of the next quadrillion years what's the latest thinking at the end of the universe it's it's not looking good it's gonna end badly so the future is miserable on the whole so the next quadrillion and it's good you asked in those terms because um basically because the universe is expanding and I didn't talk about in this lecture it's expanding faster and faster and faster all the galaxies we now see will disappear because eventually they'll be moving away from us faster than light which is allowed rely to you in high school we don't lie you just have to parse them more carefully you say nothing could travel faster than light and that's true nothing can travel through space faster than light but space can do whatever the hell it wants and space can expand faster than light and it is and it turns out if we wait two trillion years then every galaxy we now see beyond the local cluster that's bound to us will be moving away from us faster than light and will have disappear and I find it very poetic because it means in two trillion years by the way they'll still be stars main-sequence stars is w small stars and our galaxy will still exist it won't be spiracle anymore to be elliptical because a drama that was collided with it and other galaxies as well but you can imagine life forms existing and evolving but we can still say that evolving around stars in our galaxy and producing astronomers and scientists and they'll build telescopes and they'll look out and they'll see the universe we thought we lived in a hundred years ago they won't know of any other galaxies they won't know the universities expanding because our probes for the expansion universe or other galaxies so it's really it's it's not only we live at a various time namely the only time when we can know we live at a very special time which is facetious because every time it's special but but it also means that the longer we wait the less we'll see I've tried to argue to Congress with that should mean we should build more telescopes now but the two trillion years in two years are very different for Congress people and so they won't do it but anyway so the future is cold dark and empty and eventually beyond that the stars in our galaxy will burn out the amassed together to form a huge black hole which will if we wait longer due to something called Hawking radiation will evaporate into radiation and there'll be nothing left but radiation getting ever colder in a dark empty universe and that's the future it's a good place to end well let's just do let's just do one more let's just okay what's I know I know it's it's a good it's a good place of a kind of a sad place to so maybe I'm sure it's gonna be awesome well I myself I'm actually a physics major and very quickly I want to thank you for your amazing inspirational lectures eventually and one of my big inspirations for being a physicist myself cosmologists Pacific oh thank you thank you friends um so right now I'm at a still at a community college and one of my favorite hoping to transfer this semester in my physics professor he's I wouldn't call him a creationist but he's certainly a Christian Christian and when he was going through the section on cosmology specifically when we engage in the topic of fine-tuning he started essentially time doing trying to his insinuate that this must be indicative of a divine creator and he said that uh I probably wouldn't say divine but he certainly said he certainly insinuated creator and he said that the only reason why the multiverse theory exists is just to try to do a way to try to solve and get rid of this fine to any problem and I was wondering how would you respond to that I mean yeah in in in he's responding I mean a real book called the universe of nothing and a lot of people respond to it because I talked about the fact that our current pictures suggest not only the picture I've told you about our university that our universe isn't unique quite likely there are many universes and that may explain certain features of our universe and the the theologians say that's them just saying they can't explain the answer now there's three things I'd say about one is a quote that I've said often and I've seen on the cops coffee cups now but but it's true so lack of understanding is not evidence for God it's evidence of lack of understanding okay and so it is true we don't understand a lot of things but what's really neat is we try to understand them we don't just say you'll never understand its God because that's cold for not thinking okay so that's the first thing but the second thing is we've been driven to this idea of a multiverse not because it was attractive to physicists in fact most of us it's kind of repulsive in many ways because it might mean the fundamental constants of nature well I grew up wanting when I was your age wanting to be a physicist to know why the universe was the way it was but if it's just an accident it's kind of depressing right if the fundamental constants of it and if they were different we wouldn't be here right that's the center Opik principle which they are what they are because we're here to see them not because we were we were created to see them but if they've been different we wouldn't be around so there may be universes where there aren't such meetings because the laws of physics don't allow such meetings so we're not surprised that we find ourself living in a universe in which we can live it would be amazing to find the opposite you so that's it that may be true but it's not very appealing in it from a fundamental perspective but we've been driven to it so what was it it's totally different than the notion of a creator where you start with something you want and try and make all the evidence fit which it doesn't but I'll make all the evidence fit instead like I showed you here we follow where the data takes us and the data has taken us not to the idea not just to the idea that there may be a many universes but as I described in that same book all the data suggests that our universe was created spontaneously from nothing and if you asked what would a universe look like there would be created spontaneously from nothing by known laws of physics and no supernatural shenanigans it would look just like the universe we live in does that prove it no but it makes it plausible much more plausible than the fairy tale your professor believes in thank you that's that's an ending that's how - it Lawrence Krauss please gentlemen Lawrence Krauss awesome we go where the data takes us I love it I love it let's just finish out the day I'd like to invite every volunteer and every speaker that's still here please come on up onto the stage I know it's awkward and weird but come on up come on up come on everybody every volunteer every speaker please come on up to the stage we're gonna do a pic get your phones out take pictures of everybody please post this now on all of your social media come on up on stage come on up on stage we're gonna do a big picture oh look at this look at this Hass hashtag logic al la no space or anything right just no dashes altogether get your camera's out look at this look at this oh that's fantastic yes les les tall people in front please if possible les tall people in front of possible oh look at that how about a round of applause for all these people ladies and gentlemen making logic al la possible thanks to Vall our volunteers behind the curtain we had Mike we had new networking all very very diligently making stuff work there's Mike over there thanks for making it all possible are we good I think that's fantastic Thank You audience for coming don't forget there's still a dinner this evening I'm doing a concert tonight as well tickets are still available for that if you want to do that we're gonna have a fun little time and here is the the man himself here's Bruce thank you all for coming in one big hand for George making this happen thanks everybody one last announcement we have decided to put on a 2019 Logic alum so your friends tell your buddies tell your science friends tell your skeptic friends we are putting it on we have no idea where but that's okay because we have the volunteer crew and it's an all free or not free it is all free volunteer all free for me it's a volunteer crew so please thank them on the way out they spent three days not only that but one big plug for Melissa are you here Melissa Melissa give a round my coordinator spent months and months and time and her husband Tom spent time Thank You Melissa so much and I guarantee you'll get something more than just a volunteer fee next year I'll see you all next year [Music]

Channel: thegoodatheist

Views: 44,888

Rating: 4.7409639 out of 5

Keywords: Lawrence Krauss, Krauss, Logicalla, Logical-la, science, scientific conference, scientific, atheist, secular, bruce, gleason, thegoodatheist, the good atheist, atheism, los angeles

Id: V2BE8gHQ1Uw

Length: 82min 0sec (4920 seconds)

Published: Sun Sep 16 2018