(Exclusive) Lawrence Krauss New Lecture The Edge of Knowledge At Bower's Museum 2023

[Music] welcome to the edge of knowledge with Lawrence Krauss uh we are very excited to have him here in Orange County and we hope you enjoy his lecture um there will be an intermission after um he finishes the first part and you'll be encouraged to uh write down questions that you'd like him to address in the second part of our program um so I hope you enjoy it and have a good time you thanks Andy thank you and I think I think this one works and this works too good thank you it's I met many of you out there and it's nice to see you here it's it's very it's a lovely venue and so it's really nice to have a kind of intimate conversation and um as I told some of you and this is the first lecture I've really given on the new book the first full-on lecture so you're guinea pigs but but the I find it's particularly appropriate to talk about this book for for this group and for the origins project Foundation because uh we're Kindred Spirits the book is about Mysteries and this is one of my favorite quotes from Richard farman which you which is at the beginning the new book but uh and I don't feel frightened not knowing things by being lost in a Mysterious Universe without any purpose which is the way it is really is as far as I can tell and our Origins family is all about that it's people who are not afraid of not knowing things because that's an invitation to discover and we try and do that with our events like this and our the podcast where we try and bring together uh the most exciting people from today talking about issu isues that are incredibly important for the 21st century and beyond and it's really the origins of the future in that sense and with our trips a number of the people here have been on our our our Origins trips and the board members have have uh may have talked to you about it um that our next trip is in the Galapagos and I think the trip after that will be in Bhutan so go to the origins website and uh and come join us and um in any case so I think this this lovely mixing of mystery and excitement is particularly appropriate to introduce here in this in this place so I want to talk about that um I often show these two pictures because I think it puts in perspective of how much we've things have changed when I when I started to write the book uh my British publisher reminded me of a book by Sir James jeans in 1930 which was called The Mysterious Universe and uh almost everything in that book is now out of date and this was the this was the universe not not as well observed as it is here because this a beautiful telescope picture of the Andromeda galaxy the nearest large Galaxy to our own uh about 2 million light years away but it looks like our our own Galaxy would look like this if we were out at Andromeda but the important thing is in 1923 that was it people didn't know of any they didn't even know of the androma Galaxy they only knew of our galaxy the milk way was the universe and okay and 80 years later okay 100 years ago but 80 years later this is a picture from the Hubble Space Telescope and I was going to show a James web picture but doesn't look that different the it's a little more resolved but uh you now see now we know except for that in this particular image except for that that's a star every every dot every point of light in that image is a Galaxy there there were more than 100 billion galaxies in the observable universe and in an 80-year period it changed from one to 100 billion the mysteries of the universe are are are profound and evolving and I certainly hope that 80 years from now after the publication of my book that their Mysteries will have dramatically changed and it'll change because people are interested in keeping asking questions scientists and the public and the public who want to support science and who want to support progress by being willing to ask any question regardless of how uncomfortable it might be to ask that question and is not afraid to search for the answers in any case I think the book divides into five pieces and I want to pick an example from each piece and I think the first one is uh probably the area that most people that touches us most time it's the most personal of all the things time is an essential part of our lives lost time Tom we wish we'd regain I think for the beginning of each chapter I have a a quote and one this one Kurt vonet always puts things very well he said here we are Mr Pilgrim except I spelled it wrong trapped in the Amber of this moment there is no why we all are trapped in the in the moment of time and the big question is is that an illusion or not some philosophers some physicists think time may be an illusion I always think that's kind of a useless thing to say because it doesn't really matter if it's an illusion if you miss the 510 train to work and you lose your job it's not an illusion and the question is if it is an illusion the really interesting thing is how did it come about and and time is is still among all the fundamental quantities in the universe probably the the most mysterious quantity because it begs so many questions but our picture of time itself of course has changed a lot in in the last century and um we'll see if I have to stand closer to get it to go there we go before I had my eyewatch uh I wrote one of my books when I I used to visit Zurich in Switzerland and I always was desperately worried that my watch was wrong because I would take the train in and the Swiss trains are exactly on time and so I knew what time it was by take by getting to the train station and seeing if I'd missed my train and now now we all have atomic clocks on our hands so it doesn't really matter but uh Switzerland is obsessed with time in that sense because the trains go everywhere from any spot at Switzerland there's a train leaving every two minutes or so and that's not inappropriate when we're we're talking about time because the nature of time was was changed by trains um it used to be in Switzerland and throughout Europe that each Canton each City had its own time zone and that was okay when you were traveling by horse but once trains were created and you could go from City to City quickly it became very inconvenient to have many time zones and and in regularizing time became essential and of course that's what slowly happened now that regularization of time uh was important in the sense of trains and it was also important for someone who worked right opposite this big clock this is in Burn Switzerland and Einstein Albert Einstein worked in a patent office and every day he could not see in the clock but the train station and he changed our picture of time and space forever and it's not surprising that when he began to think about how to describe the new sense of time he used trains to do it and what he realized is that well Tom may be an illusion but we know the time that happens to us is quite personal and the time that happens to you is quite personal but I make the Assumption every day that your time is my time that when I'm reading the clock at 7 o' that you're reading a clock at 7 o' but it's an assumption because I can never be in two places at once and Einstein spearheaded the notion of thinking operationally what can you actually measure and realize that in fact this assumption that my time and your time are always the same is wrong and he showed it was particularly wrong when things speed up and the example he gave was uh what involved a train and and I'm not going to go into the details of Relativity except to point out one of the consequences of Relativity or actually two as you'll see in a moment one from special relativity so let's say we have a train and the conductor has gone through the train and synchronized all the clocks so they're all ticking at the same rate okay on the train the that it's 12:00 noon on one end of the train and it's 12:00 noon on the other end of the train at the same time What Einstein's theory of relativity showed and it's true in spite of the fact it may seem crazy is if that train is moving very fast relative to us and we're watching it two things happen you notice the train is squished up it's actually smaller that it looks like when it's standing still that's not a that's you might say that's just perception but it's not perception it is smaller for you it's not smaller for the people on the train both people set to people are right but the other thing that's particularly weird is that this you can look at those clocks that were synchronized and you find that they're not synchronized anymore that if it's that the clocks uh on the on the front of the train are actually ahead of the or the back of the train are actually ahead of the clocks in the front of the train so if it's 12:00 on the front of the train uh it it could be 121 one in the back of the trade this of course begs all sorts of questions about causality because if if two things are simultaneous for me but they're not simultaneous for you if one event happens after another event for me and for you one event happens before the other event and all these all sorts of Notions about causality seems to go out the window it turns out they don't there's a kind of cosmic cash 22 that I won't go into but the but what it became clear was that time was relative as is space and that depended on your state of motion and and what you presume other people are measuring in terms of time can be wrong now this was all hypothetical when Einstein developed relativity because he couldn't measure these factors we can now measure these effects every day in undergraduate physics Laboratories but there's another effect of time that didn't come from his special theory of relativity but his General general theory of relativity and it was actually demonstrated I used to work in this was in Harvard this was my office in in in in Harvard Jefferson laps and um and in the 1960s uh two physicist Robert pound and his colleague um did an experiment to demonstrate an effect that Einstein's general theory of relativity had predicted special relativity tells us that clocks take at different rates depending upon your state of motion general relativity says that gravity changes time and my clock now is ticking at a different rate than your clocks because you're closer to the Center of the Earth than I am right now the effect is so minuscule that you could never figure could measure it but uh pound and his colleague did that by using a that it was you know in the old days they they had a a radioactive Source in the basement of je Jefferson lab and then in and then they use telephones to talk from the basement to the roof and um and iron when it's radioactive emits a very specific frequency of gamma rays and what is still amazing to me is that the predicted difference between the rate of clocks from the bottom of the Harvard Jefferson labs to the top was one part in 10 the 15th one part in a million billion that's the difference but they actually were able to measure it and confirm Einstein's theory now I I mentioned this and it's prly appropriate to do it in Los Angeles because this all sounds neat and esoteric but completely divorced from your own experience but it turns out it's not about 15 years ago I was stuck in traffic in Los Angeles which happens as you all know and I wrote a an article about being stuck in traffic in Los Angeles I don't think I actually wrote it while I was stuck in traffic but it's quite possible I may have and you use this fact this obscure fact every day many of you used it to get here okay because global positioning satellites which are we all our phones our smartphones use to to to to get us places work by using time you have a number of satellites that the satellites send signals back back and forth to your phone and your or another way of putting is your phone detects signals from the satellite and sends a signal back and there are many satellites are located up uh they're moving about um 8,000 or so miles per hour some of them are 20,000 mies above the Earth's surface and you find out where you are by triang triangulation you have to see more than one satellite but if you know where the satellite is and you the length of time it takes for the signal to bounce between the satellite and you you could figure where you are on this line similarly if you could do the same thing with here you can figure out where you are on that line and that line and seeing where they intersect tells you where you are that's how global positioning satellites work they only work because they have atomic clocks because light travels so fast that that even up at 20,000 miles it takes a fraction of a second for light which travels at 186,000 m/ second in an obsc set of units that only the United States and England use um but in any case so it takes a fraction of a second to to do that and um and they have to have atomic clocks so that they so that the time is accurate but those clocks are moving fast 8,000 Miles hour or so uh which tells us a special relativity tells us that those clocks are ticking at a different rate than here but it turns out that effect is minuscule compared to the the other effect that these clocks are high above the Earth and it turns out when you Com when you uh um work out these two effects these clocks here at different places would be ticking about 38 micros seconds per day faster than the clocks on earth now light travels of a me meter in a billionth of a second one 1,000th of a microsc okay so if we did not take into account general relativity and adjust for the fact that these clocks are running at a different time because they're high up within a minute your GPS would be out by a kilometer so it's it's not esoteric at all it governs your lives to the extent that you use GPS in La I imagine most people govern their lives using GPS try to figure out how to go off the freeway and find to where they're going okay so this obscure aspect of time is really part of the central part of our existence something I'll come back to later technology changes not just the way we think about the world but the way we act and this fact that time changes due to gravity as to space is part of the central feature of general relativity which is at time in space are really different aspects of the same thing we live in something called SpaceTime but if time and space are really different aspects of the same thing that begs an important question which uh which a lot of people are interested in maybe more than GPS which is can you build a time machine this is one of the one of the known unknowns one of the edge of Knowledge Questions because the answer to this question is we don't know that's what makes it so neat we don't know we do know look it seems in general relativity like it should be possible because I could take a trip to Los Angeles and back go a round trip in space if space and time are really the same why can't I do a round trip in time general relativity says you can you can do a round trip in time in principle but can we do that in practice we don't know it turns out I can even draw a time machine um this is one kind of time machine it's called a wormhole it it's this is you know a two-dimensional representation of a curve three-dimensional universe so so all I can draw and I did draw this in the first place but it's all that we can draw and as you know if you saw the movie contact a wormhole is a shortcut through space it's a if if space is curved a wormhole could just be you know take you in a mile what might otherwise be thousands of light years away wonderful but it turns out we can prove that a that a wormhole if a stable Wormhole can exist then you can travel in time because it turns out if this end of the Wormhole is moving through space fast then a clock at this end of the Wormhole is traveling is ticking at a much slower rate than a clock at this end of the Wormhole and say F say say uh um it's moving in a big circle of five Lighty years around and you could find out that the clock here will be five years behind the clock there and so all you have to do is go Through the Wormhole you come out five years earlier and let's say you have a really fast ship and you come back and you arrive at home a year before you left all of that's possible in general relativity in principle the question is is it possible in practice and the answer is what's the answer I don't know perfect you got the right idea because we can prove that you can't make wormholes on a normal matter as Kip Thorne actually was the one with his colleagues that proved that if you have normal matter and energy then the mouth of a Wormhole that either end will collapse to form a black hole in a Time shorter than it takes to Go Through the Wormhole but maybe there are kindes of matter and energy that are different than the kind of matter and energy that we know of can you create those in the laboratory and the answer is we don't know that's the open question it depends on quantum mechanics which I'll talk about in general relativity and we don't know if time travel is possible general relativity allows it in principle most of us think it's Poss probably impossible because of all the paradoxes that would result if you had time machines like going back in time and killing your grandmother before you were born and your mother who would want to kill their grandmother I know no one want to but uh and then your mother wouldn't be born but then if she wasn't born you wouldn't be born and then how did you go back in time and kill your grandmother in the first place the kind of thing gives people's headaches Stephen Hawking the late my late friend Stephen Hawking wrote the forward for my book B the physics of Star Trek and he had said U time travel was impossible um he actually tried to demonstrate it he actually had a party in his house once he in he invited time travelers from the future no one showed up he said he said that was proof but I countered to him saying they all went back to the 1960s and no one noticed um but it's it's really an open question and if if time the neat thing about this of course is that a universe with time travel seems ridiculous seems impossible but that doesn't matter the universe doesn't care what seems impossible to us what we find palatable or likable the universe is the way it is that's the great thing about science whether you like it or not the universe is the way it is and so this open question remains an open question and maybe a hundred years from now there'll be a book that we'll be able to talk about another open question and say well we now know about time machines but time it's amazing es me that this fundamental really nothing more Central to our existence than time key facets of it still remain open questions and I love that and uh anyway so that's time space the not really the final frontier uh but I think I I think my my quote is from another one of my favorite authors if this there we go you know this quote from Douglas Adams maybe space is re is big really big you just won't believe how vastly hugely mind-bogglingly big it is I mean you may think it's a long way down the road to the chemist but that's just peanuts to space and he did you know when he wrote hitchiker's Guide to the Galaxy um he had no idea because space is much bigger than even he thought it was to to describe that I have to spend a minute or two A Brief History of Time and Space this is the history of the Universe on the slide and there's a lot there but we won't go through it but um this is today and this is going back in time this is today when the universe is 13.8 billion years old this is the Big Bang the Big Bang we really don't know what happened because the laws of physics break down there but we we can start talking about what happened shortly thereafter and we can talk about it with a straight face and what we've discovered is as far as we can tell there's no way to understand the properties of the phys of the universe that we see today why the universe looks the way it does why it's so uniform and yet why there are galaxies and when they formed the way they did unless at a very early time after the big bang the universe underwent an incredible expansion something we call inflation it expanded by an unbelievable amou more than 30 orders of magnitude in size in a time period of a millionth of a billionth of a billionth of a billionth of a billionth of a second unbelievable but it turns out naturally possible and in fact it's hard to make it not happen given the laws of fundamental physics we now know and then after that well you know the expansion happened and then inflation had to end because if it didn't if that expansion didn't end we' be wouldn't be here that's an important point in a moment and then we had the hot big bang after inflation ended the universe got hot it was a hot soup of Elementary particles with the ones we know of it maybe dark matter and then around the time when the when the uh Universe was about 110,000 of a second old the particles we know of began to form quarks combined to make protons and neutrons and a time when the universe was about between 1 second and 100 seconds old the elements began to form the Light Elements hydrogen helium lithium those are the only elements that formed in the big bag all the rest of the elements were created later in the cores of stars and um but but and this is the really amazing thing this is why we know the Big Bang really happened one of the many reasons is we can measure nuclear reaction rates in the laboratory the same nuclear reactions that would have eventually formed hydrogen helium and lithium and we can predict if the early Universe was hot about 10 billion degrees when it was 1 second old or so how much hydrogen how much helium how much lithium and it turns out the mount we predict changes Vari by over 10 orders of magnitude 25% of the universe should be helium and one part in 10 billion of the universe should be lithium guess what happens when we look out at the universe 25% of the universe is helium roughly one part in 10 billion of the universe is lithium those that's one kind of set of examples and many set of sets of observations that tell us this isn't just some theoretical construct we can test it so we know we certainly can study the Universe back to at least one second it turns out with the Large Hadron Collider we're going back to try to understand and see the physics of what the universe was like when it was uh when it was 110 billionth of a second old and as we do more experiments we can probe earlier and earlier into the history of the universe okay and then you know then after when it was about 300,000 years old something called The Cosmic microwave background formed which we can see and tells us a lot about the universe then when the universe is about a billion years old or less the James web telescope is now saying less and we can I'm happy to talk about that because I know you've been reading some articles that claim things that I won't that I'll be happy to talk about um that that galaxies form maybe a few hundred million years after the big bang and then we're here and I'm talking so that's the history of the universe but this early period determines everything it's amazing and often unheralded that if this is really right then quantum mechanics which I'll talk about a little bit later which seem so strange shouldn't be as strange as it is because it turns out if inflation happened then scales that were once so very small that quantum mechanics was important get puffed up to large scales and in fact those Quantum fluctuations in space and time and matter in the early times get eventually we can predict what will happen and they'll produce little teeny lumps in energy and density that will eventually collapse to form galaxies and we can measure them as hot and cold spots in the microwave background and inflation predicts that quantum mechanics gives exactly the kind of spectrum of fluctuations that we see in the microwave background which eventually produced galaxies planets stars planets and you so when you want to know about what quantum mechanics looks like look around the room all the lumps in the universe originated as little quantum mechanical fluctuation and inflation it's one thing but the other thing that's relevant for our understanding of space is I talked about inflation beginning and then I talked about ending but we really don't know how to make an end everywhere in general inflation keeps happening it never ended it's still going on but we're here what the you what inflation suggests is that the Universe isn't a universe it's really a Multiverse namely what happen happens is like raindrops condensing out of a of in the sky inflation is happening but locally at some place due to some interesting physics you leave inflation and prod a hot big bang and then the space between outside of our universe is still expanding incredibly fast and then maybe later on or earlier at some other point the same thing happened somewhere else and the same thing may have happened somewhere else but interestingly as you leave inflation it turns out the laws of physics in each Universe can be different in some universes you'll have galaxies a lot of them a few of them in some universes you won't and that idea of a Multiverse changes everything it could be that the reason I went into science was not a good reason I went into science to learn why the universe had to be the way it is but it may just be an accident it could be that there are an infinite number of universes over an infinite amount of time and every different kind of law of physics can happen in those different universes and those fundamental quantities that we try and understand as physicists might just be an accident of our existence and and and maybe we'll come back to the implications of that for life in a bit but you see poor Douglas Adams was just thinking of one universe as being darn big and now if we're right there can be as I say over an infinite amount of time if inflation continues infinitely long an infinite number of universes that develop and the point is they're causely disconnected from us space is expanding faster than the speed of light between these distant objects which is allowed space can do whatever the hell it wants in general relativity and so there we'll never be able to see them directly but they may exist now that sounds like metaphysics and it is but it turns out there may be ways we could indirectly prove that they exist in fact I've proposed in some papers with a friend uh Frank wilchek about how to how to measure things that would tell us we won't be able to measure them exact directly but if if what we measure is there it will tell us that they must exist it's not too different than a little over 100 years ago in 1905 when Einstein wrote four papers one of which um for his PhD thesis proved that Adams existed at the time and it's interesting to realize that in 1900 Adams were were kind of mathematical creations and people used them chemists Ed them but there was still a huge debate about whether they were real and Einstein showed by using something called Brownie and motion you can infer that atoms exist and even estimate their size but no one ever thought you'd see an atom ever now we can actually see them with our fancy kinds of electron microscopes and other kind of microscopes so the situation is very similar everyone recognizes by 1905 or 1908 that atoms existed even though they knew they'd never see them maybe one day we'll be able to make measurements of of gravitational waves it turns out new measurements of gravitational waves that will give us a direct indication that those other universes actually exist even though we'll never be able to see them right now we don't know it's an open question one we want to answer that's it for space now I want to talk about matter and uh quote do I have for this yeah I like this dirt is not dirt but only matter in the wrong place anyone who Gardens knows that uh and uh my friends in Phoenix know that a lot um there's a lot I could talk about matter you might think I'm going to talk about something wrong physics but what I want to do is um disabuse you of one of the many popular I won't say fallacies but popular misconceptions that are in the literature about quantum mechanics people love to write about the weirdest of quantum mechanics because it is weird it's I want to show you now that it's weirder than you can imagine but the stuff you read about it all is is misplaced so I want to explain quantum mechanics well I want to demonstrate quantum mechanics I might not explain it and I I want to do it a a late colleague of mine at Harvard Sydney Coleman who was a remarkable physicist to an incredibly funny guy um and and Brilliant certainly the smartest guy at Harvard when I was there and when I was there there were eight no borates but he was smarter than any of them uh he wrote he gave a lecture called quantum mechanics in your face which which changed my own picture of quantum mechanics and I just want to show you a lot of people think the quantum world is weird but really that's just an accident because we really can't see the fundamental world if you could if it's just an illusion if you could really probe the world on a basic level it would be sensible it wouldn't be quantum mechanical and there are experiments you could do in fact the year before this the Nobel Prize was given for people who demonstrated the fundamental certain fundamental characteristics of quantum mechanics like entanglement and other things and I want to show you one of the ways that you can prove that the Universe isn't sensible okay and it and and and it evolves this prop experiment which he described um here so you take three different observers they're located you know San Diego Los Angeles and San Francisco let's say and you have a central laboratory and it sends out something to those three observers three in there three Laboratories and each of those Laboratories has what what Sydney call the little Acme Little Wonder dual meure one of two things A and B and you don't know what those things are A and B you're given the black box and you you say you choose whether you're going to weather A or B each time this experiment is done and record your answer it turns out A or B could be plus or minus one if you look on the right side of the detector you'll measure a the a property if you look on the left side of the detector you'll measure the B property you choose each of the experiment choose they can't communicate with the other experimentalists because they're far away so there's no interaction between the experimentalists okay good now let's just say Observer number one measures property a Observer number two measures prop well actually sorry Observer number one measures property B Observer number two measures property a Observer number three measures property B so two observers measure B and one Observer measures a well there's obviously three different ways to do that and I'll draw them here it's you can just figure out either either a is measured there a is measured there a measured there fine now say you do those measurements and you find the following it turns out always every time you do the experiment if two people happen to measure B and one person happens to measure a again it's random they're not communicating with one other you multiply what they measure remember each thing they're measuring could be plus or minus one you always get Plus one now you have to prove this yourself it's a homework assignment I'm not going to make anyone do it now I was going to make Robert there do it in front of all of us but I promised him I wouldn't um let's say just just to show let's say you measure B to be plus B2 to be+ one and B3 to be minus one and also measure B1 to be plus one so B1 is + one B2 is + one and B3 is minus one and so that will imply that B1 and B2 here are positive okay because they're both plus one that so that will imply well in order for this always to be plus one A1 has to be minus one right you with me I hope though okay A2 has to be minus one and A3 has to be ah there we go you know what I knew would not be a shy okay so great it turns out you you can convince yourself that if this is true then it must be you'll be able to deduce it must be that if the experimenters had chosen to each measure a then the product would always be plus one if this is true then this is true and that's the homework assignment I'm not going to go through it with you but trust me on this one okay so this is always true if if these guys have have specific States then that'll always be true and since and this is always true since the measurements at each detector are independent namely the measurement of a here won't depend upon whether you measure a or b here we're assuming they're completely independent that's really important so this experiment doesn't fo this one and say did you measure a or b before they measure that one okay well that's great but now I can tell you what's actually happening in this experiment I'm going to draw things that look like mathematics but it's it turns out what's happening is is you're sing three Elementary particles to three different detectors and they're in a Quantum State that's called entangled they're in a superposition of states it turns out that's the really crazy thing particles can be in more than one configuration at the same time and what we have here is three particles and their spins are all pointing out but they're also half the time pointing down it's a superposition a coherent superposition of two states which can't happen classically either one or the other it turns out so this is pointing in the z-axis say two nights ago I I would have said the Z axis because I was in Canada but the z-axis okay A1 it turns out A1 measures a spin in the X Direction turns out the neat thing is if a particle is spinning in the Z direction and you measure whether it's spinning in the that way or that way in the X direction there's a 50% probability you'll get it spinning that way and the 50% probability you'll get that way so a measures the the X direction of the spin D measures the y direction of the spin and you always get either plus or minus one 50% of the time it turns out but what you can show is if I send this state to those three detectors that entangle state each detector measures just one particle but they're entangled they were set up to be in a specific quantum mechanical State then one can prove and again this mathematics is a little more complicated that whenever I measure one a and two B's the answer has to be plus one that will always be the case but you could also prove that whenever I measure 3 A's the answer is always minus one there's no example I know of that can demonstrate more clearly than this the fact that quantum mechanics is not sensible because if the particles were in some specific State before you measure them then this is impossible I think I wrote that down in the next slide if I can get to the next slide this is classically possible only if somehow what I measure here will affect the measurement of something over here you see if there's some spooky action at a distance then I get a different answer if I measure a and two B's then if I measure 3 A's even though the experiments are independent if somehow there's a spooky action at a distance then you can imagine okay whenever guy over there measures B I'm going to measure something different when I measure a here than if that person didn't measure B that's the only way classically you can understand it that's why people like Einstein and others talk about spooky action at a distance in spe in quantum mechanics but it's only because they're thinking about it the wrong way they're insisting about thinking about the world classically When The World Isn't classical and people write books on this about this as I'll show you so this is Sydney's argument he said why do they write long books about quantum mechanics and non-locality full of funny arrows pointing in different directions it's because I think secretly in their heart of hearts they believe it's really classical mechanics that were really putting something over on them deep deep down it's really classical mechanics so you read books about many worlds and and and spooky action existance and as as as and I I added I'm less generous than than Sydney and I say there's another reason that people write such books they want to appear profound writing books about many worlds it sounds really neat but as Sydney put it and this is really important every successful physical Theory swallows its Predators predecessors alive special relativity and general relativity swallowed newtonium mechanics every new Theory swallows the old theories and in every other area of physics I don't know why we don't we know General Welly tells us space is curved but if we insisted on talking about the universe if space wasn't curved then the results we get would be really ridiculous be strange why because we're taking a world that we know is not the world and trying to interpret the results in terms of that world the right thing is not to interpret the world in terms of Newtonian mechanics but to talk about general relativity the right way to talk about the world is not in terms of classic mechanics but in terms of quantum mechanics so you don't want to interpret the concepts of the old Theory the right way to do it is it turn is to understand the concepts of the old theory in terms of the new Theory not to describe the things that happen in the new theory in terms of the old Theory you're always going to result in something that seems absolutely crazy okay and that's getting things asked backwards so whenever we hear the interpretation of quantum mechanics in my mind whenever I hear people talk about interpretation of quantum mechanics I stop listening because that's the wrong thing what we need to do is understand how our classical world the world that seems sensible arises out of a quantum mechanical world not the other way around and I think Sydney gave a a great I think this is his example um yeah okay say all the standard nonsense claps of the way function many world spooky actens all because we insist on treating the whole system or parts of the system classically instead of understanding that not only is the thing we're observing quantum mechanical we're quantum mechanical and once we understand that we're quantum mechanical everything changes and I love the example he gave May many of you may remember um you know he said why do we see something definite like we always measure the spin of the particle being up or down we never measure we never measure to be at two places at once or doing two things at once that's because we the measurers are also quantum mechanical okay and um and he I don't know if you there's a play of Tom Stoppers and he he gave an example I love this example Tom friend is walking down the street in Cambridge and sees lud Vicken Stein standing on a street corner lost in thought and says what's bothering you ludvic and viin says I was just wondering why people say that it's natural to believe the sun went around the earth rather than the other way around and the friend says well that's because it looks like the sun goes around the earth and McKai says well tell me what would it have looked like if it had been the other way around of course it would look exactly the same and that's oops that's the the point of quantum mechanics as Sydney put it would people say that the reduction of the wave fact the wave faing collapses occurs because it looks like they say it happens because it looks like the reduction of the wave backing occurs and that's true but what I'm asking you to believe he said it's a seriously consider what it would look like if it were the other way around if all that happened was causal Evolution according to quantum mechanics and that's what so the weirdness appears to be weird but the other way around it will just be just as weird if you understand that we are quantum mechanical systems and they are quantum mechanical systems you'll realize why every measurement we make seems reasonable while the underw world is crazy and and I was motivated to include that example of matter for you because I get so so frustrated reading all this crap about quantum mechanics which is probably the most misused area of physics misunderstood and of course it develops s such a nonsense like the secret which I constantly meet people who read and and anyway but I also read books by physicists about all the weirdness of quantum mechanics and it is weird but the key thing it's only weird if we treat part of the world the way it isn't if we treat part of the world as classical when really the whole world is quantum mechanical and everything we see that seems sensible becomes completely reasonable once you understand that fact even though the quantum world is itself completely different than anything we have ever directly experienced okay we're heading in the home stretch here now because we now get to life we leave we leave the domains of cosmology and pure physics and some people I remember I was on a boat actually I was on a boat with someone in this room Bruce and there were a bunch of biologists and one of the people came came up to me and was very angry and said I hate when you physicists talk about biology okay well the point is it's not it's there's a long tradition of that anyway my quote actually is from Jean Paul S everything has been figured out except how to live and that's true the whole point about life comes from Carl Sean if you understand the origin of life you have to understand what he said the recipe for making an apple pie if you want to make an apple pie the first step of the recipe is create a universe now that's sounds vicious but when it comes to the origin of life it's probably incredibly important understanding the origin of life on Earth is intimately related to understanding the nature of the universe as I'll talk about a little bit and in the question period maybe more because I know at least one person here has questions but there's a long tradition also of physicist thinking about this question Irwin schinger the developer of quantum mechanics one of the developers of quantum mechanics 1946 wrote a very um significant book and impactful book called what is life this young guy who wanted to be an or orthologist called Jim Watson read the book and said you know what maybe genetics is more interesting than Ornithology okay and he went on with Francis quick who by the way was a physicist to discover DNA and worked with people like Max Bel delbrook who won the Nobel Prize in biology for his work on nature of Life while he was still in a physics department by the way so it I'm not usurping it's a long tradition of this connection the universe is the way it is and it isn't defined by 19th century disciplines and those disciplines are merging together more and more in the 21st century but I want to talk a little bit about life I have a picture here because if if if I ask you to def find life it's not so easy what's alive and what isn't you might say things are alive well what's life maybe life is something that has a metabolism it uses energy and it reproduces relatively Faithfully okay that's pretty good but the problem is if you use that definition fire is live is alive fire has metabolism forest fires reproduced relatively Faithfully depending upon the kind of trees in the forest that are being the the heat will be the same of course and this and and not only that they'll reproduce and grow and so you have to be a lot more careful you have to talk about a lot more things when you think about life and that's important if you're thinking about the key open question which is the origin of Life the origin of the diversity of life is an is a question that Darwin answered with natural selection but the open question that still remains that all of you ask is how did life originate how do we go from chemistry to biology the open question really at the Forefront of of much of Modern Biology and by the way it's as I'll indicate I think it's a question that's likely to be answered in the lifetime of almost everyone in this room I think it's one of those known unknowns one of those bits of edge of knowledge where we're coming our picture is changing so rapidly and new experiments are coming online that are going to change everything but when you think about life is it a question you know the virus sorry has affected all of us Co affected all of us it's a virus but most biologists say bi viruses aren't alive because they can't reproduce unless they're in your unless they hijack the Machinery of yourself so they're not alive I refuse to accept that argument I refuse to accept that I had to wear a mask and stay indoors because of something that isn't alive as far as I'm concerned Al viruses are alive and in fact viruses are important because not only they they're probably the reason we're here they kill you but they probably help create us the most important moment perhaps in the history of life on Earth happened as Carl Sean's first wife Linn margolus demonstrated when probably a virus a single cell molecule was eaten by a cell and that virus could do something the cell couldn't do it could process oxygen and prodes energy by processing oxygen it's what that happened it become was a it it became a symbiotic relationship it actually lived inside the cell We Now call it a mitochondrian and the mitochondria are the part of our cells that process oxygen which is essential for our our given life so viruses have of course have impacts but they're not all bad when the viruses get hijacked or they can hijack the cell's Machinery but sometimes they hijack the cell's Machinery to do good things and for all of us photosynthesis turned into respiration because of exactly that kind of hijacking but we we so we can understand key moments in the history of Life by looking at things like mitochondria and the genetics of mitochondria but there's still a question and it's a question that actually motivated schoninger it's a question that I still get when I debate I don't do it anymore when I used to debate creationist okay it's this famous question I forget which Bishop the question I don't want to dignify Him Anyway by name the idea is they say well look that Evolution didn't happen it couldn't have happened because it's like you know expecting nature to randomly produce the diversity of life on Earth is like imagining a hurricane blowing through a junkyard and producing a a 747 I mean it just seems impossible I mean because the Machinery of life is complicated the first argument they say is it violates the law of phys physics the second law of Thermodynamics that's why uh fit one of the reasons that motivated sh here the second law of Thermodynamics says that the world gets more disordered well that's a very parochial way of describing the second law of theramic it's not the right way the second law of Thermodynamics says if you have a closed system with no energy going in or out that system will always either will always over time get more disordered but life is in the closed system if it was we wouldn't be alive we're nourished from energy from the Sun and donuts and all the stuff you ate before he came in here that allows a system to retain and increase its complexity and it's not violating the laws of thermodynamics because it's not a closed system closed Systems canot Support life okay but nevertheless even the simplest parts of of us of our genetic code and and this is a ribosome it's I mean it's incredibly complex and and it's been a challenge to understand how you can get from simple organic molecules to an ordered system this may not look ordered but it tells you how to make proteins that make you keep you alive and it turns out while it violates all common sense as I tried to explain to you the universe doesn't care about common sense and there have been developments of I don't want to go into because it's late and um and I have about five or 10 more minutes left to do what I wanted to do are as I've often said on St stage or Richard Dawkins has said on stage with me our intuition emerged from the Savannah in Africa okay it it's amazing that it that we can do what we can do it certainly didn't give us any sense of understanding long times that's why Evolution seems like such a strange thing to people we we can understand a year or 100 years but maybe even a thousand years but a million years or a billion years just numbers okay and as as Richard likes to point out it didn't we didn't evolve to understand quantum mechanics it's amazing as an interesting side effect of whatever caused it to be genetically or natur natural selection to prefer objects that have the ability to do mathematics it's a total side effect but it's wonderful because we can understand mechanics but it still means we can't intuitively understand a lot of things but one thing that chemists are now doing John um now I forget his ne's name and in and Cambridge has done experiments showing that in extreme environments like the environments on comets on Earth it's natural to take complicated molecules and break them down that's the direction things go always it's left on their own unless you dump energy into them but in exotic environments with ultraviolet light and all sorts of things like Captain of comets it turns out you can show certain reactions will work in the other direction they'll build up complicated things from simple things in fact he's been able to build the basis of RNA showing just simple chemical reactions that could happen on comments Jack softstack who's a Nobel prize winning biologist from Harvard has turned to the origin of life has also shown that lots of other non-intuitive things happen when you cool things down chemical reactions are supposed to get slower but you can show when it comes to building complex uh chains of of organic molecules polymers that actually when you cool them down and I don't I'm happy to talk about this in the in the question period certain reactions can happen that would never happen at room temperature again comets are great places for that that's why when we look at comets we see amino acids we see the Bas we see many amino acid as we see the basis of the organic materials that that cause life to form and I'm expecting I would not be surprised within the next decade or two that someone comes up with a clear chemical pathway that naturally without any external anything external except energy from the Sun or or and and water allows chemistry to turn to an at least the basis of RNA which is what we think was the first world the RNA World preceded the DNA world but the the other thing is that the way we really May learn about the origin of life is not by looking at life on Earth the problem of the universe is we have one example of life and the other area that's changing dramatically is is the realization that we may soon be able to observationally find out if we're not alone now we may sh what we'll find out is we may share the universe with microbes but that's a big step and and one of the there are many developments recently have changed that one if you're as old as I am and you remember Bill Clinton in the White House in 1996 I don't know if you remember this he made a huge announcement that we had discovered evidence for life on Mars because people saw a martian meteorite which they' gotten from the Allen Hills in Antarctica which is where we find meteorites when we look for them why do we look for meteorites in Antarctica I just try and wake some of you up again before the end of it's white that's right so it's easy I I actually applied to do this because you don't need any skills um you just get a snowmobile and and and you arrive Along Ice in anarctica you see a rock it's from up there and so a rock was discovered that had the same composition as other Martian you know we'd sent Rovers and other things up to Mars and we know the composition of the soil there but inside when it was dissected by some chemists from Stanford there were these things that looked just like the first fossils of life on Earth and they and they thought this is extinct evidence of extinct life because Mars was once hotter and wetter okay and in fact my friend Andy no has said that who's on Rover missions has said that he would be surprised if we discovered any exted or extinct Life on Mars if it wasn't our cousins because what that rock showed us and what we now know from microbes and extreme ofs is that a rock knocked out of of Mars by a comet or something that hits the Martian surface that makes its way to Earth if microbes existed they could still exist all the way they could survive in an inert State and so it could be if you wonder what Martians look like look in the mirror it could be that life first originated on Mars and then came to Earth you don't know but that's really important it's taught us that we have to be careful when we look for life if we discover Life on Mars it may not be an independent Genesis of Life running water on Mars we've now seen and that means we know the environment of Mars was particularly successful but the really interesting places are not Mars they're like the moons of Jupiter and Saturn and Sal and eio because those are ice moons with thick kilometer thick layers of ice surrounding an ocean a salty ocean perhaps underneath we see plumes of water coming out from those oceans because some of our satellites of our our spacecraft are travel through them and we see organic materials there is a NASA Mission proposed in I think 2030 something to go to Enceladus and drill underneath the ice if we discover microbes of any sort life like we know it or not like we know it in the is in Enceladus it'll it'll be almost certainly an independent Genesis because that air region has been closed from the rest of the of the solar system and so we are living in exciting times when we may discover if we discover two independent geneses of life on Earth then it means the Galaxy which has a 100 billion stars and we now learned as I'll show you in a second that that almost all stars have planets around them 100 billion solar systems life could be ubiquitous and of course jwst is the next stage it's going to look for that and I just want to show you an image here's what we're going to see when we look at other planets in certain cases we're lucky enough to see a planet orbiting its star with the planet goes in front of the star causing the star to dim a little bit not a lot 1% or less actually when it goes behind the star it actually makes the star this isn't quite right when it goes behind the star it actually makes it brighter because it's reflecting the light from the Star as well but in any case when that happens that's neat and that's the way we've discovered extrasolar planets 4,000 of them so far but more interestingly when it goes in front of the star if it has an atmosphere the light from the Star goes through the atmosphere and then we can look at the Spectre of that light and if the atmosphere has certain elements we can see them here's here's a measurement of the atmosphere of a specific Planet who's um who's there we go gastr exoplanet wasp 96b okay we've already been able to measure water in that atmosphere but maybe we could look for other biomarkers Like Oxygen there was no free oxygen on earth when Earth formed happily otherwise we wouldn't be here if we saw an oxygen atmosphere it wouldn't be proof that life happened but maybe we'd see methane too and so you could see we may in the coming decade be able to have definitive evidence of whether there's life elsewhere in the universe microbial life whether there's intelligent life is a vastly different question and the answer to whether there's intelligence elsewhere in the universe is we don't know we're we're looking but it's a long shot but our whole picture is changing the last topic you'll be pleased to know that I wanted to go into is consciousness some of you have lost it I can tell already um and uh it's the most complicated subject of all and actually the most interesting quote about Consciousness came from the from the physicist IR warer I think it's one of the reasons why Consciousness is so hard to understand Consciousness is a singular of which the plural is unknown and that's the hard part about studying Consciousness most of us are conscious they notable people I can mention that probably are but I won't but we don't know when it comes to other species whether they're conscious it's even hard for us to know whether your Consciousness I I don't know for certainly your Consciousness is the same as mine how do I know that all of these things make understanding Consciousness very difficult and in fact if defining life was difficult Consciousness is much harder many what I discovered in my work when I tried to update my knowledge of the subject theyd spend a lot of time before talking to people was that most cognitive scientists actually don't define consciousness it's too hard to Define because we don't really know what it is what they can do is look for differences in human neurobiology compared to other organisms and look for how those differences might have evolved evolutionarily and try and pick out what may make us special if we are special but unlike legs or fins you know we could look at at at at at fossils we can measure legs and Fs but we can't look at the fossils and measure Consciousness we can't even look at the at at at other animals and unambiguously say whether they're conscious it extent species and species are around now there are debates about levels of consciousness I'm convinced my dog is conscious of me but it's not but there a lot of people who argue that's just I'm just anthropomorphizing when my dog appears to be sad or happy um and it's extremely difficult well it turns out to be even worse because what we can do is Prue behavior that doesn't tell us anything too many people associate Behavior with Consciousness and and and a really good example of why that's a bad idea comes from single-celled animals protozoa can swim away from harmful environments and even bacteria give some behavioral evidence of learning in memory they don't even have neurons so clearly it the behavior that they have to avoid Danger is not Consciousness and if that behavior um suggests to us as Consciousness in bacteria or maybe animals we've got to be very wary about assuming that and in fact beron Russell said I think somewhat factiously but nevertheless from the protozoa to man there is nowhere a very wide Gap either in structure or behavior I think the events of the world in life and times suggests that that that there may not be much difference between humans and anything else in our own species and this is I just want the last thing I want to do is show you an experiment one of the neest experiments in Consciousness that I know of from Michael Gaza UCSB um we don't even know understand our own con you don't you you have a Consciousness and you're lying to yourself all the time David H was right when he said reason is a slave of passion and the experiment that I want to talk you about is an Amazing Experiment a lovely one just a little bit about the brain the brain has two halves the left hemisphere and the right hemisphere connected by a thing called the Corpus colossum women have larger Corpus kosom than men which is why my wife tells me that women can multitask better than men I don't know if that's the case but said let's see left your left body motor control is controlled by the right hemisphere right body motor control is controlled by the left hemisphere similarly your left visual field is controlled by the right hemisphere of your brain the right visual field is controlled by the left hemisphere of your brain but speech processing is completely within the left hemisphere of the brain what happened well it turns out epileptics it was discovered that if you sever the Corpus colossum connecting the left and right hemisphere then for some epileptics you reduce the effect of seizures so it was done but when Michael and gazon and other said this these are great test cases because these are individuals where the two halves of the brain don't talk to each other let's do some experiments and this is an Amazing Experiment so they they put observers in a in a in a sitting on a on a in a table where there was a barrier so the left eye could see one thing and the right eye could see another and in the left HTH visual field they put a scene of snow in the right hemisphere they put a chicken now they allowed there was a box and they allowed the the people observing to with their left hand to pick something from the box that was characteristic of the field they were seeing the right boxs okay so what and remember the left and visual field and the right visual field are also controlled at in the same hemisphere with motor control so they were able to do that and what happened was The Observers would pick and they'd pick a snow shovel because they could they're left because they were seeing a snow scene and they' pick a chicken the right hamere all good but then they asked those people why did you pick them that but it's only the left hemisphere that controls speech and the left hemisphere can't see the snow sea okay because that's that's the right hemisphere that observes the left t f so when they when they did that what the people said at was the chicken claw goes with the chicken and you need a shovel to clean out the chicken shed so the Observer there's nothing unusual to them they knew why they were doing what they were doing but that's not why they were doing it our conscious awareness of ourselves and what we're doing is an illusion and we have to understand that's why it makes it so hard to understand Consciousness okay that's what I already said they may they made a narrative that made sense to them to the left hemisphere and we do that all the time our sense of self philosophers often say is an illusion again just like time to revert to beginning saying self our sense of self as illusion means nothing to me the question is how does that illusion arise and that's what we're trying to understand and and um you know just like time being illusion doesn't matter to you if you you're late for a job if if you kicked to the or jilted by your lover telling you that your sense of self is illusion is not really comforting and the key question is what ultimately produces that and we don't know and I think the way we may know may become just like understanding life may require us to look elsewhere in the universe understanding Consciousness may require us to create Consciousness Richard feeman once told me the way he put it to me is if if you don't if you can't um he who can do nothing knows nothing but on his Blackboard when he was after he died they looked there were a few things he wrote on the backboard and he said if you can't build it you don't understand it maybe the way we'll understand Consciousness is by building conscious things Chad G bt5 isn't conscious maybe chat G bt50 is I doubt it by the way but um or May and I doubt quantum computers will necessarily produce that but they might but interestingly enough that may be the way we learn about how Consciousness Rises but people are worried about what happens when you open the genie take it out of the box and there's huge debates and in fact a future podcast that we just recorded for the origins podcast is with the computer scientist Scot arenson who's involved in trying to understand how to make sure AI systems don't misbehave it's a fascinating challenge but I just want to point out I'm not the pessimist that in this regard that other people are and my object lesson is history in the 9th century BC and by the way this is the last thing I'm talking about just in case you're waiting the derivation of The Phoenician alphabet was introduced into Greece and evolved in a few hundred years happened in the 9th century BC what was the response of intellectuals it was viewed as the end of literature and drama being able to write was going to kill storytelling Plato said writing was an impediment to wisdom it did not capture the whole truth it propagated the illusion of knowledge and would eliminate the need for memory because if you could write it down you wouldn't have to remember stories and remembering stories was so important SOC was quoted as saying something similar he was suspicious of writing he argued that written communication would never be as clear as face-to-face communication because we couldn't ask questions of a document intriguing rather preent actually AI is like writing it's a natural byproduct of human intellect Chad GPT writes but it's a natural product and it's going to change what it means to be human but every single invention we've ever made changes what it means needs to be human and it doesn't have to be at worse I mean we don't live the way we lived before we had smartphones our whole life is different some people think it's better some people think it's worse on the whole I think most people think it's better but that's a question of debate it's nothing new I believe since I write books that a world of books is better than a world without books it made the world better it made it different but it didn't make it worse and a AI future could be better than the present or worse it's up to us Louie Pastor said fortune favors the prepared mind in my in a book before this one I wrote that that the future is charging towards us like a freight train but it's doing so on tracks that we have built we get to think about this but we don't always have to assume it's going to be worse just because the future's going to be different and just because it's going to be different to be a human being doesn't make it worse in fact it can be better Max plank said physics progresses one funeral at a time and it the beginning of Science and the first step on the road of wisdom to think about the future and to recognize that we don't know what's going to happen humility and honesty demand that we be clear about the limitations of our knowledge that's the thing I want to get across and all of you appreciate but too many people don't we shouldn't be shy about this we should celebrate it and I would celebrate it I hope I've shown you just a taste of the remarkable Mysteries of the world that are now present they are by the way and I only realized after I wrote the book exactly the same questions you all ask about the universe anyway are the same questions of interest to physicist at the forerun are we alone how did the universe originate how did life originate when I see green is the same thing as you see green those are the same questions that are driving science and the three most important words in science are I don't know and I'll leave with two quotes from Einstein the fairest thing we can experience is mysterious it's the fundamental motion that stands at the Cradle of true art and true science and you the origins audiences appreciate that that too many other people are afraid of the mysterious but the mysterious is an invitation to discover and that's what makes life worth living but to to to discover it the last thing Einstein said which I think is very important is we cannot solve problems with the same thinking we used when we created them and that's the most important lesson to understand what we don't know means that we may have to develop new ways of thinking and that's true not just in science but as is obvious this week in politics and in world Affairs and to have that mentality requires you to understand that you don't know everything and be excited about that as all of you are so I think it's time for a break thank you hour just okay good well thanks again for the questions and for your Indulgence and for being here it's really it really is a pleasure and it's always so humbling for me to see that people are interested um okay Skyler said in your lecture you mentioned time travel to the past or wormholes let's say the theory was correct say you did arrive a year in the past in the past from which you left would you then have entered into an alternative reality in which there is a reality moving a year ahead without you while simultaneously you were altering the past which has now become your present uh the answer is I don't know see a lot of these have a simple answer um Victor asked maybe a more serious question well that was a serious question it's just I don't know but some to be less forious some people have argued that that's a way around the paradoxes of time travel that when you go in the past you don't come back to the same present um some people have argued that in some now you're entering a different branch of the quantum wave function but those are the same people who write books about many universes uh you know about uh you know those people who like to mystify corn mechanics but I don't think that makes sense but but it could be that that you do change reality and and in fact wellway the strangest thing of all is that quantum gravity as I'll talk about with some of the questions space and time are intimately tied together but if you wanted to discuss the quantum mechanics of the whole universe you understand all of space but all of time so it could be that all of time is already exists and the present is that you know that the present is just a part the future is already determined and or has already happened as much as the past all these things are fascinating but we don't understand any of it um Victor says how is a society can we overcome the resistance to change our minds in the presence of evidence I really wish I knew the answer to that question I try in my own way and we try at the origins project to do just that to show people that that that you can change your mind and it's a good thing and evidence is the way to do that I um I've said this before but I'll say it again that I you know I'm at I I've been a teacher for much of my life and so there's an old saying that if the only tool you have is a hammer everything looks like a nail and I do think the only solution is education but we have to change the way we educate people in the modern world um it we we we most of us grew up in in a time of Education where it was where you learned facts and that was what school was for and that's the Le least important thing except for the basics of how to read and write and do mathematics but um beyond that facts are largely irrelevant because there are more facts in my phone than and I will ever know they're more Mis facts and so what we do in order to get to that future that you're talking about I think we have to change the way we teach students by getting them to understand critical thinking the real reason science is important is not just that it's changed the world made it better and revealed Mysteries beyond our imagination but it's because science works the scientific process should be applied should be useful to the rest of our lives constantly skeptically questioning testing retesting those are the kind of things we should teach so science shouldn't be a set of facts or biology when I kid was dissecting a frog and memorizing the parts of a frog one of the reasons I didn't become a doctor as it turns out but we need to instead of doing that we need to get people critically examining the universe and that means teaching through questioning asking questions not knowing always the answers exploring the unknown that way I was I was on a in a movie once called I forget the name of it now um it was about it was about the um the Voyager satellite it was a great movie made by an Irish director and I was in Ireland when it opened and um and it hit me then that something that I suppose should have hit me years before is that when every time a young person learns something for them it's the first time in the history of the world that that's been and so instead of teaching kids as this is what we know it we should teach them that Voyage of Discovery and that Voyage of Discovery is seductive once you start learning that way once you see the world as being a series of discoveries and how to make those discoveries then it becomes innate and I think that's the only way we'll get beyond our our current state and that means so that means educating and changing the way we educate but it doesn't just have to happen in schools it parents have to be willing to say I don't know let's find out and um it's a long slow process and I I don't know if it'll ever happen I often in my book the physics of Star Trek I think I said the most realistic thing about the Star Trek future was that everyone was scientific um compared to the world we lived in even even the um even the U therapists anyway so I you know it'd be great if we had such a future that's why I like Star Trek by the way because it presents a not dystopic future presents a future where science can actually make the world as it has and my opinion a better place but it can really impact and change society in a more rational way and my goodness if it's ever a time when we need rationality it's the current time and and I'm just incredibly depressed about that um could space and time exist separately by themselves and if so how could that be explained the answer is not really and I didn't emphasize it enough but space and time are tied together in relativity in a real way because the reason they form a four-dimensional universe of space time is that one person's space is another person's time and the analogy is a three-dimensional Universe okay where um where or a two-dimensional Universe in fact where I could have the Y Direction and The X Direction okay and I have things that happen in the y direction things that happen in the X Direction okay but I can do a rotation and now what was once the y direction is now partly the X Direction and what was the X Direction now partly the Y Direction that's why you learn trigonometry in school we understand how that happens what Einstein showed is that when I'm moving with respect to you in a sense which is a little bit more mathematically complicated but essentially same thing there's a rotation so that what was my space becomes a little bit t in fact one of the one of the questions from Raphael in fact I think uh um is why does the train get smaller when we observe it to move is exactly that that's why I put it next to this question because what happens is think about it if what really matters is the four-dimensional length of a train the three-dimensional length is just a projection just like this card okay it's a certain length you can look at it but if I turn it that way it's less long for you looking straight on right but we know that's just an illusion because it's rotated in the y direction it's less it's less long in the X Direction but it's rotated we understand there's a fundamental length that doesn't change in special relativity there's a four diens four-dimensional length that doesn't change and the three-dimensional length we measure is a projection on the space of that four-dimensional length so when a train is moving it looks shorter the three-dimensional length is shorter but remember I told you it's now spread out in time because now the front of the train and the back of the train are different times so it's got shorter in space but it's spread out in time and the four-dimensional length remains exactly constant that's it wasn't Einstein who realized that it was his Professor mckowski um and we call that Makowski space so not only can space and time not be thought of as being separate because just like we can't think of the X and Y directions separate in a world in which we can make rotation we can't think of space and time separate in a world in which we can move and and it's that four-dimensional space that is the that is invariant that never changes but the three-dimensional space and the one-dimension of time change in a more slightly more mathematically complex version of a rotation and um and uh yeah that's the so and we're just we're like those two-dimensional beings who try to imagine a three-dimensional Universe it's hard and and when I when I look at you I'm I'm taking I'm taking a slice but it's really a it's really an illusion because when I take a picture which I'm going to do because I meant to do that I'll take a picture of all of you because I like this here we go smile don't move okay and my favorite Woody Allen joke about that is why why was the picture of the earth blurry when I took a space cuz someone moved anyway um but uh when I take a picture of you I have the illusion that I'm taking right now right but it's not right now because the light for the people the back of the room took longer to get to me than the light the people in the front of the room so I'm taking a p my picture is really spread out in time but I have the illusion that it's an incident and it's because the speed of light travels so fast that this that this separation of space and time appeared to be the case but if if it was much slower then it would be obvious okay anyway anyway that's my little digression um I I I took this question because it it represents a common misconception does the fabric of space cause a massive object of Star a planet black hole Etc to push down in a certain direction for an outside body to fall towards it on Earth the trampoline example shows this you know every every Science Museum you go to has an example of you know if you push down on a she a bed sheet and a coin will go in a c around around that and that's the analogy of the curved space but the problem is it's it's it's like all analogies only an analogy the real universe is three-dimensional and and and there's no sense in which an object pushes down on anything it just curves space around it it is true that light travels in straight lines in a curved space and light will therefore bend around the earth a little bit around the earth more around a black hole as you saw for the pictures of the black hole um it can go in a complete circle but it's not pushing down on anything that that analogy is unfortunately not a good one and in fact it's even a worse analogy because you're using the gravity of the earth to make it work right push down on the trampoline and the reason the coin falls down is because the Earth is pulling it not because of the curvature if you did the experiment in Space the the coin wouldn't wouldn't would just keep going because there's no gravity so it's a nice little bit of analogy but it leads to a misconception this is the misconception so there's no sense in which objects push down they just curve space around them Kyle ask given that we can even describe Consciousness do you think a computer can become conscious is the substrate for Consciousness biological or is it information well of course the answer is I don't know but I I think it's if you ask me what I suspect which is um um that there's nothing biology I don't think is an essential part of Consciousness Consciousness is is a property of certain biological systems how many we don't know I'm a vegetarian because I don't know the answer to that question okay honestly that's one of the reasons I'm a vegetarian but um I see no fun I see no fundamental since biology is just chemistry and chemistry is just phys physics there's nothing special about biological systems that I can see and therefore I see no reason why a a non-biological system could not become conscious as I described in the book in ways I wasn't able to talk about the lecture I think they're really good arguments by a number of um U of uh neuroscientists one in particular actually from San Diego um that um that one of the central features of our ability to become conscious is our ability to sense the outside world which is required by what's called homeostasis homeost one of the properties of life that makes it different than fire is that it doesn't a fire is uncontrolled living systems are highly controlled it's really important that the chemistry of burning in our bodies because living is just controlled burning isn't uncontrolled if those reactions could happen without enzymes then all materials of the Earth would already be oxidized enzymes are needed to make reactions happen so we can control them so we can heat up or cool down or do whatever is necessary and um as a complicated system gets more complicated the the Machinery that controls the homeostasis of that system needs to become more complex suggesting the building of a nervous system which can probe not just the outside world but the internal configuration that you're in and so it's been argued by this person I think I think it might be that you know AI chat GP GPD 50 isn't going to become conscious because you have to have nerve endings you have to be able to probe the outside world and ultimately have feelings that's what nerves lead to is feelings first feelings of pain and pleasure that ultimately lead to feelings that are conscious feelings this is an argument that seems plausible to meet um but uh but ultimately I don't see any of those things as requiring biology I think it's pretty inevitable if things continue that the pro that it's likely that the dominant form of of Intelligence on the earth will become non-biological but that does not bother me Bruce asks a similar question which is what biological factors determine levels of consciousness I.E consciousness of the Universe versus consciousness of a treat you know humans versus dogs okay um although my first wife used to say men are dogs but anyway um uh uh the that's a good question and think of course the answer is we don't know but we one of the ways we can look at that and I talk about at length in the book is looking at the The evolutionary structures of the human brain versus The evolutionary structures of other mammals and in the prefrontal cortex the you could see a whole new kinds of cells um layers of cells in the way they're put together that are not present in dogs um and in fact not present the number of things not even present in our nearest primate um cousins so I think the way we could try and ultimately understand that is if we understand how those different level of cell Connections in the prefrontal cortex and elsewhere contribute to Consciousness but that's such a long way away and it may be the wrong question it may not it may ultimately even be the wrong question so um but it's it's it's right now in my opinion the best way that scientists can try and understand Consciousness is using exactly that kind of evolutionary tactic what's different not about Behavior but what's different about the way the brain is the neurobiology the brain human brain is versus that of dogs and so we we don't share much with dogs I should say we share more with birds and other primates when it comes to the ideas of of many aspects of what you might argue is consciousness or suffering um but that doesn't mean dogs don't suffer and and uh and and my my dog certainly does um apparently at least to me anyway so I think the best way to get to it Elsa asked why is lithium so important in the atmosphere well lithium is important to maybe some people in this room too I'm not sure but um uh um it's not really important in the atmosphere actually it's it turns out it it it's it's a trace element it's important and because it's useful for Batteries now and it's becoming more important and and I remember when I I I was in a movie that was filmed in Bolivia once on the on the sua Flats of Bolivia and about 30% of the world's lithium I think is there because that's you know lithium like sodium is is is makes salts and lithium is a because of like sodium of its position on the periodic table um it it it is a very good basis for making batteries so lithium I don't think was important in a in a in an atmospheric sense it's barely it's barely part of our atmosphere at all I'm not sure it's even in the atmosphere but it's being important like Rare Earth elements like lithium are becoming more and more important for human technology to make batteries and the like and and that's certainly an important consideration we talk about climate change and say how much of a climate in footprint electric cards have when you consider you need to do whole new types of of Mining and and and uh factories to develop lithium and other other Rare Earth elements all those questions are interesting questions my understanding by the way is even after including the mining uh electric car still have less of a carbon footprint um in any case so that's what I have to say about lithium um Michael ask what is more mysterious to you quantum mechanics or human behavior well the answer is obvious to me human behavior um uh um yeah because it seems to have no rules um you know I can I I can't I can I know the rules of quantum mechanics and but human behavior is uh is is REM remarkably mysterious which makes it by the way interesting to be human it's not all bad uh I think I think the fact that humans are not just rational beings is an important part of who we are and what makes it exciting to be alive and terrifying at the same time if scientists prove life is present on other planets how do they convince religious authorities that's a really good that's a good question and the answer is I don't think you'll take any any convincing because the great thing about religious people is they know the answers before you ask the questions and so when when the life is discovered if intelligent life has discovered other planets they'll say I told you so um the the the interpretation of religious texts which is infinitely malleable will be will be malleable it won't many people thought TR we'll discover another other living beings elsewhere they'll have a different you know they'll have no religion have all I I think that's highly and likely all that will happen is that religious people will their their belief will will will morph to encounter that new evidence because evidence is irrelevant for True Believers I think that's emotionally charged enough for this um um in black holes which I didn't talk about here but I do talk a lot B time and space flip Beyond The Event Horizon what might that mean and the black holes become like Elementary particles in some way well there's a lot of there's a lot to unpack there but what is interesting is that as you approach a black hole um because of the effect of of Relativity clocks slow down as seen by distant observers when you fall into a black hole your clocks get slower and slower and slower if I'm watching you and in fact they freeze on What's called the eventor Riz of black hole which is why in Russian black holes are called Frozen Stars which is a much less sexy name which is why there no Russian movies about black holes as far as I know but what it really means is kind of fascinating because it means you never really see anything fall into a black hole because time for you appears to stop if you're falling into black hole You don't notice that okay you don't and there's no sign post saying Event Horizon you fall through if it's a big enough black hole you're not even crushed when you fall through the Event Horizon if if it's big enough black hole but what is interesting is space becomes Tim like and time becomes space likee space becomes Tim likee because time as far as we can tell has only one direction towards the future that's why it's so weird if when you fall into black hole no matter what you do you always you put your foot on the gas to trying get out and you always go in the same direction towards the singularity the black hole space becomes unid unidirectional in the of of time and whereas time becomes more space likee because it turns out if you look up you see the the whole future of the universe if you look down you see the whole past in a sense and so it seems if you ta become space like if you if you describe things in those terms the space inside of black hole can be arbitrarily big because time is now space-like so what seems like space could be arbitrarily big even though a black hole is from the outside really small from the inside it could seem really big like like the cabinets in in L the Witch and the Wardrobe and that sort of thing it's very strange you you can show this using things that are called pen rolls diagrams which I which I I had a slide to show but I thought I was going to go long enough as it was so I didn't but but what happens to time and space inside of black hole are strange but understandable but what really is not understandable is what happens at the singularity at the center their time and space both and and we don't understand that at all I I just did a podcast recorded in which will appear uh sometime with Carlo relli who's written a book about white holes which and I think he's completely wrong I should say that now but but I talked to about it but he thinks there's a way that quantum mechanics can resolve this question of the singularity at a black Hall in the end of time I don't I don't buy it but you can listen to the to the our discussion Curtis Davidson ask can you briefly explain NASA's U uclid Mission what experiments will it perform and what might me we discover about Dark Matter Dark Energy the first thing about it is it isn't NASA it's EA it's the European Space Agency um which is making it U because NASA is wasting a lot of time and effort and money on human space exploration while other places try to do science um and uh in case my in case My Views are not clear on that regard um but anyway but NASA collaborates with but it's an actually an Esa Mission it will be launched in Cape canabal Al a SpaceX plane but or rocket but anyway it's a mission just to map the in an in an extremely detailed way the nature of matter in the universe the distribution of matter in the universe going as far back as we can see and by looking at that distribution matter in the universe you can trying to understand the evolution of the Universe from Early times to late times better because the farther away we look the earlier times we're looking at and dark matter and dark energy can depending upon their properties can change the way the universe be evolves and so if we can very carefully look at the evolution of structure in the universe we might get a better handle on the nature of dark matter and dark energy I'm skeptical by the way I I doubt I I I really don't think we'll get much information about dark energy that's my bet but it's you never know till you look um ask could superposition Quantum superposition be a matter of perspective for example if I look at a clock the do moves clockwise but if I'm behind the clock the do moves counterclockwise therefore the do moves both clockwise and counterclockwise no I mean it's a nice analogy but the thing I'm trying to convince you is is there's no classical analogy that works for quantum mechanics superposition is not classical because it means that things can all it really means is that that objects can interfere with each other in ways that are impossible classically really that's all that's how quantum computer works as as Scott arenson talks about in the podcast that's going to come up it's not we often say quantum mechanics allows the system to do many things at the same time and that's why Quantum mechan quantum computers are going to be so neat because they can do many calculations at the same time it's actually not that way it's just that complicated Quant uh Quant mechanical systems are doing different things but while they're doing different things they can interfere with what they're doing in other ways and you can set things up so that everything all the different possibilities will cancel out exactly except for one one possibility which will give you the right answer that's how quantum computers work but in any case any classical picture of superposition never can capture this weird fact that that you get that it's really due to something called imaginary numbers it's due to the fact that that probability amplitudes could interfere to produce probabilities we we see the world in terms of probabilities between zero and one but in quantum mechanics uh probability amplitudes can be negative and even imaginary and only after the fact do you they combine to produce probabilities that are sensible possible so it's a long degression but while your e effort to understand superposition is is laudable it can never be right because it's a classical picture that's what I tried to indicate um one set um um uh can one use the change in time from time dilation of a probe going to the Sun to deter determine if there's Dark Matter surrounding the Sun and it's an interesting question the answer is probably not because there are other ways you could probe for dark matter much more easily in fact you can use Newton you don't have to use you don't have to use Einstein and in fact I I early on wrote a paper about this and um Newton says that every um object attracts other objects and the strength of gravitational attraction goes as one over the square of the distance between the objects that brings back happy memories from high school physics for most of you for none of you I suspect um okay 1/ r s but you see if there's matter around the Sun then that it won't be 1 / R squ because the mass will change Newton say the force of gravity goes as the product of the mass of the two objects divided by the square of the distance between them but if if if there's Dark Matter around the Sun then the effective Mass attracting me further away will be larger than it was if I'm inside that that mass okay and so if I could look for variations of 1/ r squ i could S search your dark matter and a long time ago I did a calculation other this showing that unfortunately given the kind of dark matter we think there is um that there' be so little of it that you'd have to be able to measure the strength of gravity and Its Behavior to better than one part in a billion but it turns of gravity is the worst measured force in nature because it's so weak so it's beyond our ability to do that right now but if we were going to do it it'd be much easier to do it that way then look for time dilation um um a musician asks about Ai and basically how do I feel about the representation of Art and music with AI um will AI be able to create valid works or simply use current examples to Guess What in art what you know how they modify things I I sus I suspect that while while it's clear that AI systems are not good at at that right now although they could do certain kinds of art I suspect ultimately to be um there I I don't see ultimate barrier to AI producing good music and good art ju uh because it's ultimately making new connections uh with known things and I ultimately think that will be possible I don't see so I'll you know and that's scary but why is it scary you know it's just like AI I think or at least quantum computers will teach us things about quantum mechanics that we don't understand now that's great that's not bad it's not bad that a quantum computer will understand quantum mechanics better than we are to what's great is that we can create a quantum computer to do that and so you know it's okay we already take you know create I mean I'm I'm old enough to remember when do Bob Dylan first picked up an electric guitar and the impact the fact that people hated him for it but but it's just a new way of creating music anyway can you discuss your proposal with Frank wilchek to detect the Multiverse um thank you for asking that question the answer is basically it turns out what we showed was that if we can measure gravitational waves from the beginning of time from this period of inflation it can do two things it could prove that gravity is a quantum theory because there will be no gravitational ways for inflation If gravity isn't a quantum theory and that's an open question some people think maybe the reason we can't unify gravity in quantum mechanics is that grav is that at small scales gravity isn't governed by quantum mechanics so if we could measure those things we would prove that gravity is a quantum theory but also we could probe inflation and if we could probe inflation to find out the fundamental physics model of inflation then we would be able to know be able to prove mathematically whether that inflation is continuing to go on or not and so we could probe the model of inflation that produced our universe and by understanding that model we'd know whether it implied the existence of other universes so that I think that's the only hope right now for probing inflation is to find gravitational waves I spent a lot of my life early on uh are in that research area uh suggesting that we do that and we're probably a factor of only a million away from being able to do that that may sound daunting but but you know experimentalist as I like to say experimentalists aren't as dumb as they look uh um they're amazing people and they could do I never thought I I didn't talk about ligo here but um you know what we can do is just constantly amazes me and and the older I am the more in some sense I'm sad that I'm that I didn't well not sad I I I I look with wistfulness on experimentalists as a theorist I'm just amazed at what could be done and and it's really good vote ask is the Big Bag Theory dead I'm really glad you asked that vote because um that's what you hear in the newspapers and what you should always do when you read about science in the newspapers as well as politics and Foreign Affairs and everything else is be skeptical and um The Big Bang is is not dead it's alive and well uh there are always open questions at the edge of knowledge every time we look at the edge or we can see we often find inconsistencies most often those inconsistencies come from the fact that you're not quite sure what you're measuring and experiments are hard and so one of the things that people say that causes a big bang you know one of them is that we're seeing more galaxies at earlier times than we thought we would in the standard model of cosmology models I help buil um but it's a complex process and I I have known for example I've seen dark matter be killed probably five times while I've been a physicist that's one of the reasons I believe it because you know it gets resurrected and of course we all believe things that get resurrected um but uh but I see this if Dark Matter exists this can happen and then of course we realize we just didn't understand things enough numerical simulations teach us that we really were thinking about it wrong but the other thing is systematic uncertainties it's systematic uncertainties are you know in experiments we can twist dials and we can look for biases in our experiments or but when you're doing an observation you can't twist a dial in the universe and and I'm old and I remember so one of the things that is also supposed to be killing the Big Bang is that one way of measuring the expansion rate of the universe gives a number number 69 plus or minus one and another gives 72 plus or minus one so they're two or three sigma part okay holy matr big bag is dead okay when I was a junior Professor there were two measurements of the big of the great expansion of the universe one was 100 it doesn't matter what the units are 100 plus or minus 5 and one was 42 plus or minus 5 I like the 42 for obvious reasons but if you read Doug s but but uh it was obvious at the time that the observers air Bars were too small right it was obvious because 100 and and so what many of us I I remember saying the answer has to be 75 it's got to be in the middle between them what's the answer it's close to 75 so I'm suspicious of people claiming that a two Sigma un certainty in a hard measurement mean is it demonstrates something it's it could be right but there's no observation the Big Bang really happened the details of under understanding of the formation of structure may change and maybe even our details of the understanding of the nature of Dark Energy may change I'd love it I'd love to be wrong that would be great but but the these articles are ridiculous um um oh yeah last question I got through them well last question I took there's three or four more out back but there too technical I decided um do we really know what we think we know only by questioning the prevailing Paradigm can we have the next breakthrough and I think of course the answer is once again not only do I not know but I know I don't know um that I know we need to question existing paradigms but the one thing that I really want to emphasize is not knowing doesn't mean we know nothing that that's where people get wrong they say oh scientists can't science can't explain the origin of Life there must be oh in fact I thought I had that intelligent design question oh I do I'll I'll I'll answer that one here too I skipped it but um say we don't understand how life evolved therefore it had to been created by God it's it's always because you don't understand something but not understanding doesn't mean you don't understand anything what has satisfied the test of experiment will always be true new will always explain correctly the motion of baseballs and cannonballs and even Rockets around the earth okay to First approximation sure it's been subsumed by general relativity but in the domain in which it was meant to apply it applies and a billion years from now if we have a quantum theory of gravity if I take a ball and drop it it's not going to fall up so the biggest misconception people have about scien is because we don't know everything we know nothing and that's not true we know an incredible amount there's just a lot more we don't know which is what makes life interesting and and the last question I then will answer is because I forgot it is can you please comment on the theory of intelligent design of the universe because it involves some slides I took out some people have stated and have observed that look if the laws of physics were just a little bit different then we wouldn't be here and that's fascinating and therefore they argue that the Universe must have must been designed so we could be here but it amazes me that in a world in which we already know about natural selection Evolution that people ask that question the Earth wasn't designed so life could exist on it life arose on Earth because it could okay our universe wasn't designed so life could exist in fact life can't exist in MO life like us can't exist in most of the universe most of the universe is incredibly hostile and in fact the universe is trying to kill us all the time one day it'll probably succeed so the universe didn't evolved to wasn't created so life could exist life evolved in our universe because it could life evolved on Earth because it could now if there's a Multiverse of course that makes the question even more interesting because in other universes in which galaxies don't exist maybe there are life forms that are quite different than the life forms we know about those life forms would be creating physics and talking to audience see why are the laws of physics in our universe just so perfect so we could be here there must be a God okay but of course that's their universe but even if without a Multiverse and some people say you invented the Multiverse to get rid of God that would be wonderful but that's not why we the Multiverse again physicists were dragged Kicking and Screaming to the Multiverse because most of us would would prefer there to be one universe and understand exactly why it has to be the way it is rather than say the laws of physics are an accident but even if there's just one Universe again life exists on Earth because it could but we don't know that we don't know we know of one kind of life we have no idea of the kind of possibilities that could exist and and and and in my book and and I almost present a picture of my favorite science fiction story called The Black Cloud by Fred ho who is an astronomer it's a great book to read written in 1930 or something it really captures how science is done but ultimately it evolves the discovery of this cloud of gas which astronomers realize is intelligent okay and I once used to have debates with my friend Freeman Dyson about the nature of life in our universe and he he was the first one to let me convince me to read the black cloud so even in such a universe every form of life may wonder why the conditions of that are are created so it can exist but the answer is it can exist because those creation those conditions are there it's exactly the same for the universe as it is for life on Earth and I don't know why suddenly people forget to think about life on earth when they suddenly think that just because you know the laws of physics are you know if they were different we wouldn't be here somehow is is is a sign of divine intelligence and the final thing I I will say is in fact I can show that if the laws of physics were a little bit different the universe would be more conducive to life in certain cases so it's not as if we're in the ideal Universe for life if there were no dark energy in the long-term life would could and so could my battery um anyway so um there's no evidence for intelligent design let's enjoy our brief moment in the Sun and not uh create silly reasons for why we're here but rather enjoy being here as I've enjoyed being here with all of you thank you very much I guess I'll sign some books too thank you I really appreciate your your interest and patience thank [Music] you I hope you enjoyed today's conversation this podcast is produced by the origins project Foundation a nonprofit organization whose goal is to enrich your perspective of your place in the cosmos by providing access to the people who are driving the future of society in the 21st century and to the ideas that are changing our understanding of ourselves and our world to learn more please visit originpro foundation.org

Channel: The Origins Podcast

Views: 118,801

Keywords: The Origins Podcast, Lawrence Krauss, The Origins Podcast with Lawrence Krauss, The Origins Project, Science, Podcast, Culture, Physicist, Video Podcast, Physics

Id: jbzfBE0FwkI

Length: 116min 42sec (7002 seconds)

Published: Tue Jan 02 2024