Konstantin Batygin: Planet 9 and the Edge of Our Solar System | Lex Fridman Podcast #201

the following is a conversation with constantine bategan planetary astrophysicist at caltech interested in among other things the search for the distant the mysterious planet nine in the outer regions of our solar system quick mention of our sponsors squarespace literati on it and and i check them out in the description to support this podcast as a side note let me say that our little sun is orbited by not just a few planets in the planetary region but trillions of objects in the kuiper belt and the oort cloud that extends over three light years out this to me is amazing since proxima centauri the closest star to our sun is only 4.2 light years away and all of it is mostly covered in darkness when i get a chance to go out swimming in the ocean far from the shore i'm sometimes overcome by the terrifying and the exciting feeling of not knowing what's there in the deep darkness that's how i feel about the edge of our solar system one day i hope humans will travel there or at the very least ai systems that carry the flame of human consciousness this is the lex friedman podcast and here's my conversation with constantine bategan what is planet nine planet nine is an object that we believe lives in the solar system beyond the orbit of neptune it orbits the sun with a period of about 10 000 years and uh is about five earth masses so that's a hypothesized object there's some evidence uh for this kind of object there's a bunch of different explanations can you give like an overview of the planets in our solar system how many are there what do we know and not know about them at a high level all right that sounds like a good plan so look the solar system basically is comprised of two parts the inner and the outer solar system the inner solar system has the planets mercury venus earth and mars now mercury is about 40 percent of the orbital separation of where the earth is is closer to the sun venus about 70 percent uh then mars is about 160 further away from the sun than is the earth these planets that we uh one of them we occupy right are pretty small okay they're too leading order sort of heavily overgrown asteroids if you will um and this is this becomes evident when you move out further in the solar system and encounter jupiter which is 316 earth masses right 10 times the size you know and saturn is another huge one 90 earth masses at about 10 times uh the separation from the sun this is the earth and then you have uranus and neptune at 20 and 30 respectively for a long time that is where the kind of massive part of the solar system ended but what we've learned in the last 30 years is that beyond neptune there's this expansive field of icy debris a second icy asteroid belt in the solar system a lot of people have heard of the asteroid belt which lives be between mars and jupiter right like that's a pretty common thing that people like to imagine and draw on lunch boxes and stuff but beyond neptune there's a much more massive much more radially expansive field of debris pluto by the way it belongs to that second you know icy asteroid belt which we call the kuiper belt it's just a big object within that population of bodies oh pluto the planet pluto the the dwarf planet the former planet you know why is pluto not a planet anymore i mean it's tiny were you used to size matters when it comes to planets 100 100 it's a actually a fascinating story when pluto was discovered in 1930 the the reason it was discovered in the first place because astronomers at the time were looking for a seven earth mass planet somewhere beyond neptune it was hypothesized that such an object exists when they found something they interpreted that as a seven earth mass planet and immediately revised its mass downward because they couldn't resolve the object with the telescope so it looked like a just a point mass you know star rather than a physical disk they said well maybe it's not seven maybe it's one right and then so over the next um you know i guess 40 years pluto's mass kept getting revised down downwards downwards downwards until uh it was realized that's like 500 times less massive than the earth i mean like pluto's surface area is almost perfectly equal to the surface area of russia actually and you know russia is big but it's not a planet well i mean actually we can we can touch more on that that's that's another discussion uh so in some sense earlier in the century pluto represented kind of our ignorance about the edges of the solar system and perhaps planet nine is the thing that represents our ignorance about now the modern set of ignorances about the edges of our solar system that's a good way to put it by the way just imagining this belt of astero of debris at the edge of our solar system is incredible can you talk about it a little bit what is the kuiper belt and what it what is the oort cloud yeah okay so look the simple way to think about it is that if you imagine you know neptune's orbit like a circle right kind of uh maybe a factor of one and a half 1.3 uh times bigger uh on a radius of 1.3 times bigger you've got a whole collection of icy objects most of these objects are sort of the size of austin you know maybe maybe a little bit smaller if you then zoom out right and explore the orbits of the most long period kuiper belt object these are the things that have the biggest orbits and take the longest time to go around the sun then what you find is that beyond a critical orbit size beyond a critical orbit period which is about 4 000 years you start to see weird structure like all the orbits sort of point into one direction and all the orbits are kind of tilted in the same way by about 20 degrees with respect to sun this is particularly pronounced in orbits that are not heavily affected by neptune so there you start to see this weird dichotomy where there are objects which are stable which are which neptune does not mess with gravitationally and unstable objects the unstable objects are basically all over the place because they're being you know kicked around by neptune the stable orbits show this remarkable pattern of clustering we back i guess five years ago interpreted this pattern of clustering as a gravitational one-way sign the existence of a planet in a distant planet right something that is shepherding and confining these orbits together of course right you have to have some skepticism when you're when you're talking about these things you have to ask the question of okay how statistically significant is this clustering and there are many authors that have indeed called that into question we have done our own analyses and basically just like with all statistics where you know there's kind of like you know multiple ways to uh do the exercise you can either ask the question if i have a telescope that has you know surveyed this part of the sky what are the chances that i would discover this clustering that basically tells you that you have zero confidence right like that's not that does not give you a confident answer one way or another another way to do the statistics which is what we prefer to do is to take to say we have a whole night sky of discoveries in the kuiper belt right and if we have some object over there which has right tension and declination which is a way to say it's there on the sky and it has some brightness that means somebody looked over there and discovered an object of was able to discover an object of that brightness or brighter through that analysis you can construct a whole map on the sky of kind of where all of the surveys that have ever been done have collectively looked so if you do the exercise this way the false alarm probability of the clustering on which the planet nine hypothesis is built is about 0.4 wow okay so there's a million questions here one when you say bright objects why are they bright are we talking about actual objects within the kuiper belt or the stuff we see through the kupper belt this is the actual stuff we see in the kuiper belt the way you go about discovering kuiper belt objects pretty easy i mean it's easy in theory right hard in practice yeah all you do is you take snapshots of the sky right choose that direction say and take you know the high exposure snapshot then you wait a night and you do it again and then you wait another night and you do it again objects that are just random stars in the galaxy don't move on the sky whereas objects in the solar system will slowly move this is no different than if you're driving down the freeway it looks like you know trees are going by you faster than the clouds right this is parallax that's it it's just they're reflecting light off of the sun and it's going back and hitting this there's a little bit of a glimmer from the different objects that you can see based on the reflection from the sun so like there's actual light yeah it's not darkness that's right these are just big icicles basically that are just reflecting sunlight back at you it's then easy to understand why it's so hard to discover them because light has to travel to you know something like 40 times the distance um between the earth and the sun and then get reflected back was it like an hour travel or yeah that's right that's something like that because the the earth to the sun is eight minutes i believe um and so something you know yeah yeah in that in that order magnitude so that's interesting so you have to like account for all of that and then there's this huge amount of data pixels that are coming from the pictures and you have to uh integrate all that together to paint a sort of like a high estimate of the different objects can you track them can you be like that's bob like can you like yes exactly in fact uh one of them is is named joe biden i mean i'm not like this is not even a joke right is there a trump one or no no no no i don't know i haven't checked for for for that but uh like the way it works is if you discover one you right away get a license plate for it okay so like the first four numbers is the first year that this object has appeared on you know in the data set if you will and then um there's like this code that follows it which basically tells you where in the sky it is right so one of the really interesting kuiper belt objects which is very much part of the planet 9 story is called vp113 because joe biden was vice president at the time you know got nicknamed biden vp113 said yeah you got nickname button beautiful what's the fingerprint for any particular object like how do you know it's the same one okay just kind of like yeah from night to night you take a picture how do you know it's the same object yeah so the way you know is it appears in almost exactly the same part of the sky except for the move but it moves but this is why actually you need at least three nights because oftentimes asteroids which are much closer to the earth like will um appear to move only slightly but then on the third night will move away so that third knight is really there to detect acceleration now the the thing that i didn't really realize until you know i started observing together with my partner in crime and all this mike brown is just the fact that for the first year when you make these detections the only thing you really know is confidence is where it is on the night sky and how far away it is okay that's it you don't know anything about the orbit because over three days the object just moves so little right the that whole motion on the sky is entirely coming from motion of the earth right so the earth is kind of the car the object is the tree and you see it moving so then to get some confident information about what its orbit looks like you have to come back a year later um and then measure it again interesting to do three nights then come back a year later and do another three nights so you get the velocity the acceleration from the three nights and then you have the maybe the additional the additional formation because an orbit is basically described by six parameters so you at least need six independent points but in reality you need many more observations to to really pin down the orbit well and from that you're able to construct for that one particular object in orbit and then there's of course like how many objects are there there's like four-ish thousand now but like the in the future that could be like millions oh sure oh sure so in fact these things are hard to predict but there's a new observatory called the vera rubin observatory which is coming online maybe next year i mean with covet these things are a little bit more uncertain but they've actually been making great progress uh with construction and so that uh telescope is gonna sort of scan the night sky uh every day automatically and it's just it's such an efficient survey that it might uh increase the census of the distant kuiper belt the things that i'm interested in by a factor of 100 i mean that would be that would be really cool and yeah that's a that's an incredible uh maybe i mean they might just find planet nine i mean that's like almost like literally pictures like visually i mean sure yeah like the first detection you make all you know is where it is in the sky and how far away it is if something is you know 500 times away from the sun as far away from the sun as is the earth you know that's planet nine that's when the story concludes and then you can study it right now you can study yeah by the way i'm going to use that as like i don't know a pickup line or a dating strategy like see the person for three days and then don't see them at all and then see them again in in a year to determine the orbit and over time you figure out if sort of uh from a cosmic perspective this this whole thing i have no dating advice to give i was good i was going to use this as a metaphor to uh to somehow uh map it on to the human condition okay you mentioned the kuiper belt what's the oor cloud if you look at the neptune orbit as uh one then the kuiper bell is like 1.3 out there and then we get farther and farther into the darkness what so okay you've got the kind of main kuiper belt was about say 1.3 1.5 um then you have something called the scattered disc which is kind of an extension of the kuiper belt it's a bunch of these long very elliptical orbits that hug the orbit of neptune but come out very far so that the scattered disc with the current senses like the some of the longest orbits we know of um have a semi-major axis so half the orbit length roughly speaking of about a thousand thousand times the distance between the earth and the sun wow now if you keep moving out okay eventually once you're sort of you know ten thousand to a hundred thousand roughly that's where the oort cloud is now the oort cloud is a distinct population of icy bodies and it's distinct from the kuiper belt it's in fact it's so expansive that it ends roughly halfway between us and the next star um it's it's edge is just dictated by to what extent does the solar gravity reach solar gravity reaches that far yeah so it has to wow yeah so in fact imagining this is a little bit overwhelming so there's like a giant like vast icy rock thingy it's like a sphere it's like you know it's like it's an almost spherical structure that engulfs that encircles the sun and all the long period comets come from the oort cloud they come the way that they appear i mean for already i don't know hundreds of years we've been detecting occasionally like a comet will come in and it comes seemingly comes out of nowhere the reason these long period comets appear that very on very very long time scales right these oort cloud objects that are sitting you know 30 000 times as far away from the sun as is the earth actually interact with the gravity of the galaxy the tide effectively the tide that the galaxy exerts upon them and their orbits slowly change and they elongate to the point where once they their closest approach to the sun starts to reach a critical distance where ice starts to sublimate then we discover them as comets because then the ice comes off of them they look beautiful on the night sky etc but they're all coming from you know really really far away so is there are any of them coming our way from collisions like how many collisions are there or is there a bunch of space for them to move around yeah there's zero it's completely collisionless out there the physical radii of objects are so small compared to the distance between them right it's just it is truly a collisionless uh environment i don't know there i think that probably in the age of the solar system there have literally been zero collisions in the word cloud wow when you like draw a picture of the solar system everything's really close together so that everything i guess here is spaced far apart do rogue planets like flying every once in a while and join not rogue planets but rogue objects from out there oh sure oh sure yeah join the party yeah absolutely uh we've seen a couple of them um in the last three or f or so years uh maybe four years now uh one the first one uh was the one called it's been all over the news the second one was comet borisov discovered by a guy named borisov yeah so the way you know they're coming from elsewhere is unlike solar system objects which travel on elliptical paths around the sun these guys travel on hyperbolic paths so they come in say hello and then they're gone and the fact that they exist is totally like not surprising right the neptune is con constantly ejecting kuiper belt objects into interstellar space our solar system itself is sort of leaking icy debris and injecting it so presumably every you know planetary systems around other stars do exactly the same thing let me ask you about the the millions of objects that are part of the kuiper belt and the part of the ore cloud do you think some of them have primitive life it kind of makes you sad if there's like primitive life there and they're just kind of like lonely out there in space like how many of them do you think have life like bacterial life probably a negligible amount zero you know like zero was like a plus on top uh right yeah um if so you know if you and i took a little trip to the interstellar medium i think we would develop cancer and die uh real fast right that's rough yeah it's a pretty hostile radiation environment you don't actually have to go to the interstellar medium you just have to leave the earth's magnetic field too and then you're not doing so well suddenly so you know this this idea of you know life kind of traveling between places it's not it's not entirely implausible but you you really have to twist i think a lot of parameters one of the problems we have is we don't actually know how life originates right so it's kind of a second order question of survival in the interstellar medium and how resilient it is because we we think you require water but and that's certainly the case for the earth but you know we uh we really don't know for sure that said i will argue that the question of like are there aliens out there is a very boring question because the answer is of course there are right i mean like we know that there are planets around almost every star um of course there of course there are other life forms life is not some specific thing that happened on the earth and that's it right just that's a statistical impossibility yeah um yeah but the the difficult question is before even the fact that we don't know how life originates i don't think we even know what life is like definitionally yeah like formalizing a kind of picture of in terms of the mechanism we would use to to search for life out there or even when we're on a planet to say is this life is this rock that just moved from where it was yesterday life or or maybe not even rock something else i got to tell you i want to know what life is okay and i want you to show me uh i think there's a song to basically accompany every single thing we talk about today and probably uh half of them are love songs um and somehow we'll integrate george michael into the whole thing okay so your intuition is there's life everywhere in our universe do you think there's intelligent life out there i think it's entirely plausible i mean i it's entirely plausible um i think i think there's intelligent life on earth um and so yeah taking that like say whatever this thing we got on earth whether it's dolphins or humans say that's intelligent definitely dolphins i mean have you seen the dolphins well they do some cruel stuff to each other so if cruelty is uh is the definition of intelligence that they're pretty good yeah and then humans are pretty good on that regard then there's like uh uh pigs are very intelligent i got actually a chance to hang out with pigs recently and they're um aside from the fact they're trying to eat me they're very uh they're very they love food they love food but there's an intelligence to their eyes that was kind of uh like haunts me because i also love to eat meat and then to to me the thing i later ate and i was very intelligent and uh almost charismatic with the way it was expressing its uh himself herself itself was uh was quite incredible so and all that to say is if we have intelligent life here on earth if we take dolphins pigs humans from the perspective of like planetary science how unique is earth okay so earth is not a com common outcome of the planet formation process um it's probably a something on the order of maybe a one percent effect and by earth i mean it's not just an earth mass planet okay i mean the architecture of the solar system that allows the earth to exist in in its kind of very temperate um way one thing to understand uh and this is this is pretty crucial uh right it's that the earth itself formed well after the gas disk that formed the giant planets had already dissipated you see stars start out with you know the star and then a disc of gas and dust that encircles it okay from this disk of gas and dust big planets can emerge and we have over the last uh you know two three decades discovered thousands of extra solar planets as an orbit of other studs what we see is that uh many of them are you know have these expansive hydrogen helium atmospheres the fact that the earth doesn't is deeply connected to the fact that earth took about 100 million years to form so we missed that you know train so to speak to get that hydrogen helium atmosphere that's why actually we can see the sky right that's why the sky is uh well at least in most places that's why the the atmosphere is not completely opaque um with that you know kind of thinking in mind i i would argue that we're getting the kind of emergent pictures that the earth is is not you know everywhere right we there's sort of the sci-fi view of things where we go to some other star and we just land on random planets and they're all earth-like that's totally not true but the even a low probability event even if you imagine that earth is a one in a million or one in a you know one in 10 million occurrence there are 10 to the 12 stars in the galaxy right so you just you always win by by large numbers that's right by supply they save you well you've hypothesized that our our solar system once possessed a population of short-period planets that were destroyed by the evil jupiter uh migrating through the the solar nebula can you explain if i was to say what was the kind of the key outcome of searches for extrasolar planets it is that most stars are encircled by short period planets that are you know a few earth masses right so a few times bigger than the earth um and have orbital periods that kind of range from days to to weeks now if you go in and ask the solar system what's in our region right in that region it's completely empty right it's just it's astonishingly hollow and thank you from the sun is not some you know special star that decided that it was going to form the the solar system so i think you know the natural thing to assume is is that the same processes of planet formation that occurred everywhere else also occurred in the solar system following this logic it's not implausible to imagine that the solar system once possessed a system of intra mercurian like you know compact system of of planets so then we asked ourselves would such a system survive to this day and the answer is no uh at least our calculations um suggest it's highly unlikely because of the formation of jupiter and jupiter's primordial kind of wandering through the solar system would have sent this collisional field of debris that would have pushed that system of planets onto the sun so was jupiter this primordial wandering what did what did jupiter look like like why was it wandering it didn't have the orbit it has today uh we're pretty certain that giant planets like jupiter when they form they migrate the reason they migrate is you know on a detailed level perhaps difficult to explain but you know if just in a qualitative sense they form in this fluid disk of gas and dust so it's kind of like if i plop down a raft somewhere in the ocean will it stay in where you plop it down or will it kind of get carried around it's not really a good analogy because it's not like jupiter is being affected by the currents of you know gas and dust but the way it migrates is it carves out a hole in the in the disk and then uh through by interacting with the disk gravitationally right it can change its orbit the fact that the solar system has both jupiter and saturn here complicates things a lot right because it's you have to solve the problem of the evolution of the gas disk the evolution of jupiter's orbit in the gas disk plus evolution of saturn's and their mutual interaction the common outcome of solving that problem though is pretty easy to explain jupiter forms its orbit shrinks and then once saturn forms its orbit catches up basically to the orbit of jupiter and then both come out so there's this inward outward pattern of jupiter's early motion that happens sort of within the firm within the last million years of the lifetime of the solar system's primordial disk so do while this is happening if our calculations are correct which i think they are you can destroy these in this inner system of you know few earth mass planets and then in the aftermath of all this violence you form the terrestrial planets where would they come from in that case so so jupiter clears out the space and then there's a a few terrestrial planets that come in and those coming from the from the disk somewhere like one of the larger yeah what actually happens in these calculations is you leave behind a rather mass depleted like remnant remnant disk only a couple earth masses so then from that remnant population annulus of material over 100 or about 100 million years by just collisions you grow the earth and the moon and everything else you said amulous annulus and yours annulus yeah that's a beautiful word what does that mean well it's like it's like a disc that's kind of thin it's like a yeah it's something that is you know a disc that's so thin it's almost flirting with being a ring like i was gonna say this reminds me lord of the rings so like this the word just feels like it belongs in a toll canal okay uh so that that's incredible and so that in your senses you said like one percent that's a rare the way jupiter and saturn danced and cleared out and you know cleared out the the the short period debris and then changed the gravitational landscape that's a pretty rare thing too it's rare and moreover like you don't have to go to our calculations you can just ask the night sky how many stars have jupiter and saturn analogs the answer is jupiter and saturn analogs are found around only 10 of sun-mic stars so they are they themselves like you kind of have to score an a minus or better on the test to you know on the planet formation test to become a solar system analog even in that basic sense and moreover um you know low lower mass stars which are uh very numerous in the galaxy so-called m dwarfs think like zero percent of them well maybe like a negligible fraction of them have giant planets giant planets are a rare you know outcome of planet formation one of the really big problems that remain unanswered is why we don't actually understand why they're so rare how hard is it to simulate all of the things that we've been talking about each of the things we've been talking about and maybe one day all of the things we've been talking about and beyond meaning like from the initial primordial solar system you know a bunch of disks with i don't know billions trillions of objects in them like simulate that such that you eventually get a jupiter and a saturn then eventually you get the jupiter and the saturn they clear out a disc change the gravitational landscape then earth pops up like that whole thing and then be able to do that for every other system in the uh every other star in the galaxy and then be able to do that for other galaxies as well um yeah so look maybe start from the smallest simulation like what is actually being done today i mean even the smallest simulation is probably super super difficult even just like one object in the kuiper belt is probably super difficult to simulate i mean i think it's super easy i mean like it's it's just not that hard um but um you know let's let's ask the most kind of basic problem okay so the problem of having a star and something in orbit of it that you don't need a simulation for like you can just write that down on a piece of paper this gravity would like yeah i guess i guess it's important to try to uh you know one way to simulate objects in our solar system is to build the universe from scratch okay we'll get to building the universe from scratch in a sec um but let me just kind of go through the hierarchy of what you know what we do two objects two objects analytically solvable like we can figure it out very easily if you just you don't i don't think you yeah you don't need to know calculus uh it helps to know calculus but you don't necessarily need to know calculus um three objects that are gravitationally interacting the solution is chaotic doesn't matter how many simulations you do you the answer loses meaning after um after some time i feel like that is a metaphor for dating as well but go on now look yes yeah so so the fact that you go from analytically solvable to unpredictable you know when you are when your simulation goes from two up bodies to three bodies should immediately tell you that the exercise of trying to engineer a calculation where you form this whole entire solar system from scratch and hope to have some predictive answer is is a futile one right we will never uh succeed at such a simulation just to clarify you mean like explicitly having a clear equation that generalizes the the whole process enough to be able to make a prediction what do you mean actually like literally simulating the objects as a hopeless pursuit once it increases beyond three the simulating them is not a hopeless pursuit but the outcome becomes a statistical one and what's actually quite interesting is i think we have all the equations uh figured out right like you know in order to really understand this the formation of the the solar system it suffices to know gravity and magneto hydrodynamics i mean like the combination of uh maxwell's equations and you know navier-stokes equations for the fluids you need to know quantum mechanics to understand opacities and and so on but we have those equations in hand it's not that we don't have that understanding it's that putting it all together is a very very difficult and b if you were to run the same evolution twice changing you know the initial conditions by some infinitesimal amounts i'm you know minor change in your calculation to start with you would get the or you'd get a different answer this is one this is part of the reason why planetary systems are so diverse you don't have like a you know very predictive path for you start with a disk of this mass and it's around this star therefore you're going to form the solar system right you start with this and therefore you will conform this huge outcome a huge set of outcomes and some percentage of it will resemble the solar system you mentioned quantum mechanics and we're talking about cosmic scale objects you've talked about that the evolution of astrophysical disks can be modeled with uh schroedinger's equation i sure did why it's like how does quantum mechanics uh become relevant at when you consider the evolution of objects in the solar system yeah well let me take a take a step back and just say like i remember being you know utterly confused by quantum mechanics when i first learned it and the schrodinger equation which is kind of the parent equation of of that whole field you know seems to come out of nowhere right the way that the way that i was sort of explaining it i remember asking you know my professor is like but where does it come from is that like well just just like don't worry about it and just like calculate the hydrogen you know energy levels right so it's like i could do all the problems i just did not have any intuition for for where this parent you know super important equation came from now down the line i was remember i was preparing for my own lecture and i was trying to understand how waves travel in self-gravitating discs so you know again there's a very broad theory that's already developed but i was looking for some simpler way to explain it really for the purposes of teaching class and so i i thought okay what if i just imagine a disc as an infinite uh number of concentric circles right that interact with the with each other gravitationally that's a problem in some sense that um i can solve using methods from like the late 1700s right so i can write down hamiltonian well i can write down the energy function basically of their their interactions and what i found is that when you take the continuum limit when you go from discrete circles that are talking to each other gravitationally to a continuum disk suddenly this gravitational interaction among them right the the governing equation becomes the schrodinger equation and i had to think about that for a little bit did you just unify quantum mechanics and gravity no this is not the same thing as like you know fusing relativity and quantum mechanics but it did uh it did get me thinking a little bit so the fact that waves in astrophysical disks behave just like wave functions of of particles kind of like an interesting analogy because for me it's easier to imagine waves traveling through you know astrophysical disks or really just sheets of paper and the reason this is that analogy exists is because there's actually nothing quantum about the schrodinger equation the schrodinger equation is just a wave equation and all of the interpretation that comes from it is quantum but the equation itself is not a quantum being so you can use it to model waves it's way it's not turtles it's waves all the way down you can pick which level you pick the wave at and so it could be at the solar system level that you can use right and also it actually provides a pretty neat calculational tool because um it's it's difficult so we just talked about simulations but it's difficult to simulate the behavior of astrophysical disks on time scales that are in between a few orbits and their entire evolution so it's over a time scale of a few orbits you have you do a hydrodynamic you know simulation right you do that basically that's something that you can do on a modern computer on a time scale of say a week when it comes to their evolution over their entire lifetime you don't hope to resolve the orbits you just kind of hope to understand how the system behaves in between right you to get access to that as it turns out it's pretty um it's pretty cute you can use uh you can use the schrodinger equation to get the answer rapidly so it's a calculational tool that's fascinating by the way the astrophysical disks how what are they how broad is this definition okay so astrophysical disks span a huge uh huge amount of ranges they start maybe at the smallest scale they start with actually kuiper belt objects some kuiper belt objects have rings so that's maybe the smallest example of an astrophysical disc we've got this little potato shaped asteroid you know which is you know sort of the size of la or something and around it is are some rings of icy matter that object is a small astrophysical disk then you have saturn the rings of saturn you have the next set of scale you have the solar system itself when it was forming you have this then you have black hole discs you have galaxies discs are super common in the universe and the reason is that stuff rotates right i mean gravity works yeah so uh and those rings could be the material that uh composes those rings could be it could be gas it could be solid it could be anything that's right so the disc that made from which the planets emerged was predominantly hydrogen helium gas on the other hand the rings of saturn are made up of you know icicles ice little like ice cubes this big about a centimeter across that sounds refreshing so that's incredible hydrogen helium gas so in the beginning it was just hydrogen and helium around the sun how does that lead to the first formations of solid objects in terms of simulation okay here's the story um so you're like have you ever been to the desert yes i've been to the death valley and actually it was uh terrifying just as total tangent i'm distracting you but i was uh driving through it and i was really surprised because it was at first hot and then as it was getting into the evening there's this huge thunderstorm like it was raining and it got freezing cold like what the hell is it was the apocalypse yeah i had to like just sit there listening to bruce springsteen i remember and just thinking i'm probably going to die and i was okay with it because bruce springsteen was on the radio look when you've got the boss you know you're ready you're ready to meet the ball yeah so look i mean it's a good line so i'm sorry that's true um yeah by the way like to continue on this tangent i i absolutely love the southwest for this reason just um you know i know during the pandemic i drove from la to new mexico a bunch of times the madness the weather yeah the the the chaos of weather the fact that you know it'll be blazing hot one minute and then it's just like we'll decide to have a little thunderstorm maybe you'll decide to go back momentarily to like a thousand degrees and then go back to the thunderstorm it's amazing it's it's that by the way is chaos theory in action yeah right um but let's get back to talking about the desert yeah so in the desert um tumbleweeds have a tendency to roll because the wind rolls them and if you're careful you'll occasionally see this family of temple weeds where like there's like a big one and then there's a bunch of little ones that that kind of hide in its wake right and are all rolling together and still almost looks like you know a family of ducks crossing a street or something um or for example you know if you watch tour de france right you've got a whole bunch of cyclists and they're like cycling you know within 10 centimeters of each other they're not bffs right yeah but they're not yeah trying to be trying to write together they are writing together to minimize the collective uh you know air resistance if you will that uh that they experience turns out solids in the protoplanetary disk do just this there's an instability wherein solid particles right things that are a centimeter across will start to hide behind one another and form these clouds why because cumulatively that minimizes the solid component of the disk aerodynamic interaction with the gas now these clouds because they're kind of a favorable energetic condition for the dust to live in they grow grow grow grow grow until they become so massive that they collapse under their own weight that's how the first building blocks of planets form that's how the big asteroids got there that's incredible yeah so that is that simulatable or is it not useful to simulate no no that's simulatable um and people do these types of calculations it's it's really cool that's actually that's one of the many fields of planet formation theory that is really really active right now people are trying to understand all kinds of aspects of that process because of course i've explained it you know like as if there's one thing that happens turns out it's a it's a beautifully rich dynamic but the but qualitatively formation of the first building blocks actually follows the same sequence as formation of stars right stars are just clouds of gas hydrogen helium gas that sit in space and slowly cool and at some point they you know contract to a point where their gravity overtakes the thermal you know pressure support if you will and they collapse under their own weight and you get a little baby solar system that's amazing so do you think one day it will be possible to simulate the full history that took our solar system to what it is today yes and it will be useless okay so you don't think your story many of the ideas that you have about jupiter clear in the space like retelling that story in high resolution is not that important i actually think it's important but at every stage you have to you have to simul you have to design your experiments your your numerical computer experiments so that they test some specific aspect of that evolution um i am not a proponent of doing huge simulations because um even if we forget the information theory aspect of not being able to simulate in full detail the universe because if you do then you you have made an actual universe it's not the simulation right by simulation is in some sense a compression of information so therefore you must lose detail but that point aside if we are able to simulate the entire history of the solar system in excruciating detail i mean it'll be cool but it's not going to be any different from observing it right because theoretical understanding which is what ultimately i'm interested in um comes from taking complex things and reducing them down to something that you know some mechanism that you can actually quantify um that's the that's the fun part of astrophysics just kind of simulating things in extreme detail is we'll cool we'll make cool visualizations but that doesn't get to doesn't doesn't get you to any better understanding than you had before you did the simulation if you ask very specific questions then you'll be able to uh create like very highly compressed nice beautiful theories about how things evolved and then you can use those to then generalize to other solar systems to other stars and other galaxies and say something generalizable about the entire universe how difficult would it be to simulate our solar system such that we would not know the difference meaning if we are living in a simulation is there a nice think of it as a video game sure is there a nice compressible way of doing that or just kind of like you intuited with a three body situation is just a giant mess that you cannot create a video game that uh will seem realistic without actually building it so i'm you know i'm speculating but one of the yeah i know i know like you have a deep understanding of this but like for me i'm just gonna like speculate that for um at least in the types of simulations that we can do today inevitably you run into the problem of resolution right you're doesn't matter what you're doing it is discrete now um the way you would go about asking you know if what we're observing is that a simulation or uh or is that you know some real continuous thing uh is you you zoom in right you zoom in and try and find the you know the grid scale if you will um yeah i mean it's a it's a really interesting it's a really interesting question and because the solar system itself and really you know the double pendulum is chaotic right pendulum sitting on another pendulum moves unpredictably once you let them go um you really don't need to like inject any randomness into a simulation for it to to give you stochastic and unpredictable answers weather is a great example of this weather has a happen of time of you know typical weather systems have a happen of time of a few days and there's a fundamental reason why the force forecast always sucks you know two weeks in advance it's not that we don't know the equations that govern the atmosphere we know them well their solutions are meaningless though after a few days the zooming in thing is very interesting i i think about this a lot whether there'll be a time soon where we would want to stay in video game worlds whether it's virtual reality or just playing video games i mean i think that time like came in like the 90s and it's been that time well it's not just it's not just games i mean it's accelerated i just recently saw that wow and fortnite were played 140 billion hours and those are just video games yeah and that's like increasing very very quickly especially with the people coming up now and being born now and become you know becoming teenagers and so on let's have a thought experiment where it's just you and a video game character inside a room where you remove the simulation they need to simulate sort of a lot of objects if it's just you and that character how far do you need to simulate in terms of zooming in for it to be very real to you as real as reality so like first of all you kind of mentioned zooming in which is fascinating because we have these tools of science that allow us to zoom in quote unquote in all kinds of ways uh in the world around us but our cognitive abilities like our perception system as humans is very limited in terms of situations so we might be very easily fooled some of the video games like on the ps4 yeah like look pretty real to me yeah right uh i think you would really have to interrogate i mean i think even with what we have today like uh i don't know ace combat seven that's a great example right like i mean the way that the clouds are rendered uh it's i mean it looks just like when you're flying you know on a real airplane the the kind of transparency i think that the you know our perception is limited enough already to not be able to tell some of the uh you know some of the differences there's a game called uh skyrim it's an elder scrolls role playing game and i just uh i played it for quite a bit and i think i played very different than others like there'll be long searches of time where i would just walk around and look at nature in the game it's incredible oh sure it's just like the graphics is like wow i want to stay there it was better i went hiking recently it was like as good as hiking so look i know what you mean not to go on a huge video game you know tangent but like the the third like witcher game was astonishingly beautiful right especially like playing on on a good hardware machine it's like this is pretty this is pretty legit that said um you know i i don't resonate with the i want to stay here you know like one of the things that i love to do is to go to my like boxing gym and and box with a guy right like that's there's there's nothing quite like that physical you know experience like that's fascinating that might be simply an artifact of the year you were born maybe because if you're born today it almost seems like stupid to go to a gym yeah like you're going to a gym to box with a guy why not box with mike tyson when you yourself was like in his prime when you yourself are also an incredible boxer in the video game world for me there there's a multitude of reasons why i don't want to box with mike tyson right like no no no no you enjoy teeth and i want to have an ear no but your your skills in this meat space in this physical realm is very limited and takes a lot of work and you're you're uh you're a musician uh your incredible scientist you only have so much time in the in the day but in the video game world you can expand your capabilities in all kinds of dimensions that you can never have possibly have time in the physical world and so that it doesn't make sense like to to be existing to be working your ass off in the physical world when you can just be super successful uh uh in the video game world but i still you enjoy sucking and stuff yeah i i really struggling to get better i sure do i mean i think like these days with music music is a great example right we just started you know practicing live uh with my band again you know after not playing for a year and uh you know it's just it was terrible right which is just kind of a lot of the nuance you know a lot of the detail is just that detail that takes you know years of collective practice to develop uh it's just lost but it was just an incredible amount of fun way more fun than all the like studio you know sitting around and playing uh that i did you know throughout the entire year so i think there's something there's something intangible or maybe maybe tangible about being uh being in person i i sure hope you're wrong and that you know we that's not something that will get lost because i think there's like such a large part of the human condition is to hang out if we were doing this interview on zoom right i mean i'd already be i'd already be bored out of my mind [Laughter] exactly i mean there's something to that i mean i'm almost playing devil's advocate but at the same time you know i'm sure people talk about the same way at the beginning of the 20th century about horses where they're they are much more efficient they're much uh easier to maintain than cars it doesn't make sense to have you know all the ways that cars break down and there's not enough infrastructure in terms of roads for cars it doesn't make any sense like horses and like nature you could do the nature like where you know you should be living more natural life those are real you don't want machines in your life they're going to pollute your mind and the minds of young people but then eventually just cars took over so in that same way it just seems uh going back to horses just you know well you can be you can play uh uh uh what is it red dead red dead redemption redemption and uh you can ride horses in the video game more so let me return us back to planet nine uh-huh always a good place to come back to so now that we did a big historical overview of our solar system what is planet nine okay planet nine is a hypothetical object that orbits the solar system right at an orbital period of about 10 000 years and an orbit which is slightly tilted with respect to the plane of the solar system slightly eccentric and the object itself we think is five times more massive than the earth we have never seen planet nine in a telescope but we have gravitational evidence for it and so this is where all the stuff we've been talking about this clustering ideas maybe you can speak to the approximate location that we suspect and also the question i wanted to ask is uh what are we supposed to be imagining here because he said there's certain objects in the kuiper belt that are kind of have a direction to them that they're all like like flocking in some kind of way so that's the sense that there's some kind of gravitational object not changing their orbit but kind of confining them right yeah finding like grouping their orbits together see what would happen if planet nine were not there is these orbits that roughly share a common orientation they would just disperse right they would just become as a mutually symmetric point everywhere planet nine's gravity makes it such that these objects stay in a state that's that's basically anti-aligned with respect to the orb of planet nine um and and sort of hang out there and kind of oscillate on time scale of about a billion years that's one of the lines of evidence for the existence of planet nine there are others that's the one that's easiest to maybe visualize just because it's fun to think about orbits that all point into the same direction but i should you know emphasize that for example the existence of objects again kuiper belt objects that are heavily out of the plane of the solar system things that are tilted by say 90 degrees that's not we don't expect that as an outcome of planet formation indeed planet formation simulations have never produced such objects without some extrinsic gravitational force planet nine on the other hand generates them very readily so that provides kind of an alternative you know population of small bodies in the solar system that also get produced by planet 9 through an independent kind of gravitational effect so they're kind of there's basically five different things that the uh that planet nine does individually that are like kind of maybe a one sigma effect where you would say yeah okay if that's all it was maybe it's not no reason to jump up and down but because it's it's mult it's a multitude of these puzzles that all are explained by one hypothesis that's that's really the the magnetism the attraction of the planet nine model so can you just clarify so most orbit most planets in the solar system orbit and approximately the same so it's flat yeah it's like one degree they the difference between them is about one degree so but nevertheless if we looked at our solar system it would look and i could see every single object it would look like a sphere the inner part where the planets are would look like you know flat right the the kuiper belt and the asteroid belt have a larger um it gets fatter and fatter yeah that's kind of like becomes a sphere that's right and if you look at the very outside it's polluted by this you know quasi-spheroidal thing nobody's of course ever seen the oort cloud right we've only seen comments that come from the oort cloud so the oort cloud which is this right population of distant debris its existence is also inferred you could say alternatively there is you know there's a big cosmic creature that occasionally you know sitting at 20 000 au and occasionally throws an icy rock towards the sound like that spaghetti monster i think it's called okay i mean so it's a mystery in many ways but you can kind of infer a bunch of things about it it's by the way both terrifying and exciting that there's this vast darkness all around us that's full of objects that are just throwing just there yeah it's actually kind of astonishing right that we have only explored a small fraction of the solar system right that that really kind of baffles me because uh remember as a student you know studying physics you know you do the problem where you put the earth around the sun you solve that and like it's one line of math and you say okay well that surely was figured out by newton so like all the interesting stuff is not in the solar system but that um it's just plainly not true there are there are mysteries in the solar system that are remarkable that we are only now starting to just kind of scratch the surface of and some of those objects probably have some information about the history of our solar system absolutely absolutely like a great example is uh you know small meteorites right small meteorites are melted right they have they're differentiated meaning some of the uh iron sinks you say how can that be because they're so small that they wouldn't have melted just from the heat of their accretion turns out the fact that the solar nebula the the disk that made the planets was polluted by aluminum 26 is in itself a remarkable thing it means the solar system did not form an isolation it formed in a giant cloud of thousands of other stars that were also forming some of which were undergoing you know going through supernova explosions some of and releasing these unstable isotopes that of which we now see kind of the traces of it's so cool do you think it's possible that life from other solar systems was injected and that that was what was uh the origin of life on earth yeah defense permea idea um that's seen as a low probability event by people who studied the original life but that's because uh then they would be out of a job well i don't think they'd be out of the job because you just then say you have to figure out how life started and there but then you have to go there we can study life on earth much easier we could study in the lab much easier because we could replicate conditions that are from an early earth much easier from a chemistry perspective from a biology perspective you can intuit a bunch of stuff you can look at different parts of earth and just to an extent i mean the early earth was completely unlike the current earth right there was no oxygen so uh one of my colleagues at caltech uh joe kirchnick is certain right something like 100 certainty that life started on mars and came to earth uh in on martian media rights um this is not a problem that i like to kind of think about too much like the origin of life it's a fascinating problem but you know it's not physics and i just like i just don't don't love it it's the same reason you don't love i thought you're a musician so music is not physics either so why are you showing 100 physics [Laughter] okay no no look uh in all seriousness though i uh there are a few things that i really really enjoy i genuinely enjoy physics i genuinely enjoy music i genuinely you know enjoy martial arts and i genuinely enjoy uh my family i should have said that all in a reverse order or something but i like to focus on these things and not worry too much about about everything else you know what i mean yes just because there is a like you said earlier there's a time constraint you can't do it all there's many mysteries all around us so um and they're all beautiful in in different ways to me that thing i love is artificial intelligence that uh perhaps i love it because eventually i'm trying to suck up to our future overlords the the question of you said there's a lot of kind of little pieces of evidence for this thing that's planet nine if we were to try to collect more evidence or be certain like a paper that says like you drop it clear we're done what what is that required does that require us sending probes out or do you think we can do it from telescopes here on earth what are the different ideas for conclusive evidence for planet nine the moment planet nine gets imaged from a telescope on earth it's done i mean it's just there can you clarify because you mentioned that before from an image would you be able to tell yes so from an image the moment you see something something that is reflecting sunlight back at you and you know that it's hundreds of times as far away from the sun as as the earth you're done so you're thinking so basically if you have a really far away thing that's big yeah you know five times the size of earth that means uh that that's fine that is planet could there be multiple objects like that i guess in principle yeah i mean there's no there's no law of physics that uh that doesn't allow you to have multiple there's also no evidence at present for there being multiple i wonder if it's possible this is like just like we're finding exoplanets whether given the size of the or cloud there's basically it's rare and rare but they're sprinkled planet nine ten eleven twelve like these yeah some got thirteen after that yeah i can just keep counting so like just something about the dynamic system like it becomes lower and lower probability event but they gather up like they they become would they become larger and larger maybe something like that and i wonder i wonder if like discovering planet nine will just like be almost like a springboard it's like well what's what's beyond that it's entirely plausible the oort cloud itself probably holds about five earth masses or seven earth masses of material right so it's not it's not nothing and the it all ultimately comes down to at what point will the observational surveys sample enough of the solar system to uh kind of reveal interesting things there's a great analogy here with neptune and the story of how neptune was discovered neptune was not discovered by looking at the sky right it was discovered by uh it was certain mathematically right so yeah the orbit of uranus when uranus was found um yes this was 1781. uh it's the kind of tracking uh both the tracking of the orbit of uranus as well as the reconstruction of the orbit of uranus immediately revealed that it was not following the orbit that it was supposed to right the the predicted orbit deviated away from where it actually was so uh in the mid eighteen hundreds right um a french mathematician by the name of orban le verrier did a beautifully sophisticated calculation which said if this is due to gravity of a more distant planet then that planet is there okay and then they found it but the point is the understanding of where to look for neptune came entirely out of celestial mechanics the case with planet nine is a little bit different because what we can do i think relatively well is predict the orbit and mass of planet nine we cannot tell you where it is on its orbit the reason is we haven't seen the kuiper belt objects complete in orbit their own orbit even once because it takes four thousand years but you know i plan to live on as an ai being uh and you know i'll i'll be tracking those uh those orbits as solid takes four or five thousand years i mean it doesn't have to be ai it could be longevity there's a lot of really exciting genetic engineering research so you'll just be a brain waiting for the for the your brain waiting for the orbit to complete for the basic kuiper belt objects that's that's right that's like kind of the worst reason to want to live a long time right just like can the brain like smoke a cigarette can you just like light one up while you're waiting or uh [Laughter] but you're making me actually realize that the one way to explore the the galaxy is by just sitting here on earth and waiting so if we can just get really good at waiting it's like a more more or these interstellar objects that fly in you can just wait for them to come to you same with the aliens you can wait for them to come to you if you get really good at waiting um then that's one way to do the exploration because eventually the thing will come to you maybe that's the entire maybe the intelligent alien civilizations get much better at waiting and so they all decide so game theoretically to start waiting and it's just a bunch of like ancient intelligent civilizations of aliens all throughout the universe they're just sitting there waiting for each other look you can't just be good at waiting you got to know how to chill okay like like you can't just like sit around and do nothing you got to be you get you got to know how to chill i honestly think that as we progress if the aliens are anything like us we enjoy loving things we do and it it's uh it's very possible that we just figure out mechanisms here on earth to enjoy our life and we just stay here on our f forever that exploration becomes less and less of an interesting thing to do and so you basically yes wait and chill you get really optimally good at chilling and thereby exploring is not that interesting so you know in terms of 4 000 years would be nothing for scientists we'll be chilling and just all kinds of scientific explorations will become possible because we'll just be here you have a paper out recently because you already mentioned some of these ideas but i'd love it if you could dig into it a little bit yeah of course the injection of inner or cloud objects into the distant kuiper belt by planet nine what is this idea of planet nine injecting objects into the kuiper belt okay let me take a brief step back and when we do calculations of planet nine we do the simulations as far as our simulations are concerned sort of the uh neptune like kind of the trans-neptunian solar system is entirely sourced from the inside namely the kuiper belt gets scattered by neptune and then planet nine does things to it and aligns the orbits and and so on and then we calculate what uh what happens on the lifetime of the solar system yada yada during the pandemic one of the kind of questions we asked ourselves this is indeed something we mike and i uh mike brown whose partner in crime on this and i do regularly is we say how can we a disprove ourselves and b how can we improve our simulations like what's missing one idea that maybe should have been obvious in retrospect is that all of our simulations treated the solar system as some isolated creature right but the solar system did not form in isolation right it formed in this cluster of stars and during that phase of forming together with thousands of other stars we believe the solar system formed this almost spherical population of icy debris that sits maybe at a few thousand times the separation between the earth and the sun maybe even a little bit closer if planet nine's not there that population is completely dormant and these objects just slowly orbit the the sun nothing interesting had happens to them ever but what we realized that if planet nine is there planet nine can actually grab some of those objects and gravitationally re-inject them into the distant solar system so we thought okay let's look into this with numerical experiments do do our simulations does this process work and if it works uh what are its consequences so it turns out indeed not only does planet nine inject these distant inner or cloud objects into the kuiper belt they follow roughly the same pathway as the um as the objects that are being scattered out also there's this kind of river two-way river of material some of it is coming out from you know by neptune scattering some of it is moving in and if you work through the numbers you kind of at the end of the day that it it has an effect on the best fit orbit for planet nine itself so if you realize that the data set that we're observing is not entirely composed of things that came out of the solar system but also things that got re-injected back in then turns out the best fit planet nine slightly more eccentric that's kind of getting into the weeds the the point here is that uh you know the existence of planet nine itself provides this natural bridge that connects an otherwise dormant population of icy debris of the solar system with things that we're starting to directly observe so you can flow back so it's not just the river flowing one way it's maybe a smaller stream go back and backwash you want a backwash you want to incorporate that into the simulations into your understanding of those distant objects when you're trying to make sense of the various observations and so on exactly that's fascinating i gotta ask you some people think that uh many of the observations you're describing could be described by a primordial black hole first what is the primordial black hole and what do you think about this idea yeah so primordial black hole is a black hole which is made not through the usual pathway of making a black hole which is that you have a star which is uh more massive than you know 1.4 or so solar masses and basically when it runs out of fuel uh runs out of its nuclear fusion fuel it can't hold itself up anymore and just the whole thing collapses on itself right you create a um i mean one i guess simple way to think about it is you create an object with zero radius that has mass but zero radius that singularity now that's such black holes exist all over the place in the galaxy there's in fact a really big one at the center of the galaxy that's like yeah that that one's always looking at you when you're not looking okay right and it's it's always talking about you and when you turn off the lights it's it wakes up that's right um but you know so such black holes are all over the place we when they merge we get to see you know incredible gravitational waves that they emit etc etc one kind of plausible scenario however is that when the universe was forming basically during the big bang you created a whole spectrum of black holes some with masses of five earth masses some with masses of 10 earth masses like the entire you know mass spectrum size the amount some the mass of asteroids now on the smaller end over the lifetime of the universe the small ones kind of evaporate and they're not there anymore at least this is what we what the calculations tell us but five earth masses is big enough to not have evaporated so one idea is that planet nine is not a planet and instead it is a five earth mass black hole and that's why it's hard to find now can we right away from our calculations say that's definitely true or that's not true absolutely not we can't in fact our calculations tell you nothing other than the orbit and the mass and that means the black hole i mean it could be a five earth mass you know cup it could be a five earth mass hedgehog or a black hole or really anything that's five earth masses will do because the gravity of a black hole is no different than the gravity of a planet right if the sun became a black hole tomorrow it would be dark but or the earth would keep orbiting it and like this notion that oh black holes suck everything in it's it's not that's like a sci-fi notion right it's just mass what would be the difference between a black hole and a planet in terms of observationally uh observationally the difference would be that you will never find the black hole right the truth is they're kind of um i'm actually not you know i never looked into this very carefully but there are some constraints that you can get just statistically say okay if the sun has a binary companion which is a five earth mass black hole then that means such black holes would be extremely common and you know you can sort of look for lensing events and then you say okay maybe that's not so likely but you know that said i want to emphasize that there's a limit to what our calculations uh can tell you that's the orbit and the mass so i think there's a bunch like ed whitton i think wishes it's a black hole because i think the one exciting things about black holes in our solar system is that we can go there and we can maybe study the singularity somehow because that allows us to understand some fundamental things about physics if um it's a planet so planet nine we may not you know and we go there we may not discover anything profoundly new the interesting thing perhaps you can correct me about planet nine is like the big picture of it the whole big story of the kuiper belt and all those kinds of things it's not that planet nine would be somehow fundamentally different from um from i don't know neptune in terms of um in terms of the kind of things we can learn from it so i think that there's kind of a hope that it's a black hole because it's an entirely new kind of object maybe you can uh correct me yeah i mean of course here my own biases creep in because i'm interested you know in planets around other stars and i would say i would disagree that you know we wouldn't find things that would be truly you know fundamentally new new because as it turns out the the galaxy is really good at making five or three earth mass objects right the most common type of planet that we see that we you know discover orbiting around other stars there's a few earth masses in the solar system there's no analog for that right we go from one earth mass object which is this one and to skipping to neptune and uranus which themselves are actually relatively poorly understood especially uranus from the interior structure point of view if planet nine is a planet going there will give us the closest window and to understanding what other planets look like and um i will you know i'll say this that you know planets kind of in terms of their complexity on some logarithmic scale fall somewhere between a star and an insect right an insect is way more complicated than a star right just there's all kinds of physical processes and really biochemical processes that occur inside of an insect that just make a star look like you know somebody is like playing with the spring or something yeah right so the i i think you know it would be you know arguably you know more interesting to go to um you know to go to planet nine if it's a planet because black holes are simple they're just kind of they're basically macroscopic like particles yeah right and so just like you mentioned in terms of complexity so it's possible that planet nine as opposed to being like homogeneous is like super like heterogeneous is a bunch of cool stuff going on absolutely that could give us an intuition i never thought about that that it's basically earth number two in terms of size and gives us starts giving us intuition that could be generalizable to earth-like planets elsewhere in the galaxy yeah pluto is also in the sense like you know pluto is a tiny tiny thing right just like you would imagine there's just a tiny ball of ice like who cares but the new horizons images of pluto reveal so much remarkable structure right they reveal glaciers flowing and these are glaciers not made out of water ice but you know co ice it turns out at those temperatures right of like 40 or so kelvin water ice looks like metal right it doesn't flow at all but then ice made up of carbon monoxide starts to flow i mean there's just like all kinds of really cool uh phenomena that you otherwise just wouldn't really even imagine that occur so yeah i mean there's a reason why i like planets well let me ask you i find uh as i read the idea that edwin was thinking about this kind of stuff fascinating so he he's a mathematical physicist who's uh very interested in string theory won the fields metal for his work in mathematics so i read that he proposed a fleet of probes accelerated by radiation pressure that could discover a planet nine primordial black holes location uh what do you think about this idea of sending a bunch of probes out there yeah look the way the the idea is a cool one right you go and you say you know launch them basically isotropically you track where they go and uh if i understand the idea correctly you basically measure the deflection and then you say okay there must be something there since the the probe trajectories are being altered oh so the measurement the basic sensory mechanism is the it's not like you have sensors on the probes it's more like you're because you're very precisely able to capture to measure the trajectory of the probes you can then infer the gravitational fields and i think i think that's the basic idea um you know back a few years ago we had conversations like these with um you know engineers from jpl they more or less convinced me that this is much more difficult than it seems because you don't at that level of precision right things like solar flares matter right solar flares right are completely chaotic you can't predict which where a solar flare will happen that will drive radiation pressure gradients you don't know where every single asteroid is so like actually doing that problem i think it's possible but it's it's not a trivial matter right well i wonder not just about planet nine i wonder if that's kind of the future of doing science in our solar system is to just launch a huge number of probes so like a whole order of magnitude many orders of magnitude larger numbers of probes and then starting for a bunch of different stuff not just gravity but everything else so in this regard i actually think there is a huge revolution that's to some extent already started right the standard kind of like time scale for a nasa mission is that you like propose it and it launches i don't know like 150 years after you propose i'm over exaggerating but yeah you know it's just like some huge development cycle yeah and it gets delayed 55 times like that is not going away yeah right the the really cutting edge things you have to do it this way because you don't know what you're building so to speak but the cubesat kind of world is starting to um you know provide an avenue for like you know launching something that costs you know a few million dollars and has a turnaround time scale of like a couple years you can imagine doing you know phd theses where you design the mission the mission goes to where you're going and you do the science all within a time span of five six years that is has not been fully executed on yet but i absolutely think that's on the horizon and we're not talking a decade i think we're talking like this decade yeah and the company is accelerating all this uh with uh blue origin and and uh spacex there's a bunch of more cubesat oriented companies that are pushing this forward uh well let me ask you let me ask you on that topic what do you think about either one elon musk with spacex uh going to mars i think he wants spacex to be the first to put a first human on mars and then uh jeff bezos got to give him props wants to be the first to fly his own rocket out into space so you know wasn't there a guy who like built his rocket out of garbage yeah this was like a couple years ago and somewhere in the desert he launched himself i'm not tracking this closely but i think i am familiar with folks who built their own rocket to try to prove the earth is flat yes that's the guy i'm talking about yeah he was also like he also jumped some limousine yeah for truly revolutionary minds uh greater men than either you or i but yeah so look it's been astonishing to watch how really over the last like decade the commercial sector took over this uh you know this industry that traditionally has really been like a you know a government thing to do um motivated primarily by the the competition between nations like the cold war sure and now it's motivated more more and more by the natural forces of capitalism yes that's right so um okay here i have i have many ideas about i think on the one hand right like what spacex has been able to do for example phenomenal um if that brings down the price of spacex within that turnaround time scale for space exploration which i think it inevitably will um that's a huge you know that's a huge boost to the to the human condition the same time right if we're talking astronomy right there they're also it comes at a huge cost right and the starling satellites is a great example of that cost right at one point uh in fact i was just camping and the mojave was a with a friend of mine and they saw you know this uh the string of satellites just kind of like you know appear and then disappear uh into nowhere so that is beginning to interfere with you know earth-based observations so i think it's there's tremendous potential there it's also important to be responsible about how it's executed now with mars and the whole idea of you know exploring mars right i don't have like strong opinions on whether a manned mission is is required or not required um but i do think you know we need to focus the thing to keep in mind is that i i generally kind of uh i'm not signed on if it will to the idea that mars is some kind of a safe haven that we can uh you know escape to right mars sucks right like living on mars if you if you want to live on mars like you can have that experience by going to the mojave desert and camping and it's just like it's it's just not a great well it's interesting but there's something captivating about that kind of mission of us striving out into space and by making mars in some ways habitable for at least like months at a time i think would lead to engineering breakthroughs that would make life like in many ways much better on earth like it would we'll come up with ideas we totally don't expect yet both on the robotics side on the food engineering side on the you know maybe like we'll switch from what like there'll be huge breakthroughs in insect farming as as exciting as i find that idea to be that in you know our in the ways we consume protein maybe uh it'll revolutionize we do factory farming which is full of cruelty and you know and torture of animals will revolutionize that completely because of our like we don't we shouldn't need to go to mars to revolutionize life here on earth but at the same time i shouldn't need a deadline to get done but i do need it and then the same way i think we need mars there's something about the human spirit that loves that longing for i i agree with that thesis the going to the moon right and the that whole endeavor has you know has captivated the imagination of so many and it has uh it has led to incredible kind of incredible ideas really and and probably in non-linear ways right not like okay we went to the moon therefore some person here has thought of this and yes in in that similar sense i think you know space exploration is there's something there's some real magnetism about it and it's on a genetic level right like we have this need to keep exploring right when we're done uh with a certain frontier we move on to the next frontier all that i'm saying is that i'm not moving to mars to live there permanently uh ever you know and i think that you know i'm glad you paid you you noted the kind of degradation of the earth right i think that is a true kind of the leading order challenge of our great engineering that's a bunch of a bunch of engineering problems i'm most interested in this space because as i've read extensively it's apparently very difficult to have sex in space and so i just want that problem to be solved because i think once we solve the sex and space problem we'll revolutionize sex here on earth thereby increasing the fun on earth and um the consequences of that can only be good i mean you can you've got a clear plan right and and it sounds like uh yeah i'm submitting proposals to nasa as we said that's right i keep getting rejected i don't know why okay uh you need better diagrams better better pictures i should have thought of that you a while ago mentioned that you know there's certain aspects in the history of the solar system and earth that resulted that it could have resulted in an opaque atmosphere but it didn't we couldn't see the stars um and uh somebody mentioned to me a little bit ago it's almost like a philosophical question for you do you think humans like human society would develop as it did or at all if we couldn't see the stars it would be drastically different just dr if it ever did develop so i think some of the early developments right of like fire and you know fire you know first of all that atmosphere would be so hot because you know if you have an opaque atmosphere the temperature at the bottom is is huge um so we would be very different beings to start with we'd have it could be cloudy in certain kinds of ways that you could still get okay think about like uh like a greenhouse right a greenhouse is cloudy effectively uh but it's it's super hot um yeah it's hard to avoid having an atmosphere if you have an opaque atmosphere it's hard to right venus is a great example right venus is i don't remember exactly how many degrees and but it's hundreds in celsius right it's not a hundred it's hundreds uh even though it's only a little bit closer to the sun that temperature is entirely coming from the fact that the atmosphere is thick so it's just a sauna of sorts yeah yeah you go there you know you feel refreshed after you come back you know but if you stay there i mean so okay take that as an assumption this is a philosophical question not a biological one so you have a life that develops under these extremely hot conditions yeah so let's see so much of the early evolution of mankind uh was driven by exploration yeah right and the kind of interest and stars originated in part as a tool to guide that exploration right i mean that in itself i think would be a huge uh you know a huge differential in the way that we you know our our our evolution on this planet yes i mean stars is that's brilliant so even in that aspect but even in further aspects uh astronomy just shows up in basically every single development in the history of science up until the 20th century it shows up so i wonder without that if we had we would have if we would even get like calculus yeah look that's a great i mean that's a great point newton in part developed calculus because he was interested in understanding explaining kepler's laws right in general that whole mechanistic understanding of the night sky right replacing a religious understanding where you interpret you know this is you know this whatever fire god writing his you know uh little chariot across the sky as opposed to you know this is some mechanistic set of laws that transformed humanity and arguably put us on the on the course that we're on today right the entirety of the last 400 years and the development of kind of our technological world that we live in today was sparked by by that right abandoning an effectively you know a non-secular view of the natural world and and kind of thing okay this can be understood and if it can be understood it can be utilized we can create our own uh variants of this absolutely we would be a very very different species without astronomy this i think extends beyond just astronomy right there there are questions like why do we need to spend money on x right where x can be anything like paleontology like right uh the mating patterns of uh penguins yeah that's like essential that's right um i think you know there's a tremendous uh underappreciation for the usefulness of useless knowledge right i mean uh that's brilliant i didn't come up with this this was this is a little book by the guy who started the institute for advanced studies but um you know it's it's so true so much of the electronics that are on this table right work on maxwell's equations maxwell weren't wasn't sitting around in the 1800s saying you know i hope one day you know uh we'll make you know a couple mics so you know a couple uh you know a couple guys can have this conversation right that that wasn't at no at no point was that the motivation and yet you know it gave us the world that we have today and the answer is if you a purely pragmatic person if you don't care at all about kind of the human condition none of this the answer is uh you can tax it right like the useless things have been have created way more capital than useful things and the sad thing i mean first of all it's really important to think about and it's brilliant in the in the following context like neil degrasse tyson has this book about the role of military-based funding in the development of science and then so much of technological breakthroughs in the 20th century had to do with humans working on different military things and then the outcome of that had nothing to do with military it had some military application but their impact was much much bigger than the military the splitting of the atom is is a kind of a canonical example of this we all know the tragedy that you know arises from splitting of the atom and and yet you know so much i mean the atom itself does not care for what purpose it is being split so so i wonder if if we you take took the same amount of funding as we used for war and poured it into like totally seemingly useless things like the mating patterns of penguins we would get the internet anyway i i think so i think so and uh you know perhaps more of the internet would have uh would have penguins you know so we're both joking but in some sense like i wonder it's not the the penguins because penguins is more about sort of biology but all useless kind of tinkering and all kinds of uh in all kinds of avenues and also because military applications are often um burdened by the secrecy required so it's often like so much uh the openness is lacking and if we learned anything from the last few decades is that when there's openness and science that accelerates the development of science that's right that's true the openness of science truly you know it benefits everybody the notion that if you know i share my science with you then you're gonna catch up and like know the same thing that is a short-sighted viewpoint because if you catch up and you open you know you you discover something that puts me in a position to do the next step right it's just so i absolutely agree with um with all this i mean uh the kind of question of like military funding versus non-military funding is is obviously a complicated one but at the end of the day i think we have to get over the notion as a society that we are going to you know pay for this and then we will get that right that's true if you're buying like i don't know toilet paper or something right it's just not true in the intellectual pursuit that's not how it works and sometimes it'll fail right like sometimes like a huge fraction of what i do right i come up with an idea i think oh it's great and then i work it out it's totally not great right it fails immediately failure is not a sign that the initial pursuit was worthless right failure is just part of this kind of this whole exploration thing and we should fund more and more of this exploration the variety of the exploration i think it was linus pauling or somebody from you know that generation of scientists and you know a good way to have good ideas is to have a lot of ideas right so that's i think that's true um if you are conservative in your thinking if you worry about proposing something that's going to fail and oh what if you know like i there's no science police that's going to come and arrest you for proposing the wrong thing and you know it's also just like why would you why would you do science if you're afraid of you know taking that step it'd be so much better to propose things that are that are plausible that are interesting and then for a fraction of them to be wrong than to just kind of you know make incremental progress all your life right speaking of wild ideas let me ask you about the thing we mentioned previously which is this interstellar object a muamoa could it be space junk from a distant alien civilization you can't immediately discount that by saying absolutely it cannot anything can be a space junk i mean from that point of view can any of the kuiper belt objects we see okay you know be space beijing anything on the night sky can in principle be space junk and kuiper belt would catch interstellar objects potentially and like force them into an orbit if they're like small enough uh not the kuiper belt itself but you can imagine like jupiter family comets being captured uh you know so so you can actually capture things it's even easier to do this very early in the solar system like early in the solar system's life while it's still in a cluster of stars um it's unavoidable that you capture debris whether it be natural debris or unnatural debris or just debris of some kind from other stars that it's like a daycare center right like everybody passes their infections on to other kids yeah um you know or more and more there's been a lot of discussion about and there's been a lot of interest in this over like is it is it aliens or is it not but let's like if you just kind of look at the facts like what we know about it is it's kind of like a weird shape and it also accelerated yeah right like that's the two those are those are the two interesting uh things about it there are um there are puzzles about it and perhaps the most uh daring resolution to this puzzle is that it's not you know aliens or it's not like a rock it's actually a piece of hydrogen ice so this is a friend of mine you know daryl seligman greg laughlin came up with this uh idea where that in giant molecular clouds that are just clouds of hydrogen helium gas that live in live throughout the galaxy at their cores you can condense ice to become these hydrogen you know icebergs if you will and then uh that explains many of the aspects of uh in fact i think that explains all of the mystery how it becomes elongated because basically the hydrogen ice sublimates and kind of like a bar of soap that you know slowly kind of elongates as you uh as you strip away the the surface layers uh how it was able to accelerate because of a jet that is produced from you know the hydrogen coming off of it but you can't see it because it's hydrogen gas like all of this stuff uh kind of falls together nicely i'm i'm intrigued by that idea truly because it's like if that's true that's a new type of astrophysical object and it would be produced by what's the monster that produced initially that kind of object so this is giant molecular molecular clouds they're everywhere i mean they are the fact that they exist is not are they rogue clouds or are they part of like an oort cloud no no they're not so clouds yeah they're just floating about yeah so if you go like a lot of people imagine the galaxy as being a you know a bunch of stars right and they're just orbiting right but the truth is if you fly between stars you run into clouds uh they don't have any large object that creates orbits they're just floating about just floating but why are they floating together oh they just flowed together for time and not well so these are the these eventually become the nurseries of stars so as they as they cool they contract and uh you know then collapse into stars or into groups of stars but some of them they the starless molecular clouds according to the calculations that daryl and greg did can uh can create these like icicles of hydrogen ice i wonder why they would be flying so fast because they seem to be moving pretty fast that's just because of the acceleration due to uh due to the sun if you stop i mean it's like take something really far away let it go and the sun is here by the time it comes close to the sun right it's moving pretty fast so that's an attractive explanation i think not so much because uh it's cool but it makes a clear prediction right of when their rubin observatory comes online next year or so we will discover many many more of these objects right and they have um so i like i like theories that are falsifiable right not not just testable but falsifiable it's good to have a falsifiable theory where you can say that's not true uh aliens is one that's fundamentally difficult to say no that's not aliens the interesting thing to me if you look at one alien civilization and then we look at the things it produces in terms of if we were to try to detect the alien civilization the there's like uh say there's 10 billion aliens there would probably be trillions of dumb drone type things produced by the aliens and then be many many many more orders of magnitude of junk so like if you were to look for an alien civilization in my mind you would be looking for the junk that's the more efficient thing to look for so i'm not saying has any characteristics of space junk but it kind of opened my eyes like to the idea that we shouldn't necessarily be looking to the queen of the ant colony we should be looking at i don't know i don't know like the traces of alien life that doesn't look intelligent in any way may not even look like life it could be just garbage we should be looking for garbage just generically garbage that's producible by uh unnatural uh forces i mean for me at least that was kind of interesting because if you have a successful alien civilization that we will be producing many more orders and magnitude of junk and that'll be easier potentially to detect well so you have to produce the junk but you have to also lunch launch it so this is the this is where i mean let's let's imagine disposal yeah but let's imagine we are a successful civilization that you know has made it to space we clearly have right um and yes we're in the infancy of that pursuit but you know we've launched i don't know how many satellites um probably if you count gps satellites it must be at least thousands it's it's certainly thousands i don't know if it's over ten thousand yeah but it's done that but it's on that like a large order of magnitude how many of the things that we've launched will ever leave the solar system i think two two well maybe the voyager the voyager one voyager two i don't know if the pioneer so maybe three like oh there's also a tesla roadster out there uh that that one it will never leave the solar system it'll just i think that one will eventually collide with mars that can be spacex's first mars destination um but look so there's an energetic cost to interstellar travel uh which is really hard to overcome and when when we think about you know generically what do we look for in an alien civilization oftentimes we tend to imagine that the thing you look for is the thing that we're doing right now yeah right so i think that um you know if i if i look at the future right i mean for a while like okay if aliens are are out there they must be broadcasting and radio right that radio um you know the amount that we broadcast in radio has diminished tremendously in the last 50 years but we're doing a lot more computation right what are the signs of computation like that's a good that's an interesting question to ask right where i don't know i think something on the order of a few percent of the entire electrical grid last year went to mining bitcoin right uh you know well yeah the there could be a lot of in the future different consequences of the computation which i mean by unbiased but it could be robotics it could be artificial intelligence so we may be looking for intelligent looking objects like that's what i meant by probes like things that move in kind of artificial ways but the emergence of ai is not an if right it's it's happening right in front of our eyes and the energetic costs associated with that are becoming you know a tangible problem so i think you know if you imagine kind of extrapolating that into the future right what are the you know what becomes the bottleneck right the bottleneck might be powering you know powering the broadly speaking not one air but powering that entire ai ecosystem right so i don't know i think you know space junk isn't is kind of uh it's an interesting idea but it's heavily influenced by like sci-fi of 1950s where by 2020 we're all like flying to the moon um and so we produce a lot of space junk i'm not sure if that's the pathway that alien civilizations take i've also never seen an alien civilization that's that's true but if your theory of chill turns out to be true and then we don't you know we don't necessarily explore we seize the exploration phase of uh like alien civilizations quickly sees the exploration phase of their um of their efforts then uh then perhaps they'll just be chilling in a particular space expanding slowly but then using up a lot of resources and then have to have a lot of garbage disposal that sends stuff out and the other you know the other idea was that it could be a relay that uh you almost have like these gps like markers these sent throughout which i think is kind of interesting it's uh similar to this probe idea of sending a large number of probes out to measure gravitational um to to to measure basically yeah the the gravitational field essentially i mean a lot of people at cal tech and mit are trying to measure gravitational fields and there's there's a lot of ideas of sending uh stuff out there that accurately measures those gravitational fields uh to have a greater understanding of the early universe but then you might realize that communication through gravitation through gravity is actually much more effective than than radio waves for example something like that and then you send out i mean okay if you're an alien civilization that's able to have gigantic masses like basically we're getting there as a as a civilization no we're not not even close well i mean yeah okay i i mean like be able to sort of uh play with black holes that kind of thing so we're talking about a whole nother diff order of magnitude and masses then it may be very effective to send signals via gravitational waves i actually my sense is that all of these things are genuinely difficult to predict you know and i don't mean like to to kind of shy away i just i really mean if you think if you take um imagination of what the future looked like from you know 500 years ago right it's just it is so hard to conceive of the impossible right so um [Music] it's it's almost like um you know it's almost limiting to try and imagine things that are an order of magnitude uh you know or two orders of magnitude ahead in terms of progress just because you know you mentioned cars before you know if you were to ask people what they wanted in 1870 is faster buggies right so um so i think the whole like kind of you know alien conversation inevitably gets gets limited by by our entire kind of collective um astrophysical lack of imagination so to push back a little bit i find that it's really interesting to talk about these wild ideas about the future whether it's aliens whether it's ai with brilliant people like yourself who are focused on very particular tools of science we have today to solve very particular like rigorous scientific questions and it's almost like putting on this wild dreamy hat like some percent of the time and say like what are like what would alien civilizations look like what would alien trash look like well what would our own civilization that sends out trillions of ai systems out there like hal 9000 but 10 000 out there what would that look like and you're right any one prediction is probably going to be horrendously wrong but there's something about creating these kind of wild predictions that kind of opens up there's a huge magnetism to it right and some of some of it um you know i mean some of the jules verne novels did a phenomenal job predicting the future right uh that that actually was a great example of what you're talking about like allowing your imagination to run free i mean i just hope i just hope there there's dragons that's like i love dragons yeah dragons are the best but see the cool thing about science fiction and these kinds of conversations it doesn't just predict the future i think some of these things will create the future pla planting the idea this will help the humans are amazing like fake it till you make it humans are really good at uh taking an idea that seems impossible at the time and for one any one individual human that idea is like a it's like planting a seed yes that eventually materializes itself it's weird it's weird science fiction can create science drive some of it it drives the science i agree with you and uh and i think in this regard you know i i'm like a sucker for for sci-fi um it's it's all i listen to like now when i when i run and um and some of it is completely implausible right and it's like i don't care it's it's so it's uh it's both entertaining and uh you know it's just like it's imagination you know about the black clouds book i think this by fred hoyle this is like this has great connections with sort of a lot of the advancements that are happening in nlp um right now right with you know transformer models and so on but uh you know it's this black cloud shows up in in the solar system and then you know people try to send radio and then it learns to talk back at you wow you know so anyway we don't have to talk at all about it but it's just it's something worth checking out with that on the alien front with the black claw to me and exactly and the llp front and also just explainability of ai it's fascinating just a very question stephen wolfram looked at this with the movie arrival it's like what would be the common language that we would discover the the reason that's really interesting to me is we have aliens here on earth japanese japanese is the obvious answer japanese yeah that would be the common maybe it would be music actually that's more likely it wouldn't be a language it would be art that they would communicate but you know i i do believe that we have i'm with stephen wolfram on this a little bit that to me computation like programs we write that you know that they're kind of intelligent creatures and i feel like we haven't found the common language to talk with them like our little creations that are artificial are not born with the whatever that innate thing that produces language with us and like coming up with mechanisms for communicating with them uh is um is an effort that feels like it will produce some incredible discoveries you can even think of if you think that math is discovered mathematics in itself is a kind of um oh yeah it's an innate construction of of the world we live in um i think we are you know a part of the way there because pre-1950 right computers who were human beings that would carry out arithmetic right and i think it was ulam um who worked in los alamos at the at the time like towards the end of the second world war wrote something about how you know in the future right computers will not be just arithmetic tool but will be truly an interactive you know thing with which you could do experiments right at the time the notion of doing an experiment not like in the lab with some beakers but uh an experiment on a computer designing an experiment a numerical experiment was a new one that's like you know 70 of what i do is i design com you know i write code terrible code to be uh clear like but you know i write code that creates an experiment which is a which is a simulation so in that sense i think we're beginning to interact with the computer in in a way that you're saying not as just a you know fancy calculator not as just a you know call-in request type of thing but but you know something that can generate uh generate insights that are otherwise completely unattainable right they're unattainable by doing analytical mathematics yeah and there's uh like with the alpha fold two we're now trying we're now starting to crack open biology so being able to simulate at first trivial biological systems and hopefully down the line complex biological systems right my hope is to be able to simulate psychology psychological like sociological systems like humans i've you know um a large part of my work at mit was on autonomous vehicles and the fascinating thing to me was about pedestrians human pedestrians interacting with autonomous vehicles and simulating those systems without murdering humans would be very useful but nevertheless is exceptionally difficult yeah i would say so when is my mustang going to drive itself right i'm not even joking it looks like yeah yeah i it turns out it's much difficult it's much more difficult than we imagined yeah and and i suppose that's the kind of the progress of science is just like you know going to mars it's probably going to turn out to be way more difficult to imagine sending out probes to investigate planet nine at the edge of our solar system might turn out to be way more difficult than we imagined but we do it anyway yeah and we figure it out in the end it's actually more of a great i mean going sending humans to mars is way more complicated than huma sending humans to the moon you'd think just like naively yeah both are in space who cares like if you go there why don't you go there um you know just life support is uh is an extremely expensive thing yeah there's a bunch of extra challenges but i disagree with you i would be one of the early people to go i used to think not yeah i used to think i'd be one of the first maybe million to go once you have a little bit of a society i think i'm i'm upgrading myself to the first like ten thousand yeah that's right from the front of the cabin not completely front but like it would be interesting to die i'm okay with uh death sucks but i kind of like the idea of dying on mars of all the places to die i gotta say in this regard like i don't wanna die on mars i don't no no i would much rather die on earth uh i mean death is is fundamentally boring right like death is a very boring experience but i mean i've never died before so i don't know from first-hand experience as far as you know yeah it could be a reincarnation all those kinds of things so you mean uh where would you die uh if you had to choose oh man um okay so and you know i would definitely you know there's a question of who i'd want to die with you know i'd prefer not to die alone uh but like you know surrounded by family would be uh would be preferable where i think northern new mexico and i'm not even joking like this is not a random place it's just like would that be your favorite place on earth not necessarily like favorite place on earth to to to reside you know indefinitely but it is it is one of the most beautiful places i've i've ever been to uh so you know there's something i don't know there's something attractive about about going you know returning to nature in a beautiful uh place let me ask you about another aspect of your life that is full of beauty music okay you're a musician uh the absurd question i have to ask what is the greatest song of all time oh objectively speaking the greatest song of all time i suppose that could change moment to moment day to day but if you were forced to answer for this particular moment in your life that's something that pops to mind this could be both philosophically this could be technically as a musician like what you enjoy maybe lyrics like for me it's lyrics is very important so absolutely i would probably be my choice would be lyrics based i don't want to answer in terms of just technical uh you know technical prowess i think technical prowess is impressive right it's just like it's impressive what can be done i wouldn't place that into the category of the greatest music ever written some the classical music uh that's that's written is undeniably beautiful but i don't want to consider that category of music either uh just because you know so if i if i have to limit uh the scope of this philosophical discussion uh to you know the kind of music that i listen to you know probably what's my age again by blink 182. it's just you know it's a solid one it's got you know said nobody ever that's a good song i don't know if you're joking no i i i am joking it's a good one but it's it was yeah i mean what's my age you get yeah yeah no i mean it would probably you know songwriting-wise i think the beatles came pretty close to the influential to you i was like the beatles yeah love the beatles i love the beatles uh let it be yesterday yeah like straw i think strawberry feels forever is is one you know what what one of my favorite beetle songs is it's uh you know in my life right that's not it's it's hard to imagine how whatever 24 year old wrote that it is one of the most uh introspective pieces of music ever you know i'm a huge pink floyd fan and so i think you know if you were to you can sort of look at the entire dark side of the moon album and as you know getting pretty close up there to the pinnacle of what you know can be created so you know time's a great song yeah it's a great song just the entirety of just the instruments the lyrics the the the feeling created by a song like pink floyd can create feelings the entire experience i mean you have that with the wall of just uh transporting you into another place songs don't not many songs could do that as as well not many artists can do that as well as pink floyd did there are a lot of bands that you can kind of say oh yeah like if you take blink 182 right if you have no idea like if you are listening to sort of that type of pop punk for the first time it's difficult to differentiate between blink 182 and like some 41 and the thousand of other like lesser known bands that all sounded the whole they all had that sparkling production uh feel they all kind of sounded the same right when with pink floyd it's hard to find another band that you're like well is this one pink floor like you know yeah when you're listening to that what you're listening to that the uniqueness that that's fascinating you know in the calculation of the greatest song in the greatest band of all time you could probably you probably actually quantify this like scientifically is like how unique uh if you play different songs how well are people able to recognize whether it's this band or not and that you know that's probably a huge component to greatness like if the world would miss it if it was gone yes yes so but there's also the human story things like i would say output johnny cash's cover of hurt as one of the greatest songs of all time and that has less to do with the song but your interaction with the interaction with it but also the human the full story of the human so like it's not just if i just heard the song it'd be like okay that but if it it's the full story of it also the video component for that particular song so like that you can't discount the full experience of it absolutely you know i have no confusion about not about being you know anywhere uh you know in in that league but i just like i sometimes think about you know music that is being uh produced today feels oftentimes feels like like kind of clothes like clothes that you buy at like h m and you wear three times before they rip and you throw away so like so much of it is it's not bad it's just kind of forgettable right like the fact that we're talking about pink floyd in 2021 is in itself an interesting uh question why are we talking about pink floyd and it's there's something unforgettable about them and unforgettable about the the art that they created that could be the markets that like so spotify has created this kind of market where the the incentives for creating music that last is much lower because there's so much more music right you just want something that shines bright for a short amount of time makes a lot of money and moves on and i mean the same thing you see with the news and all those kinds of things we're just living in a shorter and shorter shorter like uh time scale in terms of our attention spans and that um nevertheless when we look at the long arc of history of music perhaps there will be some songs from today that will last as much as pink floyd we're just unable to see it yeah just the collected works of nickelback exactly you know you never know you never know justin bieber it could have yeah he could be a contender i've recently started listening to justin bieber just understand what people are talking about and you know i'll just keep my comments to myself on that one it's too good to explain in the words we're not the greatness that is the biebs uh you as a musician so you uh you write your own music you uh play guitar you sing um maybe can you give an overview of the role music is played in your life you're one of the you're a world-class scientist and so it's kind of fascinating to see somebody in your position who's also a great musician and and and uh still loves playing music yeah well i wouldn't call myself a great musician like you know one of the best of all time yeah that's right like we were saying offline confidence is like the most essential thing about that's right exactly it's the confidence and kind of like moodiness right yeah um yeah look i mean music plays an absolutely essential role in in everything i do because i lose if i stop playing for one reason or another say i'm traveling i notably lose creativity in every other aspect of my life right there's something i don't view you know playing music as a separate endeavor from doing science or doing doing whatever it's all it's all part of that same creative thing which is distinct from i don't know uh pressing a button or like you know so it's not a break from science it's a part of your science it's absolutely a it's a part of it's it's i would say you know it's a thing that enables the science right the science would you know suck even more than it does already uh without the music and that means like the creating of the the writing of the music or is it just even playing other people's stuff is it is it all of it yeah it's it's definitely both um yeah and also just you know i love i love to play guitar i love to sing you know my wife tolerates my uh my screeching singing you know and uh even kind of likes it so yeah so people should check out your stuff you have a great voice so i i love your stuff um is there something you're you're super busy is there something you could say about practicing uh for musicians for guitar for you're also in a band so like that whole how you can manage that is there some tricks or some hacks to um being a lifelong musician while being like super busy so i would say you know the way that i optimize um my life is i try to i try to do you know the thing that i'm passionate about in a moment um and put that at the top of the priority list there are moments when you know you just you feel inspired to play music and if you're in the middle of something if you can avoid if that can be put on hold just do it right there are times when you get inspired about something scientific um you know i do my best to drop everything go into that you know mode of that isolated mode and and execute upon that so it's a chaotic you know i think i have a pretty chaotic lifestyle where i'm always doing kind of multiple things and jumping between uh between what i'm doing but at the end of the day it's it's not like um you know those those moments of inspiration are actually kind of rare right like most of the time all of us are just doing kind of uh doing the stuff that get that needs to get done if you do the disservice to yourself of saying oh i'm inspired to you know do this calculation figure it figure this out but i've got to answer email or just like do something something silly um you know that is a um that is nothing more than the service and also like i have some social media presence but i i mostly stay off of you know social media to you know just frankly because like i don't kind of i don't enjoy the mental cycles that it uh yeah it robs you of that the yeah yeah those those precious moments that could be filled with inspiration in your in your other pursuits um but there's something to maybe you and i are different this like i i try to play at least 10 minutes of guitar every day like almost on the technical side like keeping that bass uh of of basic competence going and i mean the same way like writers will get in front of a paper no matter what that kind of thing it just feels like that for my life has been essential to to to the daily ritual of it otherwise days turn into weeks weeks or into months and you haven't played guitar for months no no i i i understand for me i think it's it's been like if we have a gig coming up we'll definitely yeah that's right no like we we will uh we will sharpen up uh definitely you know especially co coming up to again it's like you know we're not trying to make money with this this is like just for the uh for that satisfaction of doing something doing something well right um but overall i would say most i play guitar most days most days and you know when i put kids to sleep i i play guitar you know with them and we like just make up random songs about you know about her a cat or something you know like we just do kind of random stuff but you know music is always involved in that process yeah keeping it fun you have russian roots i sure do were you born in russia i was yeah when did you come here so i came to the us in very the very end of 99 but um so i was like almost 14 years old but along the way we spent six years in japan so like we moved from russia to japan in 94 and then to the us in 99 so like elementary school all interesting school in japan so elementary school in japan yeah so that's interesting that do you still speak russian sure okay okay maybe i'll uh let me ask you in russian um [Music] is is [Laughter] so for people who don't speak russian constantine was uh talking about basically his first in 1992 interaction with capitalism which is pepsi and at first he discovered pepsi and then he discovered coke and he was confused how such uh how such theft could occur like an intellectual property theft and remember pepsi arrived to the soviet union first and there's some there's some complicated story which i don't uh quite understand the details of for a while pepsi like commanded submarines or something yeah pepsi had like a fleet of soviet submarines that did they were sponsoring tanks and this fascinating yeah and i and i remember there's certain things that trickled in like mcdonald's i remember that was a big deal oh yeah certainly for the west absolutely so i mean we went to mcdonald's and we stood on i mean this is this is absurd right from kind of looking at it from today's perspective but we stood in line for like six hours to get into this mcdonald's and i remember inside i was just like a billion people and i'm just taking a bite out of that big mac like wow what was it an incredible experience for you so like what is this taste of the west like uh did you enjoy it i enjoyed the fact that i mean this is like i was getting into the weeds but i really enjoyed the fact that the top of the bun had those seeds you know like and i remember how on the commercials like the big mac would kind of bounce i was like the seeds how did they inject the seeds into the bread like amazing right so i think it was uh artistry yeah you enjoyed the artistry of the culinary exactly it was the you know it was the food art that kind of that is the big mac actually i still don't know the answer to that how do they get the sesame seeds on the better to not know the answer you just wander at the mystery of it all yeah i remember it being exceptionally delicious but i i'm with you i don't know you didn't mention how transformative pepsi was but to me basically sugar-based stuff like like pepsi was uh or a coke i don't remember which one we partook in but that was an incredible experience yeah yeah yeah yeah no absolutely and uh you know i think it's um you know it was an important and and formative uh formative period i sometimes i guess rely on that a little bit uh you know in my daily life because uh i remember like the early 90s were real rough you know like my parents were kind of on the on the bottom of the spectrum in terms of uh you know in terms of financial well-being so um kind of like just when i run into trouble not like you know money trouble just any kind of trouble these days it just kind of is not uh particularly meaningful when you compare it to that that turbulent time of the early 90s and the other thing is i think there's there's like an advantage to to being you know an immigrant which is that you get you go through the mental exercise of changing your environment completely early in your life right you go it's by no means you know pleasant in the moment right but like going into japanese elementary school right like i didn't go to a some like private you know thing i just went to a regular like japanese public elementary school and i was the non-japanese person in my class so just like the learning japanese and just kind of so that's a super humbling experience in many ways was when you like made fun of all that kind of stuff oh yeah being the outsider oh absolutely but you know you kind of do you kind of do that and then you kind of then you just kind of are okay with with stuff you know what i mean and so like doing that again in middle school in the us it was arguably easy because i was like yeah well i've already done this before so i think it kind of prepares you mentally a little bit for for switching up for whatever you know changes that will come up for the rest of your life so i um i wouldn't trade that that experience really for anything it's a huge aspect of who i am and i'm sure you can relate to a lot of this yes is there advice from your life that you can give to young people today high school college you know about their career or maybe about life in general i'm not like a career coach but i like that's right like i'm definitely not a life coach i don't have it all figured out but i think there's a um there's a perpetual cycle of of um you know thinking that there is a um there's kind of like a template for success right maybe there is but i in my experience i haven't seen it right um you know i would say people in high school right so much of their focus is on getting straight a's filling their cv with this and this and this so that it looks impressive right um that that is not i think a good way to optimize your life right do the thing that fills your life with passion do the thing that fills your life with with interest and you know do that perpetually right a straight a student you know is really impressive but also you know somewhat boring right so so i i think you know injection of more of that kind of um interest into into the lives of young people would go a long way in in just both upping their level of happiness and then just kind of ensuring that looking forward they are not suffering from a can you know perpetual condition of oh i have to satisfy these like you know check boxes to to do well right because you can lose yourself in that whole process for the rest of your life but it's nice if it's possible like max tegmark was exceptionally good at this at mit figure out how you can spend a small part of your percent of your efforts that such that your cv looks really impressive yeah absolutely there's no like without a doubt like that's that's a baseline that you need to have um and then so like spend most of your time doing like amazing things you're passionate about but such that it uh uh kind of like planet nine produces objects that uh that feed your cv uh like slowly over time so getting good grades in high school maybe doing extracurricular activities or or in terms of like you know for programmers that's producing code that you can show up on github like leaving traces like um throughout your efforts such that your cv looks impressive to the rest of the world in fact i mean this is somewhat along the lines of what i'm talking about we see like getting like good grades is important but grades are not a tangible like product like you cannot out you know show your a and and have your a live a separate life from you code very much does right um music very much takes on you know provided somebody else listens to it right right provide like takes on a life of its own that's kind of what i mean right doing doing stuff that uh that can then get separated from from you is is exceptionally attractive right it's like a it's like a fun and uh and it's also very impressive to others i think we're moving to a world where grades mean less and less like certifications mean less and less if you look at especially again in the computing fields getting a degree finishing your um currently just getting finishing your degree whether it's bachelor's or master's a phd is less important than the things you've actually put out into the world right right and that's a fascinating kind of that's a that's great that in that sense the meritocracy is in its richest most beautiful form is is starting to win out yeah it's weird because like you know my understanding and i'm not like i don't know the history of science well enough to to speak very confidently about this but you know the advisor of my advisor of my advisor from undergrad uh like didn't have a phd right so i think it was a more common thing back in the day even in uh the academic sector to you know not have you know faraday like faraday didn't know algebra when drew diagrams about you know magnetic fields like his faraday's law was derived entirely from intuition so uh it is interesting to to how the world of academia has evolved into a you got to do this and then get phd then you have to post doc once and twice and maybe thrice and then like you you move on so you know it does i do wonder you know if we're you know if there's a better i think we're heading there but it's a fascinating historical perspective like that we might have just tried this whole thing out uh for a while where we put a lot more emphasis on grades and certificates and um degrees and all those kinds of things i think the difference historically is like we can actually using the internet show off the show off ourselves and our creations better and better and more effectively whether that's code or producing videos or all those kinds of things that's right you can become a certified drone pilot that's true of all the of all the things you want to pick yeah for sure or you could just fly make youtube videos against hundreds of thousands of views with your drone and never getting a certificate um that's probably illegal don't do it what do you think is uh the meaning of this whole thing so you look at planets they they seem to orbit stuff um without without asking the why question and for some reason life emerged on earth such that it led to big brains that can ask the big why question do you think there's an answer to it um i'm not sure what the question is like what meaning of life the meaning of life um it's 42. it's 42. yeah but you know aside from that it's um you know why i think if the question you're asking is like why we do all this right yeah um it's part of the human condition right human beings are fundamentally i feel like non like sort of stochastic and fundamentally interested in in kind of expanding our own understanding of the world around us and creating stuff to enable that understanding so we're like a stochastic fundamentalist so like there's just a bunch of randomness that really doesn't seem like it has a good explanation and yet there's a kind of direction to our being that we just keep wanting to create and to understand that's right i've met people that are you know that claim to be anti-science right um and yet in their anti-science you know discussion like well like if you're so you know scientific then how why don't you explain to me how i don't know this works and like it always there's that fundamental speed of curiosity and interest that is common to to all of us that is absolutely what makes us human right and and i i'm in a privileged position of being able to you know to have that be my my job right i think as uh you know as time evolves forward you know when the kind of economy changes i mean we're already starting to see you know shift towards that type of you know creative uh you know enterprise as being as emerging as taking over a bigger and bigger chunk of the sector it's not yet i think the dominant uh portion of the economy by any account but if we compare this to like you know sometime when the dominant thing you would do would be to you know go to a factory and do the same exact thing right i think you know there's a tide there and things are sort of headed in that direction yeah life's becoming more and more fun i can't wait uh honestly what i can't wait to just chill just just chill terminal point of this chill and wait for those kuiper belt objects to complete one orbit i'm gonna credit you with this idea uh i do hope that we definitively discover uh proof that there is a planet nine out there in the next few years so you can sit back with a cigar a cigarette or vodka or wine and just uh say i told you so that's already happening i'm gonna do that later tonight as i mentioned uh confidence is essential to being a rock star i really appreciate you uh explaining so many fascinating things to me today i really appreciate the work that you do out there and um i really appreciate you talking with me today thank you pleasure thanks for having me on thanks for listening to this conversation with constantine botegan and thank you to squarespace literati onit and and i check them out in the description to support this podcast and now let me leave you with some words from douglas adams in the hitchhiker's guide to the galaxy far out in the uncharted backwaters of the unfashionable end of the western spiral arm of the galaxy lies a small unregarded yellow sun orbiting this at a distance of roughly 92 million miles is an utterly insignificant little blue green planet whose ape descendant life forms are so amazingly primitive that they still think digital watches are a pretty neat idea thank you for listening and hope to see you next time you

Channel: Lex Fridman

Views: 740,196

Keywords: agi, ai, ai podcast, artificial intelligence, artificial intelligence podcast, astronomy, caltech, konstantin batygin, kuiper belt, lex ai, lex fridman, lex jre, lex mit, lex podcast, mit ai, oort cloud, origin of life, oumuamua, planet nine, planets, seventh season, solar system

Id: tm7poMupE8k

Length: 159min 53sec (9593 seconds)

Published: Sun Jul 18 2021

Reddit Comments

[u/KantLockeMeIn]

I have never heard of Konstantin before, but I love this guy! He's got such awareness of what a physics newbie would understand and keep his explanations at that simple level... and with a great sense of humor.

[u/CraftBeerMountaineer]

Just in time for my 2.5 hour flight

[u/valschermjager]

Konstantin: "The rings of Saturn are made up of icicles, like, little ice cubes this big, about a centimeter across."

Lex: "That sounds refreshing."

X-)

[u/Gods-Right_Hand]

Outstanding performance by Lex on this one. Truly a talented guy.

[u/paltipus]

dude. I was listening to this on spotify and I was certain that he was an old wise man ( deep voice, knowledge, etc) but then the reference to blink-182 got my attention. I had to look at the video and bum, surprise surprise.

Excellent conversation!

[u/coniunctio]

We should be searching for garbage [to find aliens]

Great podcast, but minor quibble with this. Wouldn't an advanced, space-faring civilization use a closed loop waste cycle, like a Mr. Fusion?