Frank Wilczek: Physics of Quarks, Dark Matter, Complexity, Life & Aliens | Lex Fridman Podcast #187

the following is a conversation with. frank wilceck a theoretical physicist at. mit. who won the nobel prize for the. co-discovery of. asymptotic freedom in the theory of. strong interaction. quick mention of our sponsors the. information. netsuite expressvpn blinkist. and a sleep check them out in the. description to support this podcast. as a side note let me say a word about. asymptotic freedom. protons and neutrons make up the nucleus. of an atom strong interaction.

is responsible for the strong nuclear. force that binds them. but strong interaction also holds. together the quarks. that make up the protons and neutrons. frank wilcek. david gross and david pulitzer came up. with a theory postulating. that when quarks come really close to. one another the attraction abates. and they behave like free particles this. is called. asymptotic freedom this happens at. very very high energies which is also. where all the fun is this is the lex.

friedman podcast. and here is my conversation with frank. wilcheck. what is the most beautiful idea in. physics. the most beautiful idea in physics is. that we can get a compact description of. the world that's. very precise and very full. at the level of the operating system of. the world. um that's an extraordinary gift.

and we get we get worried when we. uh have find discrepancies between our. uh description of the world and and. what's actually observed. at the level even of a part in a billion. you actually have this quote. from einstein that the the most. incomprehensible thing. about the universe is it's co is that it. is comprehensible something like that. yes that's so that's the most beautiful. surprise that i think uh.

that that really was the to me the. most profound result of the scientific. revolution of this. of the 17th century with uh. the shining example of newtonian physics. that you could. aspire to completeness precision. and a concise description of the world. of the operating system. and it's gotten better and better over. the years. and that's the continuing miracle now. there are a lot of beautiful. sub-miracles too.

the form of the equations is governed by. high degrees of symmetry and. and they have a very surprising kind of. mind-expanding structure especially in. quantum mechanics. but if we have to say that the single. most. beautiful revelation is that. in fact uh the world is comprehensible. would you say that's a fact or hope it's. a fact. we can do we you can point to things.

like. uh the rise of. uh gross. pro gross national products grow you. know per capita. around the world as a result of the. scientific revolution you can see it all. around you. uh uh uh in in recent developments with. exponents. so exponential production of wealth. control of nature. at uh a very profound level. where we do things like sense tiny tiny.

tiny tiny vibrations. to tell that there are black holes. colliding far away. or we uh test laws as i. alluded to whether to part in a billion. and do. you know things and what appear on the. surface to be entirely different. conceptual universes i mean on the one. hand. pencil and paper or nowadays computers. that that. calculate abstractions and on the other. hand magnets and accelerators and. detectors that look at the.

behavior of fundamental particles and. and these. different universes have to agree or. else we get very upset. and that's uh it's an amazing thing if. you think about it so. and it's telling us that we do. understand a lot about nature at a very. profound. level and uh. there are still things we don't. understand of course but. as we get better and better answers and. better and better.

ability to address difficult questions. we can ask. more and more ambitious questions well i. guess the hope. part of that is because we are. surrounded by mystery. so we've one way to say it if you look. at the growth the. gdp over time that we figured out quite. a lot and we're. able to improve the quality of life. because of that. and we've figured out some fundamental. things about this universe but we still. don't know how much mystery there is. and it's also possible that there's some.

things that are in fact. incomprehensible to both our minds. and the tools of science like we the. the sad thing is we may not know it. because. in fact they are incomprehensible and. that's the open question is. how much of the universe is. comprehensible if we figured out. the the everything uh what's inside the. black hole. and everything that happened at the. moment of the big bang. does that still give us the key to. understanding the human mind.

and the the emergence of all the. beautiful complexity we see around us. that's not uh like when i when i see. these objects. like i don't know if you've seen them. like cellular automata. uh all these kinds of objects where the. from simple rules emerges complexity yes. it makes you wonder maybe it's not. reducible to simple beautiful. equations the whole thing only parts of. it. that's the tension i was getting at with. the hope well. when we say the universe is. comprehensible we have to.

kind of draw careful distinctions about. or uh. definitions about what what we mean by. by that. uh both the university and the con and. the comprehensive. exactly right so uh the. so in certain areas. of understanding reality. we've made extraordinary progress i. would say. in understanding fundamental physical.

processes. and getting very precise equations that. really work and. allow us to do uh the profound sculpting. of matter. you know to make computers and iphones. and everything else and they really work. and they're extraordinary productions. uh on the other but uh. and that's all based on the laws of. quantum mechanics and you know they. really. and they really work and then uh. and they give us tremendous control of. nature.

on the other hand uh as i said as with. as we get better answers we can also ask. more ambitious questions and there are. certainly things that. have been observed even in the. in what would be usually called the. realm of physics that aren't understood. for instance there seems to be another. source of mass in the universe the. so-called dark matter. that we don't know what it is and it's a. very interesting question what it is. then uh but also as you were alluding to.

there. there's it's one thing to know the basic. equations. it's another thing to be able to solve. them. in in important cases so we run a. we run up against the limits of that in. things like. chemistry where we'd like to be able to. design molecules and predict their. behavior. from the equations we think the. equations could do that. in principle but but uh. in practice it's very challenging to. solve them in.

in all but very simple cases uh. and then there's the other thing which. is that a lot of what we're interested. in. is uh historically conditioned it's not. uh it's not a matter of the fundamental. equations but about. what has evolved or come out. of of the early universe and formed into. people and frogs and societies and. things. and the laws of physic the basic laws of. physics only take you so far.

in the in that it kind of provides a. foundation but doesn't. really you need entirely different. concepts to deal with. uh those kind of uh and. all we one thing i can say about that is. that the laws themselves. point out their limitations that they. kind of their laws for dynamical. evolution so they tell you what happens. if you have a certain starting point but. they don't tell you what the starting. point. should be at least yeah and.

uh the other the other thing that. emerges from the equations themselves. is the phenomena of chaos. and sensitivity to initial conditions. which tells us that you have that. there are intrinsic limitations on how. well we can spell out the. consequences of the laws if we try to. apply them see all the apple pie. if you want to what does it make an. apple pie from scratch.

you have to build the universe or. something like that well. you're much better off starting with. apples than starting with quarks. let's put it that way in your uh book a. beautiful question you ask. does the world embody beautiful ideas so. the book is centered around this. very interesting question it's like. shakespeare you can like dig in and read. into all the different interpretations. of this question. but at the high level what to use the. connection between. beauty of the world and physics of the.

world. in a sense we now have a lot of insight. into what the. the laws are the for the form they take. that and. allow us to understand matter in great. depth and control it. as we as we've discussed uh. it's an extraordinary thing how. mathematically ideal. those equations turn out to be in the. early days of greek philosophy. uh plato had this model of.

atoms built out of the five perfectly. symmetrical platonic solids so there was. somehow the idea that mathematical. symmetry. uh should govern the world and uh we've. outplated plato by far. in modern physics because we have. symmetries that are much more extensive. much more powerful. that turn out to be uh the ingredients. out of which we construct our theory of. the world. and and it works and uh.

so that's certainly beautiful so. the the math the idea of symmetry which. is. uh a driving inspiration. in much of human art uh especially a. decorative art or like the alhambra or. in. wallpaper designs or things you see. around you everywhere. uh also turns out to be the dominant. theme in. modern fundamental physics symmetry and.

its manifestations. the laws turn out to be very to have. these tremendous amounts of symmetry you. can change. the symbols and move them around in. different ways and they still have. the same consequences uh. that so that's that's. uh beautiful and uh. that that uh these things uh these. different. these concepts that humans find. appealing.

also turn out to be the concepts that. govern how the world actually works. and i don't think that's an accident i. think the humans. were evolved to be able to interact with. the world in. in ways that are advantageous and to. learn from it. and so we are naturally evolved or. designed to enjoy beauty and. and it's a symmetry and this and the. world has it and that's no. that's why we that's why we resonate.

with it well it's interesting that the. ideas of symmetry emerge at. all at many levels of. the hierarchy of the universe so. you're talking about particles but it. also is. at the level of chemistry and biology. and. um and the fact that our. cognitive sort of our perception system. and whatever our cognition is also finds. it appealing or somehow our sense of.

what is beautiful is grounded in this. idea of symmetry or the breaking of. symmetry. symmetry is at the core of our. conception of beauty whether it's the. breaking or the non-breaking of the. symmetry. it makes you wonder why. why like uh so i come from russia. in the in the question of dostoyevsky. he's. he has said that beauty will save the. world maybe. maybe as a physicist you can tell me. what do you think he meant by that.

i don't i don't know if it saves the. world but it does turn out to be a. tremendous source of insight into the. world. when we uh investigate kind of the. the most fundamental interactions things. that are. hard to access because they occur at. very short distances between. very uh. special kinds of particles whose. properties are only revealed at high. energies.

we don't have much to go on from. everyday life but so we have when we. guess what the. so we and then the experiments are. difficult to do so you can't. you can't really uh follow a very. uh holy empirical procedure to. sort of step in the baconian style. figure out the laws kind of step by step. just by accumulating a lot of data. what we actually do is guess and the. guesses. are kind of aesthetic really what what. would be a nice description.

that's consistent with what we know and. then you try it out and see if it works. and then. and by gosh it does in in some. in many profound cases uh so. there's that but there's another source. of symmetry which i didn't. talk so much about in uh. in a beautiful question but does. uh relate to your comments and i think. very much relates to. uh the source of symmetry that we find.

in biology. and uh in. in our in our heads you know in our. brain. which is that uh although i'd. well it is discussed a bit in in a. beautiful question and and. also in fundamentals is that. when you have. symmetry is also a very important means. of construction.

so when you have for instance simple. viruses. that that need to construct their coat. their protein coat the coats often take. the form of platonic solids. and the reason is that the viruses are. really dumb. and they only know how to do one thing. so they make a pentagon then they make. another pentagon and they make another. pentagon and they. all glue together in the same way and. that makes a very symmetrical. object sort of so the rules of. development when you have simple rules.

and they. go they work again and again you get. symmetrical patterns that's it's kind of. in in fact it's a recipe also for. generating. fractals you know really like uh. the kind of broccoli that has all this. internal structure and i. wish i had a picture to ship that many. people remember it from the. from the uh uh from the supermarket. and then and you say how did a vegetable. get so intelligent to make such a.

beautiful object of all this. fractal structure and the the the secret. is stupidity you just do the same thing. over and over again. and uh in our brains also you know we've. we came out we start from single cells. and they reproduce and they they're each. one. does basically roughly the same thing. they. they uh the the program evolves in time. of course. different different modules get turned.

on and off genetic. different regions of the genetic code. get turned on and off. but uh but basically a lot of the same. things are going on and they're simple. things and so you produce the same. patterns over and over again and that's. a recipe for producing symmetry because. you're getting the same thing. in many many places and if you look at. for instance the beautiful drawings of. rahman ikahal the great neuroanatomist. who drew the structure of different. organs.

like the hippocampus you see it's very. regular. and very intricate and. it's symmetry in in this in. in that sense it's because it's it's. it's many repeated units that that. uh you can take from one place to the. other and see that they look more or. less the same. but what you're describing this kind of. beauty that we're talking about now. is a very small sample. in terms of space-time in a very big.

world. in a very short brief. moment in this long history in your book. fundamentals. 10 keys to reality i'd really recommend. people read it. you uh you say that space and time are. pretty big. or very big how big are we talking about. like what uh. can you draw can you tell a brief. history. of space and time it's easy to. tell a brief history but the details get.

very. involved of course but uh one thing i'd. like to say is that. if if if you take a broad enough view. the history of the universe is simpler. than the history of sweden say. because you don't you your standards are. lower for for. but just to make it a a a. quantitative i'll just give a few. highlights and it's it's. it's a little bit easier to talk about. time. uh so let's start with that the big bang.

occurred. we think the universe was much hotter. and denser and more uniform. about 13.8 billion years ago and that's. what we call the big. bang and it's been expanding and cooling. the matter in it has been expanding and. cooling. ever since so in a real sense the. universe is 13.8 billion years old. that's a big number kind of hard to. think about. a a nice way to think about it though is. to map. it on to one year so if.

so let's say the universe just linearly. map the time intervals from. 13.8 billion years on to one year so. the the big bang then is that on january. 1st at. 12 a.m and. uh you wait for quite a long time. before the dinosaur has emerged the. dinosaurs emerge on christmas. it turns out almost 12 months later.

getting close to the end yes. and the extinction event that uh. let mammals and ultimately humans. inherit the earth from from the. dinosaurs occurred on december 30th. and all of human history is a small part. of the last day. and so so yes so we. we're occupying only a human lifetime is. a. very very infinitesimal part of this uh.

interval of these gigantic cosmic. reaches of time uh and. in space we can tell a very similar. story in fact. a very uh it's convenient to think. that the size of the universe is. the distance that light can travel in. 13.8 billion years that's. so it's 13.8 billion light years. that's that's how far you can see out. that's how far.

things can signals can reach us from. and um that. is a big distance. because compared to that uh the the. universe. that the earth is a fraction of a light. second. so again we it's really really big. and so we have if we want to think about. the universe as a whole in space and. time.

we really need a different kind of. imagination. it's not it's not something you can. grasp in terms of psychological time in. a useful way you have to think. you know you have to use exponential. notation and abstract concepts. to really get any uh hold on on. on these vast times and spaces. on the other hand let me hasten to add. that that doesn't make us small.

or make the time that. we have to us small because uh. again looking at those pictures of. you know what our minds are in some. sense of components of our minds these. beautiful drawings of the cellular. patterns inside the brain. you see that there are many many many. processing units. and if you analyze how fast they operate. i try to estimate how many thoughts a.

person can have in a lifetime that's. kind of a fuzzy question but i'm very. proud that i. i was able to define it pretty precisely. and it turns out we can we have time for. billions. of meaningful thoughts you know in a. lifetime. so so it's a lot we shouldn't we. shouldn't think of ourselves as terribly. small. either in space or in time because. although we're. small in those dimensions compared to. the universe where. we're large compared to.

meaningful units of processing. information. and and being able to conceptualize and. understand things. yeah but 99 of those thoughts are. probably. food sex or internet related but yeah. yeah well they're not that's right only. like point one is nobel prize winning. ideas. but that's true but uh you know there's. more to life than winning nobel prizes. how did you um do that calculate can you. maybe break that apart a little bit just.

kind of. for fun sort of an intuition of how we. calculate the number of thoughts the. number of thoughts right there they're. it's necessarily imprecise because a lot. of things are going on in different ways. and what is a thought. but there are several things that point. to more or less the same. [Music]. uh rate of being able to have meaningful. thoughts. uh for instance i'm the one that i think. is. maybe the most penetrating is uh.

how fast we can we can process visual. images how to how do we do that. if you've ever watched old movies. you can see that that when well any. movie. in fact that in a motion picture is. really not a motion picture it's. a series of snapshots that are playing. one after the other. and it's the because our brains. also work that way we take snapshots of. the world. integrate over a certain time and then.

go on to the next one and then. by post-processing create the illusion. of continuity and flow. we can deal with that and uh. the if the flicker rate is too slow. then you start to see that it's not it's. a series of snapshots. and you can ask what is the what is the. crossover when does it change from being. something that. that is matched to our processing speed. versus. too fast and and it turns out about 40. per second.

and then if you take 40 per second as. as how well we how fast we can process. visual images you get. to several billions of thoughts uh. if you similarly if you ask what. what are some of the fastest things that. people can do well you can they can play. video games they can play the piano very. fast if. if they're skilled at it and again you. get to similar. uh units or how fast can people talk you. get to sim. you know within a couple of orders of. magnitude you get more or less to the.

same. idea so uh so that's how. you can say that that there's there's. billions of. meaning there's room for billions of. meaningful thoughts. yeah i won't argue for exactly 2 billion. versus 1.8 billion it's not that kind of. question but. but i think any estimate that's. reasonable will come out. within say a hundred billion and a. hundred million. so it's a lot. [Laughter].

it would be interesting to map out for. an individual human being. the landscape of thoughts that they've. sort of traveled if you think of. thoughts as a set of trajectories uh. what what that landscape looks like i. mean. i've been recently really thinking about. uh. this richard dawkins idea of memes. and just all these ideas and the. evolution of ideas inside of one. particular human mind.

and how there's there then changed and. evolved by. interaction with other human beings it's. interesting to think about. so if you think the numbers billions. you you think there's also social. interaction so these aren't. uh like there's interaction in the same. way you have. interaction with particles there's. interaction between human thoughts. uh that are perhaps that's that. interaction in itself is fundamental to. the process. of thinking like without social.

interaction we would be. like stuck like walking in a circle we. need. we need the perturbation of other humans. to create. change in evolution once you bring in. concepts of uh. interactions and correlations and. relations. then you have what's called a. combinatorial explosion. that the number of possibilities rap. expands exponentially technically with. the number of. the number of things you're considering. and.

uh it can easily rapidly outstrip these. these billions of thoughts that we're. talking about so. we we definitely uh cannot by brute. force. master complex situations and. or think about think of all the. possibilities in complex situations i. mean you know. even even something as relatively simple. as chess. is still something that human beings. can't comprehend completely even the. best players lose. still sometimes lose and they.

consistently lose to computers these. days. uh and in computer science there's a. concept of. np complete so large classes of problems. when you scale them up beyond. a few individuals become intractable. and so that in that sense uh the world. is inexhaustible. but and that makes it beautiful that we. can make uh. any laws that generalize. efficiently and well can compress all of.

that. combinatorial complexity just like a. simple rule that that itself is. beautiful. it's a happy situation and i i think. that that we can. find general principles of. sort of of the operating system that. are comprehensible simple extremely. powerful. and let us control things uh very well. and and ask profound questions. and on the other hand that the world is. going to be inexhaustible. that once we start asking about.

relationships and how they evolve. and social interactions and the the. the we'll never have a theory of. everything in any meaningful sense. because. of everything everything truly. everything is. uh can i ask you about the big bang uh. so we talked about the space and time. are really big. but then and we humans give a lot of. meaning to the word space. and time in our in our like daily lives.

but then can we talk about this moment. of beginning. and how we're supposed to think about it. that at the moment the big bang. everything was uh. what like infinitely small and then it. just. blew up we have to be careful here. because there's a. there's a common misconception that. the big that the big bang is like the. explosion of a bomb in empty space. that that uh fills up the surrounding.

place. it is space it is yeah as we understand. it. it's the fact it's the the fact or the. hypothesis but. well supported up to a point that that. that everywhere in the whole universe. early in the history uh matter came. together into a very hot. very dense if you run it backwards in. time. matter comes together into a very hot.

very dense and yet very homogeneous. plasma of all the different kinds of. elementary particles and quarks and. anti-quarks and gluons and photons and. electrons and anti-electrons everything. you know all of that stuff. like really hot really really. really hot we're talking about uh way. way hotter than the surface of the sun. uh you know well in fact if you. take the equations as we as they come.

the the prediction is that the. temperature just goes to infinity but. then the equations. uh break down we don't you know we don't. don't really. with their various the equations become. infinity equals infinity so they don't. feel. that it's called a singularity we don't. really know uh this is running the. equations backwards so you can't really. get a sensible. idea of what happened before the big. bang we don't you know so. we need different equations to address. the very earliest. moments uh that uh.

but so things were hotter and denser we. don't. really know why things started out that. way. we do we have a lot of evidence that. they did start out that way. uh but since most of the. uh you know we don't get to visit there. and do controlled experiments most most. of the. most of the record is is very very. processed and.

we have to we have to use uh very. uh subtle techniques and powerful. instruments to. to get information that has survived. get closer and closer to the get closer. and closer to. the the beginning of things and. what's revealed there is that uh. as i said there what there undoubtedly. was a period when. everything in the universe that we have. been able to look at. and understand and that's consistent.

with everything. is uh um. the was in a condition where it was much. much hotter. and much much denser but still obeying. the laws of physics as we know them. today. and and then you start with that so all. the matter is in equilibrium. uh and then with small quantum. fluctuations and run it forward. and then it produces in at least in.

broad. strokes the universe we see around us. today. do you think we'll ever be able to with. the tools of physics. with the way sciences with the way the. human mind is we'll ever be able to get. to the moment of the big bang in our. understanding. or even the moment before the big bang. can we understand what happened before. the big bang i'm. i'm optimistic both that we'll. be able to uh measure more.

so observe more and that we'll be able. to figure out more. so uh they're very very tangible. prospects. for uh observing the. extremely early universe so much even. much earlier than we can. observe now uh through looking at. gravitational waves. gravitational waves since they interact. so weakly. with ordinary matter uh. sort of send an un a minimally processed.

signal from the big bang it's a very. weak. signal because it's traveled a long way. and diffused over long spaces. but uh but people are gearing up to try. to detect. gravitational waves that could have come. from the early universe yeah ligo's. incredible engineering project is the. most sensitive. precise yes devices on earth. the fact that humans can build something. like that is uh. truly awe-inspiring from an engineering.

perspective right. and but these gravitational waves from. the early universe would probably be. of a much longer wavelength than lyco is. capable of. sensing so there's a beautiful. project uh that's contemplated. to put lasers in different parts. different locations in the solar system. you know we really really separated by. uh solar system scale differences like.

artificial planets or moons. in different places and and see the tiny. motions of those relative to one another. as a signal of. of radiation from the big bang we can. also maybe. indirectly see the imprint of. gravitational waves from the early. universe. on uh the photons the the microwave. background radiation. that that is our present way of of. seeing. into the earliest universe but those. those photons. interact much more strongly with matter.

they're much more strongly processed so. they don't. give us directly such an unprocessed. view of the early universe of the very. early universe. but if gravitational waves leave some. imprint. on that as they move through uh. we could detect that too and people are. trying our. as we speak working very hard towards uh. towards that goal it's so exciting to. think about a sensor the size of a solar. system.

like uh that would be a fantastic i mean. that would be a pinnacle. artifact of human endeavor to me it. would be. such uh such an inspiring thing. that just we want to know. and we go to these extraordinary lengths. of making. gigantic things that are also very. sophisticated because what you're trying. to do. you you have to understand how they move. you have to understand. uh the properties of light that that are. being used interference between light.

and. you have to be able to make the light. with lasers and understand the quantum. theory and. get the timing exactly right you know. it's an extraordinary. endeavor involving all kinds of. knowledge from the very strong. very small to the very large and all in. the service of. uh curiosity and built on a grand scale. so yeah. if we did that i love that you're. inspired both by by the power of theory.

and the power of experiments so this is. the both both i think are. exceptionally impressive that the human. mind can come up with theories. that give us a peek into how the. universe works but also. construct tools that are way bigger than. uh. the the evolutionary origins we came. from right. and by the way you know the fact that we. can design those things and they work. yeah is an extraordinary demonstration. that we really do. understand a lot and then.

in some ways and it's our ability to. answer. questions that also leads us to be able. to address more ambitious questions. so you mentioned that at the at the big. bang. in the early days things are pretty. homogeneous. yes but uh here we are sitting on earth. to uh hairless apes you could say. with microphones in talking about the. brief history of things you said it's. much harder to describe sweden than it.

is. um the universe so there's a lot of. complexity. there's a lot of interesting details. here so how does this complexity come to. be do you think. it seems like there's these pockets yeah. we don't know how rare of like. uh we're hairless apes just emerge yeah. and then they came from the initial soup. that was homogeneous. was that uh yeah accident. well we understand there we understand. in broad.

outlines how it could happen. we certainly don't understand why it. happened exactly and the way it did or. but but uh or you know. there are certainly open questions about. the origins of life and how inevitable. the emergence of intelligence was and. and how that happened. but uh in the very broadest terms. uh the universe early on. was quite homogeneous but not completely. homogeneous.

there are there were part in 10 000. fluctuations in density within this. primordial plasma and. uh as time goes on. there's an instability which causes. those density contrasts. to increase there's a gravitational. instability where it's denser. the gravitational attractions are. stronger and so that brings in more. matter and it gets even denser. and so on and so on so so there's a.

natural. tendency of matter to clump because of. gravitational interactions. and then the equations get complicated. when you have lots of things. clumping together uh then you know then. then we know what the laws are but we. have to to a certain extent wave our. hands about what what. what happens but uh the basic. understanding of chemistry says that if. things. and and the physics of radiation tells.

us that if. as things start to clump together they. can radiate give off some. energy so they don't just they slow down. they as a result they lose energy they. conglomerate together. cool down form things like stars form. things like planets. and so in broad terms there's no mystery. there's. that that's what the scenario that's. what the equations tell. you should happen but because. it's a process involving many many.

fundament individual units uh. the the the application of the laws that. govern. individual units to these things is is. very delicate uh you know. computationally very difficult. and more profoundly uh the equations. have this probability of chaos or. sensitivity to initial conditions which. tells you. tiny differences in the initial state. can lead to enormous differences.

in the subsequent behavior so so. physics fundamental physics at some. point says. okay chemists biologists this is your. problem. and and uh and then. again in broad terms we know how. uh it's conceivable that that the. humans and things like that can can uh. that how complex structure can emerge. it's a matter of uh having.

the right kind of temperature and the. right kind of stuff. so you need you need to be able to make. chemical bonds that are reasonably. stable and. be able to make complex structures and. we're very fortunate that carbon has. this. ability to make uh backbones and. elaborate branchings and things so you. can get complex things that we call. biochemistry. and and yet the bonds can be broken a.

little bit with the help of. energetic injections from the sun so you. have to have. both the possibility of changing but. also the possible. useful degree of stability and we know. at that. very very broad level. physics can tell you that it's. conceivable yeah if you want to know. what actually. what what's what what really happened. what really can happen then you have to. work a bit to. go to chemistry if you have if you want. to know what actually happened. then you really have to consult the.

fossil record in biologists and so. so uh but but it's it so these. these ways of addressing the issue. are complementary in a sense they but. they uh. they uh they use different kinds of. concepts they use different. uh languages and they address different. kinds of questions but. they're they're not inconsistent they're. just. complimentary it's kind of interesting. to think about.

those early fluctuations as our. earliest ancestors yes that's right so. it's far it's amazing to think that uh. you know this is. the modern answer to the uh. or the modern version of uh. the what the hindu philosophers had that. art thou. if you ask what okay that those those. little quantum fluctuations in the early.

universe. are the seeds out of which uh complexity. including uh plausibly humans really. evolve you don't need anything else that. brings up the question. of uh asking for a friend here if. there's. uh you know other pockets of complexity. commonly called as uh alien intelligent. civilizations out there well we don't. know for sure but i.

i have a strong suspicion that the. answer is yes because. the uh the one. case we do have at hand to study. here on earth uh we sort of know what. the conditions were that were helpful to. life the right kind of temperature the. right kind of star. that that keeps maintains that. temperature for a long time the liquid. environment of water. and once those conditions.

emerged on earth which was roughly four. and a half billion years ago it wasn't. very long before. what we call life started to leave. relics. so we can find the. forms of life primitive forms of life. that are almost. as old as the earth itself in the sense. that once the earth. became reason was was returned from a. a a very hot boiling thing and cooled. off into a solid mass with.

it with water uh life emerged very very. quickly so. so it seems that these general. conditions for life. uh are enough to to make it happen. uh relatively quickly now. the other lesson i would i think that. one can uh draw from this one example. it's dangerous to. the drug lessons from one example but. that's all we've got. uh and uh that that the emergence of.

intelligent life is a different. issue altogether it uh that took a long. time. and seems to have been pretty contingent. uh the you know the the for a long time. well for most most of the history of. life. it was single-celled things. you know uh yes even multicellular life. only rose about 600 million years ago.

so much after you know so and the the. uh and then. intelligence is kind of a luxury you. know if you think. uh many more kinds of creatures. have uh big stomachs. than big brains and in fact uh most most. most have no brains at all in any. reasonable sense. that that then uh and the dinosaurs. ruled for a long long time and some of.

them were pretty smart but. they they were at best bird brains. because you know birds. came from the dinosaurs uh and. uh and it could have stayed that way you. know and and. then human and the emergence of humans. was very contingent and kind of a. very very recent development on. evolutionary time scales. and uh you can argue about the level of. human intelligence but it's you know i. think it's. that that's what we're talking about and. it's very it's very impressive and can.

ask these kinds of questions and discuss. them intelligently. uh the uh so. i guess my my so this is a long-winded. answer or justification of. my feeling is that uh the. conditions for life. in some form are probably con. satisfied many many places around the. universe.

even and even within our galaxy uh. i'm not so sure about the emergence of. intelligent life. or the emergence of technological uh. civilizations that that that seems. uh much more much more contingent and. special and. we might it's conceivable to me that. we're the only example. in the galaxy or although. yeah i don't know one way or the other i. i have different opinions on different. days of the week well one of the things.

that worries me. in in uh in the spirit of being humble. that our particular kind of intelligence. is not very special so there's all kinds. of different intelligences. and even more broadly there could be. many different. kinds of life yes so the basic. definition and i just had. i think somebody that you know sarah. walker i just had a very long. conversation with her. about even just the very basic question. of trying to define.

what is life from a physics perspective. yeah even that question within itself i. think one of the most fundamental. questions. in science and physics and everything is. just. trying to get a hold trying to get some. universal laws around the. ideas of what is life because that kind. of unlocks a bunch of things around. life intelligence consciousness all. those kinds of things. i agree with you in a sense but i think. that's a dangerous question because. the the answer can't be any more precise.

than the question. and the uh the the question what is life. kind of assumes that we have a. definition of life and that it's a. natural phenomena that that can be. distinguished. but that really there are edge cases. like viruses and. uh some people would like to say that uh. electrons have consciousness and they. you know. so you can't if you really have fuzzy. concepts. it's uh it's very hard to to reach.

precise kinds of scientific answers. but i think there's a very fruitful. question that's. adjacent to it which is has been pursued. in different forms. for quite a while and is now becoming. very sophisticated. in reaching in new directions and that. is. what are the states of matter that are. possible you know so. in high school or grade school you. learn about solid solids liquids and.

gases but that really just scratches the. surface. of different ways that are. distinguishable that matter can. form into uh. macroscopically different meaningful. patterns that we call phases. and then there are precise definitions. of what we mean by phases of matter. but then uh and that have been worked. out fruitful. over the decades and we're discovering. new states of matter all the time. and kind of having to work at what we.

mean by. matter we're discovering the. capabilities of matter. to organize in interesting ways. and uh. some of them like liquid crystals. are important ingredients of life our. cell membranes are liquid crystals. and that's very important to the way. they work. recently there's been a development in. where we're talking about. uh states of matter that not only.

not that are not static but that have. dynamics that have that uh. have characteristic patterns not only in. space but in time. these are called time crystals and. that's that's been a development that's. just in the last decade or so it's. really. really flourishing uh and. so uh is there a state of matter that. cause or. group of states of matter that. corresponds to life. uh maybe but but the answer can't be any.

more definite than the question. so i mean i i got to push back on the. the the quite. those are just words i mean i i i. disagree with you the. the the question points to a direction. the answer might be able to be to be. more precise than the question. because because uh just as you're saying. there. there's uh that we could be discovering. certain. characteristics and patterns that are. associated with a certain.

type of matter macroscopically speaking. and that that we can then uh be able to. post facto say this is let's. sign the word life well kind of matter i. agree with that completely that that's. that's uh but that's so it's not a. disagreement. it's very frequent in physics that where. in science that. uh words that are in common use gets. get refined and reprocessed into.

scientific terms that's happened for. things like force and. energy uh and. so we've in a way we we find out what. the useful definition. is uh or symmetry for instance. and the common usage may be quite. different from the scientific usage but. the scientific usage. is special and takes on a life of its. own and we find out what the. the useful version of it is. uh what the the fruitful version of it.

is. so i do think so in that spirit. i think if we uh can. identify states of matter. that or linked states of matter. that can carry on processes of uh. self-reproduction and development. and information processing. we should say we we might be tempted to.

classify those. as like things as life yeah well can i. ask you about the craziest one. which is uh the one we know. maybe least about which is consciousness. is it possible that there are certain. kinds of matter would be able to. classify. as um conscious meaning. like the so there's uh the pan cyclists. right with the philosophers who kind of. try to imply that uh all matter has some.

degree of consciousness and yeah you can. almost construct like a physics of. consciousness. yes do you um. again we're in such early days of this. but nevertheless it seems useful to talk. about is. is there some sense from a physical. perspective to make sense of. consciousness. again consciousness is uh. imprecise a very imprecise word and. loaded with. uh connotations that i think we should. we. don't want to start a scientific.

analysis with that i don't think. uh it's often been. important in science to start with. simple cases. and work up uh consciousness i think. what. most people think of when you talk about. consciousness is okay. i'm what am i doing in the in the world. this is my experience i have a rich. experience rich inner life and. experience of. and uh where is that in the equations. and.

i think that's a great question a great. great question and actually i think. i'm gearing up to spend part of the i. mean. to try to address that in coming years. one version of asking that question just. as you said now. is what is the simplest yeah formulation. of. that to study i think i think i'm much. more comfortable with the idea of. studying self-awareness. as opposed to consciousness because that. that sort of gets rid of the mystical. aura of the thing and self-awareness.

is uh in simple you know the. i think uh contiguous at least. with ideas about feedback so. if you have a system that looks at its. own state. and responds to it that's a kind of. self-awareness. and more sophisticated versions could be. like. in information processing things. computers that look into their own. internal state and do something about it.

and i think that could also be. done in neural nets this is called. recurrent neural nets which are hard to. understand and kind of a frontier of. the the uh uh so i think understanding. those. and gradually building up a kind of. uh profound. ability to un to uh. conceptualize different levels of.

self-awareness what do you have to not. know and what do you have to know. and when do you know that you don't know. it or when do you know what do you think. you know that you don't really know. the the these uh i think uh. clarifying those issues when we clarify. those issues and get a rich theory. around uh self-awareness i think. the that will illuminate. the questions about consciousness in a. way that you know scratching your chin. and talking about qualia and blah blah.

blah blah. is never going to do well i also have a. different approach to the whole thing so. there's from a robotics perspective you. can engineer. things that exhibit yes qualities of. consciousness without understanding. well well the how things work. and from that perspective you uh. it's like a back door like enter through. the psychology door. precisely the car yeah i think we're on.

we're on the same wavelength here i. think that. and let me just add one comment which is. uh i think we should try to understand. consciousness as we experience it. uh in in as. in evolutionary terms and ask ourselves. why why does it happen this thing seems. useful. why is it useful why is it useful. i think we've got a conscious eye watch.

here interesting quest thank you siri. okay yeah. get back i'll get back to you later uh. yeah uh um and i think what we're gonna. i'm i'm morally certain that what's. going to emerge from. analyzing recurrent neural nets and. robotic design and advanced computer. design. is that having this kind of. looking at the internal state.

in a structured way that. that doesn't look at everything as guys. has it's encapsulated looks at highly. processed information and very selective. and makes. choices without knowing how they're made. there's so there'll also be an. unconscious. i think that that is going to be turn. out to be. really essential to doing efficient. information processing. and that's why it evolved. because it's it's it's it's helpful.

in uh because brains come at a high cost. yeah so there has to be there has to be. a good why and there's a reason. yeah they're rare in evolution uh. you and uh big brains are rare in. evolution and they. they come at a big cost you mean if you. you they. they they have high metabolic. demands uh they require. you know very active lifestyle warm.

bloodedness. and take away from the. ability to support metabolism of. digestion and so so it's it's uh. it comes at a high cost it has to it has. to pay back. yeah i think it has a lot of value in. social interaction so i. actually i'm spending the rest of the. day today and uh. with uh our friends uh. that are our legged friends in robotic. form at boston dynamics. and i think so.

my probably biggest passion is human. robot interaction. and it seems that consciousness from the. perspective of the robot is very useful. to improve the human robot interaction. experience. the first the display of consciousness. but then to me there's a gray area. between the display of consciousness and. consciousness itself. if you think of consciousness from an. evolutionary perspective. it seems like a useful tool in human. communication so yes.

um it's certainly well whatever. consciousness it. will turn out to be i think uh. addressing it. through its use yes and working up from. simple cases and also. working up from engineering experience. in trying to do efficient computation. including. efficient management of social. interactions. is going to really shed light on these. questions as i said in a way that. sort of musing abstractly about. consciousness never would.

so as i mentioned i talked to sarah. walker and. first of all she says hi spoke very. highly of you one of her concerns about. physics. and physicists and humans is that. we may not fully understand the system. that we're inside of meaning. like there may be limits to the kind of. physics we do. in trying to understand the system of. which we're. part of so like the the observer.

is also the observed in in that sense. it seems like the the um. our tools of understanding the world. i mean this is mostly centered around. the questions of what is life. trying to understand the patterns that. uh that are characteristic of life and. intelligence all those kinds of things. um we we're not we're not using the. right tools. because we're in the system is there is. there something that resonates with you.

there almost well yeah yes we do have we. we have limitations of course uh. in the amount of information we can. process. uh on the other hand we can get help. from our silicon friends. and we uh we can get help from all kinds. of instruments that make up for for our. perceptual deficits. and uh we have to and we can use. at a conceptual level we can use.

different kinds of concepts to address. different kinds of questions so i'm not. sure exactly. what problem she's talking about it's a. problem akin to. an organism living on a in a 2g plane. trying to understand. a three-dimensional world well we can do. that i mean you know we. in fact we you know for practical. purposes most of our experience. is two-dimensional it's hard to move. vertically and yet we've produced. conceptually a three-dimensional.

symmetry and in fact. four-dimensional space-time uh so. you know by thinking in appropriate ways. and. using instruments and demand and getting. consistent accounts and rich accounts. we find out what concepts are uh. uh uh necessary and. uh i don't see any end in sight of the. process. or any uh show stoppers because.

let me give you an example i mean for. instance uh. uh qcd our theory of the strong. interaction has. nice equations which i helped to. discover what's qcd. quantum chromodynamics so it's our. theory. of the strong interaction the. interaction that is responsible for. nuclear physics so it's the interaction. that governs how quarks and gluons. interact with each other and make. make protons and neutrons and all the. strong the.

related particles and among many things. in physics it's one of the. four basic forces of nature as we. presently understand it. uh and. uh so we have beautiful equations which. we can. test in very special circumstances. uh uh using at high high energies at. accelerator so we're. certain that these equations are correct. you know prizes are given for it and so.

people try to knock it down and they. can't and yeah they they the. they uh uh but. uh but the situations in which you can. calculate the consequences of these. equations are very limited. so for instance no one has been. able to demonstrate that. this theory which is built on. quarks and gluons which no one that. which you don't observe.

actually produces protons and neutrons. and the things you do observe this is. called the problem of confinement. so no one's been able to prove that. analytically in a way that a human can. understand. on the other hand we can take these. equations. to a computer to gigantic computers and. compute. and by god you get the world. from it the so these equations. in a way that we don't.

understand in terms of human concepts we. cut we. we can't do the calculations but our. machines can do them. so with the help of what i like to call. our silicon friends and. their their descendants in the future we. can. understand in a different way that. allows us to understand more. but i don't think we'll ever no no human. is ever going to be able to calculus. solve those equations in the same way so.

so but but i think that's you know when. we find limitations to. our natural abilities we can. try to find works or workarounds and. sometimes that's appropriate concepts. sometimes it's appropriate instruments. sometimes it's a combination of the two. but i think. uh it's premature to. get defeatist about it i don't see. anything i don't see any. uh any logical.

contradiction or paradox or limitation. that that will bring this process to a. halt. well i think the idea is to continue. thinking outside the box in different. directions meaning. just like how the math allows us to. think of multiple dimensions. outside of our perception system uh sort. of. thinking uh um you know coming up with. new tools of mathematics or computation. or. all those kinds of things to to.

to to take different perspectives on our. universe. well i'm all for that you know and i i. kind of have even elevated it into a. principle which is of complementarity. following boar that you need different. ways of thinking. even about the same things in order to. do justice to their reality and answer. different kinds of questions about them. i mean we've several times alluded to. the fact that. human beings are hard to understand and.

the concepts that. you use to understand human beings if. you want to. prescribe drugs for them or see what's. going to happen if. if they move very fast or get ex. or are exposed to radiation and so that. requires one kind of thinking that's. very. physical uh based. based on the fact that the materials. that we're made out of. on the other hand if you want to. understand how a person's going to. behave in a different kind of situation.

you need entirely different concepts. from psychology and. there's nothing wrong with that you can. have different ways of addressing. the same material that are useful for. different purposes right. can you describe this idea which is. fascinating of complementarity a little. bit sort of uh. first of all what uh. state is the principle what is it and. second of all. what are good examples starting from. quantum mechanics you used to mention.

psychology. let's talk about this more it's like one. in your new book one of the most. fascinating ideas actually. i think it's a wonderful yeah it's it's. sort of to me it's it's well it's the. culminating chapter of the book and i. think. uh since the whole book is about the big. lessons or big takeaways. from profound understanding of the. physical world that we've understood. that we've achieved uh including that. it's mysterious in some ways. the uh this was the the.

the final overarching. uh lesson complementarity and uh. it's a. approach it's so unlike some of these. other things which are just facts about. the world. like the world is both big and small and. different sessions is this. and is is big but we're not small think. the things we talked about earlier. uh and the fact that the universe is. comprehensible and how.

complexity could emerge from simplicity. and those things are. uh in some in the broad sense facts. about the world. complementarity is more an attitude. towards the world. encouraged by the facts about the world. and uh it's. the idea the concept of the approach. that. or the realization that uh. it can be appropriate and useful.

and inevitable and unavoidable to use. very different descriptions of the same. object or the same system or the same. situation. to answer different kinds of questions. that. may be very different and even. uh mutually uninterpretable immutably. uh incomprehensible. uh but both correct somehow but both. correct and.

sources of different kinds of insight. which is so weird. yeah well but it seems to work in so. many cases it works in many cases and i. think. it's uh it's a deep fact about. the world and how we should approach it. its. most rigorous form. where it's actually a theorem if quantum. mechanics is correct. occurs in quantum mechanics where. the primary description of the world.

is in terms of wave functions but let's. not talk about the world let's just talk. about a. a particle an electron okay it's it's. it's the primary description of that. electron. is its wave function and the wave. function can be used to. predict where it's going to be. with different if you observe with it'll. be in different places with different. probabilities. or how fast it's moving and it will also. be moving in different ways with.

different probabilities that's what. quantum mechanics says. and you can predict either set of. probabilities if you. what's going to happen if i make an. observation. of the position or the velocity. but so the wave function gives you ways. of doing both of those. but to do it to get those predictions. you have to process the wave function in. different ways. you process it one way for position and. in a different way for.

momentum and those ways are. mathematically incompatible. it's like you know it's like you have a. stone and you can sculpt it. into a venus de milo or you can sculpt. it into david but you can't do both. you can uh and uh. and that's an example of complementarity. but to answer different kinds of. questions you have to analyze the system. in different ways. that are mutually incompatible. but both valid to answer different kinds.

of questions. so in that case it's a theorem but i. think. it's a much more widespread phenomena. that applies to many cases where we. can't prove it as a theorem. but uh it's a piece of wisdom if you. like and then. appears to be a a very important insight. do you uh and if you ignore it you can. get very. confused and uh.

misguided do you think this is um. a useful hack for. ideas that we don't fully understand or. is this. somehow a fundamental property of all. or many ideas that you can take. multiple perspectives and they're both. true well i think it's both. those both the answer to all questions. yes that's right. it's not either or it's both it's. paralyzing to think that.

that we live in a world that's. fundamentally. like surrounded by complementary ideas. like. uh because it uh we want universe we. somehow want to attach ourselves to. absolute truths. and absolute truths certainly don't like. the idea of. complementarity yes einstein was very. uncomfortable with complementarity. and in a broad sense the famous poor. einstein debates. revolves around this question of whether.

the complementarity that. is a foundational feature of quantum. mechanics as we have it. was is uh. a permanent feature of of the universe. and that's our description of nature. and so far quantum mechanics wins. and it's gone from triumph to triumph. whether. complementarity is rock bottom i guess. we're you know. you can never be sure i mean but but uh.

it looks awfully good and it's been very. successful and. certainly its complementarity has been. extremely. useful and fruitful in in that domain. uh including you know one of some of. einstein's. attempts to challenge it with. like the famous einstein podolsky rosen. experiment turned out to be. confirmations of. that that uh have have been.

uh useful in themselves but so thinking. about these things was fruitful but. not in the way that einstein hoped the. the uh. yeah so so as i said in in the case. of uh quantum mechanics and this. dilemma or dichotomy between processing. the wave function in different ways. it's a theorem they're mutually.

incompatible and that the physical. correlate of that is the heisenberg. certainty principle that you can't have. position and momentum. determined at once uh. but uh in other cases like. one that i like to talk like to think. about is or like to. point out as an example is is free will. and determinism. it's much less. of a theorem and more more a uh. more a a kind of uh.

way of thinking about things that i. think is. uh reassuring and. avoids a lot of unnecessary quarreling. and confusion the quarreling i'm okay. with. and the confusion i'm okay with i mean. people debate about difficult ideas. but the the question is whether it could. be almost. a fundamental truth i think it is a. fundamental truth. free will is both an illusion.

and not yes i think that's correct and i. loaded the reason why people say quantum. mechanics is weird. and complementarity is is is a big part. of that. you know to say that the our actual. whole world is weird. the whole hierarchy of the universe is. weird in this. kind of particular way and. it's it's quite profound but it's also. um.

humbling because it's like. we're we're never going to be on sturdy. ground in the way that humans. like to be it's like you have to embrace. that uh. well this this this whole thing is is uh. like unsteady mess it's one of it's one. of many. lessons in humility that that we. uh run into in profound understanding of. the world. i mean uh the copernican revolution was.

one. that's that the earth is not the center. of the universe. uh darwinian evolution is another that. uh. humans are not the pinnacle of uh. of uh you know of of. god's creation uh the the uh. uh and the. uh apparent result. of uh uh deep understanding of physical. reality that. the mind emerges from matter and human.

there's you know. there's there's no uh no call. on special life forces or souls uh. these are all lessons in humility and. i actually find complementarity. a uh a liberating concept. it's it's a okay you know yeah it is in. a way. uh that is what i remember there's a. there's a story about dr johnson.

and he's talking with boswell and. boswell. was they were discussing a sermon that. they both both heard and the. the sort of culmination of of the sermon. was. the the the speaker saying i accept the. universe. and dr johnson said well he damn well. better. and and there's a certain uh there's a. certain joy in accepting the universe. because it's mind expanding. and uh.

you know it and to me complementarity. also suggests tolerance. suggests opportunities for understanding. different different understanding things. in different ways that add. add to rather than detract from. uh understanding so uh i think it's it's. an up. it's an opportunity for mind expansion. and.

demanding that there's only one way to. think about things. can be very limiting and the free will. one that's a trippy one though i think. to think like i am the decider of my own. actions. and at the same time i'm not is uh. is tricky to think about but it's there. does seem to be some kind of profound. truth in that. i get well i think it is tied up it will. turn out to be tied up when we. understand things better.

with these issues of self-awareness and. i think so. and where we get what what we perceive. as making choices what does that really. mean and. what's going on under the hood and. but i'm i'm speculating about a future. understanding that's not in place. at present your sense there will always. be uh. like as you dig into the self-awareness. thing there'll always. be some places where complementarity is. going to show up oh definitely. yeah i mean it will be uh.

how should i say there'll be kind of a. god's eye view. which sees everything that's going on. in the computer or the the brain and. then there's the brain's own view. or the or the central processor or. whatever it is that's the. what we call the the the the self the. consciousness. that's all only aware of a very small. part of it and those are very different. those are the the so uh the god's eye. view can be deterministic. while the the the the self view.

sees free will and that's i i'm pretty. sure that's how it's going to work out. actually and but as it as it stands free. will. is a concept that we definitely at least. i feel i definitely experience i can. choose to do one thing than another. and other people i think are. sufficiently similar to me that i. i trust that they feel the same way.

and it's an essential concept in. psychology and law. and so forth but uh. at the same time i think that mind. emerges from matter. and that there's an alternative. description of matter that's you know up. to subtleties about quantum mechanics. which i don't think are relevant here. uh really is deterministic let me ask. you about some particles. okay first the absurd question almost.

like a question that like plato would. ask. what is the smallest thing in the. universe. as far as we know the the. fundamental particles out of which we. build. our most successful description of. nature. are points they have zero they have. don't have. any internal structure that's. they uh so that's as small as can be.

to uh so what does that mean. operationally that means. if you that they obey equations that. describe. entities that are singular. concentrations of energy momentum. angular momentum the things that. particles have but localized at. individual points now uh that. mathematical structure is. only revealed partially in the world.

because to. to process the wave function in a way. that that that. accesses information about the precise. position of things you have to apply a. lot of energy. and that's not you know we that's an. idealization that you can apply infinite. amount of energy to determine a. precise position but at the mathematical. level. uh we build the world out of particles. that are points. so do they actually exist and what are. we talking about so like oh they exist. so let me ask sort of uh do quarks exist.

yes. two electrons exist yes two photons. exist yes. but what does it mean for them to exist. okay so well. the hard answer to that the precise. answer. is that uh we construct the world. out of equations that contain entities. that. uh are reproducible that exist in. vast numbers throughout the universe.

that have definite properties of. mass spin. and a few others that. we call electrons and the what what an. electron is is defined. by the equations that it satisfies. theoretically. and we find that there are many many. exemplars of that of that entity. in in the physical world so intellect in.

the case of electrons we can. you know isolate them and study them in. individual ones in great detail. and we can check that they all actually. are. identical and. that's why chemistry works and yes so so. so that in that case uh it's very. tangible similarly with photons you can. study them individually they're the. units of light. uh and uh nowadays it's very practical. to study individual photons and.

determine their. uh their spin and their other basic. properties and. uh uh and check out the equations in. great detail. for quarks and gluons which are the. other. two main ingredients of uh. our model of matter that's so successful. uh it's a little more complicated. because the quarks and gluons. that appear in our equations don't. appear directly as particles you can.

isolate. and study individually they always occur. within bound to what are called bound. states or structures like protons. a proton roughly speaking is composed of. three quarks and a lot of gluons but. we can detect them in a remarkably. direct way actually nowadays. whereas at relatively low energies. uh the behavior of quarks is complicated.

at high energies they can prop they can. propagate through space relatively. freely. for a while and we can see their tracks. so ultimately they get recaptured into. protons and other. mesons and funny things but for a short. time. they propagate freely and while that. happens we can. take snapshots and see see their. manifestations. uh this is the actually this kind of.

thing is exactly what i got the nobel. prize for. predicting that this would work and. similarly for gluons although. you can't uh you can't isolate them as. individual particles and study them in. the same way we study electrons. say uh you can. use them to as use them theoretically as. entities out of which you. build tangible description tangible. things that we actually do observe uh. but also.

you can uh at accelerators at high. energy you can liberate them for brief. periods of time and study wow. and and get convincing evidence that. they. they they leave tracks and then you can. get convincing evidence that they were. there and. and have the properties that that we. wanted them to have can we talk about. asymptotic freedom this very idea that. you won the nobel prize for. yeah so it describes a. very weird effect to me uh.

the the weird in the following way so. the. the the you know the way i think of most. forces or interactions the closer you. are. the stronger the effect the the stronger. the force yeah. right with with quarks uh. the closer they are the the less so the. strong interaction. and in fact they basically act like free. particles when they're. very close that's right yes well but.

this requires a huge amount of energy. like can you describe me um. why how does this even work. how weird it is proper description. must bring in uh quantum mechanics and. relativity and. it's uh so a proper description. and equations so a proper description. really is is probably. uh more more more than we have time for.

and then. uh we require quite a bit of patience on. your part but uh. how does relativity come into play wait. wait. relativity is important because. when when we talk about. trying to think about short distances we. have to think about. very large momenta and very large moment. are connected to very large energy. in relativity and so the connection.

between. how things behave at short distances and. how things behave at high energy. uh really is connected through. relativity in. sort of a slightly backhanded way. quantum mechanics indicates that short. to get to analyze short distances. uh you need to bring in probes. that carry a lot of momentum. this again is related to uncertainty. because.

uh it's the fact that you have to bring. in a lot of momentum. that interferes with the possibility of. determining. position and momentum at the same time. if you want to determine position. you have to use instruments that bring. in a lot of momentum. and because of that those same. instruments can't also measure momentum. because they're disturbing the momentum. and then the momentum brings in energy. and yeah so. so that there's also the effect that. asymptotic freedom comes from.

uh the possibility of spontaneously. making uh quarks and gluons. for short amounts of time that that. fluctuate into existence and out of. existence. uh and uh the. fact that that can be done with a very. little amount of energy. and and uncertainty and energy. translates into uncertainty in time so. if you do that for a short time you can.

do that uh. well it's all it comes in a package and. you can. you can so uh i told you it would take a. while to really uh to really explain. but the uh but but. the results can be understood i mean we. can state the results. uh pretty simply i think so uh. in everyday life we do encounter some. forces that increase with distance and. kind of. turn off at short distances that's the. way rubber bands work if you think about.

it or. you if you pull them hard they they. resist and. but but they get flabby if if if the. rubber band is not. not pulled uh and so there are. that can happen uh in the physical world. but what's what's really difficult is to. see how that could be a fundamental. force that's consistent with everything. else we know. and that that's what asymptotic freedom. is it says that uh.

there are particular there's a very. particular kind of. fundamental force that involves special. particles called gluons with very. special properties. that uh enables that kind of behavior so. ex there were experiments at the time we. did our work there were experimental. indications. that quarks and gluons. did have this kind of property but uh. there were no equations that were. capable of. capturing it and we found the equations.

and showed how they work and showed how. they that they were. basically unique and this led to a. complete theory of how the strong. interaction works which is. the quantum chromodynamics uh we. mentioned earlier. and so uh. so that's the phenomenon that that. quarks. and gluons interact very very weakly. when they're close together. that's connected through relativity with. the fact that they.

also interact very very weakly at high. energies. so if you have so at high energies. the simplicity of the fundamental. interaction gets revealed. you know at the time we did our work the. clues were very subtle. but nowadays at hot at what are now high. energy accelerators it's all obvious. so we would have had a much well. somebody would have had a much easier. time. 20 years later looking at the data you. can sort of see the quarks and gluons. as i mentioned they leave these short.

tracks that uh it would have been much. much easier but but. we from fundamental from indirect clues. we were able to piece together enough. to make that behavior a prediction. rather than a. post-diction right so it becomes obvious. at high energies. it becomes very obvious when when we. first did this work. it was uh frontiers of high energy. physics. and at big international conferences. there would always be sessions on. testing qcd and whether these.

whether this proposed description of the. strong interaction was in fact correct. and so forth. and it was very exciting they were big. but. nowadays the same kind of work. but much more precise with. calculations to more accuracy and. experiments that are much. more uh precise. and comparisons that are very precise uh. now it's called calculating backgrounds. because. it's because people take this for.

granted and one of you and want to. see deviations from the theory which. would be which would be. the new discoveries yeah the cutting. edge becomes the foundation of. foundation becomes boring yes. uh uh is is there some. for basic explanation purposes is there. something to be said about. uh strong interactions in the context of. the. the strong nuclear force for the for the. attraction between. protons yeah well the neutrons versus.

the. the interaction between quarks within. protons. well quarks and gluons have the same. relation. basically to nuclear physics as. electrons and photons have to atomic and. molecular physics. so atoms and photons. are the dynamic entities that really. come into play in chemistry and.

atomic physics of course you have to add. the atomic nuclei but those are. small and relatively inert really the. dynamical. part and you know for for most purposes. of chemistry you just say. you have this tiny little nucleus which. this which. qcd gives you don't worry about it it. just it's there. the real the real action is the. electrons moving around and exchanging. and things like that. uh the uh but okay but we wanted to. understand. the nucleus too and uh.

so atoms base are sort of quantum. mechanical clouds of electrons. held together by electrical forces which. is photons and then this radiation which. is also. another aspect of photons that's where. all the fun happens is the electrons and. the photons. yeah that's right and the nuclei the. nucleus are kind of the. the uh well they're necessary they give. the positive charge. and most of the mass of matter. but they don't since.

since they're so heavy they don't move. very much in chemistry. and uh uh i'm oversimplifying. drastically they're not contributing. much of the interaction and. for most purposes in chemistry you can. just idealize them as concentrations of. positive mass and charge that. that are uh you don't have to look. inside. but people are curious what what's. inside what really. and and uh that and that was a big thing. on the agenda of 20th century physics.

starting in the. 19 well starting with the 20th century. and. unfolding throughout of trying to. understand. what forces held the atomic nucleus. together what it was and so. uh anyway the. the emerge the story that emerges from. qcd. is that very similar to the way. that well broadly similar to the way. that uh. uh clouds of electrons held together by.

electrical forces. uh give you atoms and ultimately. molecules uh protons. and neutrons are like atoms. made now out of quarks quark clouds held. together by gluons which are. like like like the photons that that. will give the electric forces. but this is giving a different force the. strong force. and uh and the residual forces between.

protons and neutrons that uh. are left over from their basic binding. are like the residual forces between. atoms that give molecules but. in the case of protons and neutrons it. gives you atomic nuclei. so again for definitional purposes uh. qcd. quantum chromodynamics is basically the. physics. of strong interaction yeah we understand. we now would unders which. i think most physicists would would say. it's the theory of.

quarks and gluons and how they interact. but it's a very precise and i think it's. fair to say very beautiful. theory based on mathematical symmetry of. a high. order uh and another thing that's. beautiful about it is. that it's kind of. in the same family as electrodynamics. the conceptual structure of this of the. equations are very similar they're based.

on having. particles that respond to charge in a. very symmetric way. in the case of electrodynamics it's. photons that respond to electric charge. in the case of. quantum chromodynamics there are three. kinds of charge that we call colors. but they're nothing like colors they. really are like different kinds of. charge. but they rhyme with the same kind of uh. like it's similar kind of dynamics. similar kind of dynamics i call i say i. like to say that qcd is like.

qed on steroids and instead of one. photon you have eight gluons instead of. one charge you have three color charges. but there's a strong family resemblance. but the context in which uh qcd does its. thing is it's. it's much higher energies like that's. where it comes to wealth. it's a stronger force so that to. access how it's works and kind of pry. things apart you have to inject more. energy.

and so that that gives us um. in some sense a hint of uh how things. were in the earlier universe yeah well. in that regard. asymptotic freedom is a tremendous. blessing because it means. things get simpler at high energy and. the universe was born free. born free that's very very good yes. chris was born so. so in atomic physics i mean a similar. thing happens in the theory of stars. stars are hot enough that uh the.

interactions between electrons and. photons are. they're they're liberated they don't. form atoms anymore they make a plasma. which in some ways is simpler to. understand. you don't have complicated chemistry and. in the early universe according to qcd. similarly atomic nuclei dissolved into. the constituent. quarks and gluons which are moving. around very fast and. interacting in relatively simple ways. and so this. uh this opened up the early universe to.

scientific. calculation can i ask you about some. other weird particles that make up our. universe. what are axions and what is the strong. cp problem. okay so uh let me start with what the. strong cp problem is. uh first of all well charge con. c is charge conjugation which is the. transformation uh the notional. transformation if you like that changes.

all particles into their anti-particles. and the concept of seek. symmetry charge conjugation symmetry is. that if you do that. you find the same laws would work. so the laws are symmetric if. the behavior that particles exhibit is. the same as the part. as the behavior you get with all their. anti-particles. uh then p is parity.

which is uh also called spatial. inversion. it's basically looking at a mirror. universe. and saying that the laws that are obeyed. in a mirror universe when you look. the the mirror images obey the same laws. as the. as the sources of their images there's. no way of telling left. right for instance that the laws don't. distinguish between left and right. uh now in the mid 20th century.

people discovered that both of those are. not quite true. that really the the equation that the. mirror universe. this the universe that's that you see. in a mirror is not. going to obey the same laws as the as. the. the universe that that that we actually. exhib. uh and interpret you could you would be. able to tell if you. did the right kind of experiments which. was the mirror and which was the real.

thing. uh anyway that that's the parody and. they show that. doesn't necessarily hold it doesn't. quite hold and that that oh. that and examining uh. what the exceptions are turned out to be. to lead to all kinds of insight about. the nature of fundamental interactions. especially properties of neutrinos and. the weak interaction it's a long story. but it's a very it's a so you just. define the c. and the p the conjugation the charge. conjugation now that i've done that i.

want to. what's the problem shove them off okay. great. because it's easier to talk about t. which is time reversal symmetry. we have very good reasons to think uh. cpt is a an accurate. symmetry of nature it's on the same. level as relativity and quantum. mechanics basically so. that better be true uh so it's. symmetric when you when you do. conjugation parity in time. and time and space reversal if you do.

all three. then you get the same physical. consequences now. so but that means that cp is equivalent. to t. but but what's observed in the world is. that t is not quite an accurate symmetry. of nature. either so most phenomena. uh of at the fundamental level. so interactions among elementary. particles and the basic. gravitational interaction uh. if you ran them backwards in time.

you'd get the same laws so if. ag again going unless this time we don't. talk about a. a mirror but we talk about a movie if. you take a movie. and then run it backwards. that's the time reversal uh it's good to. think about a mirror. in time yeah it's like a mirror in time. if you. uh if you run run the movie backwards. it would look very strange if you were.

looking at complicated objects and. uh you know a charlie chaplin movie or. whatever. they it would look very strange if you. ran it backwards in time. but at the level of basic interactions. if you. were able to look at the atoms and the. and the quarks involved. they would obey the same laws they do a. very good approximation but not exactly. so you this is not exactly that means. you could tell you could tell. but you'd have to do very very subtle.

experiments with at high energy. accelerators. to take a movie that looked different. when you ran it backwards. this was a discovery by uh. two great physicists named cronin and. jim cronin. and val fitch in the uh. in the mid-1960s previous to that over. all the centuries of development of. physics with all this precise laws. they did seem to have this gratuitous. property.

that they look the same if you run the. equations backwards. it's kind of an embarrassing property. actually because. life isn't like that so empirical. reality does not have this imagery. in any obvious way and yet the laws did. it's almost like the laws of physics are. missing something fundamental about life. if if if it holds that property right. well i mean that's. that's the embarrassing nature it's it's. yeah it's well people. worked hard and at what's.

this was a problem that's thought to. belong to the foundations of statistical. mechanics or the. foundations of thermodynamics to. understand. how behavior which is. grossly not symmetric. with respect to reversing the direction. of time in large objects. how that can emerge from equations which. are. symmetric with respect to changing the. direction of time to a very good. approximation.

and that's that's still an interesting. endeavor that's that's. that's interesting and uh actually it's. an exciting frontier of physics now to. sort of explore the boundary. between when that's true and when it's. not true when you get to smaller objects. uh and exceptions like time crystals or. uh. i definitely have to ask if i'll time. crystals in a second here but. so the cp problem and t so there's. lost all of these we're in danger of. infinite regress but we'll. convert soon so can't possibly be.

turtles all the way down. we're going to get to the bottom turtle. so so so it became. so it it got to be a real i mean it's a. really puzzling thing. uh why the laws should have this very. odd property that we don't need. and in fact it's kind of an. embarrassment. in addressing empirical reality but it. seemed to be. almost it seemed to be exactly true for. a long time and then. uh almost true and.

and in way almost true was even is more. disturbing than exactly true because. exactly true it could have been just a. fundamental feature of the world and you. know at some level you just have to take. it as it is and if it's. if it's a beautiful easily articulatable. regularity you could say that okay. that's a that's. fine as a fundamental law of nature but. to say that it's approximately true but. not exactly that's that's that's right. that's weird so uh and then. so there was great progress in.

uh the late part of the 20th century. uh in getting to an understanding of. fundamental interactions in general. that shed light on this issue uh. it turns out that the prince. basic principles of relativity and. quantum mechanics plus. the kind of high degree of symmetry that. we. found the so-called gage symmetry that. characterizes the fundamental.

interactions when you put all that. together. it's a very very constraining framework. and it has some indirect consequences. because the possible interactions are so. constrained and one of the indirect. consequences. is that the possibilities for. violating the symmetry between forwards. and backwards in time are very limited. there are basically only two.

and one of them occurs and leads to a. very rich theory that explains the. cronin fish experiment and a lot of. things that have been done subsequently. has been used to. make all kinds of successful predictions. so that's. that's turned out to be a very rich. interaction it's esoteric and the. effects are. only show up at accelerators and are. small and so on but they might have been. very important in the early universe and. lead to them be connected to the. asymmetry between matter and anti-matter.

in the present universe and so but. that's a that's another digression. the the point is that uh that was fine. that was a triumph. to say that there was one possible kind. of interaction that would violate. time reversal symmetry and sure enough. there it is and. but the other kind. doesn't occur so we still got a problem. why. doesn't it occur uh so but. we're so we're close to really finally.

understanding this profound gratuitous. feature of the world. that is almost but not quite. symmetric under reversing the direction. of time but but not quite there. and to get to understand that last. bit is a challenging frontier of physics. today. and we have a promising proposal for how. it works. which is a kind of theory of evolution.

so there's this possible. interaction which we call a coupling and. there's a numerical quantity. that tells us how strong that is and. traditionally in physics we think of. these kinds of numerical. quantities as constants of nature. that you just have to put them in. right from experiment uh they have a. certain value and that that's it and you. know. who am i to question what god do they.

just can't. well they seem to be just constantly uh. but in this case. it's been fruitful to think. and work out a theory where. that strength of interaction. [Music]. is actually not a constant it's a. fun it's a field it's a uh it's a. fields are the fundamental ingredients.

of modern physics like. there's an electron field there's a. photon field which is also called the. electromagnetic field and so. every all of these particles are. manifestations of different fields. and uh there could be a field. something that depends on space and time. so a dynamical entity. instead of just a constant here. and if you do things in a nice. way that's very symmetric very much. suggested.

aesthetically by the theory uh but but. the theory we do have. then you find that you get. a field which. as it evolves from the early universe. settles down to a value. that's just right. to make the laws very nearly. exact invariant or symmetric with.

respect to reversal of time it might. appear as a constant but it's actually a. field that evolved over time it evolved. over time. okay but when you examine this proposal. in detail you find that it hasn't quite. settled down to exactly zero there it's. still. the the field is still moving around a. little bit. and because the motion is so. uh the motion is so difficult. the the material is so rigid and this.

material that fills all the field that. fills those spaces so rich. even small amounts of motion can involve. lots of energy. and that and that energy takes the form. of uh particles fields of fields that. are in motion are always associated with. particles. and those are the axions and if you. calculate how much. energy is in these residual oscillations. these this axion gas that fills all the. universe if this fundamental theory is.

correct. you get just the right amount. to make the dark matter that astronomers. want and it has. just the right properties so i'd love to. believe that. so that might be a thing that unlocks uh. might be the key to understanding dark. matter yeah i'd like to think so. and many many physicists are coming. around to this point of view which. i've been a voice in the wilderness i. was a voice in the wilderness. for a long time but now now it's become.

very popular maybe even dominant. so almost like so this axion. particle slash field would be the thing. that explains. dark matter it explained yeah would. solve this fundamental question. of finally of why the laws are. almost but not quite exactly. the same if you run them backwards in. time and and then. seemingly in a totally different.

conceptual universe. it would also uh provide unders give us. an understanding of of the dark matter. that's not what it was. designed for and the theory wasn't. wasn't proposed with that in mind. but when you work out the equations. that's what you get that's always a good. sign. yeah actually uh i i think i vaguely. read. uh somewhere that there may be early. experimental validation. of uh uh of axion is that uh.

am i am i reading the wrong well there. have been quite a few false alarms and i. think there are some of them still. i mean people desperately want to find. this thing and. uh but i don't think i i i don't think. any of them are convincing at this point. but there are very ambitious. experiments and kind of new. you have to design new kinds of antennas. that are capable of detecting. these predicted particles and it's it's. very difficult they interact very very.

weakly if. it were easy it would have been done. already but. but i think there's good hope that we. can get down to the required sensitivity. and actually test whether these ideas. are right. [Music]. in coming years or maybe decades. and then understand one of the big. mysteries like literally big in terms of. uh. its fraction of the universe is dark. matter yes. let me ask you about you mentioned a few. times time crystals.

yeah um what are they these things are. it's a very beautiful idea when we start. to um. treat space and time as. a similar frameworks yes. right physical phenomena right that's. what motivated it what are. first of all what are crystals yeah and. what time crystals okay so. crystals are orderly arrangements of. uh atoms in space and. many materials if you cool them down.

gently. will form crystals and so we say. that that's uh a spun a state of matter. that forms spontaneously and. uh an important feature of that state of. matter. is that the end result the crystal. uh has less. symmetry than the equations that give.

rise to the crystal. so the equations the basic equations of. physics. are the same if you uh move a little bit. so you can move they're homogeneous but. crystals aren't the atoms are in. particular. place so though they have less symmetry. uh. and time crystals are the same thing in. time basically. you but of course it's not so it's not. positions of atoms.

but it's ordering uh orderly behavior. uh that certain states of matter uh. will arrange themselves into. spontaneously if you do them. if you if you treat them gently and let. them do what they want to do. but indeed repeat in that same way. indefinitely. that's the crystalline form you can also. have uh. time liquids or you can have all kinds. of other states of matter you don't have. space-time crystals where. the pattern only repeats if uh with each.

step of time you also move at a certain. a certain direction in space so so yeah. so but it's so. it's basically it's states of matter. that uh oh base. that display structure in time. spontaneously. so here's here's the difference when it. happens in time. uh it sure looks a lot like. it's motion and if it repeats. indefinitely it sure looks a lot like.

perpetual motion. yeah like uh looks like free lunch. i was told that there's no such thing as. free lunch does. does this violate laws of thermodynamics. uh. no but it requires a critical. examination of the. laws of thermodynamics i mean let me let. me say on background that the laws of. thermodynamics. are not the not fundamental laws of. physics there are things we prove. under certain circumstances emerge from.

the fundamental laws of physics. right they're not we don't posit them. separately they're. meant to be deduced and they can be. deduced under limited circumstances but. not necessarily. universally and we found finding some of. the subtleties and. sort of accept edge cases uh where they. don't. apply in a straightforward way. and this is one uh so. time crystals do obey do have this. structure in time but it's not a free.

lunch. because although in a sense things are. moving uh they're they're already doing. what they want to do. they're in there so if if you want to. extract. energy from it you're going to be foiled. because there's no. spare energy there you uh. it's or so you you can add energy to it. and kind of disturb it. but but you can't extract energy. from this motion because it's gonna it. wants to do that's the lowest energy.

configuration that there is so you can. you can't get. further energy out of it so in theory i. guess perpetual motion. uh you would be able to extract energy. from it yeah. if such a thing was to be created you. could then milk it for energy well. what's usually meant in the literature. of perpetual motion. is a kind of macroscopic motion that you. could extract. energy from and and somehow it would.

crank back up right that's that's not. the case here if you want to extract. energy uh this motion is. is not something you can extract energy. from if you. intervene in the behavior you can. uh change it but only by injecting. energy not not by taking away energy. you mentioned that a theory of. everything. may be quite difficult to come by a. theory of everything broadly defined. meaning like truly a theory of. everything.

but let's look at a more narrow theory. of everything which is that. what the way it's used in often in. physics. is a a theory that unifies. our current uh. laws of physics general relativity. quantum field theory df thoughts. on this dream of a of a theory of. everything in physics. how close are we is there any promising. ideas out there in your view. well it would be nice to have it would.

be aesthetically pleasing. uh will be useful no probably not. well i'm i shouldn't no it's dangerous. to say. that but uh probably not i think we. not not in certainly not in the uh. foreseeable future. uh maybe to understand black holes yeah. but that's. that's yes maybe to understand black. holes but. that's not useful and.

and well not only i mean only to. understand. it's it's it's worse of course you know. it's not useful in the sense that we're. not going to be. basing any technology any time soon on. black holes. but it's it's more severe than that i. would say it's that. the kinds of questions about black holes. that we can't answer within the. framework of existing theory. are ones that are not.

going to be susceptible to astronomical. observation. in the foreseeable future they're. questions about. very very small black holes when. when quantum effects come into play or. uh so that black holes are. you know not not black holes they're. they're they're they're emitting hawk. this discovery of hawking called hawking. radiation. which for astronomical black holes is a. tiny.

tiny effect that's no one have no one. has ever observed it's a prediction. that's never. been changed like supermassive black. holes that doesn't apply no. no the the predicted rate of radiation. from those black holes is so tiny that. it's absolutely unobservable and is. overwhelmed by all kinds of other. effects. uh so uh. so it's not practical in the sense of. technology it's not even practical. in the sense of uh application to. astronomy.

we our existing theory of. uh general relativity and quantum theory. and our theory of the the different. fundamental forces is perfectly adequate. to. all prep all problems of. technology for sure. and almost all. problems of astrophysics and.

cosmology that appear except. with the with the notable exception of. the. extremely early universe if you want to. ask what happened before the big bang or. what happened right at the big bang. which would be a great thing to. understand of course uh. yes we don't but but what about the. engineering question. so if we look at space travel so. uh i think you've spoken with him uh. eric weinstein. really um uh you know he says.

things like we want to get off this. planet his intuition is. almost a motivator for the engineering. project. of space exploration in order for us to. crack this problem. of becoming a multi-planetary species we. have to solve the physics problem his. intuition is like if we figure out this. what he calls the source code which is. like. like like like a theory of everything. might give us clues.

on how to start hacking the fabric of. reality. like getting shortcuts right it might i. can't say that you know. i can't say that it won't but i can say. that. in the 1970s and early 1980s. we achieved. huge steps in understanding matter. qcd much better understanding of the. weak interaction. much under better understanding of.

quantum mechanics in general. and it's had minimal uh minimal impact. on time on rocket design. unprecedented on rocket design on. anything any technology. whatsoever and now we're talking about. much more esoteric things. and since i don't know what they are i. can't say for sure that they won't. affect technology but i'm very very. skeptical that. they would affect technology the uh uh. the because you know to access them you. need to.

very exotic circumstances to make new. kinds of particles with high energy you. need accelerators that are. you know it's very expensive and you. don't produce many many of them and so. forth you know. it's just uh it's a pipe dream i think. yeah about space exploration. yes i'm not sure exactly what he has in. mind and. but uh to me uh. it's more a problem of of. something between biology and.

i think human bodies are not well. adapted. to space even mars. or even you know which is the closest. thing to a kind of. human environment that we're going to. find anywhere close by. uh very very difficult to maintain. humans on mars. uh and gonna be you know very expensive. and very you know.

very unstable and but i think the pros. however uh if we. take a broader view of what it means to. bring human civilization. outside of the earth if we're satisfied. with. you know sending minds out there that we. can. converse with and actuators and that. that we can in uh uh manipulate and.

sensors that we can get feedback from i. think that's. that's where it's at and for sure i. think that's so much. so much more realistic and uh. and i think that that's the long-term. future of uh. the space exploration it's not hauling. human bodies all over the place and. that's that's that's just silly but. it's possible that it's human bodies um. so like you said it's a biology problem. what's possible is that um we extend.

human lifespan. in some way just we have to look at a. bigger picture it could be just like. you're saying. by sending robots with actuators and. kind of extending the the our limbs. but it could also be extending some. aspect of our minds of information. and it could be cyborgs it could be uh. it could be. no we're talking it could be you know it. could. it could be uh human brains or.

cells that realize something like human. brain architecture. uh within uh. within artificial environments you know. shells if you like. that that are more adapted to the. conditions of space. and uh that yeah so that that's entirely. man machine hybrids. as well as sort of remote uh. uh outposts that we can communicate with. i think yeah i think those those will.

happen. and uh yeah yeah to me there's some. sense in which. as opposed to understanding the physics. of. the the the the fundamental fabric of. the universe. i think getting to the physics of life. the physics of intelligence the physics. of consciousness. will the physics of information uh. that that that brings. from which life emerges that will allow.

us to do space exploration. yeah well i think physics in the larger. sense has a lot to contribute here. not the physics of finding fundamental. new laws in the sense of. uh you know another quark or axions even. physics in the sense of you know physics. has a lot of experience. in analyzing complex situations and. analyzing new states of matter and. devising new kinds of instruments.

that do clever things we you know the. the physics in that sense has enormous. amounts to contribute. to uh this kind of endeavor. but i don't think that looking for. a so-called theory of any everything has. much. to do with it at all what advice would. you give. to a young person today. with a bit of fire in their eyes high. school student college student. thinking about what to do with their. life maybe advice about.

career or bigger advice about life in. general. well first read fundamentals because. there i've tried. i've tried to to uh give some coherent. uh deep advice that's the fundamentals. ten keys. to reality by train cool check so that's. a good place available. everywhere if you want to learn but i. can tell you. uh the uh is there an audiobook. yes there is an audio book that's.

awesome yeah i think. it's like i can give three pieces of. wise advice. that i think are generally applicable. one is to cast a wide net. to really look around and see. what looks promising what catches your. imagination. uh and. and promise yeah and those you have to. balance those two things you can have. things that catch your imagination but.

don't look promising in the sense that. the questions aren't ripe. or uh but and and things that you. in part of what makes things uh. attractive. is that whether you thought you liked. them or not is this if you can see that. there's ferment and new ideas coming up. that become that's attractive in itself. so uh when i started out i thought i was. and when i was an undergraduate i. intended to study philosophy or. questions of how mind emerges from. matter but. i thought that wasn't really right.

timing isn't right yeah the ripe was the. timing wasn't right for the kind of. mathematical thinking and. conceptualization that i really enjoy. and good at. but uh so that that's one thing cast a. wide net look around. uh and that's that's. a pretty easy thing to do today because. because of the internet you can look. you can look at all kinds of things you.

have to be careful though because. there's a lot of crap. also but uh you you know you you can. sort of tell the difference if you. if you do a little digging uh the the uh. so don't don't don't settle on just you. know what your thesis advisor tells you. to do or what your teacher tells you to. do look for yourself and and and. get a sense of what what what seems. promising. uh not what seemed promising 10 years. ago or. the uh so that's one.

uh another thing is to. is kind of complementary to that well. they're all complimentary. complementary to that uh is to read. history and read the masters of the. history of ideas and masters of ideas i. benefited enormously from as. as in early in my career from reading.

in physics einstein. in the original and feynman's lectures. as they were coming out. and darwin you know these. you can you can learn what it in galileo. you can learn. what it is to wrestle with difficult. ideas and how great minds did that you. can learn a lot about. uh style how how to ex write your ideas. up and. express them in in clear ways. and also just just a couple that with uh.

i also enjoy reading biographies. and biographies yes similarly right like. so it gives you the context. the context of the human being that. created those right and. brings it down to earth in the sense. that you know it was really human beings. who did this it's not. uh and and they made mistakes and. yeah uh i also you know i also got. inspiration from bertrand russell who's. a big hero and h.g. wells and yeah so uh read read the. masters. make contact with great minds and when.

you are. sort of narrowing down on a subject. learn about the history of the subject. because. that really puts in context what you're. trying to do and. and also gives a sense of community and. grandeur to the whole enterprise. uh and then the third piece of advice is. complementary to both those which is. sort of. to uh to get. the basics under control as soon as. possible.

so if you want to do theoretical work in. science. you know you you you have to learn. calculus multivariable calculus complex. variables group theory. nowadays you have to be highly computer. literate. uh if you want to do experimental work. you also have to be computer literate. then you have to learn about electronics. and. optics and instruments and so so get. that. under control as soon as possible. because it's like learning a language uh. to do.

to to produce great works and express. yourself fluently and with confidence. uh it should be your native language. these things should be like your native. language so you're not you're not. wondering. um what is a derivative this is just. part of your. you know part it's it's uh it's in your. bones so to speak you know. and the sooner that you can do that then. the the better so those all those things. can be done in parallel and should be.

you've accomplished some incredible. things in your life but. uh the sad thing about this. thing we have is it ends uh. do you um do you think about your. mortality. are you afraid of death uh well. well afraid is the wrong way i mean uh. let's define things i wish it weren't. gonna happen. and i'd like to but uh uh do you think. about it. i say occasionally i think about well i.

think about it very operationally in the. sense that. uh there's always a trade-off between. exploration and exploitation this is a. classic subject in computer science. actually in machine learning. uh that when you're in an unusual. circumstance you you want to explore to. see what. what the landscape is and what the. gathered data. but then at some point you want to use. that. make decide make choices and say this is.

what i'm going to do and exploit the. knowledge you've accumulated. and uh the longer. the period of exploitation you. anticipate. the more exploration you should do in. new directions. and so for me i've had to sort of adjust. the balance of. exploration and uh uh. exploitation and that said you've. explored quite a lot. yeah well i i'm still i haven't shut off.

the exploitation at all i'm still hoping. the exploration right i'm still hoping. for 10 or 15 years of top flight. performance but. the uh. several years ago now when i was 50. years old. i i was at the institute for advanced. study and my office was right under. freeman dyson's office and we were kind. of friendly and. uh and you know he found out it was my. my 50th birthday and said. congratulations and uh you should feel.

liberated because. no one expects much of a 50 year old. theoretical physicist. and he and he obviously had felt. liberated by uh. by by reaching a certain age and yeah. there is something to that. uh i fee you know i feel i don't have to. catch i don't have to. keep in touch with the latest. hypertechnical developments in particle. physics or string theory or so. like uh because i'm not gonna i'm really.

not gonna. be exploiting that i but i but but where. i am exploring. uh in these directions of machine. learning and. and things like that and and but then. but i'm also concentrating. within physics on exploiting directions. that i've already established and the. laws that we already have. and doing things like uh. i'm very actively involved in trying to. design. helping people experimentalists and uh.

engineers even to design antennas that. are capable of. detecting axions so there and that's. there we're deep in the exploitation. stage it's not a matter of finding the. new laws but of. really you know using the laws we have. to to. to kind of finish the story off so so. it's complicated but but but. but i'm you know i'm very happy with my. life right now and uh. i'm enjoying it and i don't want to.

cloud that by. thinking too much that that it's uh. going to come to an end. you know it's a gift i didn't earn is. there a good. thing to say about why. this gift that you've gotten and didn't. deserve is so damn enjoyable. so like what's the meaning of this thing. of life. to me interacting with people i love.

my family and i have a very wide circle. of friends now and i'm. trying to produce some institutions that. will survive me. as well as my as the work and. and it's just it's how should i say. it's a positive feedback work. loop when you do something and if. people appreciate it and and then you. want to do more and they. get rewarded and it's just uh how should.

i say this is another gift that i didn't. earn and don't understand but i. i have a dopamine system and. uh yeah i'm happy to use it and. it seems to get energized by uh. by the creative process but yeah process. inspiration very much so. and all of that started from the. little fluctuations. [Laughter]. shortly after the big bang frank well. whatever the those initial conditions.

and fluctuation did that created you. i'm glad they did this is uh thank you. for all the work you've done. for the many people you've inspired for. the many of the billion. most of your ideas were pretty useless. of the bill several billions. as it is for all humans but uh you had. quite a few. truly special ideas and uh thank you for. bringing those to the world and thank. you for wasting your valuable time with. me today. it's truly enough it's been a joy and i. hope people uh.

enjoy it and and and i think you know. the kind of mind expansion that i've. enjoyed. by interacting with physical reality. at this deep level i think can be. conveyed to and. enjoyed by many many people and that's i. that's one of my missions in life. thanks for listening to this. conversation with frank wilcheck and. thank you to. the information netsuite expressvpn. blinkist and eight sleep check them out. in the description to support this.

podcast. and now let me leave you with some words. from albert einstein. nothing happens until something moves. thanks for listening and hope to see you. next time.