Konstantin Batygin: Planet 9 and the Edge of Our Solar System

00:00:00.000 | The following is a conversation with Konstantin Batygin,

00:00:03.640 | planetary astrophysicist at Caltech,

00:00:06.480 | interested in, among other things,

00:00:09.000 | the search for the distant, the mysterious Planet Nine

00:00:13.000 | in the outer regions of our solar system.

00:00:15.820 | Quick mention of our sponsors,

00:00:17.480 | Squarespace, Litterati, Onnit, and Ni.

00:00:21.720 | Check them out in the description to support this podcast.

00:00:25.080 | As a side note, let me say that our little sun

00:00:27.740 | is orbited by not just a few planets

00:00:30.080 | in the planetary region,

00:00:31.560 | but trillions of objects in the Kuiper belt

00:00:34.640 | and the Oort cloud that extends over three light years out.

00:00:39.320 | This to me is amazing, since Proxima Centauri,

00:00:42.200 | the closest star to our sun, is only 4.2 light years away,

00:00:46.640 | and all of it is mostly covered in darkness.

00:00:50.140 | When I get a chance to go out swimming in the ocean,

00:00:52.280 | far from the shore, I'm sometimes overcome

00:00:55.000 | by the terrifying and the exciting feeling

00:00:57.980 | of not knowing what's there in the deep darkness.

00:01:01.300 | That's how I feel about the edge of our solar system.

00:01:04.060 | One day, I hope humans will travel there,

00:01:07.060 | or at the very least, AI systems

00:01:09.300 | that carry the flame of human consciousness.

00:01:12.140 | This is the Lux Friedman Podcast,

00:01:14.340 | and here's my conversation with Konstantin Batygin.

00:01:17.680 | What is Planet Nine?

00:01:21.100 | Planet Nine is an object that we believe

00:01:25.200 | lives in the solar system beyond the orbit of Neptune.

00:01:28.160 | It orbits the sun with a period of about 10,000 years,

00:01:33.080 | and is about five Earth masses.

00:01:36.400 | - So that's a hypothesized object.

00:01:38.440 | There's some evidence for this kind of object.

00:01:41.800 | There's a bunch of different explanations.

00:01:44.040 | Can you give an overview of the planets in our solar system?

00:01:48.440 | How many are there?

00:01:50.020 | What do we know and not know about them at a high level?

00:01:53.640 | - All right, that sounds like a good plan.

00:01:55.520 | So look, the solar system basically is comprised

00:01:59.200 | of two parts, the inner and the outer solar system.

00:02:02.080 | The inner solar system has the planets,

00:02:05.360 | Mercury, Venus, Earth, and Mars.

00:02:07.700 | Now, Mercury is about 40% of the orbital separation

00:02:12.700 | where the Earth is.

00:02:15.000 | It's closer to the sun.

00:02:16.240 | Venus is about 70%.

00:02:19.460 | Then Mars is about 160% further away

00:02:24.460 | from the sun than is the Earth.

00:02:27.120 | These planets that we, one of them we occupy,

00:02:31.940 | are pretty small.

00:02:33.540 | They're two leading order,

00:02:36.220 | sort of heavily overgrown asteroids, if you will.

00:02:39.280 | And this becomes evident when you move out

00:02:44.620 | further in the solar system and encounter Jupiter,

00:02:47.300 | which is 316 Earth masses, 10 times the size.

00:02:52.300 | Saturn is another huge one, 90 Earth masses

00:02:57.660 | at about 10 times the separation from the sun

00:03:02.020 | as is the Earth.

00:03:02.860 | And then you have Uranus and Neptune

00:03:04.600 | at 20 and 30, respectively.

00:03:07.420 | For a long time, that is where the kind of massive part

00:03:12.740 | of the solar system ended.

00:03:15.260 | But what we've learned in the last 30 years

00:03:18.620 | is that beyond Neptune, there's this expansive field

00:03:23.420 | of icy debris, a second icy asteroid belt

00:03:26.980 | in the solar system.

00:03:27.820 | A lot of people have heard of the asteroid belt,

00:03:30.980 | which lives between Mars and Jupiter.

00:03:33.860 | That's a pretty common thing that people like to imagine

00:03:38.500 | and draw on lunchboxes and stuff.

00:03:40.820 | But beyond Neptune, there's a much more massive

00:03:43.420 | and much more radially expansive field of debris.

00:03:48.420 | Pluto, by the way, it belongs to that second

00:03:53.340 | icy asteroid belt, which we call the Kuiper belt.

00:03:55.660 | It's just a big object within that population of bodies.

00:03:59.780 | - Pluto the planet.

00:04:01.020 | - Pluto, the dwarf planet, the former planet.

00:04:05.020 | - Why is Pluto not a planet anymore?

00:04:07.940 | - I mean, it's tiny.

00:04:09.260 | We used to-- - Size matters

00:04:10.940 | when it comes to planets.

00:04:11.900 | - 100%, 100%.

00:04:13.620 | It's actually a fascinating story.

00:04:15.780 | When Pluto was discovered in 1930,

00:04:18.820 | the reason it was discovered in the first place

00:04:22.060 | is because astronomers at the time were looking

00:04:24.300 | for a seven-Earth mass planet somewhere beyond Neptune.

00:04:28.780 | It was hypothesized that such an object exists.

00:04:31.940 | When they found something, they interpreted that

00:04:35.100 | as a seven-Earth mass planet and immediately revised

00:04:38.940 | its mass downward because they couldn't resolve

00:04:41.620 | the object with the telescope.

00:04:42.940 | So, it looked like just a point mass star

00:04:46.180 | rather than a physical disk.

00:04:48.060 | They said, well, maybe it's not seven, maybe it's one.

00:04:50.660 | And then, over the next, I guess, 40 years,

00:04:55.060 | Pluto's mass kept getting revised downwards,

00:04:58.260 | downwards, downwards, until it was realized

00:05:01.780 | that it's like 500 times less massive than the Earth.

00:05:05.700 | I mean, Pluto's surface area is almost perfectly equal

00:05:10.700 | to the surface area of Russia, actually.

00:05:14.100 | And, you know, Russia's big, but it's not a planet.

00:05:16.700 | (Lex laughing)

00:05:17.700 | Well, I mean, actually, we can touch more on that.

00:05:20.220 | - That's another discussion.

00:05:22.540 | So, in some sense, earlier in the century,

00:05:25.860 | Pluto represented kind of our ignorance

00:05:28.700 | about the edges of the solar system.

00:05:31.180 | And perhaps, planet nine is the thing

00:05:33.580 | that represents our ignorance about, now,

00:05:36.540 | the modern set of ignorances

00:05:39.500 | about the edges of our solar system.

00:05:41.100 | - That's a good way to put it.

00:05:42.460 | - By the way, just imagining this belt of debris

00:05:46.900 | at the edge of our solar system is incredible.

00:05:50.300 | Can you talk about it a little bit?

00:05:51.620 | What is the Kuiper belt, and what is the Oort cloud?

00:05:56.380 | - Yeah, okay, so look, the simple way to think about it

00:05:59.940 | is that if you imagine, you know, Neptune's orbit

00:06:03.180 | like a circle, right?

00:06:05.060 | Kind of maybe a factor of 1 1/2, 1.3 times bigger,

00:06:10.060 | on a radius of 1.3 times bigger,

00:06:15.220 | you've got a whole collection of icy objects.

00:06:18.260 | Most of these objects are sort of the size of Austin,

00:06:22.900 | you know, maybe a little bit smaller.

00:06:26.060 | If you then zoom out, right,

00:06:30.140 | and explore the orbits of the most long period

00:06:35.220 | Kuiper belt object, these are the things

00:06:36.900 | that have the biggest orbits,

00:06:39.460 | and take the longest time to go around the sun,

00:06:42.300 | then what you find is that beyond a critical orbit size,

00:06:47.900 | beyond a critical orbit period,

00:06:49.540 | which is about 4,000 years,

00:06:51.620 | you start to see weird structure.

00:06:54.020 | Like all the orbits sort of point into one direction.

00:06:58.420 | And all the orbits are kind of tilted in the same way,

00:07:02.900 | by about 20 degrees with respect to the sun.

00:07:05.500 | This is particularly pronounced in orbits

00:07:08.420 | that are not heavily affected by Neptune.

00:07:11.020 | So there you start to see this weird dichotomy

00:07:14.020 | where there are objects which are stable,

00:07:17.140 | which Neptune does not mess with gravitationally,

00:07:21.060 | and unstable objects.

00:07:22.260 | The unstable objects are basically all over the place

00:07:24.580 | because they're being, you know, kicked around by Neptune.

00:07:27.660 | The stable orbits show this remarkable pattern

00:07:31.900 | of clustering.

00:07:33.100 | We, back I guess five years ago,

00:07:36.060 | interpreted this pattern of clustering

00:07:38.180 | as a gravitational one-way sign,

00:07:41.020 | the existence of a planet, a distant planet, right?

00:07:45.300 | Something that is shepherding

00:07:46.580 | and confining these orbits together.

00:07:49.620 | Of course, right, you have to have some skepticism

00:07:54.340 | when you're talking about these things.

00:07:56.900 | You have to ask the question of,

00:07:58.220 | okay, how statistically significant is this clustering?

00:08:01.620 | And there are many authors

00:08:03.020 | that have indeed called that into question.

00:08:06.500 | We have done our own analyses.

00:08:08.220 | And basically, just like with all statistics,

00:08:11.180 | where there's kind of like, you know,

00:08:13.860 | multiple ways to do the exercise,

00:08:18.540 | you can either ask the question of,

00:08:21.020 | if I have a telescope that has, you know,

00:08:24.460 | surveyed this part of the sky,

00:08:26.100 | what are the chances that I would discover this clustering?

00:08:30.020 | That basically tells you that you have zero confidence,

00:08:34.100 | right, like that does not give you

00:08:37.500 | a confident answer one way or another.

00:08:39.780 | Another way to do the statistics,

00:08:41.300 | which is what we prefer to do,

00:08:43.260 | is to say we have a whole night sky

00:08:47.860 | of discoveries in the Kuiper belt, right?

00:08:50.780 | And if we have some object over there,

00:08:54.060 | which has right ascension and declination,

00:08:56.380 | which is a way to say it's there on the sky,

00:08:58.500 | and it has some brightness,

00:09:00.860 | that means somebody looked over there

00:09:02.700 | and discovered an object of,

00:09:04.900 | was able to discover an object

00:09:06.660 | of that brightness or brighter.

00:09:09.180 | Through that analysis,

00:09:10.660 | you can construct a whole map on the sky

00:09:13.060 | of kind of where all of the surveys

00:09:15.180 | that have ever been done have collectively looked.

00:09:18.220 | So if you do the exercise this way,

00:09:20.900 | the false alarm probability of the clustering

00:09:24.980 | on which the Planet Nine hypothesis is built

00:09:27.580 | is about 0.4%.

00:09:29.820 | - Wow, okay, so there's a million questions here.

00:09:31.980 | One, when you say bright objects, why are they bright?

00:09:35.460 | Are we talking about actual objects within the Kuiper belt

00:09:37.860 | or the stuff we see through the Kuiper belt?

00:09:39.620 | - This is the actual stuff we see in the Kuiper belt.

00:09:42.340 | The way you go about discovering Kuiper belt objects,

00:09:45.340 | it's pretty easy.

00:09:46.300 | I mean, it's easy in theory, right, hard in practice.

00:09:50.500 | All you do is you take snapshots of the sky, right,

00:09:54.380 | choose that direction, say,

00:09:55.580 | and take the high exposure snapshot.

00:09:59.060 | Then you wait a night and you do it again,

00:10:01.700 | and then you wait another night and you do it again.

00:10:04.340 | Objects that are just random stars in the galaxy

00:10:07.420 | don't move on the sky,

00:10:09.020 | whereas objects in the solar system will slowly move.

00:10:11.860 | This is no different than if you're driving down the freeway

00:10:16.020 | it looks like trees are going by you faster than the clouds.

00:10:19.700 | Right, this is parallax.

00:10:21.420 | That's it.

00:10:22.260 | It's just they're reflecting light off of the sun

00:10:25.300 | and it's going back and hitting this.

00:10:27.260 | - There's a little bit of a glimmer

00:10:28.860 | from the different objects that you can see

00:10:31.020 | based on the reflection from the sun.

00:10:32.660 | So like there's actual light, it's not darkness.

00:10:36.000 | - That's right, these are just big icicles basically

00:10:39.260 | that are just reflecting sunlight back at you.

00:10:41.620 | It's then easy to understand why it's so hard

00:10:45.140 | to discover them because light has to travel

00:10:47.820 | to something like 40 times the distance

00:10:51.180 | between the earth and the sun and then get reflected back.

00:10:55.420 | - Was that like an hour travel?

00:10:58.020 | - Yeah, that's right, that's something like that.

00:10:59.460 | 'Cause the earth to the sun is eight minutes, I believe.

00:11:03.020 | - Something, you know.

00:11:05.140 | - Yeah, hours.

00:11:06.100 | - Yeah, in that order of magnitude.

00:11:07.900 | So that's interesting.

00:11:09.580 | So you have to account for all of that

00:11:12.180 | and then there's this huge amount of data,

00:11:15.500 | pixels that are coming from the pictures

00:11:18.140 | and you have to integrate all of that together

00:11:21.300 | to paint a sort of like a high estimate

00:11:24.620 | of the different objects.

00:11:25.660 | Can you track them?

00:11:26.620 | Can you be like, that's Bob?

00:11:27.860 | Like can you like?

00:11:28.900 | - Yes, exactly.

00:11:30.260 | In fact, one of them is named Joe Biden.

00:11:33.400 | Like this is not even a joke.

00:11:36.900 | - Is there a Trump one or no?

00:11:38.100 | - No, no.

00:11:38.940 | - Not yet.

00:11:39.780 | - I don't know, I haven't checked for that

00:11:42.780 | but like the way it works is if you discover one,

00:11:47.540 | you right away get a license plate for it.

00:11:50.940 | So like the first four numbers is the first year

00:11:54.380 | that this object has appeared on, you know,

00:11:57.940 | in the data set, if you will.

00:11:59.700 | And then there's like this code that follows it,

00:12:04.380 | which basically tells you where in the sky it is, right?

00:12:08.100 | So one of the really interesting Kuiper belt objects,

00:12:11.580 | which is very much part of the Planet Nine story

00:12:14.260 | is called VP113 because Joe Biden was vice president

00:12:19.260 | at the time, you know, got nicknamed Biden.

00:12:22.700 | - VP113, you said?

00:12:25.140 | - Yeah.

00:12:26.220 | - He got nicknamed Biden, beautiful.

00:12:28.140 | What's the fingerprint for any particular object?

00:12:32.620 | Like how do you know it's the same one?

00:12:34.260 | Or it's just kind of like, yeah, from night to night,

00:12:37.060 | you take a picture, how do you know it's the same object?

00:12:39.540 | - Yeah, so the way you know is it appears

00:12:41.740 | in almost exactly the same part of the sky

00:12:44.620 | except for it moves by.

00:12:46.300 | And this is why actually you need at least three nights

00:12:50.020 | because oftentimes asteroids, which are much closer

00:12:54.820 | to the Earth, like will appear to move only slightly,

00:12:59.820 | but then on the third night will move away.

00:13:03.540 | So that third night is really there to detect acceleration.

00:13:07.300 | Now, the thing that I didn't really realize

00:13:11.460 | until I started observing together with my partner

00:13:15.780 | in crime in all this, Mike Brown,

00:13:17.780 | is just the fact that for the first year

00:13:21.380 | when you make these detections,

00:13:23.200 | the only thing you really know with confidence

00:13:26.060 | is where it is on the night sky and how far away it is.

00:13:29.740 | Okay, that's it.

00:13:30.820 | You don't know anything about the orbit

00:13:32.740 | because over three days, the object just moves so little.

00:13:37.740 | That whole motion on the sky is entirely coming

00:13:41.140 | from motion of the Earth.

00:13:43.180 | So the Earth is kind of the car,

00:13:44.700 | the object is the tree and you see it move.

00:13:47.300 | So then to get some confident information

00:13:50.460 | about what its orbit looks like,

00:13:52.560 | you have to come back a year later

00:13:54.340 | and then measure it again.

00:13:56.340 | - Oh, interesting, so do three nights

00:13:58.020 | then come back a year later and do another three nights

00:14:01.220 | so you get the velocity of the acceleration

00:14:02.980 | from the three nights and then you have the maybe--

00:14:06.180 | - The additional.

00:14:07.020 | - The additional information.

00:14:08.340 | - 'Cause an orbit is basically described by six parameters.

00:14:11.420 | So you at least need six independent points

00:14:13.620 | but in reality you need many more observations

00:14:17.300 | to really pin down the orbit well.

00:14:20.500 | - And from that, you're able to construct

00:14:22.040 | for that one particular object an orbit

00:14:23.920 | and then there's of course, how many objects are there?

00:14:27.700 | - There's like four-ish thousand now.

00:14:31.060 | But in the future, that could be like millions.

00:14:36.060 | - Oh sure, oh sure.

00:14:39.340 | In fact, these things are hard to predict

00:14:41.060 | but there's a new observatory called

00:14:43.260 | the Vera Rubin Observatory which is coming online

00:14:47.060 | maybe next year.

00:14:48.180 | I mean, with COVID, these things are

00:14:50.380 | a little bit more uncertain

00:14:51.580 | but they've actually been making great progress

00:14:54.860 | with construction and so that telescope

00:14:59.340 | is gonna sort of scan the night sky

00:15:03.060 | every day automatically and it's such an efficient survey

00:15:07.020 | that it might increase the census of the distant Kuiper belt

00:15:12.020 | the things that I'm interested in by a factor of 100.

00:15:15.620 | I mean, that would be really cool.

00:15:18.020 | - And yeah, that's an incredible--

00:15:21.140 | - I mean, they might just find planet nine.

00:15:25.560 | I mean, that's--

00:15:27.340 | - Almost like literally pictures, like visually.

00:15:29.740 | - I mean, sure, yeah.

00:15:30.860 | The first detection you make,

00:15:32.180 | all you know is where it is in the sky

00:15:33.860 | and how far away it is.

00:15:35.660 | If something is 500 times away from the sun,

00:15:38.780 | as far away from the sun as is the earth,

00:15:40.820 | you know that's planet nine.

00:15:41.980 | That's when the story concludes.

00:15:43.620 | Then you can study it.

00:15:45.820 | - Now you can study it, yeah.

00:15:46.940 | By the way, I'm gonna use that as like,

00:15:49.500 | I don't know, a pickup line or a dating strategy.

00:15:51.620 | Like see the person for three days

00:15:54.060 | and then don't see them at all

00:15:55.140 | and then see them again in a year

00:15:57.620 | to determine the orbit.

00:15:58.900 | And over time, you figure out if sort of

00:16:02.380 | from a cosmic perspective, this whole thing works out.

00:16:07.820 | - I have no dating advice to give.

00:16:09.580 | - I was gonna use this as a metaphor

00:16:11.780 | to somehow map it onto the human condition.

00:16:15.940 | Okay, you mentioned the Kuiper belt.

00:16:17.540 | What's the Oort cloud?

00:16:18.860 | If you look at the Neptune orbit as one,

00:16:22.980 | then the Kuiper belt is like 1.3 out there.

00:16:25.860 | And then we get farther and farther into the darkness.

00:16:28.340 | What's the Oort cloud?

00:16:29.180 | - So, okay, you've got the main Kuiper belt

00:16:31.580 | which is about say 1.3, 1.5.

00:16:34.860 | Then you have something called the scattered disk,

00:16:39.100 | which is kind of an extension of the Kuiper belt.

00:16:41.620 | It's a bunch of these long, very elliptical orbits

00:16:46.220 | that hug the orbit of Neptune but come out very far.

00:16:50.140 | So, the scattered disk with the current senses,

00:16:55.140 | like some of the longest orbits we know of,

00:16:59.660 | have a semi-major axis, so half the orbit length,

00:17:06.260 | roughly speaking, of about 1,000.

00:17:08.900 | 1,000 times the distance between the Earth and the Sun.

00:17:12.140 | Now, if you keep moving out, okay,

00:17:15.300 | eventually, once you're at sort of 10,000

00:17:19.340 | to 100,000 roughly, that's where the Oort cloud is.

00:17:23.460 | Now, the Oort cloud is a distinct population of icy bodies

00:17:28.460 | and is distinct from the Kuiper belt.

00:17:30.340 | In fact, it's so expansive that it ends roughly halfway

00:17:35.300 | between us and the next star.

00:17:37.940 | Its edge is just dictated by

00:17:42.540 | to what extent does the solar gravity reach.

00:17:45.020 | - Solar gravity reaches that far?

00:17:47.060 | - Yeah.

00:17:47.900 | - It has to, wow.

00:17:49.940 | - Yeah.

00:17:50.780 | - Imagining this is a little bit overwhelming.

00:17:54.980 | So, there's like a giant, like vast, icy rock thingy.

00:17:59.980 | - It's like a sphere.

00:18:04.380 | It's like, you know, it's almost spherical structure

00:18:07.780 | that encircles the Sun.

00:18:11.620 | And all the long period comets come from the Oort cloud.

00:18:16.340 | They come, the way that they appear,

00:18:18.660 | I mean, for already, I don't know, hundreds of years,

00:18:21.620 | we've been detecting occasionally,

00:18:23.780 | like a comet will come in

00:18:26.260 | and it seemingly comes out of nowhere.

00:18:29.580 | The reason these long period comets appear

00:18:32.700 | that on very, very long timescales, right?

00:18:36.180 | These Oort cloud objects that are sitting, you know,

00:18:39.020 | 30,000 times as far away from the Sun as is the Earth

00:18:43.420 | actually interact with the gravity of the galaxy,

00:18:45.740 | the tide, effectively the tide that the galaxy

00:18:49.380 | exerts upon them and their orbits slowly change

00:18:51.980 | and they elongate to the point where once they,

00:18:56.340 | their closest approach to the Sun

00:18:58.940 | starts to reach a critical distance

00:19:01.300 | where ice starts to sublimate,

00:19:03.260 | then we discover them as comets

00:19:05.860 | because then the ice comes off of them.

00:19:08.220 | They look beautiful in the night sky, et cetera,

00:19:10.940 | but they're all coming from, you know,

00:19:13.020 | really, really far away.

00:19:14.380 | - So is there, are any of them coming our way from collisions

00:19:19.140 | like how many collisions are there

00:19:20.660 | or is there a bunch of space for them to move around?

00:19:22.820 | - Yeah, there's zero, it's completely collisionless.

00:19:25.660 | Out there, the physical radii of objects are so small

00:19:30.620 | compared to the distance between them, right?

00:19:32.940 | It's just, it is truly a collisionless environment.

00:19:37.940 | I don't know, I think that probably in the age

00:19:42.940 | of the solar system, there have literally been

00:19:46.060 | zero collisions in the Oort cloud.

00:19:48.180 | - Wow, when you like draw a picture of the solar system,

00:19:52.540 | everything's really close together,

00:19:53.820 | so everything I guess here is spaced far apart.

00:19:57.580 | Do rogue planets like fly in every once in a while

00:20:00.540 | and join, not rogue planets, but rogue objects

00:20:03.020 | from out there?

00:20:04.020 | - Oh sure, oh sure, yeah.

00:20:05.500 | - Join the party?

00:20:06.380 | - Yeah, absolutely.

00:20:07.600 | We've seen a couple of them in the last three or so years,

00:20:12.440 | maybe four years now.

00:20:13.700 | The first one was the one called Oumuamua,

00:20:20.080 | it's been all over the news.

00:20:21.980 | The second one was Comet Borisov,

00:20:25.340 | discovered by a guy named Borisov.

00:20:28.060 | Yeah, so the way you know they're coming from elsewhere

00:20:33.140 | is unlike solar system objects,

00:20:35.860 | which travel on elliptical paths around the sun,

00:20:38.540 | these guys travel on hyperbolic paths.

00:20:41.960 | So they come in, say hello, and then they're gone.

00:20:45.080 | And the fact that they exist is totally not surprising.

00:20:50.080 | The Neptune is constantly ejecting Kuiper belt objects

00:20:57.720 | into interstellar space.

00:20:59.900 | Our solar system itself is sort of leaking icy debris

00:21:04.780 | and ejecting it.

00:21:05.620 | So presumably every planetary systems around other stars

00:21:09.980 | do exactly the same thing.

00:21:11.780 | - Let me ask you about the millions of objects

00:21:15.160 | that are part of the Kuiper belt

00:21:16.620 | and part of the Oort cloud.

00:21:17.880 | Do you think some of them have primitive life?

00:21:21.140 | It kind of makes you sad.

00:21:22.880 | If there's primitive life there

00:21:24.260 | and they're just kind of lonely out there in space.

00:21:26.860 | How many of them do you think have life, bacterial life?

00:21:29.780 | - Probably a negligible amount.

00:21:31.580 | Zero with a plus on top.

00:21:35.020 | - Zero plus plus.

00:21:36.600 | - Yeah.

00:21:37.440 | (laughing)

00:21:41.020 | So if you and I took a little trip

00:21:43.980 | to the interstellar medium,

00:21:45.340 | I think we would develop cancer and die real fast.

00:21:49.180 | - That's rough.

00:21:50.300 | - Yeah, it's a pretty hostile radiation environment.

00:21:53.820 | You don't actually have to go to the interstellar medium.

00:21:56.700 | You just have to leave the Earth's magnetic field too.

00:22:00.140 | And then you're not doing so well suddenly.

00:22:03.340 | So this idea of life kind of traveling between places

00:22:08.980 | it's not entirely implausible,

00:22:11.780 | but you really have to twist, I think, a lot of parameters.

00:22:15.900 | One of the problems we have

00:22:17.420 | is we don't actually know how life originates.

00:22:19.980 | So it's kind of a second order question of survival

00:22:24.980 | in the interstellar medium and how resilient it is

00:22:27.660 | because we think you require water,

00:22:32.660 | and that's certainly the case for the Earth.

00:22:36.020 | But we really don't know for sure.

00:22:40.020 | That said, I will argue that the question of

00:22:43.700 | are there aliens out there is a very boring question

00:22:47.820 | because the answer is of course there are.

00:22:50.100 | - Right.

00:22:50.940 | - I mean, we know that there are planets

00:22:55.460 | around almost every star.

00:22:57.620 | Of course there are other life forms.

00:23:01.860 | Life is not a planet.

00:23:03.860 | Of course there are other life forms.

00:23:05.180 | Life is not some specific thing that happened on the Earth

00:23:09.620 | and that's it, right?

00:23:11.100 | That's a statistical impossibility.

00:23:13.000 | - Yeah, but the difficult question is

00:23:16.860 | before even the fact that we don't know

00:23:18.900 | how life originates,

00:23:20.700 | I don't think we even know what life is, like,

00:23:22.940 | definitionally.

00:23:24.060 | - Yeah.

00:23:24.900 | - Like, formalizing a kind of picture of,

00:23:26.780 | in terms of the mechanism we would use

00:23:29.580 | to search for life out there,

00:23:32.540 | or even when we're on a planet,

00:23:33.980 | to say, is this life?

00:23:36.420 | Is this rock that just moved

00:23:38.420 | from where it was yesterday life?

00:23:40.760 | Or maybe not even a rock, something else.

00:23:43.020 | - I gotta tell you, I wanna know what life is.

00:23:46.140 | Okay?

00:23:46.960 | And I want you to show me.

00:23:48.460 | (laughing)

00:23:50.720 | - I think there's a song to basically accompany

00:23:53.860 | every single thing we talk about today.

00:23:56.980 | And probably half of them are love songs.

00:24:00.180 | And somehow we'll integrate George Michael

00:24:01.800 | into the whole thing.

00:24:02.640 | Okay, so your intuition is there's life everywhere

00:24:05.800 | in our universe.

00:24:07.940 | Do you think there's intelligent life out there?

00:24:10.540 | - I think it's entirely plausible.

00:24:11.980 | I mean, it's entirely plausible.

00:24:14.840 | I think there's intelligent life on Earth.

00:24:19.480 | And--

00:24:21.660 | - So yeah, taking that, like, say,

00:24:23.260 | whatever this thing we got on Earth,

00:24:25.940 | whether it's dolphins or humans,

00:24:27.780 | say that's intelligent.

00:24:29.540 | - Definitely dolphins.

00:24:31.020 | - I mean, have you seen the dolphins?

00:24:33.360 | - Well, they do some cruel stuff to each other.

00:24:36.940 | So if cruelty is a definition of intelligence,

00:24:41.340 | they're pretty good.

00:24:42.500 | And then humans are pretty good in that regard.

00:24:44.900 | Then there's like, pigs are very intelligent.

00:24:48.900 | I got actually a chance to hang out with pigs recently.

00:24:51.740 | And they're, aside from the fact

00:24:54.140 | they were trying to eat me,

00:24:56.200 | they're very, they love food.

00:25:00.400 | They love food, but there's an intelligence

00:25:01.940 | to their eyes that was kind of, like, haunts me

00:25:05.820 | because I also love to eat meat.

00:25:08.540 | And then to meet the thing I later ate,

00:25:12.740 | and it was very intelligent and almost charismatic

00:25:15.820 | with the way it was expressing himself, herself, itself,

00:25:19.620 | was quite incredible.

00:25:21.340 | So all that to say is if we have intelligent life

00:25:26.100 | here on Earth, if we take dolphins, pigs, humans,

00:25:29.540 | from the perspective of planetary science,

00:25:31.740 | how unique is Earth?

00:25:33.700 | - Okay, so Earth is not a common outcome

00:25:36.860 | of the planet formation process.

00:25:39.320 | It's probably something on the order

00:25:45.440 | of maybe a 1% effect.

00:25:48.180 | And by Earth, I mean not just an Earth-mass planet, okay?

00:25:53.180 | I mean the architecture of the solar system

00:25:56.980 | that allows the Earth to exist

00:25:59.420 | in its kind of very temperate way.

00:26:02.820 | One thing to understand, and this is pretty crucial,

00:26:10.620 | is that the Earth itself formed well after the gas disk

00:26:15.620 | that formed the giant planets had already dissipated.

00:26:22.180 | You see, stars start out with the star,

00:26:26.740 | and then a disk of gas and dust that encircles it, okay?

00:26:30.380 | From this disk of gas and dust, big planets can emerge.

00:26:35.380 | And we have, over the last two, three decades,

00:26:40.260 | discovered thousands of extrasolar planets,

00:26:43.500 | as in orbit of other stars.

00:26:44.980 | What we see is that many of them

00:26:47.980 | have these expansive hydrogen-helium atmospheres.

00:26:52.940 | The fact that the Earth doesn't is deeply connected

00:26:57.940 | to the fact that Earth took about 100 million years to form.

00:27:01.480 | So we missed that train, so to speak,

00:27:04.740 | to get that hydrogen-helium atmosphere.

00:27:07.860 | That's why, actually, we can see the sky, right?

00:27:10.420 | That's why the sky is, well, at least in most places,

00:27:14.920 | that's why the atmosphere is not completely opaque.

00:27:20.420 | With that kind of thinking in mind,

00:27:23.540 | I would argue that we're getting

00:27:26.580 | the kind of emergent pictures

00:27:27.980 | that the Earth is not everywhere, right?

00:27:32.980 | There's sort of the sci-fi view of things

00:27:35.420 | where we go to some other star

00:27:36.960 | and we just land on random planets

00:27:38.700 | and they're all Earth-like.

00:27:40.180 | That's totally not true.

00:27:41.740 | But even a low-probability event,

00:27:45.720 | even if you imagine that Earth is a one in a million

00:27:49.180 | or one in 10 million occurrence,

00:27:53.940 | there are 10 to the 12 stars in the galaxy.

00:27:57.180 | So you always win by--

00:28:01.660 | - Large numbers. - That's right, by supply.

00:28:03.420 | - They save you.

00:28:04.260 | Well, you've hypothesized that our solar system

00:28:07.260 | once possessed a population of short-period planets

00:28:10.880 | that were destroyed by the evil Jupiter

00:28:13.180 | migrating through the solar nebula.

00:28:17.540 | Can you explain?

00:28:18.540 | - If I was to say what was the key outcome

00:28:21.740 | of searches for extrasolar planets,

00:28:24.060 | it is that most stars are encircled by short-period planets

00:28:28.820 | that are a few Earth masses,

00:28:33.100 | so a few times bigger than the Earth,

00:28:34.940 | and have orbital periods

00:28:37.100 | that kind of range from days to weeks.

00:28:40.640 | Now, if you go and ask the solar system

00:28:45.060 | what's in our region, in that region,

00:28:48.580 | it's completely empty.

00:28:49.780 | It's astonishingly hollow.

00:28:53.580 | And I think from the Sun is not some special star

00:28:58.580 | that decided that it was going to form the solar system.

00:29:03.140 | So I think the natural thing to assume

00:29:06.260 | is that the same processes of planet formation

00:29:09.740 | that occurred everywhere else

00:29:11.340 | also occurred in the solar system,

00:29:14.780 | following this logic.

00:29:15.700 | It's not implausible to imagine

00:29:17.900 | that the solar system once possessed

00:29:20.100 | a system of intra-Mercurian,

00:29:24.260 | like compact system of planets.

00:29:28.460 | So then we asked ourselves,

00:29:30.380 | would such a system survive to this day?

00:29:33.340 | And the answer is no.

00:29:35.380 | At least our calculations suggest it's highly unlikely

00:29:38.960 | because of the formation of Jupiter,

00:29:41.620 | and Jupiter's primordial kind of wandering

00:29:43.740 | through the solar system

00:29:44.820 | would have sent this collisional field of debris

00:29:48.180 | that would have pushed that system of planets onto the Sun.

00:29:51.580 | - So was Jupiter, this primordial wandering,

00:29:54.300 | what did Jupiter look like?

00:29:56.500 | Like why was it wandering?

00:29:58.020 | It didn't have the orbit it has today?

00:30:00.640 | - We're pretty certain that giant planets like Jupiter,

00:30:03.020 | when they form, they migrate.

00:30:05.020 | The reason they migrate is, you know,

00:30:07.980 | on a detailed level, perhaps difficult to explain,

00:30:11.540 | but just in a qualitative sense,

00:30:14.620 | they form in this fluid disk of gas and dust.

00:30:19.340 | So it's kind of like,

00:30:20.660 | then if I plop down a raft somewhere in the ocean,

00:30:24.500 | will it stay where you plop it down

00:30:27.940 | or will it kind of get carried around?

00:30:30.300 | It's not really a good analogy

00:30:32.100 | because it's not like Jupiter is being advected

00:30:34.660 | by the currents of gas and dust,

00:30:37.220 | but the way it migrates is it carves out a hole in the disk

00:30:42.220 | and then by interacting with the disk gravitationally,

00:30:47.880 | it can change its orbit.

00:30:49.940 | The fact that the solar system has both Jupiter and Saturn,

00:30:53.380 | here complicates things a lot,

00:30:55.700 | because you have to solve the problem

00:30:59.000 | of the evolution of the gas disk,

00:31:01.140 | the evolution of Jupiter's orbit in the gas disk,

00:31:03.540 | plus evolution of Saturn's and their mutual interaction.

00:31:07.460 | The common outcome of solving that problem though,

00:31:13.180 | is pretty easy to explain.

00:31:15.460 | Jupiter forms, its orbit shrinks,

00:31:18.100 | and then once Saturn forms,

00:31:20.120 | its orbit catches up basically to the orbit of Jupiter

00:31:23.200 | and then both come out.

00:31:24.780 | So there's this inward-outward pattern

00:31:26.760 | of Jupiter's early motion that happens

00:31:29.460 | sort of within the last million years

00:31:32.740 | of the lifetime of the solar system's primordial disk.

00:31:36.720 | So while this is happening,

00:31:39.180 | if our calculations are correct, which I think they are,

00:31:43.940 | you can destroy this inner system

00:31:47.580 | of few Earth-mass planets.

00:31:51.780 | And then in the aftermath of all this violence,

00:31:55.540 | you form the terrestrial planets.

00:31:58.400 | - Where would they come from in that case?

00:32:00.380 | So Jupiter clears out the space,

00:32:02.820 | and then there's a few terrestrial planets that come in,

00:32:06.100 | and those come in from the disk somewhere,

00:32:10.020 | like one of the larger objects?

00:32:12.260 | - What actually happens in these calculations,

00:32:13.940 | you leave behind a rather mass-depleted remnant disk,

00:32:18.940 | only a couple Earth-masses.

00:32:23.340 | So then from that remnant population,

00:32:28.500 | annulus of material over 100 million years,

00:32:32.900 | by just collisions, you grow the Earth

00:32:35.540 | and the moon and everything else.

00:32:37.220 | - You said amulus?

00:32:38.540 | - Annulus.

00:32:39.380 | - Annulus.

00:32:40.200 | - Annulus, yeah.

00:32:41.040 | - That's a beautiful word.

00:32:41.880 | What does that mean?

00:32:42.700 | - Well, it's like a disk that's kind of thin.

00:32:45.140 | It's like a, yeah, it's something that is, you know,

00:32:48.740 | a disk that's so thin it's almost flirting

00:32:51.180 | with being a ring.

00:32:52.100 | - Like, I was gonna say this,

00:32:54.940 | reminds me of "Lord of the Rings."

00:32:56.940 | The word just feels like it belongs in a Tolkien novel.

00:32:59.620 | Okay, so that's incredible.

00:33:02.180 | And so that, in your senses, you said like 1%,

00:33:05.260 | that's a rare, the way Jupiter and Saturn danced

00:33:09.940 | and cleared out the short period debris,

00:33:14.940 | and then changed the gravitational landscape,

00:33:18.580 | that's a pretty rare thing too.

00:33:20.220 | - It's rare, and moreover, you don't even have to go

00:33:23.500 | to our calculations.

00:33:24.800 | You can just ask the night sky,

00:33:27.180 | how many stars have Jupiter and Saturn analogs?

00:33:31.060 | And the answer is Jupiter and Saturn analogs

00:33:33.540 | are found around only 10% of sun-like stars.

00:33:36.420 | So they themselves, like you kind of have to score

00:33:38.780 | an A minus or better on the test to,

00:33:42.060 | on the planet formation test to become

00:33:44.900 | a solar system analog, even in that basic sense.

00:33:48.620 | And moreover, lower mass stars,

00:33:52.420 | which are very numerous in the galaxy,

00:33:56.400 | so-called M dwarfs, think like 0% of them,

00:34:00.320 | well, maybe like a negligible fraction of them

00:34:03.360 | have giant planets.

00:34:04.960 | Giant planets are a rare outcome of planet formation.

00:34:09.960 | One of the really big problems that remain unanswered

00:34:14.160 | is why, we don't actually understand why they're so rare.

00:34:18.320 | - How hard is it to simulate all of the things

00:34:21.200 | we've been talking about, each of the things

00:34:22.760 | we've been talking about, and maybe one day,

00:34:25.620 | all of the things we've been talking about and beyond.

00:34:28.500 | Meaning, like from the initial primordial solar system,

00:34:33.500 | you know, a bunch of disks with, I don't know,

00:34:37.380 | billions, trillions of objects in them,

00:34:39.880 | like simulate that such that you eventually get a Jupiter

00:34:44.220 | and a Saturn, and then eventually you get the Jupiter

00:34:47.100 | and the Saturn that clear out a disk,

00:34:48.420 | change the gravitational landscape, then Earth pops up.

00:34:50.940 | Like that whole thing, and then be able to do that

00:34:54.340 | for every other system, every other star in the galaxy,

00:34:59.340 | and then be able to do that for other galaxies as well.

00:35:04.260 | - Yeah, so look--

00:35:07.260 | - Maybe start from the smallest simulation,

00:35:09.340 | like what is actually being done today.

00:35:11.380 | I mean, even the smallest simulation

00:35:12.860 | is probably super, super difficult.

00:35:14.300 | Even just like one object in the Kuiper belt

00:35:16.460 | is probably super difficult to simulate.

00:35:18.340 | - I mean, I think it's super easy.

00:35:20.380 | I mean, like it's just not that hard.

00:35:23.460 | But let's ask the most kind of basic problem.

00:35:28.460 | Okay, so the problem of having a star

00:35:32.060 | and something in orbit of it,

00:35:34.880 | that you don't need a simulation for.

00:35:36.300 | Like you can just write that down on a piece of paper.

00:35:39.300 | - There's gravity, like yeah, I guess it's important

00:35:42.620 | to try to, you know, one way to simulate objects

00:35:47.760 | in our solar system is to build the universe from scratch.

00:35:50.540 | - Okay, we'll get to building the universe

00:35:52.600 | from scratch in a sec.

00:35:54.040 | But let me just kind of go through the hierarchy

00:35:56.320 | of what we do.

00:35:58.480 | - Two objects.

00:35:59.320 | - Two objects, analytically solvable,

00:36:02.240 | like we can figure it out very easily.

00:36:04.560 | If you just, I don't think you, yeah,

00:36:06.920 | you don't need to know calculus.

00:36:08.640 | It helps to know calculus,

00:36:09.800 | but you don't necessarily need to know calculus.

00:36:12.200 | Three objects that are gravitationally interacting,

00:36:16.840 | the solution is chaotic.

00:36:18.360 | Doesn't matter how many simulations you do,

00:36:21.840 | the answer loses meaning after some time.

00:36:25.280 | - I feel like that is a metaphor for dating as well,

00:36:27.640 | but go on.

00:36:28.480 | (laughing)

00:36:30.200 | - Now look, yeah, so the fact that you go

00:36:34.840 | from analytically solvable to unpredictable,

00:36:39.000 | you know, when your simulation goes from two bodies

00:36:43.280 | to three bodies, should immediately tell you

00:36:46.240 | that the exercise of trying to engineer a calculation

00:36:51.240 | where you form the entire solar system from scratch

00:36:55.280 | and hope to have some predictive answer is a futile one.

00:36:59.280 | We will never succeed at such a simulation.

00:37:03.600 | - I feel like, sorry, just to clarify,

00:37:04.640 | you mean like explicitly having a clear equation

00:37:07.640 | that generalizes the whole process enough

00:37:10.960 | to be able to make a prediction?

00:37:12.400 | Or do you mean actually like literally simulating

00:37:15.180 | the objects is a hopeless pursuit

00:37:17.040 | once it increases beyond three?

00:37:18.680 | - The simulating them is not a hopeless pursuit,

00:37:20.680 | but the outcome becomes a statistical one.

00:37:25.680 | What's actually quite interesting is I think we have

00:37:29.720 | all the equations figured out, right?

00:37:33.520 | Like, you know, in order to really understand this,

00:37:36.840 | the formation of the solar system,

00:37:38.920 | it suffices to know gravity and magnetohydrodynamics.

00:37:43.840 | I mean, like the combination of Maxwell's equations

00:37:47.340 | and, you know, Navier-Stokes equations for the fluids.

00:37:50.460 | You need to know quantum mechanics

00:37:51.860 | to understand opacities and so on.

00:37:54.680 | But we have those equations in hand.

00:37:59.060 | It's not that we don't have that understanding,

00:38:01.220 | it's that putting it all together

00:38:03.180 | is A, very, very difficult,

00:38:06.060 | and B, if you were to run the same evolution twice,

00:38:11.740 | changing the initial conditions

00:38:14.600 | by some infinitesimal amount,

00:38:16.600 | some minor change in your calculation to start with,

00:38:20.580 | you would get a different answer.

00:38:23.040 | This is one, this is part of the reason

00:38:26.840 | why planetary systems are so diverse.

00:38:29.620 | You don't have like a very predictive path

00:38:34.000 | for you start with a disk of this mass

00:38:36.760 | and it's around this star,

00:38:39.160 | therefore you're gonna form the solar system, right?

00:38:42.340 | You start with this and therefore you will form

00:38:44.580 | this huge set of outcomes and some percentage of it

00:38:49.300 | will resemble the solar system.

00:38:50.860 | - You mentioned quantum mechanics

00:38:52.180 | and we're talking about cosmic scale objects.

00:38:57.180 | You've talked about that the evolution

00:38:59.440 | of astrophysical disks can be modeled

00:39:01.520 | with Schrodinger's equation.

00:39:03.700 | - I sure did.

00:39:04.600 | - Why?

00:39:06.860 | (laughing)

00:39:07.700 | How does quantum mechanics become relevant

00:39:11.580 | when you consider the evolution of objects

00:39:14.580 | in the solar system?

00:39:15.420 | - Yeah, well, let me take a step back and just say it.

00:39:19.140 | I remember being utterly confused by quantum mechanics

00:39:24.140 | when I first learned it.

00:39:26.500 | And the Schrodinger equation,

00:39:28.700 | which is kind of the parent equation of that whole field,

00:39:33.380 | seems to come out of nowhere, right?

00:39:35.260 | The way that I was sort of explaining it,

00:39:38.980 | I remember asking my professor,

00:39:41.100 | "But where does it come from?"

00:39:42.820 | He's like, "Well, just don't worry about it

00:39:45.860 | "and just calculate the hydrogen energy levels."

00:39:50.180 | So it's like I could do all the problems,

00:39:52.340 | I just did not have any intuition

00:39:54.460 | for where this parent super important equation came from.

00:39:59.460 | Now down the line, I remember I was preparing

00:40:02.060 | for my own lecture and I was trying to understand

00:40:05.500 | how waves travel in self-gravitating disks.

00:40:09.820 | So, again, there's a very broad theory

00:40:14.820 | that's already developed,

00:40:16.740 | but I was looking for some simpler way to explain it,

00:40:19.900 | really, for the purposes of teaching class.

00:40:22.660 | And so I thought, "Okay, what if I just imagine a disk

00:40:26.820 | "as an infinite number of concentric circles, right,

00:40:31.340 | "that interact with each other gravitationally?"

00:40:34.980 | That's a problem in some sense that I can solve

00:40:40.380 | using methods from like the late 1700s, right?

00:40:44.580 | So I can write down Hamiltonian,

00:40:47.180 | well, I can write down the energy function, basically,

00:40:49.420 | of their interactions.

00:40:51.500 | And what I found is that when you take the continuum limit,

00:40:56.500 | when you go from discrete circles

00:41:00.220 | that are talking to each other gravitationally

00:41:02.020 | to a continuum disk,

00:41:04.580 | suddenly this gravitational interaction among them,

00:41:09.580 | right, the governing equation

00:41:11.740 | becomes the Schrodinger equation.

00:41:13.900 | - Yeah. - I had to think about that

00:41:15.260 | for a little bit.

00:41:16.100 | - Did you just unify quantum mechanics and gravity?

00:41:19.660 | - No, this is not the same thing as like,

00:41:22.380 | you know, fusing relativity and quantum mechanics.

00:41:25.540 | But it did get me thinking a little bit.

00:41:29.460 | So the fact that waves in astrophysical disks

00:41:33.820 | behave just like wave functions of particles

00:41:37.980 | is kind of like an interesting analogy

00:41:39.860 | because for me it's easier to imagine waves

00:41:43.060 | traveling through astrophysical disks

00:41:46.420 | or really just sheets of paper.

00:41:48.260 | And the reason this is, that analogy exists

00:41:53.100 | is because there's actually nothing quantum

00:41:55.460 | about the Schrodinger equation.

00:41:57.220 | The Schrodinger equation is just a wave equation

00:42:01.500 | and all of the interpretation that comes from it is quantum,

00:42:06.500 | but the equation itself is not a quantum being.

00:42:11.260 | - So you can use it to model waves.

00:42:13.460 | It's waves, it's not turtles, it's waves all the way down.

00:42:16.100 | You can pick which level you pick the wave at.

00:42:18.860 | And so it could be at the solar system level

00:42:20.820 | that you can use that. - Right.

00:42:22.060 | And also it actually provides

00:42:23.420 | a pretty neat calculational tool

00:42:25.380 | because it's difficult.

00:42:28.780 | So we just talked about simulations,

00:42:30.540 | but it's difficult to simulate

00:42:32.220 | the behavior of astrophysical disks

00:42:34.820 | on timescales that are in between a few orbits

00:42:39.820 | and their entire evolution.

00:42:42.260 | So it's over a timescale of a few orbits,

00:42:45.220 | you do a hydrodynamic simulation, right?

00:42:49.180 | You do, basically that's something that you can do

00:42:53.300 | on a modern computer on a timescale of say a week.

00:42:56.420 | When it comes to their evolution over their entire lifetime,

00:43:00.100 | you don't hope to resolve the orbits.

00:43:02.000 | You just kind of hope to understand

00:43:03.420 | how the system behaves in between, right?

00:43:07.100 | To get access to that, as it turns out,

00:43:09.380 | it's pretty cute.

00:43:11.460 | You can use the Schrodinger equation

00:43:13.960 | to get the answer rapidly.

00:43:15.820 | So it's a calculational tool.

00:43:17.420 | - That's fascinating.

00:43:18.240 | By the way, the astrophysical disks,

00:43:19.980 | how broad is this definition?

00:43:23.660 | - Okay, so astrophysical disks span a huge amount of ranges.

00:43:28.660 | They start maybe at the smallest scale.

00:43:33.700 | They start with actually Kuiper belt objects.

00:43:35.700 | Some Kuiper belt objects have rings.

00:43:37.720 | So that's maybe the smallest example

00:43:40.980 | of an astrophysical disk.

00:43:42.220 | You've got this little potato-shaped asteroid,

00:43:45.740 | which is sort of the size of LA or something,

00:43:49.100 | and around it are some rings of icy matter.

00:43:52.940 | That object is a small astrophysical disk.

00:43:56.940 | Then you have Saturn, the rings of Saturn.

00:43:59.800 | You have the next set of scale.

00:44:01.540 | You have the solar system itself when it was forming.

00:44:03.860 | You have a disk.

00:44:04.700 | Then you have black hole disks.

00:44:07.500 | You have galaxies.

00:44:09.500 | Disks are super common in the universe.

00:44:12.180 | The reason is that stuff rotates.

00:44:15.480 | Right, I mean, that's-- - Gravity works.

00:44:16.900 | - Yeah.

00:44:17.740 | - And those rings could be the material

00:44:20.300 | that composes those rings.

00:44:23.380 | It could be gas.

00:44:25.020 | It could be solid.

00:44:26.060 | It could be anything.

00:44:27.060 | - That's right.

00:44:27.880 | So the disk that made, from which the planets emerged,

00:44:32.880 | was predominantly hydrogen and helium gas.

00:44:36.000 | On the other hand, the rings of Saturn

00:44:38.380 | are made up of icicle, little like ice cubes this big,

00:44:43.380 | about a centimeter across.

00:44:46.820 | - That sounds refreshing.

00:44:47.900 | So that's incredible, hydrogen and helium gas.

00:44:51.020 | So in the beginning, it was just hydrogen and helium

00:44:54.980 | around the sun.

00:44:55.860 | How does that lead to the first formations of solid objects

00:45:00.100 | in terms of simulation?

00:45:01.860 | - Okay, here's the story.

00:45:03.580 | So you're like, have you ever been to the desert?

00:45:07.740 | - Yes, I've been to the Death Valley.

00:45:09.340 | And actually, it was terrifying, just a total tangent.

00:45:12.200 | I'm distracting you.

00:45:13.460 | But I was driving through it, and I was really surprised

00:45:16.680 | because it was, at first, hot.

00:45:19.180 | And then, as it was getting into the evening,

00:45:21.580 | there's this huge thunderstorm.

00:45:23.760 | It was raining, and it got freezing cold.

00:45:26.020 | Like, what the hell?

00:45:26.860 | It was the apocalypse.

00:45:28.300 | I had to just sit there, listening to Bruce Springsteen,

00:45:31.740 | I remember, and just thinking, I'm probably going to die.

00:45:34.780 | And I was okay with it

00:45:36.020 | because Bruce Springsteen was on the radio.

00:45:37.700 | - Look, when you've got the boss,

00:45:39.420 | you're ready to meet the boss.

00:45:42.140 | Yeah, so look, I mean--

00:45:44.100 | - That's a good line.

00:45:45.140 | So anyway, sorry, the desert.

00:45:46.420 | - It's true.

00:45:47.260 | Yeah, by the way, to continue on this tangent,

00:45:51.460 | I absolutely love the Southwest for this reason.

00:45:54.980 | During the pandemic, I drove from LA to New Mexico

00:46:01.420 | a bunch of times.

00:46:02.300 | - The madness of weather.

00:46:03.820 | - Yeah, the chaos of weather.

00:46:06.460 | The fact that it'll be blazing hot one minute,

00:46:08.980 | and then it's just like,

00:46:10.460 | we'll decide to have a little thunderstorm.

00:46:13.220 | Maybe we'll decide to go back momentarily

00:46:15.820 | to like a thousand degrees

00:46:17.340 | and then go back to the thunderstorm.

00:46:19.020 | It's amazing.

00:46:20.620 | That, by the way, is chaos theory in action.

00:46:23.360 | But let's get back to talking about the desert.

00:46:27.100 | So in the desert, tumbleweeds have a tendency to roll

00:46:31.420 | because the wind rolls them.

00:46:33.380 | And if you're careful,

00:46:35.740 | you'll occasionally see this family of tumbleweeds

00:46:38.140 | where there's a big one,

00:46:40.020 | and then a bunch of little ones

00:46:41.700 | that kind of hide in its wake,

00:46:44.620 | and are all rolling together

00:46:45.940 | and almost looks like a family of ducks

00:46:48.740 | crossing a street or something.

00:46:50.300 | Or for example, if you watch Tour de France,

00:46:55.980 | you've got a whole bunch of cyclists

00:46:58.060 | and they're like cycling within 10 centimeters

00:47:01.180 | of each other.

00:47:02.020 | They're not BFFs, right?

00:47:03.860 | They're not trying to ride together.

00:47:07.260 | They are riding together to minimize the collective

00:47:12.100 | air resistance, if you will, that they experience.

00:47:16.080 | Turns out solids in the protoplanetary disk do just this.

00:47:21.080 | There's an instability wherein solid particles,

00:47:26.740 | things that are a centimeter across

00:47:29.660 | will start to hide behind one another

00:47:31.740 | and form these clouds.

00:47:33.740 | Why?

00:47:34.580 | Because cumulatively that minimizes the solid component

00:47:39.500 | of this aerodynamic interaction with the gas.

00:47:43.820 | Now, these clouds,

00:47:45.060 | because they're kind of a favorable energetic condition

00:47:48.860 | for the dust to live in,

00:47:50.740 | they grow, grow, grow, grow, grow

00:47:52.980 | until they become so massive

00:47:54.340 | that they collapse under their own weight.

00:47:56.680 | That's how the first building blocks of planets form.

00:47:59.540 | That's how the big asteroids got there.

00:48:02.260 | - That's incredible.

00:48:03.100 | - Yeah.

00:48:03.940 | - So is that simulatable or is it not useful to simulate?

00:48:06.900 | - No, no, that's simulatable.

00:48:09.140 | And people do these types of calculations.

00:48:12.020 | It's really cool.

00:48:13.540 | That's actually, that's one of the many fields

00:48:16.340 | of planet formation theory that is really, really active.

00:48:19.640 | Right now, people are trying to understand

00:48:21.380 | all kinds of aspects of that process.

00:48:23.900 | Because of course, I've explained it

00:48:26.100 | like as if there's one thing that happens.

00:48:29.100 | Turns out it's a beautifully rich dynamic,

00:48:33.900 | but qualitatively formation of the first building blocks

00:48:38.640 | actually follows the same sequence

00:48:40.460 | as formation of stars, right?

00:48:42.060 | Stars are just clouds of gas, hydrogen helium gas

00:48:46.860 | that sit in space and slowly cool.

00:48:50.460 | And at some point, they contract to a point

00:48:55.460 | where their gravity overtakes the thermal pressure support,

00:48:59.740 | if you will, and they collapse under their own weight

00:49:01.820 | and you get a little baby solar system.

00:49:03.460 | - That's amazing.

00:49:04.300 | So do you think one day it will be possible

00:49:06.180 | to simulate the full history that took our solar system

00:49:11.180 | to what it is today?

00:49:13.700 | - Yes, and it will be useless.

00:49:17.380 | - Okay.

00:49:18.420 | So you don't think your story,

00:49:19.920 | many of the ideas that you have about Jupiter

00:49:22.080 | clearing the space, like retelling that story

00:49:24.820 | in high resolution is not that important?

00:49:26.800 | - I actually think it's important,

00:49:28.020 | but at every stage, you have to design your experiments,

00:49:35.780 | your numerical computer experiments

00:49:38.200 | so that they test some specific aspect of that evolution.

00:49:43.200 | I am not a proponent of doing huge simulations

00:49:48.280 | because even if we forget the information theory aspect

00:49:53.280 | of not being able to simulate in full detail the universe,

00:49:59.560 | because if you do, then you have made an actual universe.

00:50:05.180 | It's not a simulation, right?

00:50:07.040 | By simulation is in some sense, a compression of information

00:50:10.400 | so therefore you must lose detail.

00:50:13.320 | But that point aside, if we are able to simulate

00:50:18.320 | the entire history of the solar system

00:50:22.240 | in excruciating detail, I mean, it'll be cool,

00:50:26.140 | but it's not gonna be any different from observing it,

00:50:29.940 | because theoretical understanding,

00:50:34.360 | which is what ultimately I'm interested in,

00:50:36.800 | comes from taking complex things

00:50:41.420 | and reducing them down to something that,

00:50:44.240 | some mechanism that you can actually quantify.

00:50:47.180 | That's the fun part of astrophysics,

00:50:51.040 | just kind of simulating things in extreme detail

00:50:54.280 | is we'll make cool visualizations,

00:50:57.200 | but that doesn't get you to any better understanding

00:51:02.320 | than you had before you did the simulation.

00:51:05.000 | - If you ask very specific questions,

00:51:06.440 | then you'll be able to create like very highly compressed,

00:51:11.440 | nice, beautiful theories about how things evolved.

00:51:14.600 | And then you can use those to then generalize

00:51:16.440 | to other solar systems, to other stars and other galaxies,

00:51:20.680 | and then say something generalizable

00:51:23.080 | about the entire universe.

00:51:24.680 | How difficult would it be to simulate our solar system

00:51:29.680 | such that we would not know the difference?

00:51:31.860 | Meaning if we are living in a simulation,

00:51:35.680 | is there a nice, think of it as a video game,

00:51:38.800 | is there a nice compressible way of doing that?

00:51:41.520 | Or just kind of like you intuited

00:51:43.600 | with a three body situation is just a giant mess

00:51:47.480 | that you cannot create a video game

00:51:49.980 | that will seem realistic

00:51:52.840 | without actually building your scratch.

00:51:55.200 | - I'm speculating, but one of the,

00:51:59.920 | yeah, I know you have a deep understanding of this,

00:52:03.780 | but for me, I'm just gonna speculate that for,

00:52:07.980 | at least in the types of simulations that we can do today,

00:52:13.520 | inevitably you run into the problem of resolution.

00:52:17.180 | Doesn't matter what you're doing, it is discrete.

00:52:21.400 | Now, the way you would go about asking,

00:52:26.340 | what we're observing, is that a simulation

00:52:28.260 | or is that some real continuous thing,

00:52:33.260 | is you zoom in, right?

00:52:35.460 | You zoom in and try and find the grid scale, if you will.

00:52:40.460 | Yeah, I mean, it's a really interesting question.

00:52:47.780 | And because the solar system itself

00:52:54.880 | and really the double pendulum is chaotic, right?

00:52:58.760 | Pendulum sitting on another pendulum,

00:53:01.720 | moves unpredictably once you let them go.

00:53:05.620 | You really don't need to like inject any randomness

00:53:10.600 | into a simulation for it to give you stochastic

00:53:13.520 | and unpredictable answers.

00:53:15.800 | Weather is a great example of this.

00:53:18.120 | Weather has a lap of time of,

00:53:21.160 | typical weather systems have a lap of time of a few days.

00:53:25.720 | And there's a fundamental reason why the forecast

00:53:28.640 | always sucks, two weeks in advance.

00:53:31.980 | It's not that we don't know the equations

00:53:35.400 | that govern the atmosphere, we know them well.

00:53:39.080 | Their solutions are meaningless though, after a few days.

00:53:42.360 | - The zooming in thing is very interesting.

00:53:45.200 | I think about this a lot, whether there'll be a time soon

00:53:50.160 | where we would want to stay in video game worlds,

00:53:53.320 | whether it's virtual reality or just playing video games.

00:53:56.080 | - I mean, I think that time like came in like the 90s

00:54:00.080 | and it's been that time.

00:54:01.600 | - Well, it's not just came, I mean, it's accelerated.

00:54:05.400 | I just recently saw the wow and Fortnite

00:54:08.680 | were played 140 billion hours.

00:54:11.520 | And those are just video games.

00:54:13.160 | And that's like increasing very, very quickly,

00:54:15.200 | especially with the people coming up now,

00:54:17.400 | being born now and become teenagers and so on.

00:54:21.600 | - Let's have a thought experiment where it's just you

00:54:23.760 | in a video game character inside a room,

00:54:26.320 | where you remove the simulation,

00:54:28.520 | they need to simulate sort of a lot of objects.

00:54:33.000 | If it's just you and that character,

00:54:34.920 | how far do you need to simulate in terms of zooming in

00:54:39.640 | for it to be very real to you, as real as reality?

00:54:43.760 | So like, first of all, you kind of mentioned zooming in,

00:54:46.800 | which is fascinating because we have these tools of science

00:54:50.220 | that allow us to zoom in, quote unquote,

00:54:52.720 | in all kinds of ways in the world around us.

00:54:57.140 | But our cognitive abilities,

00:54:58.680 | like our perception system as humans

00:55:00.720 | is very limited in terms of zoom in.

00:55:02.520 | So we might be very easily fooled.

00:55:04.400 | - Some of the video games like on the PS4,

00:55:08.780 | like look pretty real to me, right?

00:55:11.720 | I think you would really have to interrogate.

00:55:15.360 | I mean, I think even with what we have today,

00:55:17.680 | like, I don't know, Ace Combat 7 is a great example, right?

00:55:22.640 | Like, I mean, the way that the clouds are rendered,

00:55:26.140 | it's, I mean, it looks just like when you're flying,

00:55:30.340 | you know, on a real airplane, the kind of transparency.

00:55:34.140 | I think that the, you know,

00:55:36.900 | our perception is limited enough already

00:55:40.360 | to not be able to tell some of the, you know,

00:55:44.980 | some of the differences.

00:55:46.240 | There's a game called Skyrim.

00:55:48.460 | It's an Elder Scrolls role-playing game.

00:55:51.300 | And I just, I played it for quite a bit.

00:55:55.100 | And I think I played it very different than others.

00:55:58.600 | Like there'll be long stretches of time

00:56:00.860 | where I would just walk around

00:56:01.900 | and look at nature in the game.

00:56:04.020 | It's incredible.

00:56:05.540 | - Oh, sure.

00:56:06.380 | - It's just like the graphics is like, wow,

00:56:08.940 | I want to stay there.

00:56:10.260 | It was better, I went hiking recently.

00:56:12.300 | It was like as good as hiking.

00:56:13.800 | - So look, I know what you mean.

00:56:16.060 | Not to go on a huge video game tangent,

00:56:18.920 | but like the third Witcher game

00:56:22.460 | was astonishingly beautiful, right?

00:56:25.240 | Especially like playing on a good hardware machine.

00:56:28.660 | It's like, this is pretty legit.

00:56:32.600 | That said, you know,

00:56:36.400 | I don't resonate with the, I want to stay here.

00:56:39.520 | You know, like one of the things that I love to do

00:56:43.220 | is to go to my like boxing gym and box with a guy, right?

00:56:48.220 | Like that's, there's nothing quite like that physical,

00:56:52.840 | you know, experience.

00:56:54.940 | - That's fascinating.

00:56:55.780 | That might be simply an artifact of the year you were born.

00:56:59.740 | - Maybe.

00:57:00.580 | - Because if you're born today,

00:57:02.360 | it almost seems like stupid to go to a gym.

00:57:05.280 | - Yeah.

00:57:06.120 | - Like you go to a gym to box with a guy,

00:57:08.120 | why not box with Mike Tyson when you yourself,

00:57:10.980 | like in his prime, when you yourself

00:57:13.260 | are also an incredible boxer in the video game world.

00:57:15.980 | - For me, there's a multitude of reasons

00:57:19.280 | why I don't want to box with Mike Tyson, right?

00:57:21.680 | Like I enjoy teeth, you know, and I want to have an ear.

00:57:26.340 | - No, but your skills in this meat space,

00:57:29.080 | in this physical realm is very limited

00:57:31.320 | and takes a lot of work.

00:57:32.460 | And you're a musician, you're an incredible scientist.

00:57:37.460 | You only have so much time in the day,

00:57:40.220 | but in the video game world,

00:57:41.780 | you can expand your capabilities in all kinds of dimensions

00:57:45.420 | that you can never have possibly have time

00:57:47.660 | in the physical world.

00:57:48.900 | And so that, it doesn't make sense, like to be existing,

00:57:53.300 | to be working your ass off in the physical world

00:57:56.300 | when you can just be super successful

00:57:58.620 | in the video game world.

00:58:01.300 | - But I still--

00:58:02.460 | - You enjoy sucking at stuff?

00:58:04.180 | - Yeah, I really do.

00:58:05.020 | - And struggling to get better?

00:58:06.420 | - I sure do.

00:58:07.340 | I mean, I think like these days with music,

00:58:10.020 | music is a great example, right?

00:58:12.340 | We just started practicing live with my band again,

00:58:17.340 | after not playing for a year.

00:58:19.860 | And it was terrible, right?

00:58:22.820 | We were just kind of a lot of the nuance,

00:58:25.980 | a lot of the detail is just that detail that takes

00:58:29.340 | years of collective practice to develop, it's just lost.

00:58:34.300 | But it was just an incredible amount of fun,

00:58:37.300 | way more fun than all the like studio,

00:58:40.940 | sitting around and playing that I did

00:58:43.500 | throughout the entire year.

00:58:45.180 | So I think there's something intangible

00:58:48.860 | or maybe tangible about being in person.

00:58:52.860 | I sure hope you're wrong in that,

00:58:56.540 | that's not something that will get lost

00:58:59.140 | because I think there's like such a large part

00:59:02.220 | of the human condition is to hang out.

00:59:06.180 | - If we were doing this interview on Zoom, right?

00:59:11.060 | I mean, I'd already be bored out of my mind.

00:59:15.060 | - Exactly, I mean, there's something to that.

00:59:18.220 | I mean, I'm almost playing devil's advocate,

00:59:20.060 | but at the same time, I'm sure people talk

00:59:22.820 | about the same way at the beginning of the 20th century

00:59:25.020 | about horses, where they are much more efficient,

00:59:30.020 | they're much easier to maintain than cars.

00:59:34.260 | It doesn't make sense to have,

00:59:35.700 | all the ways that cars break down

00:59:37.140 | and there's not enough infrastructure

00:59:38.860 | in terms of roads for cars.

00:59:40.740 | It doesn't make any sense, like horses and like nature,

00:59:43.260 | you could do the nature, like where,

00:59:45.500 | you should be living more natural life.

00:59:47.340 | Those are real, you don't want machines in your life

00:59:49.380 | that are going to pollute your mind

00:59:50.900 | and the minds of young people,

00:59:52.620 | but then eventually just cars took over.

00:59:54.260 | So in that same way, it just seems-

00:59:56.820 | - Going back to horses, I'm just, you know.

01:00:00.620 | - Well, you can be, you can play, what is it?

01:00:04.140 | Red Dead.

01:00:05.740 | - Red Dead Redemption, yeah.

01:00:06.780 | - Redemption and you can ride horses in the video game.

01:00:09.460 | - That's true.

01:00:10.300 | - So let me return us back to planet nine.

01:00:13.900 | - Always a good place to come back to.

01:00:15.780 | - So now that we did a big historical overview

01:00:18.300 | of our solar system, what is planet nine?

01:00:21.080 | - Okay, planet nine is a hypothetical object

01:00:26.020 | that orbits the solar system, right?

01:00:28.500 | At an orbital period of about 10,000 years

01:00:32.580 | and an orbit which is slightly tilted

01:00:36.220 | with respect to the plane of the solar system,

01:00:38.660 | slightly eccentric and the object itself,

01:00:41.860 | we think is five times more massive than the earth.

01:00:46.420 | We have never seen planet nine in a telescope,

01:00:50.540 | but we have gravitational evidence for it.

01:00:53.540 | - And so this is where all the stuff

01:00:55.420 | we've been talking about, this clustering ideas,

01:00:57.940 | maybe you can speak to the approximate location

01:01:00.500 | that we suspect and also the question I wanted to ask

01:01:03.780 | is what are we supposed to be imagining here?

01:01:07.500 | 'Cause you said there's certain objects

01:01:09.100 | in the Kuiper belt that are kind of have a direction

01:01:12.140 | to them that they're all like flocking

01:01:15.060 | in some kind of way.

01:01:16.240 | So that's the sense that there's some kind

01:01:17.780 | of gravitational object not changing their orbit,

01:01:20.840 | but kind of--

01:01:21.940 | - Confining them, right?

01:01:23.140 | - Yeah.

01:01:23.980 | - Like grouping their orbits together.

01:01:26.100 | See what would happen if planet nine were not there

01:01:29.060 | is these orbits that roughly share a common orientation,

01:01:33.420 | they would just disperse, right?

01:01:35.820 | They would just become as a mutually symmetric

01:01:38.580 | point everywhere.

01:01:39.500 | Planet nine's gravity makes it such that these objects

01:01:44.500 | stay in a state that's basically anti-aligned

01:01:48.660 | with respect to the orbit of planet nine

01:01:51.260 | and sort of hang out there and kind of oscillate

01:01:56.140 | on timescale of about a billion years.

01:01:58.420 | That's one of the lines of evidence

01:02:01.620 | for the existence of planet nine.

01:02:03.300 | There are others.

01:02:04.140 | That's the one that's easiest to maybe visualize

01:02:06.300 | just because it's fun to think about orbits

01:02:08.100 | that all point into the same direction.

01:02:10.740 | But I should emphasize that, for example,

01:02:15.140 | the existence of objects, again, Kuiper belt objects

01:02:19.020 | that are heavily out of the plane of the solar system,

01:02:21.600 | things that are tilted by say 90 degrees,

01:02:24.260 | that's not, we don't expect that as an outcome

01:02:28.740 | of planet formation.

01:02:29.900 | Indeed, planet formation simulations have never produced

01:02:33.820 | such objects without some extrinsic gravitational force.

01:02:38.820 | Planet nine, on the other hand, generates them very readily.

01:02:41.540 | So that provides kind of an alternative population

01:02:45.300 | of small bodies in the solar system

01:02:49.660 | that also get produced by planet nine

01:02:51.260 | through an independent kind of gravitational effect.

01:02:54.140 | So there's basically five different things

01:02:58.340 | that planet nine does individually

01:03:02.880 | that are like kind of maybe a one sigma effect

01:03:07.020 | where you'd say, yeah, okay, if that's all it was,

01:03:09.260 | maybe it's no reason to jump up and down.

01:03:11.260 | But because it's a multitude of these puzzles

01:03:16.180 | that all are explained by one hypothesis,

01:03:19.900 | that's really the magnetism,

01:03:22.260 | the attraction of the planet nine model.

01:03:24.360 | - So can you just clarify, so most planets

01:03:30.300 | in the solar system orbit at approximately the same,

01:03:34.740 | so it's flat.

01:03:35.660 | - Yeah, it's like one degree.

01:03:37.300 | The difference between them is about one degree.

01:03:41.460 | - But nevertheless, if we looked at our solar system,

01:03:44.580 | it would look, and I could see every single object,

01:03:47.220 | it would look like a sphere.

01:03:48.980 | The inner part where the planets are would look like flat.

01:03:53.980 | The Kuiper belt and the asteroid belt have a larger--

01:03:59.780 | - It gets fatter and fatter and fatter

01:04:02.500 | and it becomes a sphere.

01:04:03.660 | - That's right, and if you look at the very outside,

01:04:06.340 | it's polluted by this quasi-spheroidal thing.

01:04:11.060 | Nobody's, of course, ever seen the Oort cloud.

01:04:14.580 | We've only seen comets that come from the Oort cloud.

01:04:18.220 | So the Oort cloud, which is this population

01:04:21.940 | of distant debris, its existence is also inferred.

01:04:26.260 | You could say alternatively, there's a big cosmic creature

01:04:31.260 | that occasionally, sitting at 20,000 AU

01:04:34.900 | and occasionally throws an icy rock towards the sun.

01:04:37.900 | - Spaghetti monster, I think it's called.

01:04:39.980 | Okay, so it's a mystery in many ways,

01:04:44.140 | but you can kind of infer a bunch of things about it.

01:04:47.100 | By the way, both terrifying and exciting

01:04:49.060 | that there's this vast darkness all around us

01:04:51.540 | that's full of objects that are just throwing--

01:04:54.020 | - Just there, yeah.

01:04:55.460 | It's actually kind of astonishing

01:04:57.340 | that we have only explored a small fraction

01:05:02.340 | of the solar system.

01:05:03.700 | That really kind of baffles me because,

01:05:08.980 | remember as a student studying physics,

01:05:11.380 | you do the problem where you put the Earth around the sun,

01:05:15.380 | and you solve that, and it's one line of math,

01:05:18.820 | and you say, "Okay, well that surely

01:05:20.660 | "was figured out by Newton."

01:05:22.380 | So all the interesting stuff is not in the solar system,

01:05:26.020 | but that, it's just plainly not true.

01:05:30.700 | There are mysteries in the solar system

01:05:34.420 | that are remarkable that we are only now starting

01:05:38.060 | to just kind of scratch the surface of.

01:05:40.340 | - And some of those objects probably have some information

01:05:43.100 | about the history of our solar system.

01:05:44.860 | - Absolutely, absolutely.

01:05:46.420 | Like a great example is small meteorites.

01:05:50.220 | Small meteorites are melted.

01:05:53.620 | They're differentiated, meaning some of the iron sinks,

01:05:58.060 | and you say, "Well, how can that be?"

01:06:00.060 | 'Cause they're so small that they wouldn't have melted

01:06:02.140 | just from the heat of their accretion.

01:06:04.260 | Turns out the fact that the solar nebula,

01:06:07.300 | the disk that made the planets, was polluted by aluminum-26

01:06:12.220 | is in itself a remarkable thing.

01:06:13.900 | It means the solar system did not form in isolation.

01:06:17.580 | It formed in a giant cloud of thousands of other stars

01:06:21.940 | that were also forming, some of which were undergoing,

01:06:26.260 | going through supernova explosions,

01:06:28.660 | and releasing these unstable isotopes

01:06:32.540 | of which we now see kind of the traces of.

01:06:36.900 | It's so cool.

01:06:39.060 | - Do you think it's possible that life

01:06:40.700 | from other solar systems was injected

01:06:43.460 | and that was what was the origin of life on Earth?

01:06:47.900 | - Yeah, the Panspermia idea.

01:06:49.620 | - That's seen as a low probability event

01:06:52.580 | by people who studied the origin of life,

01:06:54.340 | but that's because then they would be out of a job.

01:06:57.620 | (laughs)

01:06:58.780 | - Well, I don't think they'd be out of the job,

01:07:00.540 | 'cause you just then have to figure out

01:07:02.260 | how life started there.

01:07:04.180 | - But then you have to go there.

01:07:05.360 | We can study life on Earth much easier.

01:07:07.700 | We could study it in the lab much easier

01:07:10.660 | because we could replicate conditions

01:07:12.340 | that are from an early Earth much easier

01:07:16.580 | from a chemistry perspective, from a biology perspective.

01:07:19.700 | You can intuit a bunch of stuff.

01:07:21.100 | You can look at different parts of Earth.

01:07:23.620 | - To an extent.

01:07:24.540 | I mean, the early Earth was completely unlike

01:07:27.740 | the current Earth, right?

01:07:28.720 | There was no oxygen.

01:07:29.900 | So, one of my colleagues at Caltech,

01:07:33.860 | Joe Kirshnick, is certain,

01:07:37.660 | something like 100% certainty

01:07:41.380 | that life started on Mars and came to Earth

01:07:45.420 | on Martian meteorites.

01:07:46.760 | This is not a problem that I like to kind of

01:07:52.980 | think about too much.

01:07:54.900 | Like the origin of life, it's a fascinating problem,

01:07:57.740 | but it's not physics, and I just don't love it.

01:08:02.740 | - It's the same reason you don't love,

01:08:05.060 | I thought you're a musician.

01:08:06.500 | So, music is not physics either,

01:08:08.420 | so why are you so into it?

01:08:09.260 | - It's 100% physics.

01:08:10.740 | (laughing)

01:08:13.260 | - Yeah, no, no, look, in all seriousness, though,

01:08:16.220 | there are a few things that I really, really enjoy.

01:08:20.900 | I genuinely enjoy physics.

01:08:23.340 | I genuinely enjoy music.

01:08:24.900 | I genuinely enjoy martial arts,

01:08:28.420 | and I genuinely enjoy my family.

01:08:31.500 | I should have said that all in a reverse order or something,

01:08:34.300 | but I like to focus on these things

01:08:36.900 | and not worry too much about everything else.

01:08:39.780 | You know what I mean?

01:08:40.620 | - Yes.

01:08:41.440 | - Just because there is, like you said earlier,

01:08:43.620 | there's a time constraint.

01:08:44.780 | You can't do it all.

01:08:47.340 | - There's many mysteries all around us,

01:08:49.340 | and they're all beautiful in different ways.

01:08:53.360 | To me, that thing I love is artificial intelligence,

01:08:56.180 | that perhaps I love it because eventually

01:08:59.500 | I'm trying to suck up to our future overlords.

01:09:01.820 | The question of, you said there's a lot of kind of,

01:09:06.860 | little pieces of evidence for this thing that's Planet Nine.

01:09:10.500 | If we were to try to collect more evidence

01:09:14.500 | or be certain, like a paper that says,

01:09:18.140 | like you drop it, clear, we're done,

01:09:21.620 | what does that require?

01:09:23.100 | Does that require us sending probes out,

01:09:25.420 | or do you think we can do it from telescopes here on Earth?

01:09:28.320 | What are the different ideas

01:09:29.660 | for conclusive evidence for Planet Nine?

01:09:31.880 | - The moment Planet Nine gets imaged

01:09:34.980 | from a telescope on Earth, it's done.

01:09:36.860 | I mean, it's just there.

01:09:37.940 | - Can you clarify, 'cause you mentioned that before,

01:09:40.460 | from an image, would you be able to tell?

01:09:42.940 | - Yes, so from an image, the moment you see something,

01:09:47.940 | something that is reflecting sunlight back at you,

01:09:52.980 | and you know that it's hundreds of times

01:09:57.800 | as far away from the sun as is the Earth, you're done.

01:10:02.380 | - So you're thinking, so basically,

01:10:04.020 | if you have a really far away thing that's big,

01:10:07.500 | five times the size of Earth, that means that's Planet Nine.

01:10:12.500 | - That is Planet Nine.

01:10:13.860 | - Could there be multiple objects like that, I guess?

01:10:16.180 | - In principle, yeah.

01:10:17.140 | I mean, there's no law of physics

01:10:20.100 | that doesn't allow you to have multiple objects.

01:10:22.500 | There's also no evidence present

01:10:24.700 | for there being multiple objects.

01:10:25.540 | - I wonder if it's possible,

01:10:27.060 | so just like we're finding exoplanets,

01:10:29.780 | whether given the size of the Oort cloud,

01:10:32.340 | there's basically, it's rarer and rarer,

01:10:34.780 | but there's sprinkled Planet Nine, 10, 11, 12,

01:10:39.420 | like these, some--

01:10:41.100 | - Got 13.

01:10:42.580 | - Yeah, it goes after that.

01:10:43.420 | I can just keep counting.

01:10:45.100 | So like, just something about the dynamic system,

01:10:48.320 | like it becomes lower and lower probability event,

01:10:50.580 | but they gather up, like they become,

01:10:53.340 | would they become larger and larger maybe?

01:10:55.780 | Something like that.

01:10:57.100 | I wonder, I wonder if like discovering Planet Nine

01:11:00.980 | will just like be almost like a springboard,

01:11:03.300 | it's like, well, what's beyond that?

01:11:05.500 | - It's entirely plausible.

01:11:06.740 | The Oort cloud itself probably holds about five Earth masses

01:11:11.100 | or seven Earth masses of material, right?

01:11:13.860 | So it's not nothing.

01:11:16.500 | And it all ultimately comes down to,

01:11:21.500 | at what point will the observational surveys

01:11:26.020 | sample enough of the solar system

01:11:28.660 | to kind of reveal interesting things?

01:11:32.860 | There's a great analogy here with Neptune

01:11:36.220 | and the story of how Neptune was discovered.

01:11:38.140 | Neptune was not discovered by looking at the sky, right?

01:11:42.020 | It was discovered by, it was discovered mathematically,

01:11:45.340 | right, so yeah, the orbit of Uranus,

01:11:49.460 | when Uranus was found, this was 1781,

01:11:55.100 | it's the kind of tracking of,

01:11:58.020 | both the tracking of the orbit of Uranus

01:12:00.580 | as well as the reconstruction of the orbit of Uranus

01:12:03.900 | immediately revealed that it was not following the orbit

01:12:08.260 | that it was supposed to, right?

01:12:09.780 | The predicted orbit deviated away

01:12:12.020 | from where it actually was.

01:12:13.820 | So in the mid 1800s, right, a French mathematician

01:12:18.820 | by the name of Orban Le Verrier

01:12:22.340 | did a beautifully sophisticated calculation

01:12:25.780 | which said if this is due to gravity

01:12:29.220 | of a more distant planet, then that planet is there, okay?

01:12:33.920 | And then they found it.

01:12:35.380 | But the point is the understanding of where to look

01:12:39.420 | for Neptune came entirely out of celestial mechanics.

01:12:43.580 | The case with planet nine is a little bit different

01:12:46.900 | because what we can do, I think, relatively well

01:12:49.700 | is predict the orbit and mass of planet nine.

01:12:52.020 | We cannot tell you where it is on its orbit.

01:12:54.700 | The reason is we haven't seen the Kuiper belt objects

01:12:57.900 | complete an orbit, their own orbit, even once

01:13:02.620 | because it takes 4,000 years.

01:13:04.520 | But I plan to live on as an AI being,

01:13:08.640 | and I'll be tracking those orbits as--

01:13:12.980 | - It only takes four or 5,000 years.

01:13:14.940 | I mean, it doesn't have to be AI, it could be longevity.

01:13:17.140 | There's a lot of really exciting

01:13:18.340 | genetic engineering research.

01:13:19.940 | So you'll just be a brain waiting for the,

01:13:22.260 | (laughs)

01:13:23.740 | your brain waiting for the orbit to complete

01:13:25.940 | for the basic Kuiper belt objects.

01:13:28.260 | - That's right, that's like kind of the worst reason

01:13:32.100 | to want to live a long time, right?

01:13:34.180 | Just like, can the brain smoke a cigarette?

01:13:36.500 | - I know, right?

01:13:37.340 | - Can you just light one up while you're waiting?

01:13:40.020 | - But you're making me actually realize

01:13:45.380 | that the one way to explore the galaxy

01:13:50.380 | is by just sitting here on earth and waiting.

01:13:54.560 | So if we can just get really good at waiting,

01:13:57.340 | it's like a muamua or these interstellar objects

01:13:59.900 | that fly in, you can just wait for them to come to you.

01:14:02.780 | Same with the aliens, you can wait for them to come to you.

01:14:05.340 | If you get really good at waiting,

01:14:07.040 | then that's one way to do the exploration

01:14:10.900 | 'cause eventually the thing will come to you.

01:14:13.380 | Maybe the intelligent alien civilizations

01:14:16.980 | get much better at waiting and so they all decide,

01:14:20.060 | so again, theoretically, to start waiting

01:14:21.700 | and it's just a bunch of ancient intelligent civilizations

01:14:25.500 | of aliens all throughout the universe

01:14:27.420 | that are just sitting there waiting for each other.

01:14:29.300 | - Look, you can't just be good at waiting,

01:14:31.740 | you gotta know how to chill.

01:14:33.420 | Like, you can't just sit around and do nothing.

01:14:36.220 | You gotta know how to chill.

01:14:38.300 | - I honestly think that as we progress,

01:14:41.700 | if the aliens are anything like us,

01:14:43.500 | we enjoy loving things we do

01:14:46.820 | and it's very possible that we just figure out mechanisms

01:14:50.580 | here on earth to enjoy our life

01:14:53.860 | and we just stay here on earth forever

01:14:56.420 | that exploration becomes less and less

01:14:58.900 | of an interesting thing to do.

01:15:00.300 | And so you basically, yes, wait and chill.

01:15:03.380 | You get really optimally good at chilling

01:15:05.700 | and thereby exploring is not that interesting.

01:15:09.340 | So in terms of 4,000 years, it'll be nothing for scientists.

01:15:13.060 | We'll be chilling and just all kinds

01:15:14.940 | of scientific explorations will become possible

01:15:18.120 | because we'll just be here on earth.

01:15:19.980 | - So chill.

01:15:20.820 | - So chill.

01:15:21.660 | - So chill.

01:15:22.580 | - You have a paper out recently

01:15:23.940 | 'cause you already mentioned some of these ideas

01:15:25.780 | but I'd love it if you could dig into it a little bit.

01:15:27.820 | - Yeah, of course.

01:15:28.660 | - The injection of inner Oort cloud objects

01:15:31.460 | into the distant Kuiper belt by planet nine.

01:15:34.740 | What is this idea of planet nine injecting objects

01:15:39.740 | into the Kuiper belt?

01:15:40.820 | - Okay, let me take a brief step back

01:15:43.540 | and when we do calculations of planet nine,

01:15:47.500 | when we do the simulations,

01:15:49.780 | as far as our simulations are concerned,

01:15:52.500 | sort of the Neptune,

01:15:56.620 | trans-Neptunian solar system

01:16:00.540 | is entirely sourced from the inside,

01:16:03.860 | namely the Kuiper belt gets scattered by Neptune

01:16:07.700 | and then planet nine does things to it

01:16:09.660 | and aligns the orbits and so on.

01:16:11.860 | And then we calculate what happens

01:16:14.820 | on the lifetime of the solar system, yada, yada, yada.

01:16:18.300 | During the pandemic,

01:16:19.300 | one of the kind of questions we asked ourselves,

01:16:22.260 | and this is indeed something Mike and I,

01:16:24.500 | Mike Brown, who's a partner in crime on this,

01:16:28.060 | and I do regularly is we say,

01:16:31.780 | how can we, A, disprove ourselves

01:16:35.780 | and B, how can we improve our simulations?

01:16:39.220 | Like what's missing?

01:16:40.740 | One idea that maybe should have been obvious in retrospect

01:16:45.100 | is that all of our simulations treated the solar system

01:16:48.100 | as some isolated creature, right?

01:16:50.700 | But the solar system did not form in isolation, right?

01:16:53.380 | It formed in this cluster of stars

01:16:55.820 | and during that phase of forming together

01:16:59.140 | with thousands of other stars,

01:17:01.100 | we believe the solar system formed

01:17:03.620 | this almost spherical population of icy debris

01:17:07.980 | that sits maybe at a few thousand times

01:17:12.980 | the separation between the earth and the sun,

01:17:17.460 | maybe even a little bit closer.

01:17:19.380 | If planet nine's not there,

01:17:22.540 | that population is completely dormant

01:17:24.780 | and these objects just slowly orbit the sun,

01:17:29.300 | nothing interesting happens to them ever.

01:17:32.660 | But what we realized is that if planet nine is there,

01:17:35.260 | planet nine can actually grab some of those objects

01:17:37.780 | and gravitationally re-inject them

01:17:40.060 | into the distant solar system.

01:17:42.620 | So we thought, okay, let's look into this

01:17:44.580 | with numerical experiments.

01:17:46.300 | Do our simulations, does this process work?

01:17:49.180 | And if it works, what are its consequences?

01:17:52.940 | So it turns out, indeed, not only does planet nine

01:17:57.060 | inject these distant inner Oort cloud objects

01:18:02.060 | into the Kuiper belt,

01:18:03.660 | they follow roughly the same pathway

01:18:06.740 | as the objects that are being scattered out.

01:18:10.860 | So there's this kind of two-way river of material.

01:18:14.980 | Some of it is coming out by Neptune scattering,

01:18:18.380 | some of it is moving in.

01:18:20.300 | And if you work through the numbers,

01:18:23.220 | you kind of, at the end of the day,

01:18:25.780 | that it has an effect on the best fit orbit

01:18:28.700 | for planet nine itself.

01:18:29.940 | So if you realize that the dataset that we're observing

01:18:33.780 | is not entirely composed of things

01:18:35.940 | that came out of the solar system,

01:18:37.460 | but also things that got re-injected back in,

01:18:40.500 | then turns out the best fit planet nine

01:18:42.420 | is slightly more eccentric.

01:18:43.980 | That's kind of getting into the weeds.

01:18:45.700 | The point here is that the existence of planet nine itself

01:18:50.700 | provides this natural bridge that connects

01:18:54.460 | an otherwise dormant population of icy debris

01:18:57.020 | of the solar system with things

01:18:58.660 | that we're starting to directly observe.

01:19:00.340 | - So it can flow back,

01:19:01.260 | so it's not just the river flowing one way,

01:19:03.020 | it's maybe a smaller stream go back.

01:19:05.500 | - It's backwash.

01:19:06.580 | - You want a backwash.

01:19:07.540 | You want to incorporate that into the simulations,

01:19:09.860 | into your understanding of those distant objects

01:19:12.580 | when you're trying to make sense

01:19:13.620 | of the various observations and so on.

01:19:15.540 | - Exactly. - That's fascinating.

01:19:17.500 | I gotta ask you, some people think

01:19:20.100 | that many of the observations that you're describing

01:19:24.460 | could be described by a primordial black hole.

01:19:29.100 | First, what is a primordial black hole,

01:19:31.220 | and what do you think about this idea?

01:19:32.620 | - Yeah, so a primordial black hole is a black hole

01:19:36.460 | which is made not through the usual pathway

01:19:39.140 | of making a black hole, which is that you have a star,

01:19:43.780 | which is more massive than 1.4 or so solar masses.

01:19:49.940 | And basically when it runs out of fuel,

01:19:52.700 | runs out of its nuclear fusion fuel,

01:19:56.140 | it can't hold itself up anymore,

01:19:58.340 | and just the whole thing collapses on itself.

01:20:01.380 | Right, and you create a,

01:20:02.660 | I mean, one, I guess, simple way to think about it

01:20:08.020 | is you create an object with zero radius

01:20:10.980 | that has mass but zero radius, singularity.

01:20:16.380 | Now, such black holes exist all over the place.

01:20:19.980 | In the galaxy, there's in fact a really big one

01:20:22.820 | at the center of the galaxy.

01:20:24.180 | - That one terrifies me.

01:20:25.900 | - That one's always looking at you

01:20:27.460 | when you're not looking, okay?

01:20:29.220 | Right, and it's always talking about you.

01:20:31.820 | - And when you turn off the lights, it wakes up.

01:20:34.660 | - That's right.

01:20:35.500 | But you know, so such black holes are all over the place.

01:20:40.460 | When they merge, we get to see incredible gravitational waves

01:20:44.020 | that they emit, et cetera, et cetera.

01:20:45.360 | One kind of plausible scenario, however,

01:20:47.860 | is that when the universe was forming,

01:20:50.420 | basically during the Big Bang,

01:20:52.460 | you created a whole spectrum of black holes,

01:20:57.460 | some with masses of five Earth masses,

01:21:00.060 | some with masses of 10 Earth masses,

01:21:02.180 | like the entire mass spectrum size,

01:21:05.540 | some the mass of asteroids.

01:21:08.820 | Now, on the smaller end, over the lifetime of the universe,

01:21:13.100 | the smaller ones kind of evaporate

01:21:15.480 | and they're not there anymore.

01:21:16.760 | At least this is what the calculations tell us.

01:21:20.380 | But five Earth masses is big enough to not have evaporated.

01:21:24.960 | So one idea is that planet nine is not a planet,

01:21:29.720 | and instead it is a five Earth mass black hole.

01:21:33.820 | And that's why it's hard to find.

01:21:36.920 | Now, can we right away from our calculations,

01:21:42.680 | say that's definitely true or that's not true?

01:21:44.900 | Absolutely not.

01:21:45.900 | We can't, in fact, our calculations tell you nothing

01:21:50.180 | other than the orbit and the mass.

01:21:53.540 | And that means the black hole,

01:21:56.300 | I mean, it could be a five Earth mass cup,

01:21:59.660 | it could be a five Earth mass hedgehog or a black hole,

01:22:02.900 | or really anything that's five Earth masses will do

01:22:06.340 | because the gravity of a black hole

01:22:08.640 | is no different than the gravity of a planet.

01:22:11.660 | If the sun became a black hole tomorrow,

01:22:14.640 | it would be dark, but the Earth would keep orbiting it.

01:22:17.920 | This notion that, oh, black holes suck everything in,

01:22:21.860 | it's not, that's like a sci-fi notion.

01:22:24.500 | - Right, it's just math.

01:22:25.460 | What would be the difference between a black hole

01:22:28.180 | and a planet in terms of observationally?

01:22:32.100 | - Observationally, the difference would be

01:22:34.020 | that you will never find the black hole.

01:22:36.020 | The truth is they're kind of,

01:22:39.020 | I'm actually not, I never looked into this very carefully,

01:22:43.460 | but there are some constraints

01:22:46.540 | that you can get just statistically and say,

01:22:49.540 | okay, if the sun has a binary companion,

01:22:52.820 | which is a five Earth mass black hole,

01:22:55.380 | then that means such black holes would be extremely common.

01:22:59.880 | And you can sort of look for lensing events

01:23:02.540 | and then you say, okay, maybe that's not so likely.

01:23:05.080 | But that said, I wanna emphasize

01:23:08.220 | that there's a limit to what our calculations can tell you.

01:23:12.780 | That's the orbit and the mass.

01:23:14.540 | - So I think there's a bunch, like Ed Witten,

01:23:17.300 | I think, wishes it's a black hole.

01:23:20.620 | Because I think one exciting things about black holes

01:23:23.300 | in our solar system is that we can go there

01:23:26.700 | and we can maybe study the singularity somehow,

01:23:29.500 | because that allows us to understand

01:23:30.980 | some fundamental things about physics.

01:23:33.140 | If it's a planet, so planet nine, we may not,

01:23:37.900 | and we go there, we may not discover

01:23:39.980 | anything profoundly new.

01:23:43.020 | The interesting thing, perhaps you can correct me,

01:23:45.140 | about planet nine is like the big picture of it.

01:23:48.340 | The whole big story of the Kuiper belt

01:23:50.740 | and all those kinds of things.

01:23:52.100 | It's not that planet nine would be somehow

01:23:54.540 | fundamentally different from, I don't know, Neptune,

01:23:59.540 | in terms of the kind of things we could learn from it.

01:24:03.820 | So I think that there's kind of a hope

01:24:05.520 | that it's a black hole because it's an entirely

01:24:07.700 | new kind of object.

01:24:08.820 | Maybe you can correct me.

01:24:10.620 | - Yeah, I mean, of course, here my own biases creep in

01:24:15.220 | because I'm interested in planets around other stars.

01:24:19.740 | And I would say, I would disagree that we wouldn't find

01:24:24.580 | things that would be truly fundamentally new.

01:24:29.020 | Because as it turns out, the galaxy is really good

01:24:33.740 | at making five or three Earth-mass objects.

01:24:37.620 | The most common type of planet that we see,

01:24:42.620 | that we discover orbiting around other stars

01:24:46.080 | is a few Earth masses.

01:24:47.720 | In the solar system, there's no analog for that.

01:24:49.980 | We go from one Earth-mass object, which is this one,

01:24:53.180 | to skipping to Neptune and Uranus,

01:24:55.860 | which themselves are actually relatively poorly understood,

01:24:59.780 | especially Uranus from the interior structure point of view.

01:25:03.800 | If planet nine is a planet, going there will give us

01:25:07.480 | the closest window into understanding

01:25:09.600 | what other planets look like.

01:25:11.840 | And I'll say this, that planets,

01:25:16.840 | kind of in terms of their complexity

01:25:19.720 | on some logarithmic scale, fall somewhere

01:25:23.120 | between a star and an insect.

01:25:25.920 | An insect is way more complicated than a star.

01:25:30.760 | There's all kinds of physical processes

01:25:33.560 | and really biochemical processes that occur

01:25:36.560 | inside of an insect that just make a star look like

01:25:41.560 | somebody is playing with a spring or something.

01:25:44.840 | I think it would be arguably more interesting

01:25:52.200 | to go to planet nine if it's a planet,

01:25:57.920 | 'cause black holes are simple.

01:25:59.240 | They're just kind of, they're basically

01:26:01.920 | macroscopic particles.

01:26:04.640 | - Yeah. - Right?

01:26:05.480 | - Just like the star that you mentioned

01:26:07.160 | in terms of complexity.

01:26:08.000 | So it's possible that planet nine,

01:26:10.600 | as opposed to being homogeneous, is super,

01:26:14.120 | heterogeneous, there's a bunch of cool stuff going on.

01:26:16.280 | - Absolutely. - That could give us

01:26:17.720 | intuition, I never thought about that,

01:26:19.280 | that it's just basically Earth number two

01:26:22.440 | in terms of size, and starts giving us intuition

01:26:26.560 | that could be generalizable to Earth-like planets

01:26:30.040 | elsewhere in the galaxy.

01:26:31.520 | - Yeah, Pluto is also, in the sense,

01:26:34.080 | like Pluto's a tiny, tiny thing, right?

01:26:37.000 | Just like you would imagine that it's just

01:26:39.200 | a tiny ball of ice, like who cares?

01:26:41.080 | But in the New Horizons, images of Pluto

01:26:43.960 | reveal so much remarkable structure, right?

01:26:47.240 | They reveal glaciers flowing, and these are glaciers

01:26:50.140 | not made out of water ice, but CO ice.

01:26:53.400 | It turns out, at those temperatures,

01:26:56.280 | right, of like 40 or so Kelvin,

01:26:58.920 | water ice looks like metal, right?

01:27:01.640 | It just doesn't flow at all, but then ice made up

01:27:04.000 | of carbon monoxide starts to flow.

01:27:07.360 | I mean, there's just like all kinds of really cool

01:27:10.280 | phenomena that you otherwise just wouldn't

01:27:14.200 | really even imagine that occur.

01:27:17.060 | So, yeah, I mean, there's a reason why I like planets.

01:27:20.400 | (laughing)

01:27:21.480 | - Well, let me ask you, I find, as I read,

01:27:26.280 | the idea that Ed Witten was thinking about

01:27:28.620 | this kind of stuff fascinating.

01:27:29.980 | So he's a mathematical physicist

01:27:32.440 | who's very interested in string theory,

01:27:35.840 | won the Fields Medal for his work in mathematics.

01:27:40.840 | So I read that he proposed a fleet of probes

01:27:44.640 | accelerated by radiation pressure

01:27:46.960 | that could discover a planet nine

01:27:48.640 | primordial black holes location.

01:27:51.600 | What do you think about this idea

01:27:53.640 | of sending a bunch of probes out there?

01:27:56.080 | - Yeah, look, the way, the idea is a cool one, right?

01:28:00.720 | You go and you say, you know,

01:28:04.320 | launch them basically isotropically,

01:28:06.280 | you track where they go, and if I understand

01:28:10.320 | the idea correctly, you basically measure

01:28:12.480 | the deflection and you say, okay,

01:28:15.080 | that must be something there since the probe trajectory

01:28:20.840 | are being altered.

01:28:21.680 | - Oh, so the measurement, the basic sensory mechanism

01:28:24.360 | is the, it's not like you have senses on the probes,

01:28:27.240 | it's more like you're, because you're very precisely

01:28:30.520 | able to capture, to measure the trajectory of the probes,

01:28:33.480 | you can then infer the gravitational fields.

01:28:35.640 | - Yeah, I think that's the basic idea.

01:28:38.320 | You know, back a few years ago,

01:28:41.760 | we had conversations like these with, you know,

01:28:45.760 | engineers from JPL, they more or less convinced me

01:28:50.320 | that this is much more difficult than it seems

01:28:53.560 | because you don't, at that level of precision, right,

01:28:58.560 | things like solar flares matter, right?

01:29:00.680 | Solar flares, right, are completely chaotic,

01:29:03.680 | you can't predict which, where a solar flare will happen,

01:29:07.080 | that will drive radiation pressure gradients,

01:29:10.480 | you don't know where every single asteroid is,

01:29:12.560 | so like actually doing that problem,

01:29:17.400 | I think it's possible, but it's not a trivial matter, right?

01:29:21.600 | - Well, I wonder not just about Planet Nine,

01:29:25.360 | I wonder if that's kind of the future of doing science

01:29:29.080 | in our solar system, is to just launch

01:29:31.920 | a huge number of probes, so like a whole order of magnitude,

01:29:36.000 | many orders of magnitude larger numbers of probes,

01:29:39.680 | and then start to infer a bunch of different stuff,

01:29:42.440 | not just gravity, but everything else.

01:29:44.480 | - So in this regard, I actually think

01:29:46.480 | there is a huge revolution that's,

01:29:49.640 | to some extent, already started, right?

01:29:52.040 | The standard kind of like time scale for a NASA mission

01:29:55.520 | is that you like propose it and it launches,

01:29:58.800 | I don't know, like 150 years after you propose it,

01:30:01.960 | I'm over-exaggerating, but you know,

01:30:04.120 | it's just like some huge development cycle,

01:30:07.800 | and it gets delayed 55 times,

01:30:11.320 | like that is not going away, right?

01:30:15.800 | The really cutting edge things,

01:30:18.120 | you have to do it this way because you don't know

01:30:20.240 | what you're building, so to speak.

01:30:22.000 | But the CubeSat kind of world is starting to, you know,

01:30:27.000 | provide an avenue for like launching something

01:30:32.080 | that costs, you know, a few million dollars

01:30:34.400 | and has a turnaround time scale of like a couple years.

01:30:37.920 | You can imagine doing, you know, PhD theses,

01:30:41.080 | where you design the mission,

01:30:43.120 | the mission goes to where you're going,

01:30:44.840 | and you do the science all within a time span

01:30:47.760 | of five, six years.

01:30:49.080 | That has not been fully executed on yet,

01:30:53.560 | but I absolutely think that's on the horizon,

01:30:56.000 | and we're not talking a decade.

01:30:57.880 | I think we're talking like this decade.

01:31:00.280 | - Yeah, and the company's accelerating all this

01:31:03.400 | with Blue Origin and SpaceX,

01:31:07.440 | and there's a bunch of more CubeSat-oriented companies

01:31:10.120 | that are pushing this forward.

01:31:12.120 | Well, let me ask you on that topic,

01:31:15.080 | what do you think about either one?

01:31:17.760 | Elon Musk with SpaceX going to Mars,

01:31:21.880 | I think he wants SpaceX to be the first,

01:31:23.800 | to put a first human on Mars.

01:31:25.360 | And then Jeff Bezos, got to give him props,

01:31:31.280 | wants to be the first to fly his own rocket

01:31:34.400 | out into space, so.

01:31:37.640 | - Wasn't there a guy who built his rocket out of garbage?

01:31:42.240 | - Yeah.

01:31:43.080 | - This was a couple years ago,

01:31:44.840 | and somewhere in the desert, he launched himself.

01:31:47.600 | - I'm not tracking this closely,

01:31:48.760 | but I think I am familiar with folks

01:31:51.800 | who built their own rocket

01:31:52.840 | to try to prove the Earth is flat.

01:31:54.560 | - Yes, that's the guy I'm talking about.

01:31:56.040 | Yeah, he also jumped some limousine.

01:31:58.820 | - Truly revolutionary mind.

01:32:01.960 | - That's right.

01:32:02.800 | - You have greater men than either you or I.

01:32:07.400 | But what do you--

01:32:09.080 | - So look, it's been astonishing to watch

01:32:12.400 | how really over the last decade,

01:32:15.200 | the commercial sector took over this industry

01:32:19.200 | that traditionally has really been

01:32:23.680 | like a government thing to do.

01:32:26.700 | - Motivated primarily by the competition

01:32:30.280 | between nations, like the Cold War.

01:32:32.560 | And now it's motivated more and more

01:32:36.280 | by the natural forces of capitalism.

01:32:38.720 | - Yes, that's right.

01:32:40.040 | So, okay, here I have many ideas about it.

01:32:43.880 | I think on the one hand, right,

01:32:45.440 | like what SpaceX has been able to do,

01:32:47.720 | for example, phenomenal.

01:32:49.080 | If that brings down the price of SpaceX,

01:32:55.040 | wouldn't that turn around timescale for space exploration,

01:32:57.900 | which I think it inevitably will,

01:33:00.660 | that's a huge, you know,

01:33:03.040 | that's a huge boost to the human condition.

01:33:06.480 | The same time, right, if we're talking astronomy,

01:33:09.320 | right, there also, it comes at a huge cost, right?

01:33:13.200 | And the Starlink satellites is a great example

01:33:15.760 | of that cost, right?

01:33:16.640 | At one point, in fact, I was just camping

01:33:20.480 | in the Mojave with a friend of mine,

01:33:23.640 | and they saw, you know, this string of satellites

01:33:27.200 | just kind of like, you know,

01:33:29.200 | appear and then disappear into nowhere.

01:33:32.360 | So, that is beginning to interfere with, you know,

01:33:35.560 | Earth-based observations.

01:33:37.040 | So, I think there's tremendous potential there.

01:33:41.040 | It's also important to be responsible

01:33:42.760 | about how it's executed.

01:33:44.880 | Now, with Mars and the whole idea of, you know,

01:33:48.800 | exploring Mars, right, I don't have like strong opinions

01:33:52.960 | on whether a manned mission is required or not required,

01:33:59.540 | but I do think, you know, we need to focus,

01:34:04.060 | the thing to keep in mind is that I generally kind of,

01:34:07.900 | I'm not signed on, if you will, to the idea

01:34:11.220 | that Mars is some kind of a safe haven

01:34:13.420 | that we can, you know, escape to, right?

01:34:17.780 | Mars sucks, right?

01:34:18.980 | Like living on Mars, if you wanna live on Mars,

01:34:22.500 | like you can have that experience

01:34:25.700 | by going to the Mojave Desert and camping,

01:34:28.340 | and it's just like, it's just not a great--

01:34:31.940 | - Well, it's interesting, but there's something

01:34:33.380 | captivating about that kind of mission

01:34:35.220 | of us striving out into space,

01:34:37.420 | and by making Mars in some ways habitable

01:34:42.420 | for at least like months at a time,

01:34:46.140 | I think would lead to engineering breakthroughs

01:34:48.420 | that would make life like in many ways

01:34:51.420 | much better on Earth.

01:34:52.260 | Like it will come up with ideas we totally don't expect yet,

01:34:56.280 | both on the robotic side, on the food engineering side,

01:35:00.340 | on the, you know, maybe like we'll switch from,

01:35:03.980 | like there'll be huge breakthroughs in insect farming,

01:35:07.740 | as exciting as I find that idea to be.

01:35:11.000 | In the ways we consume protein,

01:35:14.580 | maybe it'll revolutionize, we do factory farming,

01:35:18.140 | which is full of cruelty and torture of animals,

01:35:22.020 | we'll revolutionize that completely because of our,

01:35:25.020 | like we don't, we shouldn't need to go to Mars

01:35:27.780 | to revolutionize life here on Earth,

01:35:30.000 | but at the same time, I shouldn't need a deadline

01:35:32.500 | to get shit done, but I do need it.

01:35:34.980 | And then the same way, I think we need Mars.

01:35:37.440 | There's something about the human spirit

01:35:38.920 | that loves that longing for exploration.

01:35:41.080 | - I agree with that thesis.

01:35:42.800 | Going to the moon, right, and that whole endeavor

01:35:47.800 | has, you know, has captivated the imagination of so many,

01:35:53.920 | and it has led to incredible kind of,

01:35:57.760 | incredible ideas really, and probably in nonlinear ways,

01:36:01.080 | right, not like, okay, we went to the moon,

01:36:03.160 | therefore, some person here has thought of this.

01:36:06.680 | In that similar sense, I think, you know,

01:36:09.360 | space exploration is, there's something,

01:36:12.680 | there's some real magnetism about it,

01:36:15.280 | and it's on a genetic level, right?

01:36:17.400 | Like we have this need to keep exploring, right,

01:36:21.240 | when we're done with a certain frontier,

01:36:24.680 | we move on to the next frontier.

01:36:26.280 | All that I'm saying is that I'm not moving to Mars

01:36:30.040 | to live there permanently ever, you know,

01:36:32.800 | and I think that, you know, I'm glad you noted

01:36:36.640 | the kind of degradation of the Earth, right?

01:36:39.520 | I think that is a true kind of leading order

01:36:43.600 | challenge of our time. - Yeah, it's a great

01:36:45.000 | engineering, it's a bunch of engineering problems.

01:36:48.280 | I'm most interested in space 'cause,

01:36:50.660 | as I've read extensively, it's apparently very difficult

01:36:54.060 | to have sex in space, and so I just want that problem

01:36:57.160 | to be solved because I think once we solve

01:36:59.580 | the sex in space problem, we'll revolutionize sex

01:37:02.240 | here on Earth, thereby increasing the fun on Earth,

01:37:05.640 | and the consequences of that can only be good.

01:37:09.040 | - I mean, you've got a clear plan, right?

01:37:12.360 | And it sounds like-- - I'm submitting proposals

01:37:15.360 | to NASA as we speak. - That's right.

01:37:17.160 | (laughing)

01:37:18.640 | - I keep getting rejected, I don't know why.

01:37:20.560 | - Okay. (laughing)

01:37:22.640 | - You need better diagrams. - Better pictures.

01:37:25.280 | I should have thought of that.

01:37:26.520 | You a while ago mentioned that, you know,

01:37:28.600 | there's certain aspects in the history

01:37:30.680 | of the solar system and Earth that resulted,

01:37:34.240 | it could have resulted in an opaque atmosphere,

01:37:37.160 | but it didn't, we couldn't see the stars.

01:37:40.660 | And somebody mentioned to me a little bit ago,

01:37:46.360 | it's almost like a philosophical question for you,

01:37:49.160 | do you think humans, like human society would develop

01:37:54.160 | as it did or at all if we couldn't see the stars?

01:37:59.840 | - It would be drastically different,

01:38:02.880 | just drastically, if it ever did develop.

01:38:05.200 | So I think some of the early developments, right,

01:38:08.960 | of like-- - Fire.

01:38:10.680 | - Fire, you know, first of all,

01:38:12.760 | that atmosphere would be so hot 'cause, you know,

01:38:15.160 | if you have an opaque atmosphere,

01:38:17.960 | the temperature at the bottom is huge.

01:38:22.080 | So we would be very different beings to start with.

01:38:25.680 | We'd have very different-- - But it could be cloudy

01:38:27.080 | in certain kinds of ways that you could still get--

01:38:29.360 | - Okay, think about like a greenhouse, right?

01:38:32.400 | A greenhouse is cloudy, effectively, but it's super hot.

01:38:37.400 | Yeah, it's hard to avoid having an atmosphere.

01:38:41.120 | If you have an opaque atmosphere, it's hard to, right,

01:38:44.200 | Venus is a great example, right?

01:38:46.160 | Venus is, I don't remember exactly how many degrees,

01:38:50.120 | but it's hundreds in Celsius, right?

01:38:52.920 | It's not a hundred, it's hundreds.

01:38:55.260 | Even though it's only a little bit closer to the sun,

01:38:57.920 | that temperature is entirely coming from the fact

01:39:00.320 | that the atmosphere is thick.

01:39:01.740 | - So it's a sauna of sorts.

01:39:03.800 | - Yeah, yeah, you go there, you know,

01:39:05.760 | you feel refreshed after you come back, you know.

01:39:09.200 | - But if you stay there, I mean, so, okay,

01:39:11.240 | take that as an assumption.

01:39:12.960 | This is a philosophical question, not a biological one.

01:39:15.440 | So you have a life that develops

01:39:17.120 | under these extremely hot conditions.

01:39:19.240 | - Yeah, so let's see, so much of the early evolution

01:39:23.120 | of mankind was driven by exploration, right?

01:39:28.120 | And the kind of interest in stars originated in part

01:39:33.120 | as a tool to guide that exploration, right?

01:39:37.880 | I mean, that in itself, I think would be a huge,

01:39:42.680 | you know, a huge differential in the way that we,

01:39:46.040 | you know, our evolution on this planet.

01:39:49.000 | - Yeah, I mean, stars, that's brilliant.

01:39:51.480 | So even in that aspect, but even in further aspects,

01:39:55.020 | astronomy just shows up in basically every single

01:40:00.040 | development in the history of science

01:40:02.200 | up until the 20th century, it shows up.

01:40:05.380 | So I wonder without that, if we would have,

01:40:08.400 | if we would even get like calculus.

01:40:10.480 | - Yeah, look, that's a great, I mean, that's a great point.

01:40:14.560 | Newton in part developed calculus because he was interested

01:40:18.840 | in understanding, explaining Kepler's laws, right?

01:40:22.480 | In general, that whole mechanistic understanding

01:40:26.600 | of the night sky, right, replacing a religious understanding

01:40:29.960 | where you interpret, you know, this is, you know,

01:40:32.280 | this whatever fire god riding his, you know,

01:40:36.600 | a little chariot across the sky as opposed to,

01:40:39.880 | you know, this is some mechanistic set of laws

01:40:42.960 | that transformed humanity and arguably put us on the course

01:40:47.960 | that we're on today, right?

01:40:50.500 | The entirety of the last 400 years and the development

01:40:54.000 | of kind of our technological world that we live in today

01:40:59.000 | was sparked by that, right?

01:41:02.920 | Abandoning an effectively, you know, a non-secular view

01:41:07.440 | of the natural world and kind of saying,

01:41:10.360 | "Okay, this can be understood,

01:41:13.480 | and if it can be understood, it can be utilized,

01:41:15.840 | we can create our own variants of this."

01:41:19.000 | Absolutely, we would be a very, very different species

01:41:22.400 | without astronomy.

01:41:24.440 | This I think extends beyond just astronomy, right?

01:41:28.560 | There are questions like why do we need

01:41:32.120 | to spend money on X, right?

01:41:35.000 | Where X can be anything like paleontology, right?

01:41:39.840 | - The mating patterns of penguins.

01:41:42.400 | - Yeah, that's like-- - Essential.

01:41:45.000 | - That's right.

01:41:46.440 | I think, you know, there's a tremendous underappreciation

01:41:51.180 | for the usefulness of useless knowledge, right?

01:41:55.160 | I mean-- - That's brilliant.

01:41:57.520 | - I didn't come up with this.

01:41:58.520 | This is a little book by the guy who started

01:42:02.440 | the Institute for Advanced Studies,

01:42:04.280 | but it's so true.

01:42:08.880 | So much of the electronics that are on this table, right,

01:42:11.920 | work on Maxwell's equations.

01:42:13.440 | Maxwell wasn't sitting around in the 1800s saying,

01:42:18.000 | "I hope one day we'll make a couple of mics

01:42:22.720 | so a couple of guys can have this conversation," right?

01:42:30.560 | That wasn't at no point was that the motivation,

01:42:34.800 | and yet, you know, it gave us the world that we have today.

01:42:39.800 | And the answer is if you are a purely pragmatic person,

01:42:43.640 | if you don't care at all about kind of the human condition,

01:42:46.200 | none of this, the answer is you can tax it, right?

01:42:51.200 | Like useless things have created

01:42:57.520 | way more capital than useful things.

01:43:00.640 | - And the SAT, I mean, first of all,

01:43:02.440 | it's really important to think about,

01:43:04.520 | and it's brilliant, in the following context.

01:43:09.520 | Like Neil deGrasse Tyson has this book

01:43:11.320 | about the role of military-based funding

01:43:15.080 | in the development of science.

01:43:17.360 | And then so much of technological breakthroughs

01:43:21.520 | in the 20th century had to do with humans working

01:43:26.440 | on different military things.

01:43:28.320 | And then the outcome of that had nothing to do with military.

01:43:31.120 | It had some military application,

01:43:32.520 | but their impact was much, much bigger than military.

01:43:36.760 | - The splitting of the atom

01:43:38.120 | is kind of a canonical example of this.

01:43:41.480 | We all know the tragedy that arises

01:43:44.360 | from splitting of the atom, and yet, you know, so much,

01:43:48.280 | I mean, the atom itself does not care

01:43:52.200 | for what purpose it is being split.

01:43:54.480 | So, yeah. - So I wonder if we took

01:43:57.320 | the same amount of funding as we used for war

01:43:59.800 | and poured it into like totally seemingly useless things,

01:44:04.440 | like the mating patterns of penguins,

01:44:06.520 | we would get the internet anyway.

01:44:08.480 | - I think so, I think so.

01:44:10.280 | And, you know, perhaps more of the internet

01:44:13.440 | would have penguins, you know?

01:44:17.520 | - So we're both joking, but in some sense, like,

01:44:20.640 | I wonder, it's not the penguins,

01:44:22.920 | 'cause penguins is more about sort of biology,

01:44:25.560 | but all useless kind of tinkering

01:44:27.960 | and all kinds of, in all kinds of avenues.

01:44:32.680 | And also because military applications

01:44:35.080 | are often burdened by the secrecy required.

01:44:40.040 | So it's often like so much, the openness is lacking.

01:44:45.040 | And if we learned anything for the last few decades

01:44:48.000 | is that when there's openness in science

01:44:51.120 | that accelerates the development of science.

01:44:53.600 | - That's right, that's true.

01:44:55.200 | The openness of science truly, you know,

01:44:59.040 | it benefits everybody.

01:45:01.160 | The notion that if, you know, I share my science with you,

01:45:04.760 | then you're gonna catch up and like know the same thing.

01:45:08.520 | That is a short-sighted viewpoint,

01:45:10.600 | because if you catch up and you open, you know,

01:45:15.400 | you discover something,

01:45:16.960 | that puts me in a position to do the next step, right?

01:45:20.680 | It's just, so I absolutely agree with all of this.

01:45:25.680 | I mean, the kind of question of like military funding

01:45:30.160 | versus non-military funding is obviously a complicated one.

01:45:33.840 | But at the end of the day,

01:45:35.800 | I think we have to get over the notion as a society

01:45:40.800 | that we are going to, you know, pay for this,

01:45:45.280 | and then we will get that, right?

01:45:47.600 | That's true if you're buying like, I don't know,

01:45:51.520 | toilet paper or something, right?

01:45:53.080 | It's just not true in the intellectual pursuit.

01:45:55.540 | That's not how it works.

01:45:57.520 | And sometimes it'll fail, right?

01:46:00.360 | Like sometimes like a huge fraction of what I do, right?

01:46:04.080 | I come up with an idea, I think, oh, it's great.

01:46:06.480 | And then I work it out, it's totally not great, right?

01:46:08.760 | It fails immediately.

01:46:10.240 | - Failure is not a sign

01:46:12.400 | that the initial pursuit was worthless.

01:46:15.240 | Failure is just part of this kind of,

01:46:16.720 | this whole exploration thing.

01:46:18.040 | And we should fund more and more of this exploration,

01:46:21.020 | the variety of the exploration.

01:46:22.800 | - I think it was Linus Pauling or somebody from,

01:46:25.800 | you know, that generation of scientists said,

01:46:28.120 | you know, a good way to have good ideas

01:46:31.640 | is to have a lot of ideas.

01:46:33.160 | So I think that's true.

01:46:36.960 | If you are conservative in your thinking,

01:46:39.640 | if you worry about proposing something that's going to fail

01:46:43.080 | and oh, what if, you know, like,

01:46:46.480 | there's no science police that's gonna come and arrest you

01:46:49.240 | for proposing the wrong thing.

01:46:51.640 | And, you know, it's also just like,

01:46:53.920 | why would you do science if you're afraid of,

01:46:58.920 | you know, taking that step?

01:47:00.940 | It would be so much better to propose things

01:47:03.640 | that are plausible, they're interesting,

01:47:06.800 | and then for a fraction of them to be wrong

01:47:08.840 | than to just kind of, you know,

01:47:10.560 | make incremental progress all your life, right?

01:47:13.160 | - Speaking of wild ideas,

01:47:15.480 | let me ask you about the thing we mentioned previously,

01:47:18.400 | which is this interstellar object, Amu Amu.

01:47:21.720 | Could it be space junk from a distant alien civilization?

01:47:27.280 | - You can't immediately discount that

01:47:30.340 | by saying absolutely it cannot.

01:47:33.480 | Anything can be space junk.

01:47:35.080 | I mean, from that point of view,

01:47:36.280 | can any of the Kuiper belt objects we see

01:47:38.960 | could be space junk?

01:47:40.920 | Anything on the night sky can in principle be space junk.

01:47:44.800 | - And Kuiper belt would catch interstellar objects

01:47:47.160 | potentially and like force them into an orbit

01:47:50.100 | if they're like small enough?

01:47:51.840 | - Not the Kuiper belt itself,

01:47:53.640 | but you can imagine like Jupiter family comets

01:47:55.880 | being captured, you know,

01:47:57.920 | so you can actually capture things.

01:48:00.680 | It's even easier to do this very early in the solar system,

01:48:04.160 | like early in the solar system's life

01:48:06.000 | while it's still in a cluster of stars.

01:48:08.040 | It's unavoidable that you capture debris,

01:48:13.320 | whether it be natural debris or unnatural debris

01:48:15.960 | or just debris of some kind from other stars.

01:48:19.760 | It's like a daycare center, right?

01:48:22.320 | Like everybody passes their infections onto other kids.

01:48:25.600 | You know, Oumuamua, there's been a lot of discussion about,

01:48:30.480 | and there's been a lot of interest in this over,

01:48:33.160 | is it aliens or is it not?

01:48:34.800 | But let's, like, if you just kind of look at the facts,

01:48:37.840 | like what we know about it is it's kind of like a weird shape

01:48:41.780 | and it also accelerated, right?

01:48:44.720 | Like that's the two,

01:48:46.440 | those are the two interesting things about it.

01:48:50.680 | There are puzzles about it

01:48:55.400 | and perhaps the most daring resolution to this puzzle

01:49:00.400 | is that it's not, you know, aliens or it's not like a rock,

01:49:05.960 | it's actually a piece of hydrogen ice.

01:49:08.680 | So this is a friend of mine, you know,

01:49:11.740 | Daryl Seligman and Greg Laughlin came up with this idea

01:49:16.400 | where that in giant molecular clouds

01:49:19.740 | that are just clouds of hydrogen helium gas

01:49:22.660 | that live throughout the galaxy,

01:49:26.360 | at their cores, you can condense ice

01:49:29.780 | to become these hydrogen, you know, icebergs, if you will.

01:49:33.740 | And then that explains many of the aspects

01:49:37.740 | of, in fact, I think that explains

01:49:41.060 | all of the Oumuamua mystery, how it becomes elongated

01:49:45.540 | because basically the hydrogen ice sublimates

01:49:48.380 | and kind of like a bar of soap that, you know,

01:49:51.260 | slowly kind of elongates as you strip away

01:49:55.860 | the surface layers, how it was able to accelerate

01:50:00.500 | because of a jet that is produced from, you know,

01:50:03.380 | the hydrogen coming off of it, but you can't see it

01:50:05.580 | 'cause it's hydrogen gas, like all of this stuff

01:50:07.980 | kind of falls together nicely.

01:50:10.960 | I'm intrigued by that idea, truly,

01:50:14.860 | because it's like, if that's true,

01:50:17.640 | that's a new type of astrophysical object.

01:50:21.180 | - And it would be produced by,

01:50:23.820 | what's the monster that produced it initially,

01:50:25.900 | that kind of object?

01:50:27.260 | - So this is giant molecular clouds, they're everywhere.

01:50:30.420 | I mean, they are, the fact that they exist is not--

01:50:34.500 | - Are they rogue clouds or are they part of like

01:50:36.740 | an oared cloud of another solar?

01:50:38.580 | - No, no, they're rogue clouds, yeah.

01:50:39.420 | - They're just floating about?

01:50:40.720 | - Yeah, so if you go, like a lot of people imagine

01:50:43.380 | the galaxy as being a bunch of stars, right,

01:50:48.380 | and they're just orbiting, right,

01:50:50.760 | but the truth is if you fly between stars,

01:50:52.780 | you run into clouds.

01:50:55.180 | - That don't have any large object that creates orbits,

01:50:58.260 | they're just floating about.

01:50:59.100 | - They're just floating.

01:51:00.020 | - But why are they floating together?

01:51:01.700 | Are they just floating together for a time and not--

01:51:03.940 | - Well, so these eventually become the nurseries of stars.

01:51:08.780 | So as they cool, they contract and then collapse

01:51:13.780 | into stars or into groups of stars.

01:51:15.980 | But some of them, the starless molecular clouds,

01:51:20.980 | according to the calculations that Daryl and Greg did

01:51:25.900 | can create these like icicles of hydrogen ice.

01:51:30.900 | - I wonder why they would be flying so fast.

01:51:34.180 | 'Cause they seem to be moving pretty fast at a quick pace.

01:51:36.260 | - You mean Oumuamua?

01:51:37.100 | - Oumuamua, yeah.

01:51:37.940 | - Oh, that's just because of the acceleration

01:51:39.820 | due to the sun.

01:51:41.420 | If you stop, it's like, take something really far away,

01:51:46.260 | let it go, and the sun is here.

01:51:48.140 | By the time it comes close to the sun, right,

01:51:50.540 | it's moving pretty fast.

01:51:52.900 | So that's an attractive explanation, I think,

01:51:56.060 | not so much because it's cool,

01:51:58.680 | but it makes a clear prediction, right,

01:52:00.980 | of when Vera Rubin Observatory comes online next year or so,

01:52:05.980 | we will discover many, many more of these objects, right?

01:52:10.740 | And they have, so I like theories that are falsifiable,

01:52:15.740 | and not just testable, but falsifiable.

01:52:19.260 | It's good to have a falsifiable theory

01:52:21.240 | where you can say that's not true.

01:52:23.000 | Aliens is one that's fundamentally difficult

01:52:27.900 | to say, no, that's not aliens, right?

01:52:30.260 | - The interesting thing to me,

01:52:32.100 | if you look at one alien civilization,

01:52:34.320 | and then we look at the things it produces,

01:52:37.660 | in terms of if we were to try to detect

01:52:39.860 | the alien civilization, there's like,

01:52:44.460 | say there's 10 billion aliens,

01:52:47.860 | there would probably be

01:52:49.420 | trillions of dumb drone-type things produced by the aliens,

01:52:58.300 | and there'd be many, many, many more orders

01:53:01.340 | and magnitude of junk.

01:53:03.400 | So like, if you were to look for an alien civilization,

01:53:06.740 | in my mind, you would be looking for the junk.

01:53:09.700 | That's the more efficient thing to look for.

01:53:12.260 | So I'm not saying Oumuamua has any characteristics

01:53:15.860 | of space junk, but it kind of opened my eyes

01:53:18.220 | like to the idea that we shouldn't necessarily be looking

01:53:22.780 | to the queen of the ant colony.

01:53:25.420 | We should be looking at, I don't know.

01:53:27.700 | I don't know, like traces of alien life

01:53:31.020 | that doesn't look intelligent in any way,

01:53:33.500 | may not even look like life.

01:53:35.100 | It could be just garbage.

01:53:36.340 | We should be looking for garbage.

01:53:39.540 | - Just generically.

01:53:41.380 | - Garbage that's producible by unnatural forces.

01:53:46.380 | For me, at least, that was kind of interesting

01:53:49.020 | because if you have a successful alien civilization,

01:53:52.900 | that we would be producing many more orders

01:53:55.020 | and magnitude of junk, and that would be easier

01:53:57.300 | potentially to detect.

01:53:58.700 | - Well, so you have to produce the junk,

01:54:00.380 | but you have to also launch it.

01:54:02.140 | So this is where, I mean, let's imagine--

01:54:05.620 | - Garbage disposal.

01:54:06.460 | - Yeah, but let's imagine we are a successful civilization

01:54:11.300 | that has made it to space.

01:54:13.020 | We clearly have, right?

01:54:15.180 | And yes, we're in the infancy of that pursuit,

01:54:18.140 | but we've launched, I don't know how many satellites.

01:54:21.940 | Probably if you count GPS satellites,

01:54:26.100 | it must be at least thousands.

01:54:28.820 | - It's certainly thousands.

01:54:30.100 | I don't know if it's over 10,000, but it's on that order.

01:54:32.420 | - But it's on that large order of magnitude.

01:54:34.860 | How many of the things that we've launched

01:54:37.620 | will ever leave the solar system?

01:54:39.500 | I think two.

01:54:40.940 | - It's two so far.

01:54:41.780 | - Well, maybe the Voyager, the Voyager 1, Voyager 2.

01:54:44.860 | I don't know if the Pioneer.

01:54:46.820 | So maybe three.

01:54:48.180 | - Oh, there's also a Tesla Roadster out there.

01:54:50.580 | - That one, it will never leave the solar system.

01:54:54.660 | I think that one will eventually collide with Mars.

01:54:57.340 | That can be SpaceX's first Mars destination.

01:55:00.700 | But look, so there's an energetic cost

01:55:05.340 | to interstellar travel, which is really hard to overcome.

01:55:09.580 | And when we think about generically,

01:55:12.740 | what do we look for in an alien civilization?

01:55:15.180 | Oftentimes, we tend to imagine that the thing you look for

01:55:18.820 | is the thing that we're doing right now, right?

01:55:21.820 | So I think that if I look at the future, right?

01:55:26.820 | And for a while, like, okay, if aliens are out there,

01:55:30.220 | they must be broadcasting in radio, right?

01:55:33.100 | That radio, the amount that we broadcast in radio

01:55:37.980 | has diminished tremendously in the last 50 years,

01:55:42.860 | but we're doing a lot more computation, right?

01:55:46.700 | What are the signs of computation?

01:55:49.300 | Like, that's an interesting question to ask, right?

01:55:52.380 | Where, I don't know, I think something on the order

01:55:55.860 | of a few percent of the entire electrical grid last year

01:56:00.260 | went to mining Bitcoin, right?

01:56:03.060 | - Yeah, there could be a lot of, in the future,

01:56:07.780 | different consequences of the computation,

01:56:09.740 | which, I mean, I'm biased, but it could be robotics,

01:56:13.340 | it could be artificial intelligence.

01:56:14.700 | So we may be looking for intelligent-looking objects,

01:56:19.700 | like that's what I meant by probes,

01:56:22.500 | like things that move in kind of artificial ways.

01:56:25.260 | - But the emergence of AI is not an if, right?

01:56:28.780 | It's happening right in front of our eyes,

01:56:33.460 | and the energetic costs associated with that

01:56:36.980 | are becoming a tangible problem.

01:56:39.740 | So I think, if you imagine kind of extrapolating that

01:56:43.260 | into the future, right, what are the,

01:56:46.740 | what becomes the bottleneck, right?

01:56:50.340 | The bottleneck might be powering,

01:56:54.380 | powering the AI, broadly speaking, not one AI,

01:56:57.580 | but powering that entire AI ecosystem, right?

01:57:01.100 | So I don't know, I think space junk is kind of,

01:57:06.100 | it's an interesting idea, but it's heavily influenced

01:57:10.380 | by like sci-fi of 1950s, where by 2020,

01:57:13.820 | we're all like flying to the moon,

01:57:16.140 | and so we produce a lot of space junk.

01:57:19.220 | I'm not sure if that's the pathway

01:57:23.300 | that alien civilizations take.

01:57:25.980 | I've also never seen an alien civilization,

01:57:27.940 | I don't know anything. - That's true.

01:57:29.420 | But if your theory of chill turns out to be true,

01:57:34.420 | and then we don't necessarily explore,

01:57:37.620 | we seize the exploration phase of,

01:57:40.260 | like alien civilizations quickly seize

01:57:42.140 | the exploration phase of their efforts,

01:57:47.140 | then perhaps they'll just be chilling

01:57:50.380 | in a particular space, expanding slowly,

01:57:53.980 | but then using up a lot of resources,

01:57:56.020 | and then have to have a lot of garbage disposal

01:57:58.020 | that sends stuff out.

01:58:00.500 | And the other, you know, the other idea

01:58:02.460 | was that it could be a relay,

01:58:04.700 | that you'll almost have like these GPS-like markers

01:58:08.900 | that you send throughout,

01:58:10.600 | which I think is kind of interesting.

01:58:12.020 | It's similar to this probe idea

01:58:14.820 | of sending a large number of probes out

01:58:19.380 | to measure gravitational,

01:58:21.180 | to measure basically, yeah, the gravitational field,

01:58:27.500 | essentially, I mean, a lot of people at Caltech

01:58:29.820 | or at MIT are trying to measure gravitational fields,

01:58:33.060 | and there's a lot of ideas of sending stuff out there

01:58:37.220 | that accurately measures those gravitational fields

01:58:42.980 | to have a greater understanding of the early universe,

01:58:46.940 | but then you might realize that communication

01:58:49.780 | through gravitation, through gravity,

01:58:51.900 | is actually much more effective than radio waves,

01:58:54.420 | for example, something like that.

01:58:56.140 | And then you send out, I mean, okay.

01:58:59.380 | If you're an alien civilization that's able

01:59:01.180 | to have gigantic masses, like basically--

01:59:06.180 | - We're getting there as a civilization.

01:59:09.100 | - No, we're not even close.

01:59:10.860 | - Well, I mean--

01:59:11.940 | - No, okay, yeah, okay.

01:59:14.420 | I mean like be able to sort of play with black holes,

01:59:17.900 | that kind of thing.

01:59:18.740 | So we're talking about a whole 'nother order

01:59:21.140 | of magnitude of masses.

01:59:22.900 | Then it may be very effective

01:59:24.540 | to send signals via gravitational waves.

01:59:27.060 | - I actually, my sense is that all of these things

01:59:29.500 | are genuinely difficult to predict.

01:59:33.820 | And I don't mean like to kind of shy away.

01:59:36.020 | I just, I really mean if you think,

01:59:38.060 | if you take imagination of what the future will look like

01:59:43.060 | from 500 years ago, right?

01:59:46.740 | It's just, it is so hard to conceive of the impossible.

01:59:51.020 | Right, so it's almost like, you know,

01:59:56.020 | it's almost limiting to try and imagine things

01:59:58.860 | that are an order of magnitude, you know,

02:00:01.660 | or two orders of magnitude ahead in terms of progress,

02:00:04.780 | just because, you know, you mentioned cars before,

02:00:08.140 | you know, if you were to ask people what they wanted

02:00:11.540 | in 1870, it's faster buggies, right?

02:00:15.300 | So I think the whole like kind of, you know,

02:00:19.620 | alien conversation inevitably gets limited

02:00:24.380 | by our entire kind of collective astrophysical

02:00:29.380 | lack of imagination, if you know.

02:00:31.740 | - So to push back a little bit,

02:00:33.100 | I find that it's really interesting to talk about

02:00:38.020 | these wild ideas about the future,

02:00:39.740 | whether it's aliens, whether it's AI,

02:00:41.780 | with brilliant people like yourself

02:00:44.940 | who are focused on very particular tools of science

02:00:47.660 | we have today to solve very particular,

02:00:50.060 | like rigorous scientific questions.

02:00:52.220 | And it's almost like putting on this wild,

02:00:54.540 | dreamy hat like some percent of the time

02:00:56.860 | and say like, what would alien civilizations look like?

02:01:00.340 | What would alien trash look like?

02:01:03.180 | Well, what would our own civilization

02:01:05.660 | that sends out trillions of AI systems out there,

02:01:09.540 | like how 9,000, but 10,000 out there,

02:01:12.180 | what would that look like?

02:01:13.420 | And you're right, any one prediction

02:01:15.500 | is probably going to be horrendously wrong,

02:01:18.140 | but there's something about creating

02:01:19.740 | these kind of wild predictions

02:01:21.780 | that kind of opens up--

02:01:24.180 | - No, there's a huge magnetism to it, right?

02:01:26.500 | And some of it,

02:01:28.140 | I mean, some of the Jules Verne novels

02:01:34.180 | did a phenomenal job predicting the future, right?

02:01:38.100 | That actually was a great example

02:01:40.180 | of what you're talking about,

02:01:41.020 | like allowing your imagination to run free.

02:01:44.500 | I mean, I just hope there's dragons.

02:01:48.980 | That's like-- - I love dragons.

02:01:51.220 | - Yeah, dragons are the best.

02:01:52.980 | - But see, the cool thing about science fiction

02:01:57.300 | and these kinds of conversations,

02:01:58.620 | it doesn't just predict the future, I think.

02:02:01.540 | Some of these things will create the future.

02:02:04.420 | Planting the idea, humans are amazing.

02:02:09.460 | Like, fake it till you make it.

02:02:11.060 | Humans are really good at taking an idea

02:02:16.020 | that seems impossible at the time,

02:02:18.140 | and for any one individual human,

02:02:20.940 | that idea, it's like planting a seed

02:02:24.820 | that eventually materializes itself.

02:02:26.340 | It's weird.

02:02:27.180 | It's weird how science fiction can create science fiction.

02:02:30.700 | - And drive some of the-- - It drives the science.

02:02:32.540 | - I agree with you.

02:02:33.540 | And I think in this regard,

02:02:36.420 | I'm like a sucker for sci-fi.

02:02:41.340 | It's all I listen to now when I run.

02:02:46.820 | And some of it is completely implausible, right?

02:02:50.260 | And it's just like, I don't care.

02:02:51.900 | It's both entertaining

02:02:56.900 | and it's just like, it's imagination.

02:03:01.380 | You know about "The Black Clouds" book?

02:03:03.620 | I think it was by Fred Hoyle.

02:03:05.500 | This has great connections with a lot of the advancements

02:03:09.300 | that are happening in NLP right now, right?

02:03:13.660 | With transformer models and so on.

02:03:15.900 | But it's this black cloud shows up in the solar system

02:03:20.060 | and then people try to send radio

02:03:22.980 | and then it learns to talk back at you.

02:03:26.140 | So anyway, we don't have to talk at all about it,

02:03:28.900 | but it's just something worth checking out.

02:03:31.100 | - With that on the alien front, with the black cloud,

02:03:33.740 | to me, exactly, on the NLP front,

02:03:36.580 | and also just explainability of AI,

02:03:38.740 | it's fascinating.

02:03:39.820 | Just the very question,

02:03:41.260 | Stephen Wolfram looked at this with the movie "Arrival."

02:03:44.220 | It's like, what would be the common language

02:03:46.260 | that we would discover?

02:03:47.580 | The reason that's really interesting to me

02:03:49.420 | is we have aliens here on Earth now.

02:03:51.260 | - Japanese.

02:03:52.380 | - Japanese, well yeah.

02:03:53.220 | - Japanese is the obvious answer.

02:03:54.780 | - Japanese, yeah, that would be the common.

02:03:57.340 | Maybe it would be music, actually.

02:03:59.740 | That's more likely.

02:04:00.620 | It wouldn't be language.

02:04:01.620 | It would be art that they would communicate.

02:04:03.860 | But I do believe that we have,

02:04:06.340 | I'm with Stephen Wolfram on this a little bit,

02:04:09.740 | that to me, computation, like programs we write,

02:04:14.060 | they're kind of intelligent creatures

02:04:17.820 | and I feel like we haven't found the common language

02:04:20.100 | to talk with them.

02:04:21.140 | Like our little creations that are artificial

02:04:26.060 | are not born with whatever that innate thing

02:04:28.900 | that produces language with us.

02:04:31.340 | And like coming up with mechanisms

02:04:33.860 | for communicating with them

02:04:35.260 | is an effort that feels like it will produce

02:04:40.900 | some incredible discoveries.

02:04:42.500 | You can even think of,

02:04:43.520 | if you think that math is discovered,

02:04:46.220 | mathematics in itself is a kind of--

02:04:49.300 | - Oh yeah, it's an innate construction

02:04:51.340 | of the world we live in.

02:04:53.060 | I think we are part of the way there

02:04:58.340 | because pre-1950, right,

02:05:03.340 | computers were human beings

02:05:06.300 | that would carry out arithmetic, right?

02:05:08.820 | And I think it was Ulam,

02:05:10.620 | who worked in Los Alamos at the time,

02:05:15.500 | like towards the end of the Second World War,

02:05:19.140 | wrote something about how in the future,

02:05:22.620 | computers will not be just arithmetic tool,

02:05:27.340 | but will be truly an interactive thing

02:05:31.020 | with which you could do experiments.

02:05:34.300 | At the time, the notion of doing an experiment,

02:05:36.900 | not like in the lab with some beakers,

02:05:39.140 | but an experiment on a computer,

02:05:41.700 | designing an experiment, a numerical experiment,

02:05:45.460 | was a new one.

02:05:47.860 | That's like 70% of what I do is I design,

02:05:52.860 | I write code, terrible code to be clear,

02:05:57.500 | but I write code that creates an experiment,

02:06:01.860 | which is a simulation.

02:06:04.180 | So in that sense,

02:06:05.820 | I think we're beginning to interact with the computer

02:06:08.340 | in a way that you're saying,

02:06:10.100 | not as just a fancy calculator,

02:06:13.260 | not as just a call and request type of thing,

02:06:18.260 | but something that can generate insights

02:06:23.100 | that are otherwise completely unattainable, right?

02:06:26.180 | They're unattainable by doing analytical mathematics.

02:06:29.620 | - Yeah, and there's, with the AlphaFold 2,

02:06:32.900 | we're now starting to crack open biology.

02:06:36.340 | So being able to simulate at first

02:06:38.580 | trivial biological systems

02:06:40.100 | and hopefully down the line complex biological systems,

02:06:43.140 | my hope is to be able to simulate

02:06:44.980 | sociological systems like humans.

02:06:49.340 | A large part of my work at MIT was on autonomous vehicles,

02:06:56.220 | and the fascinating thing to me was about pedestrians,

02:07:00.060 | human pedestrians interacting with autonomous vehicles,

02:07:02.580 | and simulating those systems without murdering humans

02:07:05.580 | would be very useful,

02:07:06.700 | but nevertheless is exceptionally difficult.

02:07:08.500 | - Yeah, I would say so.

02:07:09.740 | When is my Mustang gonna drive itself?

02:07:11.860 | Right, I'm not even joking.

02:07:14.540 | It looks like, yeah.

02:07:16.540 | - It turns out it's much more difficult than we imagined.

02:07:21.540 | And I suppose that's the kind of,

02:07:23.700 | the progress of science is just like going to Mars,

02:07:29.620 | it's probably going to turn out

02:07:33.260 | to be way more difficult than we imagined.

02:07:35.220 | Sending out probes to investigate Planet Nine

02:07:37.660 | at the edge of our solar system

02:07:39.420 | might turn out to be way more difficult than we imagined,

02:07:41.580 | but we do it anyway, and we figure it out in the end.

02:07:44.340 | - It's actually, Mars is a great,

02:07:45.500 | I mean, sending humans to Mars,

02:07:48.660 | way more complicated than sending humans to the moon.

02:07:51.380 | You'd think just like naively,

02:07:53.900 | both are in space, who cares?

02:07:55.860 | Like, if you go there, why don't you go there?

02:08:01.260 | This life support is an extremely expensive thing, yeah.

02:08:05.300 | - There's a bunch of extra challenges,

02:08:06.860 | but I disagree with you.

02:08:07.980 | I would be one of the early people to go.

02:08:09.740 | I used to think not.

02:08:11.340 | I used to think I'd be one of the first,

02:08:12.740 | maybe million to go,

02:08:14.020 | once you have a little bit of a society.

02:08:15.980 | I think I'm upgrading myself to the first like 10,000.

02:08:19.180 | - That's right, front of the cabin.

02:08:21.740 | - Not completely front, but like,

02:08:24.300 | it'd be interesting to die.

02:08:25.740 | I'm okay with, death sucks,

02:08:29.740 | but I kind of like the idea of dying on Mars.

02:08:34.100 | - Of all the places to die,

02:08:36.020 | I gotta say in this regard,

02:08:37.380 | like, I don't wanna die on Mars.

02:08:39.940 | - You don't?

02:08:40.780 | - No, no, I would much rather die on Earth.

02:08:45.300 | I mean, death is fundamentally boring, right?

02:08:48.220 | Like, death is a very boring experience.

02:08:51.020 | I mean, I've never died before,

02:08:52.100 | so I don't know from firsthand experience.

02:08:54.260 | - As far as you know.

02:08:55.100 | - Yeah.

02:08:55.940 | - It could be a reincarnation, all those kinds of things.

02:08:57.740 | - So you mean, where would you die,

02:09:00.820 | if you had to choose?

02:09:02.780 | - Oh man, okay, so I would definitely,

02:09:08.900 | there's a question of who I'd wanna die with.

02:09:11.900 | I'd prefer not to die alone,

02:09:14.620 | but like, surrounded by family would be preferable,

02:09:20.460 | where, I think Northern New Mexico,

02:09:24.380 | and I'm not even joking, like, this is not a random,

02:09:27.220 | it's just like--

02:09:28.300 | - Would that be your favorite place on Earth?

02:09:31.180 | - Not necessarily, like, favorite place on Earth

02:09:34.100 | to reside at, you know, indefinitely,

02:09:38.380 | but it is one of the most beautiful places

02:09:41.060 | I've ever been to.

02:09:43.380 | So, you know, there's something,

02:09:45.980 | I don't know, there's something attractive about going--

02:09:49.900 | - Returning to nature in a beautiful place.

02:09:54.660 | Let me ask you about another aspect of your life

02:09:57.460 | that is full of beauty, music.

02:10:00.060 | - Okay.

02:10:00.900 | - You're a musician.

02:10:01.740 | The absurd question I have to ask,

02:10:05.340 | what is the greatest song of all time?

02:10:07.460 | - Oh.

02:10:08.300 | - Objectively speaking.

02:10:09.180 | - The greatest song of all time.

02:10:10.900 | - I suppose that could change moment to moment, day to day,

02:10:14.620 | but if you were forced to answer

02:10:16.060 | for this particular moment in your life,

02:10:18.180 | that's something that pops to mind.

02:10:20.340 | This could be both philosophically,

02:10:22.020 | this could be technically as a musician,

02:10:23.780 | like what you enjoy, maybe lyrics.

02:10:25.460 | Like for me, lyrics is very important.

02:10:28.020 | So I would probably, my choice would be lyrics-based.

02:10:32.500 | - I don't want to answer in terms of just technical,

02:10:35.420 | you know, technical prowess.

02:10:37.340 | I think technical prowess is impressive, right?

02:10:41.420 | It's just like, it's impressive what can be done.

02:10:44.900 | I wouldn't place that into the category

02:10:46.620 | of the greatest music ever written.

02:10:48.980 | Some of the classical music that's written

02:10:53.660 | is undeniably beautiful,

02:10:55.300 | but I don't want to consider that category of music either,

02:11:00.300 | just because, you know, so if I was to limit

02:11:03.700 | the scope of this philosophical discussion

02:11:08.300 | to, you know, the kind of music that I listen to,

02:11:12.260 | you know, probably "What's My Age Again" by Blink-182.

02:11:16.220 | It's just, you know, it's a solid one.

02:11:18.460 | It's got, you know.

02:11:20.180 | - Said nobody ever.

02:11:23.020 | - That's a good song.

02:11:24.020 | I don't even know if you're joking.

02:11:26.220 | - No, no, I am joking.

02:11:27.820 | It's a good one, but it's, yeah, I mean.

02:11:30.180 | - I was gonna go back as a close second.

02:11:32.180 | (laughing)

02:11:34.420 | - "What's My Age Again."

02:11:36.700 | Yeah, oh yeah.

02:11:37.860 | - No, I mean, it would probably, you know,

02:11:41.420 | songwriting-wise, I think the Beatles came pretty close to-

02:11:45.140 | - Were they influential to you?

02:11:46.540 | - Absolutely. - Like the Beatles?

02:11:47.660 | - Yeah, love the Beatles.

02:11:49.140 | I love the Beatles.

02:11:51.140 | - "Let It Be," "Yesterday," yeah.

02:11:54.700 | - I think "Strawberry Fields Forever" is one of,

02:11:57.220 | you know what one of my favorite Beatles songs is?

02:12:00.060 | It's, you know, "In My Life," right?

02:12:03.260 | That song, it's hard to imagine how whatever,

02:12:06.420 | a 24-year-old wrote that.

02:12:09.180 | It is one of the most introspective pieces of music ever.

02:12:14.180 | You know, I'm a huge Pink Floyd fan.

02:12:17.620 | And so I think, you know, if you were to,

02:12:20.380 | you can sort of look at the entire

02:12:21.780 | "Dark Side of the Moon" album,

02:12:23.900 | and as, you know, getting pretty close up there

02:12:27.820 | to the pinnacle of what, you know, can be created.

02:12:30.820 | So, you know, "Time" is a great song.

02:12:33.180 | - Yeah. - It's a great song.

02:12:34.780 | - Just the entirety of just the instruments,

02:12:38.260 | the lyrics, the feeling created by a song,

02:12:42.220 | like Pink Floyd can create feelings,

02:12:46.340 | just the entire experience.

02:12:47.820 | I mean, you have that with "The Wall"

02:12:49.220 | of just transporting you into another place.

02:12:53.620 | Songs don't, not many songs could do that as well.

02:12:58.100 | Not many artists can do that as well as Pink Floyd did.

02:13:00.460 | - There are a lot of bands that you can kind of say,

02:13:03.540 | "Oh yeah."

02:13:04.380 | Like if you take Blink-182, right?

02:13:07.180 | If you have no idea, like if you are listening

02:13:10.540 | to sort of that type of pop punk for the first time,

02:13:14.180 | it's difficult to differentiate between Blink-182

02:13:16.660 | and like Sum 41 and the thousand of other

02:13:20.780 | like lesser known bands that all sounded,

02:13:24.140 | they all had that sparkling production feel.

02:13:27.660 | They all kind of sounded the same, right?

02:13:30.980 | When with Pink Floyd, it's hard to find another band

02:13:35.420 | that you're like, "Well, is this one Pink Floyd?"

02:13:38.500 | Like you know when you're listening to Pink Floyd,

02:13:41.780 | what you're listening to.

02:13:43.300 | - The uniqueness, that's fascinating.

02:13:45.380 | You know, in the calculation of the greatest song

02:13:48.940 | and the greatest band of all time,

02:13:51.380 | you could probably actually quantify this

02:13:54.340 | like scientifically is like how unique,

02:13:58.740 | if you play different songs,

02:13:59.900 | how well are people able to recognize

02:14:01.700 | whether it's this band or not?

02:14:03.420 | And that, you know, that's probably a huge component

02:14:06.300 | to greatness.

02:14:07.140 | Like if the world would miss it if it was gone.

02:14:10.340 | - Yes, yes.

02:14:12.540 | - So, but there's also the human story things.

02:14:14.740 | Like I would say I'll put Johnny Cash's cover of "Hurt"

02:14:19.060 | as one of the greatest songs of all time.

02:14:21.980 | And that has less to do with the song.

02:14:24.580 | - But your interaction with it.

02:14:26.380 | - Interaction with it, but also the human,

02:14:28.060 | the full story of the human.

02:14:29.700 | So like, it's not just, if I just heard the song,

02:14:32.220 | I'd be like, okay.

02:14:33.220 | But if it's the full story of it,

02:14:36.780 | also the video component for that particular song.

02:14:40.220 | So like that, you can't discount the full experience of it.

02:14:43.980 | - Absolutely.

02:14:44.820 | You know, I have no confusion about not,

02:14:47.740 | about being, you know, anywhere, you know, in that lane.

02:14:52.740 | But I just like, sometimes think about, you know,

02:14:56.100 | music that is being produced today feels,

02:15:01.100 | oftentimes feels like kind of clothes,

02:15:04.900 | like clothes that you buy at like H&M

02:15:08.700 | and you wear three times before they rip and you throw away.

02:15:12.860 | So like, so much of it is, it's not bad.

02:15:16.060 | It's just kind of forgettable, right?

02:15:18.540 | Like the fact that we're talking about Pink Floyd in 2021

02:15:23.460 | is in itself an interesting question.

02:15:26.380 | Why are we talking about Pink Floyd?

02:15:28.140 | And it's, there's something unforgettable about them

02:15:30.300 | and unforgettable about the art that they created.

02:15:34.260 | - That could be the markets that like,

02:15:35.940 | so Spotify has created this kind of market

02:15:38.300 | where the incentives for creating music that lasts

02:15:43.300 | is much lower because there's so much more music.

02:15:46.300 | You just want something that shines bright

02:15:48.700 | for a short amount of time,

02:15:50.300 | makes a lot of money and moves on.

02:15:51.820 | And I mean, the same thing you see with the news

02:15:54.020 | and all those kinds of things.

02:15:54.860 | We're just living in a shorter and shorter, shorter,

02:15:57.660 | like time scale in terms of our attention spans.

02:16:01.380 | And that, nevertheless,

02:16:04.620 | when we look at the long arc of history of music,

02:16:06.620 | perhaps there will be some songs from today

02:16:09.220 | that will last as much as Pink Floyd.

02:16:11.540 | We're just unable to see it.

02:16:13.220 | - Yeah, just the collected works of Nickelback.

02:16:16.380 | - Exactly.

02:16:17.220 | You never know, you never know, Justin Bieber.

02:16:19.940 | It could be a contender.

02:16:21.620 | I've recently started listening to Justin Bieber

02:16:23.220 | just to understand what people are talking about.

02:16:25.220 | You know, I'll just keep my comments to myself on that one.

02:16:27.940 | - It's too good to explain in words.

02:16:29.860 | - The words cannot capture the greatness that is the Biebs.

02:16:35.620 | You as a musician, so you write your own music,

02:16:40.220 | you play guitar, you sing.

02:16:42.200 | Maybe can you give an overview

02:16:46.820 | of the role music has played in your life?

02:16:48.900 | You're one of the, you're a world-class scientist.

02:16:52.540 | And so it's kind of fascinating to see somebody

02:16:55.940 | in your position who is also a great musician

02:17:01.500 | and still loves playing music.

02:17:04.580 | - Yeah, well, I wouldn't call myself a great musician.

02:17:07.260 | - One of the best of all time.

02:17:08.780 | - That's right.

02:17:12.220 | - Like we were saying offline,

02:17:13.300 | confidence is like the most essential thing

02:17:15.500 | about being a rock star.

02:17:16.340 | - Exactly.

02:17:17.180 | It's the confidence and kind of like moodiness, right?

02:17:20.460 | Yeah, look, I mean, music plays an absolutely essential role

02:17:26.740 | in everything I do because I lose,

02:17:31.060 | if I stop playing for one reason or another,

02:17:34.540 | say I'm traveling, I notably lose creativity

02:17:38.340 | in every other aspect of my life, right?

02:17:41.020 | There's something, I don't view playing music

02:17:46.020 | as a separate endeavor from doing science

02:17:49.380 | or doing whatever.

02:17:50.340 | It's all part of that same creative thing,

02:17:54.420 | which is distinct from, I don't know,

02:18:00.940 | pressing a button or like, you know.

02:18:02.580 | - So it's not a break from science,

02:18:04.460 | it's a part of your science.

02:18:05.860 | - It's absolutely, it's a part of,

02:18:08.420 | I would say, it's a thing that enables the science, right?

02:18:13.420 | The science would suck even more than it does already

02:18:18.060 | without the music.

02:18:19.220 | - And that means like the creating of the,

02:18:21.060 | the writing of the music,

02:18:22.060 | or is it just even playing other people's stuff?

02:18:24.020 | Is it a whole of it?

02:18:25.380 | - Yeah, it's definitely both.

02:18:29.260 | Yeah, and also just, you know,

02:18:31.900 | I love to play guitar, love to sing, you know,

02:18:36.620 | my wife tolerates my screeching singing, you know,

02:18:41.620 | and even kind of likes it.

02:18:43.940 | - Yeah, so people should check out your stuff.

02:18:46.700 | You have a great voice, so I love your stuff.

02:18:49.860 | Is there something, you're super busy,

02:18:52.420 | is there something you could say about practicing

02:18:57.700 | for musicians, for guitar, for you're also in a band?

02:19:00.860 | So like that whole, how you can manage that,

02:19:03.740 | is there some tricks, is there some hacks

02:19:05.620 | to being a lifelong musician while being like super busy?

02:19:10.620 | - So I would say, you know,

02:19:12.900 | the way that I optimize my life is I try to,

02:19:18.220 | I try to do, you know,

02:19:19.580 | the thing that I'm passionate about in a moment

02:19:22.620 | and put that at the top of the priority list.

02:19:25.980 | There are moments when, you know,

02:19:27.820 | you just, you feel inspired to play music.

02:19:30.340 | And if you're in the middle of something,

02:19:31.700 | if you can avoid, if that can be put on hold, just do it.

02:19:35.180 | Right, there are times when you get inspired

02:19:37.580 | about something scientific, you know,

02:19:41.580 | I do my best to drop everything,

02:19:44.460 | go into that, you know, mode of,

02:19:46.940 | that isolated mode and execute upon that.

02:19:51.380 | So it's a chaotic, you know,

02:19:53.500 | I think I have a pretty chaotic lifestyle

02:19:55.820 | where I'm always doing kind of multiple things

02:19:59.020 | and jumping between what I'm doing.

02:20:03.420 | But at the end of the day,

02:20:05.220 | it's not like, you know,

02:20:09.220 | those moments of inspiration are actually kind of rare, right?

02:20:14.220 | Like most of the time,

02:20:16.220 | all of us are just doing kind of,

02:20:19.900 | doing the stuff that needs to get done.

02:20:22.860 | If you do the disservice to yourself of saying,

02:20:26.420 | oh, I'm inspired to, you know, do this calculation,

02:20:29.620 | figure this out, but I've got to answer email

02:20:33.340 | or just like do something silly, you know,

02:20:37.300 | that is nothing more than disservice.

02:20:40.780 | And also like I have some social media presence,

02:20:44.980 | but I mostly stay off of, you know, social media to,

02:20:51.420 | you know, just frankly, 'cause like,

02:20:53.500 | I don't enjoy the mental cycles that it takes over.

02:20:57.340 | - Yeah, it robs you of that, yeah,

02:21:00.060 | those precious moments that could be filled

02:21:03.860 | with inspiration in your other pursuits.

02:21:06.780 | But there's something to,

02:21:09.620 | maybe you and I are different in this.

02:21:10.980 | Like I try to play at least 10 minutes of guitar every day,

02:21:15.300 | like almost on the technical side,

02:21:19.140 | like keeping that base of basic competence going.

02:21:24.140 | And I mean, the same way like writers

02:21:29.220 | will get in front of a paper, no matter what,

02:21:31.300 | that kind of thing.

02:21:32.940 | It just feels like that for my life has been essential

02:21:36.700 | to the daily ritual of it.

02:21:39.580 | Otherwise days turn into weeks, weeks turn into months

02:21:43.020 | and you haven't played guitar for months.

02:21:45.180 | - No, no, I understand.

02:21:47.380 | For me, I think it's been like,

02:21:50.660 | if we have a gig coming up, we'll definitely--

02:21:53.140 | - You need deadlines.

02:21:53.980 | - Yeah, yeah, that's right.

02:21:54.860 | No, like we will sharpen up definitely,

02:21:59.860 | you know, especially coming up to a gig.

02:22:02.980 | It's like, you know,

02:22:05.060 | we're not trying to make money with this.

02:22:06.580 | This is like just for that satisfaction of doing something

02:22:11.580 | and doing something well, right?

02:22:15.180 | But overall, I would say most,

02:22:19.460 | I play guitar most days, most days.

02:22:22.700 | And, you know, when I put kids to sleep,

02:22:26.300 | I play guitar, you know, with them

02:22:28.780 | and we like just make up random songs about,

02:22:31.980 | you know, about our cat or something, you know,

02:22:35.220 | like we just do kind of random stuff.

02:22:38.940 | But, you know, music is always involved in that process.

02:22:41.780 | - Yeah, keeping it fun.

02:22:43.220 | You have Russian roots?

02:22:44.460 | - I sure do.

02:22:45.580 | - Were you born in Russia?

02:22:46.580 | - I was, yeah.

02:22:47.900 | - When did you come here?

02:22:49.220 | - So I came to the US in the very end of '99,

02:22:54.220 | but so I was like almost 14 years old.

02:22:59.540 | But along the way, we spent six years in Japan.

02:23:03.260 | So like we moved from Russia to Japan in '94

02:23:07.860 | and then to the US in '99.

02:23:10.500 | So then like elementary school,

02:23:12.140 | - Oh, interesting.

02:23:12.980 | - Middle school in Japan.

02:23:14.100 | - So elementary school in Japan.

02:23:16.180 | - Yeah.

02:23:17.700 | - So that's interesting, do you still speak Russian?

02:23:20.620 | - Sure.

02:23:21.460 | - Okay.

02:23:22.300 | (speaking in foreign language)

02:23:23.820 | Okay, maybe I'll, let me ask you in Russian.

02:23:27.700 | (speaking in foreign language)

02:23:31.540 | That'd be interesting to hear you speak in Russian.

02:23:33.420 | (speaking in foreign language)

02:23:37.340 | (speaking in foreign language)

02:23:41.260 | (laughing)

02:23:43.500 | (speaking in foreign language)

02:23:47.420 | (laughing)

02:23:49.660 | (speaking in foreign language)

02:23:53.580 | (speaking in foreign language)

02:23:57.500 | (laughing)

02:23:59.740 | (speaking in foreign language)

02:24:29.220 | (laughing)

02:24:30.060 | - So for people who don't speak Russian,

02:24:31.780 | Constantine was talking about basically his first

02:24:36.020 | in 1992 interaction with capitalism,

02:24:39.100 | which is Pepsi and at first he discovered Pepsi

02:24:42.700 | and then he discovered Coke and he was confused

02:24:44.900 | how such theft could occur.

02:24:48.780 | - Like an intellectual property theft.

02:24:50.340 | And remember, Pepsi arrived to the Soviet Union first

02:24:55.020 | and there's some complicated story

02:24:58.060 | which I don't quite understand the details of.

02:25:00.900 | For a while, Pepsi commanded submarines or something.

02:25:05.900 | Yeah, Pepsi had like a fleet of Soviet submarines.

02:25:09.340 | - They were sponsoring tanks and this best thing.

02:25:13.780 | And I remember there's certain things that trickled in

02:25:16.460 | like McDonald's, I remember that was a big deal.

02:25:18.580 | - Oh yeah, I remember--

02:25:19.420 | - Certain aspects of the West.

02:25:20.740 | - Absolutely, so I remember we went to McDonald's

02:25:23.460 | and we stood on, I mean, this is absurd, right,

02:25:27.540 | from kind of looking at it from today's perspective,

02:25:31.900 | but we stood in line for like six hours

02:25:34.220 | to get into this McDonald's.

02:25:35.900 | And I remember inside it was just like a billion people

02:25:40.900 | and I'm just taking a bite out of that Big Mac.

02:25:45.340 | We're like, wow.

02:25:46.860 | - Was it an incredible experience for you?

02:25:49.500 | So like, what does this taste of the West like?

02:25:52.500 | Did you enjoy it?

02:25:53.340 | - I enjoyed the fact that, I mean,

02:25:56.780 | this is getting into the weeds,

02:25:58.820 | but I really enjoyed the fact that the top of the bun

02:26:02.220 | had those seeds, and I remember how on the commercials,

02:26:07.220 | the Big Mac would kind of bounce.

02:26:09.500 | I was like, the seeds, how do they inject the seeds

02:26:11.860 | into the bread?

02:26:12.700 | Amazing, right?

02:26:15.420 | So I think it was--

02:26:16.740 | - Artistry.

02:26:18.660 | - Yeah, it was just--

02:26:19.500 | - You enjoy the artistry of the culinary experience.

02:26:21.340 | - Exactly, it was the food art that is the Big Mac.

02:26:26.060 | - Actually, I still don't know the answer to that.

02:26:27.580 | How do they get the sesame seeds on the bun?

02:26:29.100 | - It's better to not know the answer.

02:26:30.420 | (laughing)

02:26:31.420 | - You just wander the mystery of it all.

02:26:33.500 | Yeah, I remember it being exceptionally delicious,

02:26:35.380 | but I'm with you.

02:26:37.180 | I don't know, you didn't mention

02:26:39.860 | how transformative Pepsi was,

02:26:41.300 | but to me, basically sugar-based stuff,

02:26:44.260 | like Pepsi was, or Coke,

02:26:47.620 | I don't remember which one we partook in,

02:26:49.180 | but that was an incredible experience.

02:26:50.940 | - Yeah, yeah, yeah, yeah, no, absolutely.

02:26:53.220 | And I think it was an important and formative period.

02:26:58.220 | I sometimes, I guess, rely on that a little bit

02:27:08.060 | in my daily life, because I remember

02:27:10.980 | the early '90s were real rough.

02:27:15.220 | My parents were kind of on the bottom of the spectrum

02:27:21.500 | in terms of financial well-being.

02:27:26.420 | So, kind of like just when I run into trouble,

02:27:31.420 | not like money trouble,

02:27:35.180 | just any kind of trouble these days,

02:27:37.180 | it just kind of is not particularly meaningful

02:27:41.380 | when you compare it to that turbulent time

02:27:44.180 | of the early '90s.

02:27:45.420 | And the other thing is, I think there's an advantage

02:27:49.420 | to being an immigrant, which is that you go

02:27:54.060 | through the mental exercise of changing your environment

02:27:58.420 | completely early in your life.

02:28:00.700 | You go, it's by no means pleasant in the moment,

02:28:05.700 | but going into Japanese elementary school,

02:28:09.420 | I didn't go to some private thing,

02:28:14.420 | I just went to a regular Japanese public elementary school,

02:28:17.980 | and I was the non-Japanese person in my class.

02:28:22.780 | So, just like the learning Japanese and just kind of--

02:28:26.300 | - So, that's a super humbling experience in many ways,

02:28:29.300 | was when you like made fun of all that kind of stuff,

02:28:32.140 | being the outsider.

02:28:33.140 | - Oh, absolutely.

02:28:34.340 | But you kind of do that,

02:28:37.980 | and then you just kind of are okay with stuff,

02:28:42.980 | you know what I mean?

02:28:44.420 | And so, like doing that again in middle school in the US,

02:28:47.940 | it was arguably easy because I was like,

02:28:51.260 | yeah, well, I've already done this before.

02:28:53.100 | So, I think it kind of prepares you mentally a little bit

02:28:56.700 | for switching up for whatever changes that will come up

02:29:00.660 | for the rest of your life.

02:29:02.300 | So, I wouldn't trade that experience really for anything.

02:29:07.300 | It's a huge aspect of who I am,

02:29:11.420 | and I'm sure you can relate to a lot of this.

02:29:14.860 | - Yes, is there advice from your life

02:29:17.700 | that you can give to young people today,

02:29:20.300 | high school, college, about their career,

02:29:24.260 | or maybe about life in general?

02:29:26.740 | - I'm not like a career coach, but--

02:29:29.540 | - Life coach.

02:29:30.660 | - I'm definitely not a life coach,

02:29:32.020 | I don't have it all figured out.

02:29:33.620 | But I think there's a perpetual cycle of,

02:29:39.620 | you know, thinking that there is a,

02:29:42.620 | there's kind of like a template for success, right?

02:29:46.340 | Maybe there is, but in my experience,

02:29:49.540 | I haven't seen it, right?

02:29:51.140 | You know, I would say people in high school, right?

02:29:57.580 | So much of their focus is on getting straight A's,

02:30:02.740 | filling their CV with this and this and this,

02:30:05.060 | so that it looks interesting.

02:30:07.020 | And they're like, "I'm gonna do this and this

02:30:08.860 | so that it looks impressive," right?

02:30:11.580 | That is not, I think, a good way to optimize your life,

02:30:16.580 | do the thing that fills your life with passion,

02:30:20.380 | do the thing that fills your life with interest,

02:30:24.540 | and do that perpetually, right?

02:30:28.300 | A straight A student is really impressive,

02:30:33.220 | but also somewhat boring, right?

02:30:36.620 | So I think, you know, injection of more of that

02:30:40.500 | kind of interest into the lives of young people

02:30:45.260 | would go a long way in just both upping

02:30:49.060 | their level of happiness,

02:30:50.620 | and then just kind of ensuring that looking forward,

02:30:55.220 | they're not suffering from a perpetual condition of,

02:30:59.660 | "Oh, I have to satisfy these like,

02:31:01.460 | you know, check boxes to do well," right?

02:31:04.940 | 'Cause you can lose yourself in that whole process

02:31:06.740 | for the rest of your life.

02:31:07.900 | But it's nice if it's possible,

02:31:09.860 | like Max Tegmark was exceptionally good at this at MIT,

02:31:13.300 | figure out how you can spend a small part of your,

02:31:16.740 | percent of your efforts,

02:31:18.380 | such that your CV looks really impressive.

02:31:21.620 | - Yeah, absolutely.

02:31:23.780 | There's no, like, without a doubt,

02:31:26.380 | like, that's a baseline that you need to have.

02:31:29.340 | - And then spend, so like, spend most of your time

02:31:33.700 | doing like amazing things you're passionate about,

02:31:35.940 | but such that it kind of like Planet Nine

02:31:39.020 | produces objects that feed your CV,

02:31:42.860 | like slowly over time.

02:31:45.300 | So getting good grades in high school,

02:31:46.700 | maybe doing extracurricular activities,

02:31:48.780 | or in terms of like, you know, for programmers

02:31:52.260 | that's producing code that you can show up on GitHub,

02:31:54.980 | like leaving traces like throughout your efforts,

02:31:59.980 | such that your CV looks impressive to the rest of the world.

02:32:02.780 | In fact, I mean, this is somewhat along the lines

02:32:05.860 | of what I'm talking about.

02:32:07.380 | See, like getting like good grades is important,

02:32:10.460 | but grades are not a tangible like product.

02:32:14.260 | Like you cannot out, you know, show your A

02:32:17.860 | and have your A live a separate life from you.

02:32:21.300 | Code very much does, right?

02:32:23.900 | Music very much takes on, you know,

02:32:26.900 | provided somebody else listens to it, right?

02:32:30.140 | Like takes on a life of its own.

02:32:32.860 | That's kind of what I mean, right?

02:32:34.820 | Doing stuff that can then get separated from you

02:32:39.820 | is exceptionally attractive, right?

02:32:45.260 | It's like a fun and-

02:32:48.540 | - And it's also very impressive to others.

02:32:50.060 | I think we're moving to a world

02:32:51.460 | where grades mean less and less,

02:32:53.340 | like certifications mean less and less.

02:32:55.780 | If you look at, especially again, in the computing fields,

02:32:58.900 | getting a degree, finishing your,

02:33:00.780 | currently just finishing your degree,

02:33:04.580 | whether it's bachelor's or master's or PhD

02:33:07.060 | is less important than the things

02:33:08.580 | you've actually put out into the world.

02:33:10.460 | - Right, right.

02:33:11.420 | - And that's a fascinating, that's great that,

02:33:13.940 | in that sense, the meritocracy

02:33:15.620 | in its richest, most beautiful form is starting to win out.

02:33:20.900 | - Yeah, it's weird 'cause like, you know,

02:33:23.060 | my understanding, and I'm not like,

02:33:25.540 | I don't know the history of science well enough

02:33:27.500 | to speak very confidently about this,

02:33:30.300 | but the advisor of my advisor of my advisor from undergrad,

02:33:35.300 | like didn't have a PhD, right?

02:33:39.820 | So I think it was a more common thing back in the day,

02:33:43.500 | even in the academic sector to not have,

02:33:48.500 | Faraday, like Faraday didn't know algebra,

02:33:54.660 | he drew diagrams about magnetic fields,

02:33:58.540 | and his Faraday's law was derived entirely from intuition.

02:34:03.540 | So it is interesting to how the world of academia

02:34:08.580 | has evolved into a, you gotta do this and then get PhD,

02:34:13.180 | then you have to postdoc once and twice and maybe thrice,

02:34:16.700 | and then like you move on.

02:34:18.740 | So, you know, it does, I do wonder, you know, if we're,

02:34:23.780 | if there's a better approach.

02:34:25.620 | - I think we're heading there,

02:34:26.460 | but it's a fascinating historical perspective,

02:34:28.900 | like that we might've just tried this whole thing out

02:34:32.380 | for a while where we put a lot more emphasis

02:34:34.340 | on grades and certificates and degrees

02:34:36.780 | and all those kinds of things.

02:34:38.140 | I think the difference historically is,

02:34:40.400 | like we can actually, using the internet,

02:34:43.780 | show off ourselves and our creations

02:34:48.540 | better and better and more effectively,

02:34:50.340 | whether that's code or producing videos

02:34:52.940 | or all those kinds of things.

02:34:53.980 | - That's right.

02:34:54.820 | You can become a certified drone pilot.

02:34:56.720 | - Of all the things you wanna pick, yeah, for sure.

02:35:03.340 | Or you could just fly and make YouTube videos

02:35:05.140 | that gets hundreds of thousands of views with your drone

02:35:07.380 | and never getting a certificate.

02:35:08.980 | That's probably illegal, don't do it.

02:35:11.720 | What do you think is the meaning of this whole thing?

02:35:14.420 | So you look at planets, they seem to orbit stuff

02:35:20.340 | without asking the why question.

02:35:22.940 | And for some reason, life emerged on earth

02:35:25.620 | such that it led to big brains

02:35:27.300 | that can ask the big why question.

02:35:30.180 | Do you think there's an answer to it?

02:35:32.020 | - I'm not sure what the question is.

02:35:36.620 | Like what do you think? - Meaning of life?

02:35:37.980 | - The meaning of life?

02:35:39.080 | It's 42.

02:35:41.100 | - It's 42. - Yeah.

02:35:43.060 | But aside from that, it's why,

02:35:49.180 | I think the question you're asking is like,

02:35:51.740 | why we do all this, right?

02:35:54.660 | - Why we do all this?

02:35:56.020 | - It's part of the human condition, right?

02:36:00.340 | Human beings are fundamentally,

02:36:03.400 | I feel like sort of stochastic

02:36:08.900 | and fundamentally interested in kind of expanding

02:36:13.900 | our own understanding of the world around us.

02:36:17.940 | - And creating stuff to enable that understanding.

02:36:21.540 | So we're like stochastic, fundamentally stochastic.

02:36:24.180 | So like there's just a bunch of randomness

02:36:25.860 | that really doesn't seem like it has a good explanation.

02:36:29.020 | And yet there's a kind of direction to our being

02:36:32.220 | that we just keep wanting to create and to understand.

02:36:34.500 | - That's right.

02:36:35.320 | I've met people that claim to be anti-science, right?

02:36:39.800 | And yet in their anti-science discussion,

02:36:45.300 | they're like, "Well, if you're so scientific,

02:36:50.140 | then why don't you explain to me how, I don't know,

02:36:53.140 | this works."

02:36:54.140 | And like, it always, there's that fundamental--

02:36:56.700 | - There's a curiosity.

02:36:57.540 | - Seed of curiosity and interest

02:36:59.820 | that is common to all of us.

02:37:02.460 | That is absolutely what makes us human, right?

02:37:07.180 | And I'm in a privileged position of being able

02:37:11.820 | to have that be my job, right?

02:37:16.820 | I think as time evolves forward,

02:37:21.980 | the kind of economy changes,

02:37:25.820 | I mean, we're already starting to see a shift

02:37:28.140 | towards that type of creative enterprise

02:37:33.140 | as merging, taking over a bigger and bigger chunk

02:37:37.620 | of the sector.

02:37:38.980 | It's not yet, I think, the dominant portion

02:37:43.580 | of the economy by any account,

02:37:45.140 | but if we compare this to like,

02:37:47.340 | the time when the dominant thing you would do

02:37:51.860 | would be to go to a factory and do the same exact thing,

02:37:56.860 | right, I think there's a tide there

02:38:00.500 | and things are sort of headed in that direction.

02:38:02.540 | - Yeah, life's becoming more and more fun.

02:38:04.460 | I can't wait, honestly, what happens next.

02:38:06.980 | - I can't wait to just chill.

02:38:08.180 | - Just chill.

02:38:09.020 | - The terminal point of this is just chill

02:38:11.860 | and wait for those Kuiper belt objects

02:38:13.380 | to complete one orbit.

02:38:14.660 | - I'm gonna credit you with this idea.

02:38:17.300 | I do hope that we definitively discover proof

02:38:22.180 | that there is a planet nine out there in the next few years

02:38:25.020 | so you can sit back with a cigar, a cigarette,

02:38:27.340 | or vodka, or wine, and just say, I told you so.

02:38:31.900 | - That's already happening.

02:38:33.140 | (laughing)

02:38:33.980 | I'm gonna do that later tonight.

02:38:35.340 | (laughing)

02:38:36.460 | - As I mentioned, confidence is essential

02:38:38.860 | to being a rock star.

02:38:40.460 | I really appreciate you explaining

02:38:43.260 | so many fascinating things to me today.

02:38:45.020 | I really appreciate the work that you do out there

02:38:47.780 | and I really appreciate you talking with me today.

02:38:50.820 | - Alex, it was a pleasure. - Thanks, Constantin.

02:38:52.020 | - Thanks for having me on.

02:38:53.980 | - Thanks for listening to this conversation

02:38:55.500 | with Constantin Batygin and thank you to Squarespace,

02:38:59.140 | Litterati, Onnit, and Ni.

02:39:02.540 | Check them out in the description to support this podcast.

02:39:06.140 | And now, let me leave you with some words

02:39:07.780 | from Douglas Adams in "The Hitchhiker's Guide

02:39:10.180 | to the Galaxy."

02:39:11.140 | Far out in the uncharted backwaters

02:39:14.820 | of the unfashionable end of the western spiral arm

02:39:18.460 | of the galaxy lies a small, unregarded yellow sun.

02:39:23.460 | Orbiting this at a distance of roughly 92 million miles

02:39:28.220 | is an utterly insignificant little blue-green planet

02:39:31.940 | whose ape-descendant life forms

02:39:34.300 | are so amazingly primitive

02:39:36.420 | that they still think digital watches

02:39:38.860 | are a pretty neat idea.

02:39:40.820 | Thank you for listening.

02:39:42.820 | I hope to see you next time.

02:39:44.660 | (upbeat music)

02:39:47.240 | (upbeat music)

02:39:49.820 | [BLANK_AUDIO]

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

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