Sara Walker: The Origin of Life on Earth and Alien Worlds

00:00:00.000 | The following is a conversation with Sarah Walker,

00:00:02.440 | an astrobiologist and theoretical physicist

00:00:05.000 | at Arizona State University and the Santa Fe Institute.

00:00:08.620 | She's interested in the origin of life,

00:00:10.960 | how to find life on other worlds,

00:00:13.540 | and in general, the more fundamental question

00:00:15.880 | of what even life is.

00:00:18.160 | She seeks to discover the universal laws

00:00:20.280 | that describe living systems on earth and elsewhere

00:00:23.420 | using physics, biology, and computation.

00:00:27.460 | Quick mention of our sponsors, Athletic Greens,

00:00:30.360 | NetSuite, Blinkist, and Magic Spoon.

00:00:33.360 | Check them out in the description to support this podcast.

00:00:36.260 | As a side note, let me say that my hope for this podcast

00:00:39.380 | is to try and alternate between technical

00:00:42.060 | and non-technical discussions,

00:00:44.000 | to jump from the big picture

00:00:45.680 | down to specific detailed research

00:00:48.000 | and back to the big picture,

00:00:49.800 | and to do so with scientists and non-scientists.

00:00:53.680 | Long-term, I hope to alternate between discussions

00:00:56.340 | of cutting-edge research in AI, physics, biology,

00:00:59.920 | to topics of music, sport, and history,

00:01:03.280 | and then back to AI.

00:01:05.360 | AI is home.

00:01:06.680 | I hope you come along with me

00:01:08.260 | for that wild, oscillating journey.

00:01:11.520 | Some people message me saying to slow down

00:01:14.340 | since they're falling behind on the episodes

00:01:16.040 | of this podcast.

00:01:17.760 | To their disappointment, I have to say

00:01:19.960 | that I'll probably do more episodes, not less,

00:01:22.560 | but you really don't need to listen to every episode.

00:01:25.600 | Just listen to the ones that spark your curiosity.

00:01:28.540 | Think about it like a party full of strangers.

00:01:30.720 | You don't have to talk to everyone.

00:01:32.760 | Just walk over to the ones who look interesting

00:01:34.840 | and get to know them.

00:01:36.320 | And if you're lucky, that one conversation with a stranger

00:01:39.420 | might change the direction of your life.

00:01:41.680 | And it's a short life, so be picky with the strangers

00:01:44.280 | you talk to at this metaphorical party.

00:01:47.560 | This is the Lux Friedman Podcast,

00:01:49.560 | and here is my conversation with Sarah Walker.

00:01:53.460 | How did life originate on Earth?

00:01:55.680 | What are the various hypotheses

00:01:57.520 | for how life originated on Earth?

00:02:00.040 | - Yeah, so I guess you're asking a historical question,

00:02:03.160 | which is always a good place to start thinking about life.

00:02:06.060 | So there's a lot of ideas about how life started on Earth.

00:02:10.680 | Probably the most popular is what's called

00:02:12.640 | the RNA world scenario.

00:02:15.560 | So this idea is probably the one

00:02:17.960 | that you'll see most reported in the news,

00:02:21.000 | and is based on the idea that there are

00:02:24.960 | molecules in our bodies that relay genetic information,

00:02:31.420 | and we know those as DNA, obviously,

00:02:33.460 | but there's also sort of an intermediary

00:02:35.980 | called RNA, ribonucleic acid,

00:02:38.940 | that also plays the role of proteins.

00:02:41.260 | And people came up with this idea in the '80s

00:02:44.780 | that maybe that was the first genetic material

00:02:47.220 | because it could play both roles

00:02:48.620 | of being genetic and performing catalysis.

00:02:52.420 | And then somehow that idea got reduced

00:02:54.780 | to this idea that there was a molecule

00:02:57.580 | that emerged on early Earth

00:02:59.300 | and underwent Darwinian evolution,

00:03:01.660 | and that was the start of life.

00:03:03.380 | So there's a lot of assumptions packed in there

00:03:06.420 | that we could unpack,

00:03:08.360 | but that's sort of the leading hypothesis.

00:03:10.260 | There's also other ideas about life starting as metabolism,

00:03:13.300 | and so that's more connected

00:03:14.700 | to the geochemistry of early Earth,

00:03:17.420 | and would be kind of more focused on this idea

00:03:19.580 | that you get some kind of catalytic cycle

00:03:21.980 | of molecules that can reproduce themselves

00:03:24.100 | and form some kind of metabolism,

00:03:25.900 | and then life starts basically as self-organization,

00:03:28.340 | and then you have to explain how evolution comes later.

00:03:31.340 | - Right, so that's the difference

00:03:32.740 | between sort of energy and genetic code?

00:03:35.740 | So like energy and information,

00:03:37.500 | are those the two kind of things there?

00:03:39.660 | - Yeah, I think that's a good way of putting it.

00:03:41.260 | It's kind of funny 'cause I think most of the people

00:03:44.380 | that think about these things are really disciplinary biased,

00:03:46.820 | so the people that tend to think about genetics

00:03:48.540 | come from a biology background

00:03:49.820 | and they're really evolution-focused,

00:03:51.660 | and so they're worried about

00:03:52.980 | where does the information come from

00:03:54.620 | and how does it change over time,

00:03:55.860 | but they're talking about information in a really narrow way

00:03:57.920 | where they're talking about a genetic sequence,

00:04:00.460 | and then most of the people that think about metabolism,

00:04:04.060 | origins of life scenarios,

00:04:05.500 | tend to be people like physicists or geochemists

00:04:07.980 | that are worried about what are the energy sources

00:04:09.620 | and what kinds of organization

00:04:11.940 | can you get out of those energy sources.

00:04:14.140 | - Okay, so which one's your favorite?

00:04:15.900 | - I don't like either.

00:04:17.500 | - Okay, can we talk about them

00:04:19.260 | for a little bit longer though?

00:04:20.380 | - Yeah, no, that's fine.

00:04:21.580 | (laughing)

00:04:23.740 | - So okay, so there's early Earth.

00:04:26.060 | What was that like?

00:04:27.060 | Was there just mostly covered by oceans?

00:04:29.240 | Was there heat sources, energy sources?

00:04:31.740 | So if we talk about the metabolism view

00:04:35.300 | of the origin of life, where was the source of energy?

00:04:38.420 | - Probably the most popular view

00:04:39.740 | for where the origin of life happened on Earth

00:04:42.260 | is hydrothermal vents because they had sufficient energy,

00:04:45.540 | and so we don't really know a lot about early Earth.

00:04:50.220 | We have some ideas about when oceans first formed

00:04:53.460 | and things like that, but the time of the origin of life

00:04:55.460 | is kind of not well understood or pinned down,

00:04:59.140 | and the conditions on Earth at that time are not well known.

00:05:02.280 | But a lot of people do think

00:05:03.620 | that there was probably hydrothermal vents,

00:05:05.620 | which are really hot, chemically active regions,

00:05:10.060 | say on the sea floor in modern times,

00:05:12.680 | which also would have been present on early Earth,

00:05:14.740 | and they would have provided energy and organics

00:05:17.980 | and basically all of the right conditions

00:05:20.180 | for the origins of life, which is one of the reasons

00:05:23.220 | that we look for these hydrothermal systems

00:05:24.820 | when we're talking about life elsewhere too.

00:05:27.300 | - Okay, and for the genetic code,

00:05:30.020 | the idea is that the RNA is the first,

00:05:32.180 | like why would RNA be the first moment you can say it's life?

00:05:37.180 | I guess the idea is it could both

00:05:39.460 | have persistent information,

00:05:42.920 | and then it can also do some of the work of like, what,

00:05:46.320 | creating a self-sustaining organism?

00:05:49.080 | - Yeah, that's the basic idea.

00:05:50.900 | So the idea is you have, in an RNA molecule,

00:05:54.560 | you have a sequence of characters, say,

00:05:56.280 | so you can treat it like a string in a computer,

00:05:58.760 | and it can be copied, so information can be propagated,

00:06:02.740 | which is important for evolution,

00:06:05.960 | because evolution happens

00:06:07.340 | by having inheritance of information.

00:06:09.540 | So for example, like my eyes are brown

00:06:11.580 | because my mother's eyes were brown.

00:06:13.880 | So you need that copying of information,

00:06:16.180 | but then you also have the ability to perform catalysis,

00:06:21.180 | which means that that RNA molecule

00:06:24.400 | is not inert in that environment,

00:06:26.040 | but it actually interacts with something

00:06:27.980 | and could potentially mediate, say, a metabolism

00:06:31.280 | that could then fuel the actual reproduction

00:06:34.000 | of that molecule.

00:06:35.420 | So in some ways, people think that RNA gives you,

00:06:40.920 | you know, the most bang for your buck in a single molecule,

00:06:44.520 | and therefore, you know, it gives you all the features

00:06:47.220 | that you might think are life.

00:06:48.940 | And so this is sort of where this RNA world conjecture

00:06:52.360 | came from, is because of those two properties.

00:06:54.600 | - Isn't it amazing that RNA came to be in general?

00:06:59.120 | Isn't it? - Yes, that is amazing.

00:07:01.140 | - Okay, so we're not talking down about RNA.

00:07:03.680 | - No, no, I love RNA.

00:07:04.840 | It's one of my favorite molecules.

00:07:06.200 | I think it's beautiful. - It's just not step one.

00:07:08.760 | - Yeah, I think the issue,

00:07:10.860 | it's not even the RNA world is a problem.

00:07:13.020 | And actually, if you really dig into it,

00:07:16.860 | the RNA world is not one hypothesis.

00:07:19.380 | It is a set of hypotheses.

00:07:21.220 | And they range from a molecule of RNA spontaneously emerged

00:07:27.340 | on the early Earth and started evolving,

00:07:29.740 | which is kind of like the hardest RNA world scenario,

00:07:31.840 | which is the one I cited,

00:07:32.820 | and I get a little animated about

00:07:36.620 | 'cause it seems so blatantly wrong to me,

00:07:39.340 | but that's a separate story.

00:07:40.740 | And then the other one is actually something I agree with,

00:07:43.140 | which is that you can say there was an RNA world

00:07:46.500 | because RNA was the first genetic material

00:07:49.180 | for life on Earth.

00:07:50.340 | So an RNA world could just be the earliest organisms

00:07:54.740 | that had genetics in a modern sense,

00:07:57.540 | didn't have DNA evolved yet, they had RNA.

00:08:00.040 | Right, and so that's sort of a softer RNA world scenario

00:08:03.820 | in the sense that it doesn't mean

00:08:05.220 | it was the first thing that happened,

00:08:07.180 | but it was a thing that definitely was part

00:08:10.460 | of the lineage of events that led to us.

00:08:12.820 | - So if life was like a best of album,

00:08:16.300 | it would be one of the songs on there.

00:08:18.860 | - Yes. - One of the early songs.

00:08:19.900 | Okay.

00:08:20.740 | - It's on the greatest hits.

00:08:21.700 | - Greatest hits, that's the word I was looking for.

00:08:23.760 | Okay, did life, do you think, originate once, twice,

00:08:28.760 | three times on Earth, multiple times?

00:08:30.780 | What do you think?

00:08:31.800 | - I think that's a really difficult question.

00:08:34.340 | - Is it an important question?

00:08:35.540 | - It's a super important question, no.

00:08:37.260 | No, it's a really important question.

00:08:39.100 | There's a lot of questions in that question.

00:08:45.540 | So one of the first ones that I think needs to be addressed

00:08:48.620 | is is the original life a continuous process on our planet?

00:08:52.040 | So we think about the original life as something

00:08:54.420 | that happened on Earth, say, almost four billion years ago,

00:08:58.200 | because we have evidence of life emerging

00:09:00.080 | very early on our planet.

00:09:02.740 | And then an original life event, quote unquote,

00:09:06.140 | a singular event, whatever that was, happened.

00:09:08.660 | And then all life on Earth that we know

00:09:11.420 | is a descendant of that particular event

00:09:13.800 | in our universe, right?

00:09:14.820 | And so, but we don't have any idea one way or the other

00:09:19.820 | if the original life is happening repeatedly,

00:09:25.060 | and maybe it's just not taking off

00:09:26.340 | because life is already established.

00:09:27.700 | That's an argument that people will make.

00:09:29.580 | Or maybe there are alternative forms of life on Earth

00:09:33.180 | that we don't even recognize.

00:09:35.380 | So this is the idea of a shadow biosphere,

00:09:36.900 | that there actually might just be

00:09:38.100 | completely other life on Earth,

00:09:39.540 | but it's so alien that we don't even know what it is.

00:09:42.980 | - I'm gonna have to talk to you about the shadow biosphere.

00:09:45.460 | - Yeah, that's a fun one.

00:09:46.460 | - In a second, but first, let me ask for the other

00:09:48.980 | alternative, which is panspermia.

00:09:51.460 | - Right.

00:09:52.280 | - So that's the idea, the hypothesis that life exists

00:09:55.340 | elsewhere in the universe and got to us

00:09:57.340 | in like an asteroid or a planetoid or some,

00:10:00.860 | according to Wikipedia, space dust,

00:10:02.660 | whatever the heck that is.

00:10:03.960 | It sounds fun, but basically it rode along

00:10:08.420 | whatever kind of rock and got to us.

00:10:11.820 | Do you think that's at all a possibility?

00:10:15.020 | - Sure, so I think the reason that most

00:10:17.540 | original life scientists are interested

00:10:19.700 | in the original life on Earth and say not the original life

00:10:24.340 | on Mars and then panspermia, the exchange of life

00:10:27.820 | between planets being the explanation,

00:10:29.380 | is once you start removing the original life from Earth,

00:10:32.020 | you know even less about it than you do

00:10:34.840 | if you study it on Earth.

00:10:36.060 | Although I think there are ways of reformulating the problem.

00:10:38.780 | This is why I said earlier, oh, you mean the historical

00:10:41.580 | original life problem, you don't mean the problem

00:10:43.860 | of how does life arise in the universe

00:10:45.900 | and what the universal principles are,

00:10:47.340 | because there's this historic problem,

00:10:48.780 | how did it happen on early Earth?

00:10:50.420 | And there's a more tractable general problem

00:10:53.140 | of how does it happen?

00:10:54.260 | And how does it happen is something

00:10:56.580 | we can actually ask in the lab.

00:10:57.980 | How did it happen on early Earth

00:11:00.740 | is a much more detailed and nuanced question.

00:11:04.220 | It requires detailed knowledge of what was happening

00:11:06.500 | on early Earth that we don't have.

00:11:08.980 | And I'm personally more interested in general mechanisms,

00:11:11.380 | so to me it doesn't matter if it happened on Earth

00:11:13.180 | or it happened on Mars.

00:11:15.180 | It just matters that it happened.

00:11:16.700 | We have evidence it happened.

00:11:18.520 | The question is, did it happen more than once

00:11:20.220 | in our universe?

00:11:21.340 | And so the reason I don't find panspermia

00:11:24.300 | as a particularly, I think it's a fascinating hypothesis.

00:11:28.780 | I definitely think it's possible.

00:11:31.020 | And I in particular think it's possible

00:11:33.860 | once you get to the stage of life where you have technology

00:11:36.180 | because then you obviously can spread out into the cosmos.

00:11:40.280 | But it's also possible for microbes

00:11:41.980 | because we know that certain microorganisms

00:11:45.460 | can survive the journey in space

00:11:47.060 | and they can live in a rock and go between Mars and Earth.

00:11:50.980 | Like people have done experiments

00:11:51.980 | to try to prove that could work.

00:11:54.140 | So in that scenario, it's super cool

00:11:57.100 | 'cause then you get planetary exchange.

00:11:58.340 | But say we go look for life on Mars

00:12:00.560 | and it ends up being exactly the same life we have on Earth,

00:12:02.780 | biochemically speaking,

00:12:04.360 | then we haven't really discovered something new

00:12:05.740 | about the universe.

00:12:06.980 | What kind of aliens are possible?

00:12:08.580 | Were there other original life events?

00:12:10.780 | If all the life we ever find

00:12:12.980 | is the same original life event in the universe,

00:12:14.740 | it doesn't help me solve my problem.

00:12:16.580 | - But it's possible that that would be a sign

00:12:19.380 | that you could separate the environment

00:12:22.260 | from the basic ingredients.

00:12:24.780 | - Yes, that's true.

00:12:25.860 | - You can have like a life gun

00:12:27.860 | that you shoot throughout the universe.

00:12:30.140 | And then like once you shoot it,

00:12:33.180 | it's like the Simpsons with a make-up gun.

00:12:34.900 | That was a great episode.

00:12:36.300 | When you shoot this life gun, it'll find the Earth's.

00:12:40.860 | It'll like get sticky.

00:12:42.340 | It'll stick to the Earth's.

00:12:44.140 | And that kind of reduces the barrier

00:12:46.820 | of like the time it takes,

00:12:49.580 | the luck it takes to actually from nothing,

00:12:52.860 | from the basic chemistry,

00:12:54.620 | from the basic physics of the universe

00:12:56.260 | for the life to spring up.

00:12:58.500 | - Yeah, I think this is actually super important

00:13:00.740 | to just think about like does life

00:13:04.100 | getting seated on a planet

00:13:05.500 | have to be geochemically compatible with that planet?

00:13:08.820 | So you're suggesting like we could just shoot guns in space

00:13:11.340 | and like life could go to Mars

00:13:13.140 | and then it would just live there and be happy there.

00:13:16.500 | But that's actually an open question.

00:13:18.420 | So one of the things I was gonna say

00:13:19.500 | in response to your question

00:13:20.820 | about whether the origin of life happened once

00:13:23.180 | or multiple times is for me personally right now

00:13:25.860 | in my thinking, although this changes on a weekly basis,

00:13:28.420 | but is that I think of life more as a planetary phenomena.

00:13:31.780 | So I think the origin of life

00:13:32.780 | because life is so intimately tied to planetary cycles

00:13:37.420 | and planetary processes.

00:13:38.940 | And this goes all the way back

00:13:40.020 | through the history of our planet

00:13:41.580 | that the origin of life itself grew out of geochemistry

00:13:44.260 | and became coupled and controlled geochemistry.

00:13:46.340 | And when we start to talk about life existing on the planet

00:13:49.220 | is when we have evidence of life

00:13:51.260 | actually influencing properties of the planet.

00:13:54.180 | And so if life is a planetary property,

00:13:59.260 | then going to Mars is not a trivial thing

00:14:01.700 | because you basically have to make Mars more Earth-like.

00:14:05.540 | And so in some sense,

00:14:07.620 | like when I think about sort of long-term vision

00:14:09.500 | of humans in space, for example,

00:14:11.740 | really what you're talking about when you're saying

00:14:14.060 | let's send our civilization to Mars

00:14:16.660 | is you're not saying let's send our civilization to Mars,

00:14:18.700 | you're saying let's reproduce our planet on Mars.

00:14:21.940 | Like the information from our planet

00:14:23.260 | actually has to go to Mars and make Mars more Earth-like,

00:14:26.220 | which means that you're now having a reproduction process,

00:14:28.600 | like a cell reproduces itself

00:14:29.980 | to propagate information in the future.

00:14:32.580 | Planets have to figure out how to reproduce their conditions

00:14:35.320 | including geochemical conditions on other planets

00:14:38.020 | in order to actually reproduce life in the universe,

00:14:40.400 | which is kind of a little bit radical.

00:14:41.740 | But I think for long-term sustainability

00:14:44.380 | of life on a planet, that's absolutely essential.

00:14:47.300 | - Okay, so if we were to think about

00:14:50.380 | life as a planetary phenomena,

00:14:52.800 | and so life on Mars would be best

00:14:55.100 | if it's way different than life on Earth,

00:14:57.580 | we have to ask the very basic question of what is life?

00:15:02.580 | - I actually don't think that's the right question to ask.

00:15:06.180 | It took me a long time to get there, right?

00:15:07.700 | - You cross it out?

00:15:08.780 | - Yeah, you cross it off your list, it's wrong.

00:15:11.660 | - Next question.

00:15:13.020 | - No, no, no, I mean, I think it has an answer,

00:15:15.220 | but I think part of the problem is,

00:15:17.100 | most of the places in science where we get really stuck

00:15:20.060 | is because we don't know what questions to ask.

00:15:22.260 | And so you can't answer a question

00:15:24.020 | if you're asking the wrong question.

00:15:25.860 | And I think the way I think about it

00:15:29.380 | is obviously I'm interested in what life is,

00:15:31.180 | so I'm being a little cheeky when I say

00:15:32.500 | that's the wrong question to ask.

00:15:33.580 | That's exactly the question

00:15:35.420 | that's the core of my existence.

00:15:37.140 | But I think the way of framing that is

00:15:41.300 | what is it about our universe that allows features

00:15:44.940 | that we associate life to be there?

00:15:47.460 | And so really what I guess when I'm asking that question,

00:15:50.340 | what I'm after is an explanatory framework

00:15:52.660 | for what life is, right?

00:15:54.380 | And so most people, they try to go in and define life

00:15:57.420 | and they say, well, life is, say,

00:15:59.700 | a self-reproducing chemical system

00:16:01.700 | capable of Darwinian evolution.

00:16:03.020 | That's a very popular definition for life.

00:16:05.460 | Or life is something that metabolizes and eats.

00:16:08.380 | That is not how I think about life.

00:16:10.100 | What I think about life is there are principles

00:16:13.300 | and laws that govern our universe

00:16:15.660 | that we don't understand yet

00:16:18.020 | that have something to do with how information interacts

00:16:22.380 | with the physical world.

00:16:23.700 | I don't know exactly what I mean even when I say that

00:16:26.340 | because we don't know these rules.

00:16:28.500 | But it's a little bit like, I like to use analogies.

00:16:32.220 | You'll give me time to be like a little long-winded

00:16:34.540 | for a second, even in essay.

00:16:36.740 | But sort of like if you look at the history of physics,

00:16:39.580 | for example, this is like,

00:16:40.780 | so we are in the period of the development

00:16:43.620 | of thought on our planet

00:16:46.180 | where we don't understand what we are yet, right?

00:16:49.140 | There was a period of thought in the history of our planet

00:16:51.700 | where we didn't understand what gravity was.

00:16:53.860 | And we didn't understand, for example,

00:16:55.740 | that the planets in the heavens were actually planets

00:16:59.340 | or that they operated by the same laws that we did.

00:17:02.060 | And so there has been this sort of progression

00:17:05.140 | of getting a deeper understanding

00:17:07.460 | of explaining basic phenomena like,

00:17:09.580 | I'm not gonna drop the cup, I'll drop the water bottle.

00:17:11.340 | There you go.

00:17:12.180 | Okay, that fell, right?

00:17:13.140 | But why did that fall?

00:17:14.300 | This is why I'm a theorist, not an experimentalist.

00:17:19.220 | - That could have gone wrong in so many ways.

00:17:20.820 | - I know, it could have,

00:17:21.660 | especially if I did the cup and it smashed.

00:17:23.660 | Anyway.

00:17:24.500 | So if you think, you take this view

00:17:28.700 | that there's sort of some missing principles,

00:17:30.460 | I associate them to information.

00:17:33.700 | And what the sort of feeling there is,

00:17:36.380 | there's some missing explanatory framework

00:17:39.060 | for how our universe works.

00:17:40.420 | And if we understood that physics,

00:17:42.380 | it would explain what we are.

00:17:44.540 | It might also explain a lot of other features

00:17:46.220 | we don't associate to life.

00:17:48.580 | And so it's a little like people accept the fact

00:17:51.740 | that gravity is a universal phenomena.

00:17:54.300 | But when we wanna study gravity,

00:17:55.500 | we study things like large scale,

00:17:57.380 | galactic structures or black holes or planets.

00:18:02.700 | If we wanna understand information

00:18:04.340 | and how it operates in the physical world,

00:18:05.820 | we study intelligent systems or living systems

00:18:08.340 | because they are the manifestation of that physics.

00:18:10.940 | And the fact that we can't see that clearly yet,

00:18:13.860 | or we don't have that explanatory framework,

00:18:15.660 | I think it's just because we haven't been thinking

00:18:17.380 | about the problem deeply enough.

00:18:18.660 | But I feel like if you're explaining something,

00:18:21.460 | you're deriving it from some more fundamental property.

00:18:24.100 | And of course, I have to say I'm wearing my physicist hat.

00:18:28.740 | So I have a huge bias of liking simple,

00:18:31.700 | elegant explanations of the universe

00:18:33.860 | that really are compelling.

00:18:37.340 | But I think one of the things that I've sort of,

00:18:39.940 | maybe in some ways rejected my training as a physicist

00:18:42.540 | is that most of the elegant explanations

00:18:44.580 | that we have so far don't include us in the universe.

00:18:47.220 | And I can't help but think there's something really special

00:18:49.740 | about what we are,

00:18:50.580 | and there have to be some deep principles at play there.

00:18:52.900 | And so that's sort of my perspective on it.

00:18:57.420 | Now, when you ask me what life is,

00:18:59.460 | I have some ideas of what I think it is.

00:19:02.060 | But I think that we haven't gotten there yet

00:19:04.820 | because we haven't been able to see that structure.

00:19:07.420 | And just to go back to the gravity example,

00:19:09.300 | it's a little like, in ancient times, they didn't know,

00:19:12.380 | I was talking about stars and heavens and things,

00:19:14.540 | they didn't know those were governed

00:19:16.780 | by the same principles as that starting to experiment.

00:19:19.260 | Here's where I was going with it.

00:19:20.900 | Once you realize, like Newton did,

00:19:22.900 | that heavenly motions and earthly motions

00:19:25.780 | are governed by the same principles

00:19:27.100 | and you unify terrestrial and celestial motion,

00:19:29.060 | you get these more powerful ideas.

00:19:31.220 | And I think where life is,

00:19:33.940 | is somehow unifying these abstract ideas

00:19:36.380 | of computation and information

00:19:38.500 | with the physical world, with matter,

00:19:40.660 | and realizing that there's some explanatory framework

00:19:43.700 | that's not physics and it's not computation,

00:19:46.900 | but it's something that's deeper.

00:19:49.580 | - So answering the question of what is life

00:19:52.060 | requires deeply understanding something about the universe

00:19:55.900 | as information processing, the universe as computation.

00:19:58.860 | - Sort of. - It's something about,

00:20:00.620 | like, would, once you come up with an answer

00:20:03.500 | to what is life, will the words information

00:20:06.380 | and computation be in the paragraph?

00:20:08.460 | - No, I don't think so. - God damn it, okay.

00:20:10.460 | - I know, it doesn't help, does it?

00:20:11.780 | I know, I hate, actually, I hate this about what I do

00:20:13.980 | because it's so hard to communicate, right, with words.

00:20:16.380 | Like, when you have words that are ideas

00:20:20.500 | that have historically described one thing

00:20:22.700 | and you're trying to describe something

00:20:24.200 | people haven't seen yet, and the words just don't fit.

00:20:27.900 | - So what's wrong, is it too ambiguous?

00:20:30.420 | The word information?

00:20:31.540 | We could switch to binary if you want.

00:20:33.380 | - Yeah, no, I don't think it's binary either.

00:20:35.220 | I think information's just loaded.

00:20:36.980 | I use it, so the other way I might talk about it

00:20:39.260 | is the physics of causation, but I think that's worse

00:20:41.980 | because causation is an even more loaded word

00:20:43.940 | than information.

00:20:46.740 | - So causation is fundamental, you think?

00:20:48.780 | - I do, yeah, and in some sense, I think the physics,

00:20:52.220 | so this is the really radical part.

00:20:53.780 | Some sense, like, when I really think about it

00:20:55.500 | sort of most deeply, what I think life is

00:20:58.460 | is actually the physics of existence.

00:21:00.140 | What gets to exist and why?

00:21:01.900 | And for simple elementary particles,

00:21:04.780 | that's not very complicated

00:21:05.820 | 'cause the interactions are simple,

00:21:06.980 | but for things like you and me and human civilizations,

00:21:11.060 | what comes next in the universe

00:21:13.500 | is really dependent on what came before,

00:21:15.660 | and there's a huge space of possibilities

00:21:17.340 | of things that can exist, and when I say information

00:21:19.820 | and causation, what I mean is,

00:21:21.740 | why is it that cups evolved in the universe

00:21:24.900 | and not some other object that could deliver water

00:21:27.540 | and not spill it?

00:21:29.740 | I don't know what you would call it.

00:21:31.540 | Maybe it wouldn't be a cup, but it's a huge,

00:21:33.940 | people talk about the space of things that could exist

00:21:38.940 | as being actually infinitely large, right?

00:21:40.820 | I don't know if I believe in infinity,

00:21:43.420 | but I do think that there is something very interesting

00:21:47.380 | about the problem of what exists

00:21:51.980 | in its relationship to life.

00:21:53.260 | - So do you think the set of things

00:21:55.700 | that could exist is finite?

00:21:57.780 | So it's very large, but if we were to think

00:22:00.700 | about the physics of existence,

00:22:02.660 | like how many shapes of mugs can there be?

00:22:06.900 | Like is, in the initial programming--

00:22:10.020 | - I should go to the math department for that.

00:22:13.020 | - So that's not a topology question.

00:22:14.700 | I just mean, maybe another way to ask is,

00:22:17.780 | what do you think is fundamental to the universe

00:22:20.340 | and what is emergent?

00:22:21.660 | So if existence, are we supposed to think of that

00:22:24.780 | as somehow fundamental, you think?

00:22:26.900 | - So there's a couple of problems in physics

00:22:28.660 | that I think this is related to.

00:22:29.820 | One is, why does mathematics work

00:22:31.380 | at describing reality so well?

00:22:33.300 | And then there is this problem of,

00:22:35.620 | we don't understand why the laws of physics

00:22:37.660 | are the way they are, or why certain things get to exist,

00:22:40.660 | or what put in place the initial condition of our universe.

00:22:44.060 | There's all of these sort of really deep and big problems,

00:22:47.420 | and they all indirectly are related, I think,

00:22:51.900 | to the same kind of thing that,

00:22:55.420 | our physics is really good

00:22:56.900 | if you specify the initial condition

00:22:58.660 | at specifying a certain sequence of events,

00:23:01.060 | but it doesn't deal with the fact

00:23:03.220 | that other things could have happened,

00:23:05.020 | which is kind of an informational property,

00:23:06.660 | like a counterfactual property.

00:23:08.340 | And it's not good at explaining

00:23:12.220 | this conversation right now.

00:23:15.860 | There are certain things that are outside

00:23:17.700 | the explanatory reach of current physics,

00:23:19.660 | and I think they require looking at it

00:23:22.940 | from a completely different direction.

00:23:25.100 | And so I don't wanna have to fine tune

00:23:26.980 | the initial condition of the universe

00:23:28.860 | to specify precisely all the information

00:23:30.740 | in this conversation.

00:23:31.580 | I think that's a ridiculous assertion.

00:23:33.620 | But that's sort of how people wanna frame it

00:23:35.620 | when they're talking about,

00:23:36.920 | the standard model is sufficient

00:23:40.580 | if we had computing power to basically explain

00:23:42.900 | all of life and our existence.

00:23:44.660 | - An interesting thing you said is,

00:23:46.260 | the way we think about information computation

00:23:48.620 | is by observing a particular kind of systems on Earth

00:23:53.380 | that exhibits something we think of as intelligence.

00:23:56.860 | But that's like looking at, I guess,

00:23:59.980 | the tip of an iceberg,

00:24:01.060 | and we should be really looking at the fundamentals

00:24:03.060 | of the iceberg, like what makes water and ice

00:24:08.060 | and the chemistry from which intelligence emerges.

00:24:12.740 | - Yes, yes. - Essentially.

00:24:14.700 | - We can't just couple the information from the physics,

00:24:17.140 | and I think that's what we've gotten really good at doing,

00:24:19.300 | especially with sort of the modern age

00:24:23.540 | where software is so abstracted from hardware.

00:24:28.540 | But the entire process of biological evolution

00:24:31.780 | has basically been built,

00:24:33.300 | like been building layers of increasing abstraction.

00:24:36.700 | And so it's really hard to see that physics in us,

00:24:39.300 | but it's much clearer to see it in molecules.

00:24:42.540 | - Yeah, but I guess I'm trying to figure out,

00:24:44.820 | what do you think are the best tools to look at it?

00:24:48.580 | What do you think?

00:24:49.500 | - An open mind?

00:24:51.700 | Is that a tool? (laughs)

00:24:53.500 | - What's the physics of an open mind?

00:24:55.300 | - I think if we solve that, we'll solve everything.

00:24:58.580 | I'm saying an open mind

00:24:59.660 | because I think the biggest stumbling block

00:25:02.500 | to understanding sort of the things

00:25:05.900 | I've been trying to articulate,

00:25:07.260 | or, and when I talk also with colleagues

00:25:09.020 | that are thinking deeply about these same issues,

00:25:11.660 | is none of it is inconsistent with what we know.

00:25:15.420 | It's just such a radically different perception

00:25:18.260 | of the way we understand things now

00:25:19.700 | that it's hard for people to get there.

00:25:21.340 | And in some ways you have to almost forget

00:25:23.140 | what you've learned in order to learn something new, right?

00:25:25.900 | So I feel like most of my career

00:25:27.900 | trying to understand the problem of life

00:25:29.900 | has been variously forgetting and then relearning

00:25:33.860 | things that I learned in physics.

00:25:35.620 | And I think you have to have a capacity to learn things,

00:25:40.620 | but then accept that things that you learned

00:25:44.460 | might not be true.

00:25:47.300 | Or might need refinement or reframing.

00:25:50.900 | And the best way I can say that

00:25:53.340 | is just like with a physics education,

00:25:54.700 | there are just certain things you're told in undergrad

00:25:56.940 | that are like facts about the world.

00:25:58.980 | And your physics professors never tell you

00:26:01.300 | that those facts actually emerge from a human mind, right?

00:26:04.300 | So we're taught to think about,

00:26:05.500 | say the laws of physics, for example,

00:26:07.420 | as this like autonomous thing

00:26:09.460 | that exists outside of our universe

00:26:10.780 | and tells our universe how it works.

00:26:12.580 | But the laws of physics were invented by human minds

00:26:15.500 | to describe things that are regularities

00:26:17.460 | in our everyday experience.

00:26:19.420 | They don't exist autonomous to the universe.

00:26:21.620 | - Right, so it's like turtles on top of turtles,

00:26:23.940 | but eventually it gets to the human mind

00:26:26.380 | and then you have to explain the human mind

00:26:28.460 | with the turtles.

00:26:29.300 | - Yes.

00:26:30.140 | - So you have to, it comes from humans,

00:26:32.660 | this understanding, this simplification of the universe,

00:26:34.780 | these models.

00:26:36.380 | There's a guy named Stephen Wolfram,

00:26:38.300 | there's a concept called cellular automata.

00:26:42.060 | So there's some mysteries in these systems

00:26:47.060 | that are computational in nature

00:26:49.460 | that have maybe echoes of the kind of mysteries

00:26:54.060 | we should need to solve to understand what is life.

00:26:57.840 | So if we could talk, take a computational view of things,

00:27:04.100 | do you think there's something compelling

00:27:06.260 | to reducing everything down to computation,

00:27:09.900 | like the universe is computation,

00:27:12.060 | and then trying to understand life.

00:27:15.280 | So throw away the biology, throw away the chemistry,

00:27:18.900 | throw away even the physics that you learn

00:27:21.240 | undergrad and graduate school,

00:27:22.940 | and more look at these simple little systems,

00:27:25.980 | whether it's cellular automata

00:27:27.100 | or whatever the heck kind of computational systems

00:27:29.660 | that operate on simple local rules

00:27:31.580 | and then create complexity as they evolve.

00:27:36.260 | Is it at all, do you think, productive

00:27:39.500 | to focus on those kinds of systems

00:27:42.140 | to get an inkling of what is life?

00:27:44.260 | And if it is, do you think it's possible

00:27:48.780 | to come up with some kind of laws and principles

00:27:51.620 | about what makes life in those computational systems?

00:27:56.140 | - So I like cellular automata,

00:27:57.420 | I think they're good toy models,

00:27:59.580 | but mostly where I've thought about them and used them

00:28:02.620 | is to actually, let's say, poke at

00:28:07.620 | sort of the current conceptual framework that we have

00:28:10.900 | and see where the flaws are.

00:28:12.260 | So I think the part that you're talking about

00:28:15.660 | that people find intriguing is that

00:28:17.260 | if you have a fairly simple rule

00:28:19.660 | and you specify some initial condition

00:28:21.600 | and you run that rule on that initial condition,

00:28:23.500 | you could get really complex patterns emerging.

00:28:26.500 | And ooh, doesn't that look lifelike?

00:28:28.400 | - Well, it's like really surprising,

00:28:32.460 | isn't it really surprising? - It is really surprising.

00:28:33.820 | And they're beautiful.

00:28:35.260 | And I think they have a lot of nice features

00:28:37.800 | associated to them.

00:28:39.740 | I think the things that I find,

00:28:42.340 | yeah, so I do think as a proof of principle

00:28:46.500 | that you can get complex things

00:28:47.740 | emerging from simple rules, they're great.

00:28:50.500 | As a sort of proof of principle

00:28:52.580 | about some of the ways that we might think of computation

00:28:56.780 | as being sort of a fundamental principle

00:28:59.480 | for dynamical systems and maybe the evolution

00:29:02.020 | of the universe as a whole,

00:29:03.300 | they're a great model system.

00:29:05.720 | As an explanatory framework for life,

00:29:07.880 | I think they're a bit problematic

00:29:10.940 | for the same reason that the laws of physics

00:29:14.140 | are a bit problematic.

00:29:16.340 | And the clearest way I can articulate that

00:29:19.340 | is like cellular automata are actually cast

00:29:22.480 | in sort of a conceptual framework

00:29:24.900 | for how the universe should be described

00:29:26.580 | that goes all the way back to Newton, in fact,

00:29:29.660 | with this idea that we can have a fixed law of motion,

00:29:33.740 | which exists sort of, it's given to you.

00:29:36.120 | The great programmer in the sky gave you this equation

00:29:40.500 | or this rule, and then you just run with it.

00:29:43.420 | And the rule doesn't have,

00:29:45.100 | so a good feature of the rule

00:29:46.620 | is it doesn't have specified in the rule

00:29:49.200 | information about the patterns it generates.

00:29:51.100 | So you wouldn't want, for example,

00:29:53.860 | my cup or my water bottle or me sitting here

00:29:57.020 | to be specified in the laws of physics.

00:29:58.660 | That would be ridiculous 'cause it wouldn't be

00:30:00.000 | a very simple explanation of all the things happening.

00:30:02.020 | It'd have to explain everything.

00:30:03.620 | So, and cellular automata have that feature,

00:30:06.220 | and the laws of physics have that feature.

00:30:08.480 | But you also need to specify the initial condition.

00:30:13.140 | And it also, it basically means that everything that happens

00:30:17.100 | is sort of a consequence of that initial condition.

00:30:19.860 | And I think this kind of framework

00:30:21.820 | is just not the right one for biology.

00:30:25.100 | And part of the way that it's easiest to see this

00:30:28.300 | is a lot of people talk about self-reference

00:30:31.900 | being important in life.

00:30:33.500 | The fact that, you know, like the genome

00:30:36.900 | has information encoded in it.

00:30:39.300 | That information gets read out.

00:30:41.740 | It specifies something about the architecture of a cell.

00:30:45.180 | The architecture of the cell includes the genome.

00:30:47.140 | So the genome has basically self-referential information.

00:30:49.900 | Self-reference obviously comes up in computational law

00:30:53.060 | because it's kind of foundational to Turing's work

00:30:56.740 | and what Gödel did with the incompleteness theorems

00:30:58.980 | and things.

00:30:59.820 | So there's a lot of parallels there,

00:31:02.620 | and people have talked about that at depth.

00:31:05.500 | But the other way of kind of thinking about it

00:31:06.860 | in terms of like a more physics-y way of talking about it

00:31:10.180 | is that what it looks like in biology

00:31:12.340 | is that the rules or the laws depend on the state.

00:31:15.960 | This is typical in computer science.

00:31:17.380 | This is obvious to you.

00:31:18.580 | You know, the update rule depends

00:31:19.900 | on the state of the machine, right?

00:31:21.020 | But you know, you don't think about, you know,

00:31:24.880 | that being sort of the dynamic in physics.

00:31:27.620 | It's, you know, the rules given to you,

00:31:29.020 | and then it, you know, it's a very special subclass,

00:31:31.740 | say, of computations if, you know,

00:31:33.820 | you don't ever change the update.

00:31:36.660 | But in biology, it seems to be that the state

00:31:38.420 | and the law change together as a function of time,

00:31:41.060 | and we don't have that as a paradigm in physics.

00:31:43.820 | And so a lot of people have talked about this

00:31:45.700 | as being kind of a perplexing feature

00:31:47.620 | that maybe there are certain scenarios

00:31:49.820 | where the laws of physics or the laws

00:31:51.740 | that govern a particular system

00:31:53.060 | actually change as a function of state of that system.

00:31:56.620 | - That's trippy.

00:31:57.460 | - Yeah.

00:31:58.300 | - So yeah, the hope of physics,

00:32:00.260 | it's a hope, I guess, but often stated

00:32:03.260 | as a underlying assumption is that the law is static.

00:32:08.260 | - Right.

00:32:10.140 | - Okay.

00:32:10.980 | - And even having laws that vary in time,

00:32:12.820 | not even as a function of the state,

00:32:14.220 | is very radical when you--

00:32:16.900 | - The time in general.

00:32:17.940 | - Yeah.

00:32:18.780 | - Like, you wanna remove time from the equation

00:32:21.060 | as much as possible.

00:32:22.060 | - Yeah, I do.

00:32:24.260 | There's some interesting things in this,

00:32:25.620 | like when we think more deeply about the actual physics

00:32:29.160 | that we're trying to propose governs life,

00:32:31.700 | me with collaborators, and then also other people

00:32:33.680 | that think about similar things,

00:32:35.200 | that time might actually be fundamental,

00:32:36.800 | and there really is an ordering to time.

00:32:38.900 | And that events in the universe are unique

00:32:41.060 | because they have a particular, they happen,

00:32:44.000 | like an object in the universe requires

00:32:45.700 | a certain history of events in order to exist,

00:32:48.320 | which therefore suggests that time

00:32:49.680 | really does have an ordering.

00:32:50.600 | I'm not talking about the flow of time

00:32:51.680 | and our perception of time,

00:32:52.520 | just the ordering of events.

00:32:53.700 | - Causation of things.

00:32:54.540 | - Yes, causation, there's that word again.

00:32:56.680 | - So causation, that's when you say time,

00:32:58.680 | you mean causation.

00:32:59.520 | - Yes.

00:33:00.800 | - In your proposed model of the physics of life,

00:33:05.400 | the fundamental thing would be causation.

00:33:08.320 | If you were to bet your money on one particular horse

00:33:11.600 | or whatever.

00:33:12.440 | - Yes.

00:33:13.280 | - And then space is emergent?

00:33:15.480 | - Yes.

00:33:16.320 | - So everything's emergent except time.

00:33:19.160 | - Kind of, yeah, or causation.

00:33:21.080 | - And laws change all the time.

00:33:22.720 | Why does it look like laws are the same?

00:33:24.800 | - Well, because, well one way,

00:33:27.960 | and I actually, this idea comes from Lee Cronin

00:33:30.000 | 'cause I work with him very closely on these things,

00:33:31.840 | is that the laws of physics look the way they do

00:33:33.760 | because they're low memory laws.

00:33:35.560 | So they don't require a lot of information to specify them.

00:33:37.820 | They're very easy for the universe to implement.

00:33:39.720 | But if you get something like me, for example,

00:33:42.080 | I require a four billion year history

00:33:43.600 | to exist in the universe.

00:33:44.520 | I come with a lot of historical baggage.

00:33:47.080 | And that's part of what I am as a set of causes

00:33:49.360 | that exist in the universe.

00:33:50.720 | So I have local rules that apply to me

00:33:55.240 | that are associated with sort of the information

00:33:57.040 | in my history that aren't universal

00:33:59.240 | to every object in the universe.

00:34:01.040 | And there are some things that are very easy

00:34:03.880 | to implement, low memory rules,

00:34:06.040 | that apply to everything in the universe.

00:34:08.840 | - So there's no shortcuts to you.

00:34:10.600 | - No.

00:34:11.440 | So yeah, I don't believe in things like Boltzmann brains

00:34:13.600 | or fluctuations out of the vacuum

00:34:17.280 | that can produce things like your desk ornaments.

00:34:19.780 | I actually think they require a particular causal chain

00:34:24.520 | of events to exist.

00:34:25.640 | - Well, I appreciate the togetherness of that.

00:34:28.600 | But so how does that, if we have to simulate

00:34:32.160 | the entire universe to create the ornaments

00:34:35.240 | in the two of us, how are we supposed

00:34:38.080 | to create engineer life in a lab?

00:34:41.080 | - Yeah, that's, this goes back to sort of the critique

00:34:44.680 | of the RNA world.

00:34:45.520 | I think one of the problems,

00:34:46.920 | and I'll get to answering your question,

00:34:48.360 | but I think this is kind of relevant here.

00:34:50.320 | One of the problems of the RNA world,

00:34:52.840 | when we test it in the laboratory,

00:34:54.280 | is how much information we're putting into the experiment.

00:34:57.320 | We specify the flask, we make pure reagents,

00:35:00.080 | we mix them, we take them out,

00:35:01.880 | we put them in the next flask, we change the pH,

00:35:04.440 | we change the UV light, and then we get a molecule.

00:35:07.120 | And it's not even an RNA molecule necessarily,

00:35:09.080 | it might just be a base, right?

00:35:11.160 | And so people don't usually think about the fact

00:35:14.720 | that we're agents in the universe making that experiment,

00:35:17.880 | and therefore we put a little bit of life

00:35:19.480 | into that experiment.

00:35:20.560 | Because it's part of our biological lineage,

00:35:23.760 | in the same sense that a cup,

00:35:24.960 | or I am a part of the biological lineage.

00:35:26.840 | The experiment is-- - Our ideas are injecting life.

00:35:31.160 | - Yes. - To the experiment.

00:35:32.000 | - And the constraints that we put on the experiments.

00:35:34.160 | Because those conditions wouldn't exist in the universe,

00:35:36.760 | on planet Earth at that time,

00:35:38.560 | without us as the boundary condition, right?

00:35:40.400 | So-- - Even though we're not actually

00:35:42.400 | adding any actual chemistry or biology

00:35:45.120 | that could be identified as life,

00:35:47.600 | are the constraints we're adding to the experiment,

00:35:49.800 | the design of the experiment.

00:35:51.240 | - Yeah, you can think of the design of the experiment

00:35:52.560 | as a program, you put information in.

00:35:54.280 | It's an algorithmic procedure

00:35:55.760 | that you design the experiment.

00:35:57.160 | And so the origin of life problem becomes one

00:36:01.000 | of minimizing the information we put into physics,

00:36:04.880 | to actually watch the spontaneous origin of life.

00:36:07.120 | - Can we have, so can, is it possible in the lab

00:36:09.840 | to have an information vacuum then?

00:36:12.200 | So like-- - If we could, we would,

00:36:13.760 | that would be amazing, I don't know.

00:36:15.440 | That's a good question for, more for Lee.

00:36:17.680 | - Yeah, you guys, by the way,

00:36:18.680 | for people who don't know Lee Cronin,

00:36:20.160 | is, you guys are colleagues. - Yeah.

00:36:23.160 | - And I've gotten the chance to listen

00:36:25.720 | to the two of you talking.

00:36:26.960 | There's great chemistry,

00:36:28.280 | and you're brilliant at brainstorming together.

00:36:30.560 | And there's a really exciting community here

00:36:34.400 | of brilliant people from different disciplines

00:36:36.880 | working on the problem. - Yeah.

00:36:38.360 | - Of life, of complexity, of, I don't know, whatever.

00:36:42.400 | The words fail us to describe the exact problem

00:36:45.200 | we're trying to actually-- - Right.

00:36:46.600 | - Understand here, intelligence, all those kinds of things.

00:36:50.120 | Okay, so what, from a lab perspective,

00:36:55.120 | so Lee, I guess, would you call him a chemist?

00:36:57.820 | No, what is he? - I think by training,

00:36:59.360 | he's a chemist, but I think most of the people

00:37:01.000 | that work in the field we do have lost their discipline.

00:37:03.400 | (laughing)

00:37:04.800 | That's why I couldn't answer your question earlier.

00:37:06.920 | - Okay. - I don't know what you call him.

00:37:08.360 | - Yeah. - I don't know

00:37:09.200 | what I call myself.

00:37:10.020 | I don't know what I call any of my friends.

00:37:11.880 | - So why is it so hard to create,

00:37:14.840 | and it's an interesting question,

00:37:16.920 | to create biological life in the lab?

00:37:19.400 | Like, from your perspective,

00:37:21.800 | is that an important problem to work on,

00:37:23.980 | to try to recreate the historical origin of life on Earth,

00:37:28.980 | or echoes of the historical origin?

00:37:31.120 | - I think echoes is more appropriate.

00:37:32.760 | I don't think asking the question

00:37:34.920 | of what was the exact historical sequence of events,

00:37:37.680 | and engineering every step in the process

00:37:40.440 | to make exactly the chemistry of life on Earth

00:37:42.960 | as we know it is a meaningful way of asking the question.

00:37:46.340 | And it's a little bit like,

00:37:47.800 | you know, since you're in computer science,

00:37:50.980 | like if you know the answer to a problem,

00:37:53.440 | it's easier to find a program to specify the output, right?

00:37:56.020 | But if you don't know the answer a priori,

00:37:58.080 | you know, finding an algorithm for,

00:37:59.720 | like say finding a prime or something,

00:38:01.040 | it's easy to, you know, verify it's a prime number.

00:38:05.000 | It's hard to find the next prime.

00:38:07.480 | And the way the original life is structured right now,

00:38:10.960 | and the historical problem is,

00:38:13.040 | you know the answer, and you're trying to retrodict it

00:38:15.640 | by breaking it down into the set of procedures

00:38:17.600 | where you're putting a lot of information in.

00:38:19.480 | And what we need to do is ask the question of,

00:38:22.520 | how is it that the rules of how our universe is structured

00:38:26.200 | permit things like life to exist,

00:38:28.120 | and what is the phenomena of life?

00:38:29.800 | And those questions are obviously

00:38:31.440 | essentially the same question.

00:38:33.140 | And so you're looking essentially for this missing physics,

00:38:37.880 | this missing explanation for what we are,

00:38:39.760 | and you need to set up proper experiments

00:38:41.760 | that are gonna allow you to probe

00:38:43.560 | the vast complexity of chemistry in an unconstrained way

00:38:47.500 | with as little information put in as possible

00:38:50.240 | to see when things, when does information actually emerge?

00:38:53.980 | How does it emerge?

00:38:55.400 | What is it?

00:38:57.360 | And part of the sort of conjecture we have is

00:39:01.080 | that this physics only becomes relevant,

00:39:03.200 | or at least this is my personal conjecture,

00:39:05.840 | and it's sort of validated by this kind of theory

00:39:09.400 | experiment collaboration that we have working in this area.

00:39:14.400 | That this, you know, sort of,

00:39:17.160 | I made the point about like gravity existing everywhere,

00:39:19.080 | right, but when you study an atomic nucleus,

00:39:22.300 | you don't care about gravity.

00:39:23.400 | It's not relevant physics there, right?

00:39:24.960 | It's weak, it doesn't matter.

00:39:27.700 | And so this idea that there's kind of a physics

00:39:31.660 | associated with information,

00:39:33.820 | for me, it's very evident that that physics

00:39:37.340 | doesn't become relevant until you need information

00:39:39.960 | to specify the existence of a particular object.

00:39:42.540 | And the scale of reality where that happens is in chemistry

00:39:46.060 | because of the combinatorial diversity of chemical objects

00:39:49.780 | that can exist far out exceeds

00:39:52.740 | the amount of resources in our universe.

00:39:54.740 | So if you want it, you can't make every possible protein

00:39:57.620 | of length, you know, 200 amino acids,

00:40:00.380 | there's not enough resources.

00:40:01.940 | So in order for this particular protein to exist,

00:40:05.100 | and this protein to exist in high abundance,

00:40:07.580 | means that you have to have a system that has knowledge

00:40:10.660 | of the existence of that protein and can build it.

00:40:12.940 | - So existence comes to be at the chemical level.

00:40:15.620 | So existence is most,

00:40:17.820 | is best understood at the chemical level.

00:40:20.740 | - It's most evident.

00:40:22.100 | It's a little bit like,

00:40:23.100 | nobody argues that gravity doesn't exist

00:40:24.900 | in an atomic nucleus, it's just not relevant physics there.

00:40:27.860 | - So the physics of information--

00:40:29.860 | - Is everywhere, it exists at every combinatorial scale,

00:40:32.500 | but it becomes more and more relevant

00:40:34.220 | the more set of possibilities that could exist.

00:40:36.740 | Because you have to specify more and more

00:40:39.380 | about why this thing exists and not the infinite,

00:40:41.820 | it's not an infinite set, but you know,

00:40:43.340 | the set of, undefined set of other things that could exist.

00:40:46.180 | - So can I ask a weird question?

00:40:49.340 | Which is, so let's look into the future.

00:40:53.300 | - I try that every day, it never works.

00:40:55.260 | - So say a Nobel Prize is given in physics,

00:41:00.140 | maybe chemistry, for discovering the origin of life.

00:41:05.140 | No, but not the historical origin.

00:41:09.180 | Some kind of thing that we're talking about.

00:41:11.440 | What exactly would,

00:41:15.660 | what do you think that,

00:41:20.700 | what do you think that person,

00:41:22.500 | maybe you, did to get that Nobel Prize?

00:41:24.740 | Like what would they have to have done?

00:41:26.260 | 'Cause you could do a bunch of experiments

00:41:27.780 | that go like with an aha moment.

00:41:30.660 | Like you rarely get the Nobel Prize

00:41:33.760 | for like, you've solved everything, we're done.

00:41:37.100 | It's like some inkling of some deep truth.

00:41:40.900 | Like what do you think that would actually look like?

00:41:43.260 | Would it be an experimental result?

00:41:45.180 | I mean, it will have to have some kind of experimental,

00:41:48.860 | maybe validation component.

00:41:50.340 | So what would that look like?

00:41:52.300 | - This is an excellent question.

00:41:54.660 | I wanna, sorry, I'm gonna make a quick point,

00:41:57.260 | which is just a slight tangent.

00:41:58.740 | But you know, like when people ask about the origin of mass

00:42:01.260 | and like looking for the Higgs mechanism and things,

00:42:03.280 | they never are like, we need to find the historical origins

00:42:06.020 | of life in the early,

00:42:06.940 | although those things are related, right?

00:42:08.420 | So this problem of origins of life in the lab,

00:42:11.460 | I think is really important.

00:42:12.620 | But the Higgs is a good example

00:42:14.540 | because you had theory to guide it.

00:42:15.980 | So somehow you need to have an explanatory framework

00:42:20.220 | that can say that we should be looking for these features

00:42:24.820 | and explain why they might be there

00:42:27.900 | and then be able to do the experiment

00:42:29.540 | and demonstrate that it matches with the theory.

00:42:31.580 | But it has to be something that is outside

00:42:34.300 | sort of the paradigm of what we might expect

00:42:36.320 | based on what we know, right?

00:42:37.500 | So this is a really sort of tall order.

00:42:40.420 | And I think,

00:42:42.580 | I mean, I guess the way people would think about it

00:42:46.300 | is like, you know, if you had a bacteria

00:42:48.000 | that climbed out of your test tube or something,

00:42:49.820 | and it was like, you know, moving around on the surface,

00:42:51.660 | that would be ultimate validation.

00:42:53.020 | You saw the original life in an experiment.

00:42:55.120 | But I don't think that's quite what we're looking for.

00:42:57.440 | I think what we're looking for is evidence

00:43:01.960 | of when information that originated

00:43:06.020 | within the bounds of your experiment,

00:43:08.400 | and you can demonstrably prove emerged spontaneously

00:43:11.980 | in your experiment, wasn't put in by you,

00:43:14.620 | actually started to govern the future dynamics

00:43:17.720 | of that system and specify it.

00:43:20.120 | And you could somehow relate those two features directly.

00:43:23.520 | So you know that the program specifying

00:43:26.260 | what's happening in that system

00:43:27.560 | is actually internal to that system.

00:43:29.700 | Like say you have a chemical thing in a box.

00:43:32.080 | - Well, so that's one Nobel Prize winning experiment,

00:43:36.340 | which is like information in some fundamental way

00:43:39.920 | originated within the constraints of the system

00:43:42.880 | without you injecting anything.

00:43:44.600 | But another experiment is you injected something

00:43:49.040 | and got out information.

00:43:52.720 | So like you injected, I don't know,

00:43:55.760 | like some sugar and like something

00:43:59.960 | that doesn't necessarily feel like it should be information.

00:44:03.400 | - Yeah, so actually no, I mean, sugar is information, right?

00:44:07.140 | So part of the argument here is that every physical object

00:44:10.120 | is, well, it's information,

00:44:12.920 | but it's a set of causal histories

00:44:14.620 | and also a set of possible futures.

00:44:16.680 | So there is an experiment that I've talked a lot about

00:44:20.520 | with Lee Cronin, but also with Michael Lachman

00:44:22.120 | and Chris Kempis who are at Santa Fe,

00:44:23.900 | about this idea that sometimes we talk about

00:44:25.800 | as like seeding assembly,

00:44:27.880 | which is you take a high complexity,

00:44:30.560 | like an object that exists in the universe

00:44:32.880 | because of a long causal history,

00:44:34.880 | and you seed it into a system of lower causal history.

00:44:38.640 | And then suddenly you see all of this complexity

00:44:40.840 | being generated.

00:44:41.960 | So I think another validation of the physics would be,

00:44:44.960 | say you engineer an organism

00:44:46.960 | by purposefully introducing something

00:44:49.760 | where you understand the relationship

00:44:51.240 | between the causal history of the organism

00:44:54.080 | and the say very complex chemical set of ingredients

00:44:57.560 | you're adding to it.

00:44:58.920 | And then you can predict the future evolution of that system

00:45:02.000 | to some statistical set of constraints

00:45:05.880 | and possibilities for what it will look like in the future.

00:45:10.100 | You know, I'm a physical structure,

00:45:12.520 | obviously like I'm composed of atoms,

00:45:15.240 | the configuration of them

00:45:16.680 | and the fact that they happen to be me

00:45:19.400 | is because I'm not actually my atoms,

00:45:22.080 | I am a informational pattern

00:45:24.680 | that keeps repatterning those atoms into Sarah.

00:45:28.960 | And I have also associated to me

00:45:32.000 | like a space of possible things that could exist

00:45:36.240 | that I can help mediate come into existence

00:45:38.200 | because of the information in my history.

00:45:41.240 | And so when you understand sort of that

00:45:45.760 | time is a real thing embedded in a physical object,

00:45:49.180 | then it becomes possible to talk about

00:45:52.960 | how histories when they interact,

00:45:57.000 | and a history is not a unique thing,

00:45:58.460 | it's a set of possibilities.

00:45:59.920 | When they interact,

00:46:00.760 | how do they specify what's coming next?

00:46:03.240 | And then where does the novelty come from in that structure?

00:46:05.320 | 'Cause some of it is kind of things

00:46:06.640 | that haven't existed in the past can exist in the future.

00:46:09.960 | - Let me ask about this entity that you call Sarah.

00:46:12.840 | - Yes.

00:46:14.180 | I talk to myself, put myself in third person sometimes,

00:46:16.880 | I don't know why.

00:46:17.720 | - So maybe this is a good time to bring up consciousness.

00:46:22.440 | - Sure.

00:46:23.280 | It's been here all along.

00:46:26.600 | - Well, has it?

00:46:28.240 | So that's--

00:46:29.080 | - At least in this conversation,

00:46:30.560 | I think I've been conscious most of it,

00:46:31.920 | but maybe I haven't.

00:46:32.760 | - Well, yeah, so speak for yourself.

00:46:34.800 | You're projecting your consciousness onto me.

00:46:37.960 | You don't know if I'm conscious or not.

00:46:39.760 | - No, I don't.

00:46:41.080 | You're right.

00:46:41.920 | - Is that, you talked about the physics of existence,

00:46:45.140 | you talked about the emergence of causality,

00:46:50.140 | sorry, you talked about causality and time

00:46:52.720 | being fundamental to the universe.

00:46:54.560 | Where does consciousness fit into all of this?

00:46:58.460 | Like, do you draw any kind of inspiration or value

00:47:03.460 | with the idea of panpsychism

00:47:05.440 | that maybe one of the things that we ought to understand

00:47:09.720 | is the physics of consciousness?

00:47:12.040 | Like, one of the missing pieces

00:47:15.200 | in the physics view of the world

00:47:17.440 | is understanding the physics of consciousness.

00:47:20.440 | Or like that word has so many concepts underneath it,

00:47:24.860 | but let's put it,

00:47:26.880 | let's put consciousness as a label on a black box of mystery

00:47:30.700 | that we don't understand.

00:47:32.340 | Do you think that black box holds the key

00:47:36.580 | to finally answering the question of the physics of life?

00:47:40.780 | - The problems are absolutely related.

00:47:42.260 | I think most, and I'm interested in both

00:47:44.720 | because I'm just interested in what we are.

00:47:46.340 | And to me, the most interesting feature

00:47:48.140 | of what we are is our minds

00:47:49.460 | and the way they interact with other minds.

00:47:51.300 | Like minds are the most beautiful thing

00:47:52.660 | that exists in the universe.

00:47:53.560 | So how did they come to be?

00:47:55.340 | - Sorry to interrupt.

00:47:56.220 | So when you say we, you mean humans.

00:47:58.460 | - I mean humans right now,

00:47:59.580 | but that's because I'm a human, or at least I think I am.

00:48:02.460 | - You think there's something special to this particular?

00:48:05.060 | - No, no, no, no, no.

00:48:06.500 | No, I don't, I'm not a human-centric thinker.

00:48:11.300 | - But are you one entity?

00:48:12.580 | You said a bunch of stuff came together to make a Sarah.

00:48:15.420 | Like, do you think of yourself as one entity

00:48:18.180 | or are you just a bunch of different components?

00:48:20.780 | Like, is there any value to understand the physics of Sarah?

00:48:23.740 | Like, or are you just a bunch of different things

00:48:26.340 | that are like a nice little temporary side effect?

00:48:30.100 | - Yeah, you could think of me as a bundle of information

00:48:33.060 | that just became temporarily aggregated into your individual.

00:48:35.940 | Yeah, that's fine.

00:48:37.300 | I agree with that view.

00:48:38.460 | (laughing)

00:48:40.540 | I'll take that as a compliment, actually.

00:48:42.540 | - But nevertheless, that bundle of information

00:48:46.540 | has become conscious,

00:48:47.860 | or at least keeps calling herself conscious.

00:48:50.980 | - Yeah, I think I'm conscious right now,

00:48:52.600 | but I might not be, but that's okay.

00:48:55.100 | Or you wouldn't know.

00:48:56.380 | So yeah, so this is the problem.

00:48:57.700 | So yeah, usually people,

00:48:59.060 | when they are talking about consciousness,

00:49:00.380 | are worried about the subjective experience.

00:49:02.300 | And so I think that's why you're saying,

00:49:04.140 | I don't know if you're conscious

00:49:05.100 | because I don't know if you're experiencing

00:49:06.900 | this conversation right now.

00:49:08.300 | And nor do you know if I'm experiencing

00:49:11.460 | the conversation right now.

00:49:12.960 | And so this is why this is called

00:49:14.300 | the hard problem of consciousness,

00:49:15.400 | because it seems impenetrable from the outside

00:49:17.540 | to know if something's having a conscious experience.

00:49:21.500 | And I really like the idea of also

00:49:24.780 | the hard problem of matter,

00:49:26.220 | which is related to the hard problem of consciousness,

00:49:28.940 | which is you don't know the intrinsic properties

00:49:31.620 | of an electron not interacting,

00:49:33.300 | say for example, with anything else in the universe.

00:49:35.260 | All the properties of anything that exists in the universe

00:49:38.200 | are defined by its interaction,

00:49:39.500 | because you have to interact with it

00:49:40.900 | in order to be able to observe it.

00:49:42.420 | So we can only actually know the things

00:49:44.500 | that are observable from the outside.

00:49:46.260 | And so this is one of the reasons

00:49:47.700 | that consciousness is hard for science,

00:49:49.400 | because you're asking questions about something

00:49:51.980 | that's subjective and supposed to be intrinsic

00:49:54.160 | to what that thing is as it exists

00:49:56.340 | and how it feels about existing.

00:49:57.980 | And so I have thought a lot about this problem

00:50:02.580 | and its relationship to the problem of life.

00:50:05.460 | And the only thing I can come up with

00:50:07.180 | to try to make that problem scientifically tractable

00:50:12.180 | and also relate it to how I think about the physics of life

00:50:17.980 | is to ask the question,

00:50:20.360 | are there things that can only happen in the universe

00:50:23.500 | because there are physical systems

00:50:26.260 | that have subjective experience?

00:50:28.800 | So does subjective experience have different causes,

00:50:32.040 | things that it can cause to occur

00:50:35.060 | that would happen in the absence of that?

00:50:38.640 | I don't know the answer to that question,

00:50:40.120 | but I think that's a meaningful way

00:50:42.100 | of asking the question of consciousness.

00:50:43.660 | I can't ask if you're having experience right now,

00:50:46.620 | but I can ask if you having experience right now

00:50:49.180 | changes something about you

00:50:50.860 | and the way you interact with the world.

00:50:52.780 | - So does stuff happen?

00:50:56.940 | It's a good question to ask,

00:50:57.780 | does stuff happen if consciousness is--

00:51:00.380 | - Then it's a real physical thing, right?

00:51:03.180 | It has physical consequences.

00:51:04.460 | I'm a physicist, I'm biased, so I don't, you know,

00:51:06.900 | I can't get rid of that bias.

00:51:08.260 | It's really deeply ingrained.

00:51:10.340 | I've tried, but it's hard.

00:51:12.180 | - But I mean, you're saying information is physical too.

00:51:14.700 | So like virtual reality and simulation,

00:51:16.420 | all that program is physical too.

00:51:18.340 | - Yes, everything's physical.

00:51:19.420 | It's just not physical the way it's represented in our minds

00:51:22.940 | - Right, so you, I love your Twitter.

00:51:25.580 | So you tweet these like deep thoughts, deep thoughts.

00:51:29.740 | - That's what a theorist does

00:51:30.740 | when she's trying to experiment.

00:51:32.340 | - Is tweet?

00:51:34.220 | - Yes.

00:51:35.420 | - Sitting there, I mean, I can just imagine

00:51:37.900 | you sitting there for like hours

00:51:39.140 | and all of a sudden just like this thought comes out

00:51:41.460 | and you get a little like inkling into the thought process.

00:51:46.460 | - Yeah, usually it's like when I'm running between things

00:51:48.860 | and I'm like, I've got deep thoughts.

00:51:50.980 | - Well, yeah, so you--

00:51:52.300 | - Deep thoughts are hard to articulate.

00:51:53.660 | - One of the things you tweet is ideologically,

00:51:56.580 | there are many parallels between the search

00:51:58.700 | for neural correlates of consciousness

00:52:01.620 | and for chemical correlates of life.

00:52:04.260 | How the neuroscience and astrobiology communities

00:52:07.500 | treat those correlates is entirely different.

00:52:10.460 | Can you elaborate against this kind of the parallels?

00:52:14.660 | It has to do a little bit with the consciousness

00:52:16.500 | and the matter thing you're talking about.

00:52:20.060 | - Yeah, it does.

00:52:20.940 | And I can't remember what state of mind I was

00:52:23.020 | when I was actually thinking about that.

00:52:24.420 | But I think part of it is--

00:52:27.100 | - I bet you never thought you're gonna have to

00:52:28.940 | analyze your own tweets.

00:52:29.940 | - No, I didn't.

00:52:31.020 | It's an interesting historical juxtaposition of thinking.

00:52:34.860 | So yeah.

00:52:35.700 | - So the tweet is a historical--

00:52:37.860 | - Hey, you're doing an assembly experiment right now

00:52:40.140 | 'cause you're bringing a thought from the past

00:52:41.620 | into the present and trying to actually--

00:52:43.300 | - In the lab.

00:52:44.220 | - Yeah, yeah, yeah.

00:52:45.060 | This is experimental science right here

00:52:47.660 | on the podcast live.

00:52:48.860 | - So go, let's see how the consciousness evolves on this one.

00:52:53.780 | - Yeah, so in neuroscience, it's kind of accepted

00:52:57.700 | that we can't get at the subjective aspect of consciousness.

00:53:01.580 | So people are very interested in what would be

00:53:04.620 | a correlate of consciousness.

00:53:06.300 | - What's a correlate?

00:53:09.580 | - A correlate is a feature that relates

00:53:13.260 | to conscious activity.

00:53:14.460 | So for example, a verbal report is a correlate

00:53:18.700 | of consciousness because I can tell you when I'm conscious.

00:53:22.900 | And then when I'm sleeping, for example,

00:53:25.020 | I can't tell you I'm conscious.

00:53:26.220 | So we have this assumption that you're not conscious

00:53:28.700 | when you're sleeping and you're conscious when you're awake.

00:53:31.820 | And so that's sort of like a very obvious example.

00:53:35.500 | But neuroscientists, which I'm no neuroscientist

00:53:38.820 | and I'm not an expert in this field.

00:53:41.100 | But they have very sophisticated ways of measuring activity

00:53:44.100 | in our brain and trying to relate that to verbal report

00:53:47.620 | and other proxies for whether someone

00:53:49.580 | is experiencing something.

00:53:51.260 | And that's what is meant by neural correlates.

00:53:54.780 | And then so when people are trying to think about

00:53:58.260 | studying consciousness or developing theories

00:54:02.420 | for consciousness, they often are trying to build

00:54:06.180 | an experimental bridge to these neural correlates.

00:54:09.820 | Recognizing the fact that a neural correlate

00:54:11.980 | may or may not correspond to consciousness

00:54:15.140 | because that problem's hard

00:54:17.100 | and there's all these associated issues to it.

00:54:19.840 | - So that's from a neuroscience perspective,

00:54:22.180 | it's like fake it till you make it.

00:54:23.580 | So you-- - Pretty much, yeah.

00:54:24.780 | - You fake whatever the correlates are

00:54:26.500 | and hopefully that's going to summon

00:54:31.180 | the thing that is consciousness.

00:54:32.660 | - Yeah, something like that.

00:54:33.740 | - And so the same thing on the chemical correlates of life.

00:54:37.940 | That sounds like, that's an awesome concept.

00:54:39.860 | Is that something that people--

00:54:41.220 | - No, I just made that up.

00:54:42.260 | - Okay.

00:54:43.100 | - That was original to that tweet.

00:54:43.980 | You can cite the tweet.

00:54:45.620 | Maybe I'll write it in a paper someday.

00:54:48.300 | - Chemical correlates of life, that's a good title.

00:54:50.580 | I mean, first of all, your paper is true

00:54:52.900 | that people should check out, have great titles.

00:54:55.540 | - Thank you.

00:54:56.500 | - Papers you're involved with.

00:54:58.140 | So your tweets and titles are stellar

00:55:01.340 | and also your ideas,

00:55:02.620 | but the tweets and titles are much more important.

00:55:04.940 | - Of course.

00:55:05.780 | - So--

00:55:06.620 | - Ideas will live longer.

00:55:07.620 | - Yeah.

00:55:09.980 | - They're much more diffuse though.

00:55:12.260 | - Well, yeah, the tweet is the Trojan horse

00:55:15.340 | for the idea that sticks on for a long time.

00:55:18.020 | Okay, so is there anything to say

00:55:19.380 | about the chemical correlates of life?

00:55:20.860 | You're saying they're similar kind of ways

00:55:24.180 | of thinking about it,

00:55:25.700 | but you mentioned about the communities.

00:55:30.620 | - Yeah, so I think in astrobiology,

00:55:32.700 | there's no concept of chemical correlates of life.

00:55:37.820 | We don't think about it that way.

00:55:38.980 | We think if we find molecules

00:55:40.780 | that are involved in biology, we found life.

00:55:44.500 | So I think one of my motivations there

00:55:48.020 | was just to separate the fact

00:55:49.260 | that life has abstract properties associated to it.

00:55:53.180 | They become imprinted in material substrates

00:55:56.460 | and those substrates are correlates for that thing,

00:55:59.540 | but they are not necessarily the thing

00:56:01.220 | we're actually looking for.

00:56:02.060 | The thing that we're looking for

00:56:03.380 | is the physics that's organizing that system to begin with,

00:56:05.860 | not the particular molecules.

00:56:07.340 | In the same sense that your consciousness

00:56:10.900 | is not your brain.

00:56:12.460 | It's instantiated in your brain.

00:56:17.060 | It has to have a physical substrate,

00:56:18.820 | but the matter is not the thing that you're looking at.

00:56:22.340 | It's some other, at least not in the way

00:56:24.340 | that we have come to look at matter

00:56:27.020 | with traditional physics and things.

00:56:28.340 | There's something else there

00:56:29.620 | and it might be this feature of history I was talking about

00:56:31.820 | or time being actually physically represented there.

00:56:35.900 | - Do you think consciousness can be engineered?

00:56:38.620 | - Yes.

00:56:40.100 | - In the same way that life can be engineered?

00:56:41.460 | - Wow, that was a fast answer.

00:56:42.420 | I didn't even think about that.

00:56:43.380 | That's interesting.

00:56:44.700 | - You don't have a free will.

00:56:46.300 | - No, I do have free will, but it's interesting

00:56:48.300 | 'cause I mean--

00:56:49.500 | - Now you're backtracking.

00:56:51.980 | - No, no, I do--

00:56:52.820 | - And that was predestined.

00:56:53.740 | - Yeah, no, no.

00:56:55.780 | No, I do believe in free will,

00:56:56.980 | but I also think that there's kind of an interesting,

00:56:59.740 | speaking about consciousness,

00:57:03.300 | what are you consciously aware of

00:57:04.580 | versus what is your subconscious brain

00:57:07.580 | actually processing and doing?

00:57:08.900 | And sometimes there's conflict

00:57:10.540 | between your consciousness and your subconsciousness

00:57:13.140 | or your consciousness is a little slower

00:57:14.900 | than your subconscious.

00:57:16.220 | And intuition is a really important feature of that.

00:57:18.780 | And so a lot of the ways I do my science

00:57:20.580 | is guided by intuition.

00:57:22.300 | So when I give fast answers like that,

00:57:23.860 | I think it's usually because I haven't really thought

00:57:25.380 | about them and therefore that's probably telling me something.

00:57:29.060 | - Let's continue the deep analysis of your tweets.

00:57:31.580 | You said that determinism in a tweet,

00:57:35.900 | determinism and randomness play important roles

00:57:38.540 | in understanding what life is.

00:57:40.580 | So let me ask on this topic of free will,

00:57:42.540 | what is determinism, what is randomness,

00:57:45.700 | and why the heck do they have anything to do

00:57:48.220 | with understanding life?

00:57:50.260 | - Yeah, and you threw free will in there,

00:57:52.620 | just throwing all the stuff in the bag.

00:57:55.020 | - Are they not related?

00:57:55.940 | Determinism and randomness? - No, no, they are related.

00:57:58.060 | No, no, sorry, I was being unfair.

00:58:00.380 | - You didn't even capitalize the tweet, by the way.

00:58:02.340 | It was all lowercase.

00:58:03.580 | - I must have been angry.

00:58:05.180 | - Oh, that was, can you analyze the emotion behind that?

00:58:08.220 | - No, I actually-- - Is it frustration?

00:58:09.900 | - Yeah, maybe.

00:58:10.900 | So I already argued that I don't think that can happen

00:58:14.260 | without that whole causal history.

00:58:16.140 | And so I guess in some sense,

00:58:18.500 | the determinism for me arises because of the causal history.

00:58:23.500 | And I'm not really sure actually about whether

00:58:26.820 | the universe is random or deterministic.

00:58:29.020 | I just had this sort of intuition for a long time.

00:58:32.180 | I'm not sure if I agree with it anymore,

00:58:34.100 | but it's still kind of lingering,

00:58:35.380 | and I don't know what to do with this question.

00:58:37.240 | But it seems to me, so you asked the question,

00:58:40.540 | what is life?

00:58:41.460 | But you could also, why life?

00:58:42.880 | Why does life exist?

00:58:43.740 | What does the universe need life for?

00:58:45.620 | Not that the universe has needs,

00:58:46.840 | but we have to anthropocentrize things sometimes

00:58:48.920 | to talk about them.

00:58:50.780 | And I had this feeling that if it was possible

00:58:53.900 | for a cup or a desk ornament or a phone on Mars

00:58:57.260 | to spontaneously fluctuate into existence,

00:58:59.580 | the universe didn't need life to create those objects.

00:59:01.780 | It wasn't necessary for their existence.

00:59:03.380 | It was just a random fluke event.

00:59:05.700 | And so somehow to me, it seems that it can't be

00:59:09.140 | that those things form by random processes.

00:59:11.860 | They actually have to have a set of causes

00:59:14.180 | that accrue and form those things,

00:59:17.300 | and they have to have that history.

00:59:18.860 | And so it seems to me that life was somehow deeply related

00:59:23.420 | to the question of whether the underlying rules

00:59:25.980 | of our universe had randomness in them

00:59:27.680 | or they were fully deterministic.

00:59:29.140 | And in some ways, you can think about life

00:59:30.620 | as being the most deterministic part of physics

00:59:33.940 | because it's where the causes are precise in some sense.

00:59:38.940 | - Or most stable?

00:59:40.380 | So like-- - Most stable, yes.

00:59:41.900 | Most reliable.

00:59:43.020 | - Most reliable for the tools of physics.

00:59:47.180 | But what--

00:59:48.220 | - Right, well, so--

00:59:49.060 | - Where's randomness come from then?

00:59:50.700 | Okay, so you were speaking with--

00:59:54.420 | - I've gone in a tangent,

00:59:55.780 | so I'm not sure where we are in the, yeah.

00:59:57.780 | - All of the universe is a kind of tangent,

01:00:00.820 | so we're embracing the tangent.

01:00:03.340 | So free will, you believe-- - Yes.

01:00:07.260 | - At this current time that you have free will--

01:00:09.420 | - I believe my whole life I have free will.

01:00:11.100 | What is illusion?

01:00:11.940 | No, just kidding.

01:00:12.760 | (Lex laughing)

01:00:13.600 | I still believe it.

01:00:14.440 | - You still believe it.

01:00:15.260 | So at the same time, you think that

01:00:18.940 | in your conception of the universe,

01:00:20.860 | causality seems to be pretty fundamental.

01:00:23.140 | - That's right.

01:00:23.980 | - Which kind of wants the universe to be deterministic.

01:00:27.400 | So how the heck--

01:00:29.260 | - Because I'm a determ--

01:00:30.100 | - Do you think you have a free will

01:00:31.260 | and yet you value causality?

01:00:33.380 | - Because I depart from the conception of physics

01:00:39.800 | that you can write down an initial condition

01:00:42.780 | and a fixed law of motion

01:00:43.900 | and that will describe everything.

01:00:45.780 | There's no incompatibility

01:00:47.180 | if you are willing to reject that assertion.

01:00:49.540 | - So where's the randomness,

01:00:51.180 | where's the magic that gives birth to the free will?

01:00:54.220 | Is it the randomness of the laws of physics?

01:00:56.900 | - No, in my mind what free will is

01:01:00.100 | is the fact that I as a physical system

01:01:03.260 | have causal control over certain things.

01:01:05.380 | I don't have causal control over everything,

01:01:06.980 | but I have a certain set of things.

01:01:09.060 | And I'm also, as I described,

01:01:12.100 | sort of a nexus of a particular set of histories

01:01:15.380 | that exist in the universe

01:01:16.220 | and a particular set of futures that might exist.

01:01:18.660 | And those futures that might exist

01:01:20.660 | are in part specified by my physical configuration as me.

01:01:25.660 | And therefore, it may not be free will

01:01:29.580 | in the traditional sense.

01:01:30.760 | I don't even know what people mean

01:01:31.960 | when they're talking about free will, honestly.

01:01:33.460 | It's like the whole discussion's really muddled.

01:01:35.500 | But in the sense that I am a causal agent,

01:01:38.360 | if you wanna call it that, that exists in the universe,

01:01:40.740 | and there are certain things that happen

01:01:42.180 | because I exist as me, then yes, I have free will.

01:01:45.620 | - No, but do you, Sarah,

01:01:49.300 | have a choice about what's going to happen next?

01:01:51.620 | - Oh, I see.

01:01:52.780 | - Could I have, if I run this universe again--

01:01:56.100 | - Yes, I think so.

01:01:57.380 | - You have a choice.

01:01:58.580 | Where's the choice come from?

01:02:00.220 | - I think that's related to the physics of consciousness.

01:02:02.260 | So one of the things I didn't say about that,

01:02:03.940 | I don't know, maybe this is me just being hopeful

01:02:06.820 | because maybe I just wanna have free will.

01:02:08.700 | But I don't think that we can rule out the possibility

01:02:10.860 | because I don't think that we understand enough

01:02:13.060 | about any of these problems.

01:02:14.460 | But I think one of the things that's interesting for me

01:02:16.460 | about the sort of inversion of the question

01:02:18.900 | of consciousness that I proposed

01:02:21.100 | is one of the features that we do

01:02:24.140 | is we have imagination, right?

01:02:27.060 | And people don't think about imagination

01:02:28.580 | as a physical thing, but it is a physical thing.

01:02:30.820 | It exists in the universe, right?

01:02:32.540 | And so I'm really intrigued by the fact that, say,

01:02:35.620 | humans for, you know, another physical system

01:02:38.260 | could do this too, it's not special to humans,

01:02:39.780 | but for centuries imagined flying machines and rockets

01:02:44.260 | and then we finally built them, right?

01:02:45.820 | So they were represented in our minds

01:02:47.660 | and on the pages of things that we drew

01:02:50.060 | for hundreds of years before we could build

01:02:51.860 | those physical objects in the universe.

01:02:54.060 | But certainly the existence of rockets is in part

01:02:58.140 | caused by the fact that we could imagine them.

01:03:03.660 | And so there seems to be this property

01:03:07.940 | that some things don't exist,

01:03:09.900 | they've never physically existed in the universe,

01:03:12.100 | but we can imagine the possibility of them existing

01:03:14.700 | and then cause them to exist,

01:03:16.540 | maybe individually or collectively.

01:03:18.500 | And I think that property is related to what I would say

01:03:21.780 | about having choice or free will,

01:03:23.220 | because that set of possibilities,

01:03:24.940 | that thing, those set of things that you can imagine

01:03:27.380 | is not constrained to your local physical environment

01:03:29.740 | and history.

01:03:30.660 | And this is what's a little bit different

01:03:32.060 | about intelligence as we see it in humans

01:03:34.460 | and AI that we wanna build than biological intelligence

01:03:37.860 | because biological intelligence is predicated completely

01:03:40.700 | on the history of things that's seen in the past.

01:03:42.540 | But something happened with the neural architectures

01:03:45.460 | that evolved in multicellular organisms

01:03:48.020 | that they don't just have access to the past history

01:03:50.460 | of their particular set of events,

01:03:52.460 | but they can imagine things that haven't happened,

01:03:55.180 | aren't on their timeline,

01:03:56.220 | and as long as they're consistent with the laws of physics,

01:03:58.120 | make them happen.

01:03:59.620 | - So this is fascinating.

01:04:02.380 | - It's trippy physics, but it exists, so there you go.

01:04:05.420 | - I mean, in some sense, if you look at like

01:04:07.820 | general relativity and gravity morphing space-time,

01:04:11.940 | in that same way, maybe whatever the physics

01:04:14.260 | of consciousness might be, it might be morphing,

01:04:17.420 | that's like what free will is.

01:04:18.820 | It's morphing like the space,

01:04:21.620 | just like ideas make rockets come to life.

01:04:25.060 | It's somehow changing the space of possible realizations

01:04:30.060 | of like whatever's, yeah, okay.

01:04:33.340 | - Life is kind of basically, if you wanna think about it,

01:04:35.580 | like life is sort of changing the probability distributions

01:04:38.540 | over what can exist.

01:04:39.380 | That's the physics of what life is,

01:04:41.020 | and then consciousness is this sort of layered property,

01:04:43.460 | your imagination on top of it,

01:04:45.220 | that kind of scrambles that a little bit more

01:04:47.300 | and like has access to, I don't know.

01:04:50.580 | It's kind of, we don't know how to describe it, right?

01:04:53.100 | Like that's why it's interesting, but--

01:04:54.260 | - But it's probabilistic, so you do think

01:04:56.140 | like God plays dice, so let me--

01:04:58.620 | - No, I think the description's probabilistic.

01:05:00.580 | I don't necessarily think the underlying physics

01:05:05.180 | is probabilistic.

01:05:06.300 | I think the way that we can describe this physics

01:05:09.540 | is going to be probabilistic and statistical,

01:05:12.260 | but the underlying, like when we take measurements

01:05:13.940 | in the lab, but the underlying physics itself

01:05:16.000 | might still be deterministic.

01:05:17.100 | I don't know, maybe I'm, it's hard to know

01:05:20.940 | what concepts to hold onto,

01:05:22.340 | so I find myself constantly rejecting concepts,

01:05:24.780 | but then I have to grab another one

01:05:26.220 | and try to hold onto something from intellectual history.

01:05:29.660 | - Well, it's possible that our mind is not able

01:05:31.340 | to hold the correct concepts in mind at all.

01:05:33.420 | Like we're not able to even conceive of them correctly.

01:05:36.100 | Maybe the words deterministic or random

01:05:39.020 | are not the right even words, concepts to be holding.

01:05:42.380 | But maybe you can talk to the theory of everything,

01:05:46.580 | this attempt in the current set of physical laws

01:05:49.340 | to try to unify them.

01:05:50.880 | Is there any hope that once a theory of everything

01:05:55.300 | is developed, and by theory of everything,

01:05:56.860 | I mean in a narrow sense of unifying quantum field theory

01:06:00.300 | and general relativity, do you think that will contain

01:06:03.260 | some, like in order to do that unification,

01:06:08.260 | you would have to get something that would then give hints

01:06:11.860 | about the physics of life, physics of existence,

01:06:15.020 | physics of consciousness?

01:06:15.860 | - Yeah, I used to not, but I actually,

01:06:19.180 | I have become increasingly convinced that it probably will.

01:06:23.880 | And part of the reason is, I think I've talked

01:06:26.840 | a little bit already about these holes in physics,

01:06:29.300 | like these, the theories we have in physics,

01:06:32.620 | you know, they have problems, they have lots of problems,

01:06:35.340 | and they're very deep problems,

01:06:37.140 | and we don't know how to patch them.

01:06:39.060 | And some of those problems become very evident

01:06:41.200 | when you try to patch quantum mechanics

01:06:43.460 | and general relativity together.

01:06:45.660 | So there is this kind of interesting feature

01:06:47.540 | that some of the ways of patching that

01:06:49.860 | might actually closely resemble the physics of life.

01:06:54.180 | And so the place where that actually comes up most,

01:06:56.420 | and actually we just had a workshop in the Beyond Center

01:06:58.740 | where I work at Arizona State University,

01:07:00.580 | and Lee Smolin made this point that he thinks

01:07:02.740 | that the theory of quantum gravity, when we solve it,

01:07:05.080 | is gonna be the same theory that gives rise to life.

01:07:08.460 | And I think that I agree with him on some levels

01:07:11.460 | because there's something very interesting

01:07:12.940 | where if you look at these sort of causal set theories

01:07:16.160 | of gravity, where they're looking for space

01:07:18.660 | as being emergent, and so space-time is an emergent concept

01:07:23.620 | from a causal set, which is also sort of related,

01:07:26.180 | I think, to what Wolfram's doing with his physics project.

01:07:29.180 | It's the same kind of underlying math

01:07:30.780 | that we have in this theory that we've been developing

01:07:32.900 | related to life called assembly theory,

01:07:35.540 | which is basically trying to look at complex objects

01:07:39.780 | like molecules and bacteria and living things

01:07:43.860 | as basically being assembled from a set of component parts

01:07:51.460 | and that they actually encode all the possible histories

01:07:54.640 | that they could have in that physical object.

01:07:56.620 | So mathematically, all these ideas, I think,

01:07:59.000 | are related.

01:07:59.840 | I think a lot of people are thinking about this

01:08:00.680 | from different perspectives.

01:08:02.280 | And then constructor theory that David Deutsch

01:08:04.460 | and Chiara Marleto have been developing

01:08:05.960 | is a totally different angle on it,

01:08:07.580 | but I think getting at some similar ideas.

01:08:09.100 | So it's a really interesting time right now, I think,

01:08:11.180 | for the frontiers of physics and how it's relating

01:08:13.700 | to maybe deeper principles about what life is.

01:08:15.940 | So short answer, yes.

01:08:17.100 | Long-winded answer, rewind.

01:08:19.200 | - Can we talk about aliens?

01:08:22.780 | - Anytime.

01:08:23.620 | (laughing)

01:08:25.660 | - So one, I think one interesting way

01:08:28.340 | to sneak up on the question of what is life

01:08:31.220 | is to ask what should we look for in alien life?

01:08:36.140 | If we were to look out into our galaxy

01:08:40.620 | and into the universe and come up with a framework

01:08:44.320 | of how to detect alien life,

01:08:47.500 | what should we be looking for?

01:08:49.660 | Is there a set of rules?

01:08:53.580 | It's both the tools and the tools that are,

01:08:57.980 | serve as sensors for certain kind of properties of life.

01:09:01.700 | So what should we look for in alien life?

01:09:05.420 | - Yeah, so we have a paper actually coming out on Monday,

01:09:08.020 | which is collaboration.

01:09:09.660 | It's actually really Lee Cronin's lab,

01:09:11.700 | but my group worked with him on it

01:09:12.940 | and we're working on the theory,

01:09:13.860 | which is this idea that we should look for life

01:09:18.060 | as high assembly objects.

01:09:20.340 | What we mean by that is,

01:09:22.420 | which is actually observationally measurable.

01:09:24.460 | And this is one of the reasons

01:09:25.420 | that I started working with Lee on these ideas

01:09:27.220 | is because being a theorist, it's easy to work in a vacuum.

01:09:30.020 | It's very hard to connect abstract ideas

01:09:32.600 | about the nature of life

01:09:33.700 | to anything that's experimentally tractable.

01:09:35.900 | But what his lab has been able to do

01:09:39.500 | is develop this method where they look at a molecule

01:09:43.180 | and they break it apart into all its component parts.

01:09:46.220 | And so you say you have some elementary building blocks

01:09:48.460 | and you can build up all the ways of putting those together

01:09:51.220 | to make the original object.

01:09:52.740 | And then you look for the shortest path in that space.

01:09:55.300 | And you say that's sort of the assembly number

01:09:59.140 | associated to that object.

01:10:00.940 | And if that number's higher,

01:10:02.900 | it assumes that a longer causal history

01:10:05.860 | is necessary to produce that object

01:10:07.500 | or more information is necessary

01:10:08.820 | to specify the creation of that object in the universe.

01:10:11.480 | Now that kind of idea at a superficial level

01:10:14.220 | has existed for a long time.

01:10:15.840 | That kind of idea as a physical observable of molecules

01:10:19.260 | is completely novel.

01:10:20.820 | And what his lab has been able to show

01:10:22.860 | is that if you look at a bunch of samples

01:10:24.580 | of non-biological things and biological things,

01:10:26.860 | there's this kind of threshold of assembly

01:10:31.380 | where as far as the experimental evidence is

01:10:34.940 | and also your intuition would suggest

01:10:38.120 | that non-biological systems don't produce things

01:10:41.240 | with high assembly number.

01:10:43.220 | So this goes back to the idea

01:10:44.740 | like a protein's not gonna spontaneously fluctuate

01:10:47.120 | into existence on the surface of Mars.

01:10:48.740 | It requires an evolutionary process

01:10:50.180 | and a biological architecture to produce a protein.

01:10:52.700 | You generalize that argument,

01:10:54.340 | you know a complex molecule or a cup or a desk ornament

01:10:58.860 | in this sort of abstract idea of assembly spaces

01:11:02.020 | as being the causal history of objects.

01:11:04.620 | And you can talk about the shortest path

01:11:06.300 | from elementary objects to an object

01:11:08.500 | given an elementary set of operations.

01:11:11.000 | And you can experimentally measure that with a mass spec.

01:11:14.260 | And that's basically sort of the idea.

01:11:16.700 | - That's really fascinating.

01:11:17.700 | I can't get out of my head.

01:11:19.100 | I'd start imagining Legos

01:11:20.860 | and all the Legos I've ever built and how many steps.

01:11:23.380 | What is the shortest path to the final--

01:11:25.340 | - Right, right.

01:11:26.180 | - To find a little Lego castles.

01:11:28.460 | - So yeah, so then like asking

01:11:30.660 | about going to look for alien life,

01:11:31.840 | the idea is most of the instruments that NASA builds,

01:11:35.580 | for example, or any of the space agencies

01:11:37.500 | looking for life in the universe

01:11:38.620 | are looking for chemical correlates of life, right?

01:11:42.020 | But here we have something

01:11:43.380 | that is based on properties of molecules.

01:11:46.300 | It's not a chemical correlate.

01:11:47.860 | It's agnostic.

01:11:49.140 | It doesn't care about the molecule.

01:11:50.540 | It cares about what is the history necessary

01:11:54.260 | to produce this molecule.

01:11:56.340 | How complex is it in terms of how much time is needing,

01:11:58.780 | how much information is required to produce it.

01:12:00.860 | - So when you observe a thing on another planet,

01:12:04.220 | you're essentially,

01:12:06.500 | the process looks like reverse engineering,

01:12:08.540 | trying to figure out what is the shortest path

01:12:10.500 | to create that thing.

01:12:11.620 | - Yeah, so most, yeah.

01:12:12.980 | And I would say most,

01:12:14.300 | like most examples of biology or technology

01:12:16.700 | don't take the shortest path, right?

01:12:18.100 | But the shortest path is a bound on how hard it is

01:12:20.140 | for the universe to make that.

01:12:21.660 | - Yeah, and I guess you and Lee are saying

01:12:25.100 | that there's a heuristic,

01:12:26.580 | that's a good metric for,

01:12:29.260 | like better perhaps than chemical correlates.

01:12:31.620 | - Yes, because it doesn't,

01:12:33.380 | it's not contingent on looking for the chemistry of life

01:12:36.780 | on Earth, on other planets.

01:12:38.940 | And it also has a deeper explanatory framework

01:12:42.020 | associated to it, as far as the kind of theory

01:12:44.660 | that we're trying to develop

01:12:45.700 | associated to what life is.

01:12:47.260 | And I think this is one of the problems I have

01:12:48.900 | in my field personally in astrobiology,

01:12:51.620 | is people observe something on Earth,

01:12:53.940 | say oxygen in the atmosphere,

01:12:56.140 | or an amino acid in a cell,

01:12:58.460 | and then they say,

01:12:59.500 | let's go look for that on another planet.

01:13:02.260 | Let's look for oxygen on exoplanets,

01:13:04.060 | or let's look for amino acids on Mars.

01:13:06.300 | And then they assume that's a way of looking for life.

01:13:09.140 | Or even phosphine on Venus.

01:13:13.540 | But you know, like there's all these examples

01:13:15.220 | of let's look for one molecule.

01:13:17.220 | A molecule is not life.

01:13:18.420 | Life is a system that patterns

01:13:20.980 | particular structures into matter.

01:13:22.460 | That's like, that's what it is.

01:13:24.460 | And it doesn't care what molecules are there.

01:13:26.780 | It's something about the patterns

01:13:28.180 | and that structure and that history.

01:13:30.180 | And if you're looking for a molecule,

01:13:33.260 | you're not testing any hypotheses

01:13:34.700 | about the nature of what life is.

01:13:36.220 | It doesn't tell me anything

01:13:37.460 | if we discover oxygen on an exoplanet

01:13:39.060 | about what kind of life is there.

01:13:40.220 | Just oxygen on an exoplanet.

01:13:42.060 | It's not, there's,

01:13:44.020 | I guess I think like when you think about the question,

01:13:46.660 | are we alone in the universe?

01:13:47.780 | That's a pretty fricking deep question.

01:13:49.500 | It should have a fricking deep answer.

01:13:51.020 | It shouldn't just be there's a molecule on an exoplanet.

01:13:53.020 | Wow, we solved the problem.

01:13:54.520 | It should tell us something meaningful about our existence.

01:13:56.540 | And I feel like we've fallen short

01:13:58.980 | on how we're searching for life

01:14:01.180 | in terms of actually searching for things like us

01:14:05.260 | in this kind of deeper way.

01:14:06.960 | - But how do you do that initial kind of,

01:14:10.380 | say I'm walking down the street

01:14:12.060 | and I'm looking for that double take test of like,

01:14:15.540 | like what the hell is that?

01:14:17.180 | Like that initial,

01:14:19.700 | like how do we look for the possibility of weirdness

01:14:24.180 | or the possibility of high assembly number?

01:14:27.220 | What would aliens look like

01:14:30.060 | if they don't have two eyes and are green?

01:14:32.740 | - If I knew, I would have probably already solved the problem.

01:14:35.500 | - Right, there's another Nobel prize in there somewhere.

01:14:37.620 | - Yeah, somewhere in there.

01:14:39.860 | Well, I think it's kind of,

01:14:41.300 | so there is a bias here, right?

01:14:43.180 | So we've evolved to recognize life on earth, right?

01:14:45.940 | Like I, you know, children at a very early age

01:14:48.660 | can tell the difference between a puppy and a plant

01:14:50.700 | and then the plant and a chair, for example,

01:14:53.460 | you know, like it just, it seems innate.

01:14:55.740 | And so I think, and also because we're life,

01:14:58.560 | you know, I think like there's this implicit bias

01:15:02.620 | that we should know it when we see it

01:15:03.900 | and it should be completely obvious to us.

01:15:06.820 | But there are a lot of features of our universe

01:15:08.980 | that are not completely obvious to us.

01:15:10.420 | Like the fact that this table is made of atoms

01:15:12.420 | and that I'm sitting in a gravitational

01:15:14.620 | potential well right now.

01:15:16.100 | And I guess my point with this is,

01:15:19.500 | I think life is much less obvious than we think it is.

01:15:23.280 | And so it could be in many more forms than we think it is.

01:15:27.100 | And I guess this goes back to the point

01:15:28.760 | about being open-minded that we may not know

01:15:31.720 | what alien life looks like.

01:15:33.020 | It might not even be possible to interact with alien life

01:15:35.500 | 'cause maybe something about, you know,

01:15:38.100 | our informational lineage, it makes it impossible

01:15:41.260 | for information from an alien to be copied to us.

01:15:43.900 | Therefore there's no, you know,

01:15:46.060 | so to speak communication channel.

01:15:47.820 | And I don't mean, you know, verbal communication,

01:15:49.860 | just it's not in our observational space.

01:15:53.000 | Like, you know, like, you know,

01:15:54.700 | there's fundamental questions about why we observe

01:15:57.300 | the universe in position rather than momentum,

01:15:59.060 | but we also, you know, observe it

01:16:01.460 | in terms of certain informational patterns and things.

01:16:03.660 | Like that's what our brain constructs

01:16:05.020 | and maybe aliens just interact

01:16:07.340 | with a different part of reality than we do.

01:16:08.660 | That's wildly speculative, but I think--

01:16:10.660 | - But it's possible.

01:16:12.860 | - It's possible and I think it's consistent with the physics.

01:16:15.140 | So I think the best ways we can ask questions

01:16:17.180 | are about life and chemistry and asking questions

01:16:20.580 | about if information is a real physical thing,

01:16:23.340 | what would its signatures be in matter?

01:16:25.700 | And how do we recognize those?

01:16:28.940 | And I think the ones that are most obvious

01:16:31.540 | are the ones I've already articulated.

01:16:33.080 | You have these objects that seem completely improbable

01:16:35.680 | for the universe to produce

01:16:36.900 | because the universe doesn't have the design

01:16:39.140 | of that object in the laws.

01:16:40.980 | So therefore, an object had to evolve.

01:16:44.500 | We talk, we call it evolution,

01:16:46.740 | but it had to be produced by the universe

01:16:48.500 | that then had all of the possible tasks

01:16:51.380 | to make that object specified.

01:16:54.700 | - I mean, there's some, like,

01:16:56.020 | there's an engineering question here of,

01:16:59.140 | are there sensors we can create that can give us,

01:17:02.100 | can help us discover certain pockets

01:17:05.740 | of high assemblies, aliens?

01:17:08.460 | Like, I mean, there is a hope,

01:17:10.980 | setting dogs and chairs aside,

01:17:14.660 | there's a hope that visually we could detect.

01:17:19.460 | Like, because our universe,

01:17:22.860 | I mean, at least the way we look at it now,

01:17:24.500 | like this three-dimensional, like space-time,

01:17:27.220 | we can visually comprehend it.

01:17:29.380 | It's interesting to think, like, if we got to hang out,

01:17:32.780 | you know, if there's an alien in this room,

01:17:35.900 | like, would we be able to detect it

01:17:37.760 | with our current sensors?

01:17:39.340 | Not the fancy kinds, but like webcams.

01:17:41.700 | - Like, say, standing over there?

01:17:43.340 | - Yeah, standing over there,

01:17:44.460 | or maybe like in this carpet.

01:17:45.860 | See, there's all these kinds of patterns, right?

01:17:47.580 | - Yeah.

01:17:48.420 | - I don't know if this carpet is an alien.

01:17:52.900 | - Well, so I see what you're saying.

01:17:55.160 | So assembly theory is pretty general.

01:17:57.820 | Like, I mean, we've been applying it to molecules

01:18:00.020 | because it makes sense to apply it to molecules,

01:18:02.160 | but it's supposed to explain life,

01:18:05.080 | you know, like the physics of life.

01:18:07.200 | So it should explain, you know, the things in this room

01:18:09.300 | in addition to molecules.

01:18:11.280 | So I guess, and you can apply it to images and things.

01:18:14.640 | So I guess the idea, you know, you could explore

01:18:18.600 | is just looking at everything on planet Earth

01:18:21.280 | in terms of its assembly structure,

01:18:23.200 | and then looking for things

01:18:24.960 | that aren't part of our biological lineage.

01:18:27.080 | If they have high assembly, they might be aliens on Earth.

01:18:29.440 | - I mean, that is a very kind of

01:18:30.880 | rigorous computer vision question.

01:18:32.320 | Can we visually, is there a strong correlation

01:18:36.600 | between certain kind of high assembly objects

01:18:38.560 | when they get to the scale where they're visually observable

01:18:42.080 | and some, like when it's, say, projected onto a 2D plane,

01:18:47.080 | can we figure out something?

01:18:49.720 | - I'm glad you brought up the computer vision point

01:18:51.520 | 'cause for a while I had this kind of thought in my mind

01:18:53.600 | that we can't even see ourselves clearly.

01:18:55.240 | So one of the things, you know,

01:18:56.560 | people are worried about artificial intelligence

01:18:58.000 | for a lot of reasons, but I think it's really fascinating

01:18:59.920 | 'cause it's like the first time in history

01:19:03.360 | that we're building a system

01:19:04.480 | that can help us understand ourselves.

01:19:06.400 | So like, you know, people talk about AI physics,

01:19:08.600 | but like, you know, when I look at another person,

01:19:12.560 | I don't see them as a four billion year lineage,

01:19:15.440 | but that's what they are, and so is everything here, right?

01:19:18.200 | So imagine that we built artificial systems

01:19:21.480 | that could actually see that feature of us.

01:19:24.320 | What else would they see?

01:19:25.680 | And I think that's what you're asking.

01:19:28.720 | And I think that would be so cool.

01:19:31.920 | (both laughing)

01:19:34.360 | I want that to happen,

01:19:35.400 | but I think we're a little ways off from it,

01:19:37.160 | but yeah, we're going there, I hope.

01:19:40.240 | - Okay, let me ask you, I apologize ahead of time,

01:19:43.440 | but let me ask you the internet question.

01:19:45.200 | So you're a physicist, you ask rigorous questions

01:19:47.600 | about the physics of existence

01:19:49.680 | and these models of high assembly objects.

01:19:52.880 | Now, when the internet would see an alien,

01:19:55.200 | they would ask two questions.

01:19:56.480 | One, can I eat it?

01:19:58.160 | And two, can I have sex with it?

01:20:00.000 | - Yes.

01:20:00.840 | - So... (laughs)

01:20:02.480 | - All the existential questions.

01:20:04.600 | Those are very important.

01:20:05.440 | - The internet is very sophisticated.

01:20:07.160 | - It really is.

01:20:08.000 | It's gotten our basal cognition pretty good.

01:20:10.600 | - So you kind of mentioned that it's very difficult.

01:20:12.640 | It's possible that we may not be even able

01:20:15.040 | to communicate with it.

01:20:16.120 | - Right, I think the internet has more hope than we do.

01:20:18.560 | - Yeah, it's a hopeful place, yes.

01:20:20.520 | Do you think in terms of like interacting

01:20:23.720 | on this very primal level of sharing resources,

01:20:27.760 | like what would aliens eat?

01:20:28.920 | What would we eat?

01:20:29.920 | Would we eat the same thing?

01:20:31.440 | Could we potentially eat each other?

01:20:33.960 | One person eats the other or the aliens eat us.

01:20:37.280 | And the same thing with not sex in general reproduction,

01:20:40.680 | but genetically mixing stuff.

01:20:42.360 | Like would we be able to mix genetic information?

01:20:46.600 | - Maybe not genetic, but maybe information, right?

01:20:48.800 | And I think part of your question is like,

01:20:50.520 | so if you think of life as like this history

01:20:54.200 | of events that happen in the universe,

01:20:55.600 | like there's this question of like,

01:20:57.000 | how divergent are those histories, right?

01:20:59.320 | So when we get to the scale of technology,

01:21:00.920 | it's possible to imagine,

01:21:02.920 | imagine, although we can't even do it,

01:21:04.560 | like imagine all the possible technologies

01:21:06.200 | that could exist in the universe.

01:21:07.320 | But if you think about all the possible chemistries,

01:21:09.080 | somehow that seems like a lower dimensional space

01:21:11.320 | and a lower set of possibilities.

01:21:13.160 | So it might be that like when we interact with aliens,

01:21:16.280 | we do have to go back to those more basal levels

01:21:19.560 | to figure out sort of what the map is, right?

01:21:23.160 | Like the sort of where we have a common history.

01:21:26.160 | We must have a common history somewhere in the universe,

01:21:29.280 | but in order to be able to actually interact

01:21:31.820 | in a meaningful way, you have to have some shared history.

01:21:34.000 | I mean, the reason we can exchange genetic information

01:21:36.000 | and eat each other's food or eat each other as food

01:21:39.520 | is because we have a shared history.

01:21:41.160 | - So we have to find that shared history.

01:21:43.160 | We have to find the common ancestor

01:21:44.680 | in this causality map, this causality tree.

01:21:47.640 | - Yes, and we have a last universal common ancestor

01:21:50.040 | for all life on earth, which I think is sort of the nexus

01:21:52.280 | of that causality map for life on earth.

01:21:54.520 | But the question is, where would other aliens diverge

01:21:58.120 | on that map? - That's really interesting.

01:22:00.120 | So say there's a lot of aliens out there in the universe,

01:22:04.780 | each set of organisms would probably have like a number,

01:22:08.660 | you know, like Erdos number of like how far,

01:22:13.240 | like how far our common ancestor is.

01:22:16.040 | And so the closer the common ancestor, like it is on earth,

01:22:19.680 | the more like each other, the more likely we are

01:22:21.920 | to be able to have sexual reproduction.

01:22:24.200 | - Well, it's like sort of like humans

01:22:25.300 | having common culture and languages, right?

01:22:27.240 | - Yeah, exactly, language, communication.

01:22:30.160 | - It might take a lot of work though with an alien

01:22:32.400 | 'cause you really have to get over a language barrier.

01:22:35.640 | - Oh boy, so it's communication, it's resources.

01:22:40.120 | I mean, it's the whole.

01:22:43.600 | - And I think tied into that is the questions

01:22:46.360 | of like who's gonna harm who.

01:22:48.320 | And actually definitions of harm.

01:22:49.800 | - And whether your parents approve,

01:22:50.960 | you know, all those kind of questions.

01:22:52.840 | - Whether the common ancestor approves, yeah.

01:22:55.000 | It's just very true.

01:22:56.280 | How many alien civilizations do you think are out there?

01:23:00.860 | - I don't have intuition for that,

01:23:03.960 | which I have always thought was deeply intriguing.

01:23:07.480 | So, and part of this, I mean, I say it specifically

01:23:11.480 | as I don't have intuition for that

01:23:12.740 | because it's like one of those questions

01:23:14.200 | that you feel around for a while

01:23:15.520 | and you really just, you can't see it,

01:23:19.400 | even though it might be right there.

01:23:20.900 | And in that sense, it's a little like

01:23:24.240 | the quantum to classical transition.

01:23:25.860 | You're like really talking about

01:23:26.800 | two different kinds of physics.

01:23:28.040 | And I think that's kind of part of the problem.

01:23:29.400 | Once we understand the physics,

01:23:30.420 | that question might become more meaningful.

01:23:33.080 | But there's also this other issue.

01:23:34.780 | And this was really instilled on me

01:23:37.760 | by my mentor, Paul Davies, when I was a postdoc

01:23:39.740 | 'cause he always talks about how, you know,

01:23:42.280 | whether aliens are common or rare is kind of just,

01:23:45.880 | you know, it follows a wave of popularity

01:23:49.280 | and it just depends on like the mood of, you know,

01:23:51.400 | what the culture is at the time.

01:23:53.240 | And I always thought that was kind of

01:23:54.080 | an intriguing observation,

01:23:55.860 | but also there's this set of points about

01:23:58.440 | if you go by the observational evidence,

01:24:00.000 | which we're supposed to do as scientists, right?

01:24:02.280 | You know, we have evidence of us

01:24:08.680 | and one original life event from which we emerged.

01:24:11.640 | And people wanna make arguments

01:24:13.160 | that because that event was rapid

01:24:15.800 | or because there's other planets

01:24:17.320 | that have properties similar to ours,

01:24:18.800 | that that event should be common.

01:24:20.480 | But you actually can't reason on that

01:24:22.080 | because our existence observing that event

01:24:23.780 | is contingent on that event happening,

01:24:25.780 | which means it could have been completely improbable

01:24:27.880 | or very common.

01:24:29.400 | And Brandon Carter like clearly articulated that

01:24:31.840 | in terms of anthropic arguments a few decades ago.

01:24:35.440 | So there is this kind of issue

01:24:38.000 | that we have to contend with dealing with life

01:24:39.880 | that's closer to home than we have to deal with

01:24:41.920 | with any other problems in physics,

01:24:43.680 | which we're talking about the physics of ourselves.

01:24:45.840 | And when you're asking about the original life event,

01:24:47.700 | that event happening in the universe,

01:24:49.000 | at least it's like our existence is contingent on it.

01:24:51.640 | And so you can think about sort of fine tuning arguments

01:24:55.840 | that way too.

01:24:56.680 | So, but the sort of other part of it is like,

01:25:00.040 | when I think about how likely it is,

01:25:03.240 | I think it's because we don't understand this mechanism yet

01:25:06.360 | about how information can be generated spontaneously.

01:25:10.880 | That I like, 'cause I can't see that physics clearly yet,

01:25:13.880 | even though I have a lot of,

01:25:15.840 | like some things around the space of it in my mind,

01:25:18.720 | I can't articulate how likely that process is.

01:25:22.520 | So my honest answer is, I don't know.

01:25:24.220 | And sometimes that feels like a cop out,

01:25:25.960 | but I feel like that's a more honest answer

01:25:27.440 | and a more meaningful way of making progress

01:25:29.840 | than what a lot of people wanna do, which is say,

01:25:32.800 | oh, well, we have a one in 10 chance of having it

01:25:34.880 | on an exoplanet with Earth-like properties

01:25:36.520 | because there's lots of Earth-like planets out there

01:25:38.800 | and life happened fast on Earth.

01:25:40.360 | - Well, so, kind of a follow-up question,

01:25:43.000 | but as a side comment,

01:25:45.360 | what I really am enjoying about the way

01:25:47.400 | you're talking about human beings is you always say,

01:25:50.120 | and not to make yourself conscious about it,

01:25:51.640 | 'cause I really, really enjoy it, that you say we.

01:25:54.520 | - Yes. - You don't say humans.

01:25:57.400 | You say, 'cause oftentimes, like, you know,

01:26:00.240 | I don't know, evolutionary biologists

01:26:01.800 | will kind of put yourself out as an observer,

01:26:05.440 | but it's kind of fascinating to think

01:26:08.280 | that you as a human are struggling about your own origins.

01:26:11.080 | - Yes, that's the problem, and yeah,

01:26:13.760 | and I think, I don't do that deliberately,

01:26:17.200 | but I do think that way,

01:26:18.480 | and this is sort of the inversion

01:26:19.800 | from the logic of physics,

01:26:20.880 | because physics, as it's always been constructed,

01:26:23.540 | has treated us as external observers of the universe,

01:26:26.440 | and we are not part of the universe,

01:26:27.720 | and this is why the problem of life, I think,

01:26:29.700 | demands completely new thinking,

01:26:31.360 | because we have to think about ourselves

01:26:33.640 | as minds that exist in the universe,

01:26:35.640 | and are at this particular moment in history,

01:26:37.840 | and looking out at the things around us,

01:26:39.720 | and trying to understand what we are inside the system,

01:26:42.760 | not outside the system.

01:26:43.880 | We don't have descriptions at a fundamental level

01:26:46.840 | that describe us as inside the system,

01:26:48.880 | and this was my problem with cellular automata also.

01:26:51.320 | You're always an external observer for a cellular automata.

01:26:54.240 | You're not in the system.

01:26:55.320 | What does a cellular automata look like from the inside?

01:26:58.040 | - I think you just broke my brain with that question.

01:27:00.960 | - Exactly, but that's the fundamental--

01:27:01.800 | - I thought about that for a long time, but.

01:27:03.320 | (laughing)

01:27:05.840 | - Yeah, that's a really clean formulation

01:27:08.800 | of a very fundamental question,

01:27:10.640 | 'cause you can only, to understand cellular automata,

01:27:13.640 | you have to be inside of it,

01:27:15.000 | but as a human, sort of a poetic, romantic question,

01:27:20.880 | does it make you sad?

01:27:22.120 | Does it make you hopeful, whether we're alone or not?

01:27:27.120 | In the different possible versions of that,

01:27:31.060 | if we're the highest assembly object in the entire universe,

01:27:36.060 | does that give you--

01:27:36.980 | - At this moment in time, maybe.

01:27:38.180 | - At this moment in the causality--

01:27:39.860 | - 'Cause we may, I assume we have a future.

01:27:41.860 | - Well, we definitely have a future.

01:27:43.500 | The question is where that future decreases the assembly.

01:27:48.420 | It could be we're at the peak, or we could be just--

01:27:52.860 | - That would be inconsistent with the physics in my mind,

01:27:55.780 | but, so I should give a caveat.

01:27:59.140 | I've given the caveat that I'm biased as a physicist,

01:28:01.580 | but I'm also biased as an eternal optimist,

01:28:03.580 | so pretty much all of my modes of operation

01:28:06.580 | for building theories about the world

01:28:08.140 | are not like an Occam's razor,

01:28:10.180 | what's the simplest explanation,

01:28:11.660 | but what's the most optimistic explanation?

01:28:14.460 | And part of the reason for that is if you really think

01:28:17.380 | explanations have causal power,

01:28:20.460 | in the sense that the fact that we have theories

01:28:23.180 | about the world has enabled technologies

01:28:24.980 | and physically transformed the world around us.

01:28:27.580 | I think I have to take seriously that

01:28:29.140 | as a part of the physics I wanna describe,

01:28:31.420 | and try to build theories of reality

01:28:35.900 | that are optimistic about what's coming next,

01:28:37.860 | because the theories are in part

01:28:39.140 | the causes of what comes next.

01:28:40.660 | - So there could be a physics of hope

01:28:45.060 | or a physics of optimism in there too.

01:28:46.940 | - Yes.

01:28:48.060 | - 'Cause that seems like also, I mean,

01:28:51.140 | optimism does seem to be a kind of engine

01:28:53.980 | that results in innovation.

01:28:56.260 | - Yes.

01:28:57.100 | - So this is, like, why the hell

01:28:59.660 | are we trying to come up with new stuff?

01:29:02.060 | - Oh, so I made this point about thinking

01:29:04.660 | life is the physics of existence,

01:29:06.140 | and it's not just the physics of existence,

01:29:07.820 | it's the physics of more things existing.

01:29:11.380 | So I think one of these drives--

01:29:12.700 | - Creativity.

01:29:13.660 | - Yeah, creativity, like optimism.

01:29:15.700 | People like entropy, I don't like entropy

01:29:19.940 | as it was formulated in the 1800s,

01:29:21.380 | I think it's an antiquated concept,

01:29:22.820 | but this idea of maximizing over the possible number

01:29:27.620 | of states that could exist.

01:29:28.860 | Imagine the universe is actually trying to maximize

01:29:31.060 | over the number of things that could physically exist.

01:29:33.340 | What would be the best way to do that?

01:29:34.700 | The best way to do that would be

01:29:35.620 | evolve intelligent technological things

01:29:37.780 | that could explore that space.

01:29:39.260 | - So okay, that's talking about alien life

01:29:43.860 | out there in the universe,

01:29:45.220 | but you've also earlier in the conversation

01:29:46.980 | mentioned the shadow biosphere.

01:29:50.180 | So is it possible?

01:29:52.780 | That we have weird life here on Earth

01:29:56.340 | that we're just not,

01:29:58.460 | like even in a high assembly formulation of life,

01:30:02.180 | that we're just not paying attention to, we're blind to?

01:30:07.020 | Like life we're potentially able to detect,

01:30:09.500 | but we're blind to?

01:30:10.500 | And maybe you could say, what is the shadow biosphere?

01:30:12.380 | - Sure, sure.

01:30:13.340 | Yeah, the shadow biosphere is this idea

01:30:15.180 | that there might have been other original life events

01:30:17.940 | that happened on Earth that were independent

01:30:20.980 | from the original life event that led to us

01:30:24.020 | and all of the life that we know on Earth.

01:30:26.340 | And therefore there could be aliens

01:30:29.340 | in the sense they have a different origin event

01:30:32.100 | living among us.

01:30:33.260 | And it was proposed by a number of people,

01:30:37.140 | but one of them was Paul Davies

01:30:39.900 | that I mentioned earlier as my mentor.

01:30:41.180 | And he has a really cute way of saying

01:30:42.940 | that aliens could be right under our noses

01:30:44.780 | or even in our noses.

01:30:46.100 | With a British accent, it sounds better.

01:30:50.340 | But anyway, so the idea is like,

01:30:53.740 | it could literally be anywhere around us.

01:30:56.420 | And if you think actually about the discovery

01:30:58.220 | of like viruses and bacteria,

01:31:00.220 | for a long time, they were kind of a shadow biosphere.

01:31:02.380 | It was life that was around us, but invisible.

01:31:06.060 | But this takes it a little bit further

01:31:09.780 | in saying that all of those examples, viruses, bacteria,

01:31:13.100 | and everything that we've discovered so far

01:31:14.940 | has this common ancestry

01:31:16.140 | and the last universal common ancestor of life on Earth.

01:31:18.580 | So maybe there was a different origin event

01:31:20.500 | and that life is weirder still and might be among us

01:31:24.500 | and we could find it.

01:31:25.620 | We don't have to go out and the stars look for aliens

01:31:28.540 | just here on Earth.

01:31:29.660 | - Do you think that's a serious possibility

01:31:32.940 | that we should explore with the tools of science?

01:31:35.220 | Like this should be a serious effort?

01:31:36.900 | - I think yes and no.

01:31:39.580 | And I mean, yes, because I think it's a serious hypothesis

01:31:44.300 | and I think it's worth exploring

01:31:46.340 | and it is certainly more economical

01:31:48.860 | to look for signs of alien life on Earth

01:31:52.060 | than it is to go and build spacecraft

01:31:54.180 | and send robots to other planets.

01:31:56.300 | And that was one of the reasons it was proposed is,

01:31:58.340 | well, if we do find an example

01:31:59.740 | of another original life on Earth,

01:32:01.980 | it's hugely informative

01:32:03.260 | because it means the original life is not a rare event.

01:32:05.460 | If it happened twice on the same planet,

01:32:08.060 | that means it's probably pretty probable

01:32:09.580 | given conditions are right.

01:32:11.660 | So it has huge potential scientific impact,

01:32:14.180 | not to mention the fact that you might have

01:32:15.660 | like biochemistry and stuff that's informative

01:32:17.620 | for like medicine and stuff like that.

01:32:19.060 | But I think that the thing for me

01:32:22.220 | that's challenging about it,

01:32:23.340 | and this really comes from my own work,

01:32:24.700 | like thinking about life as a planetary scale process

01:32:28.900 | and also trying to understand

01:32:31.020 | sometimes what I call like

01:32:31.940 | the statistical mechanics of biochemistry,

01:32:33.860 | but large scale statistical patterns

01:32:35.660 | in the chemistry that life uses on Earth.

01:32:38.460 | There are a lot of regularities there

01:32:40.740 | and life does seem to have planetary scale organization

01:32:45.740 | that's consistent even with some of the patterns

01:32:47.900 | that we see at the individual scale.

01:32:49.300 | So if you think life is a planetary scale phenomena

01:32:52.100 | and the chemistry of life has to be sort of,

01:32:54.300 | not just, it's not,

01:32:56.580 | an individual is not necessarily

01:32:58.140 | the fundamental unit of life, right?

01:33:00.060 | The fundamental unit of life

01:33:01.260 | is these informational lineages

01:33:03.900 | and they're kind of,

01:33:05.300 | they intersect over spatial scales.

01:33:08.340 | So everything on Earth is kind of related

01:33:10.420 | by the common causal history.

01:33:12.540 | So it's hard for me,

01:33:14.180 | based on the way I think about the physics

01:33:15.980 | and also some of the stuff that my group has done,

01:33:19.140 | to really think that there could be evidence

01:33:22.700 | or there could be a second sample of life on Earth.

01:33:25.180 | But I think there are ways

01:33:26.340 | that we need to be more concrete about that.

01:33:28.620 | And I have thought a little bit about,

01:33:30.700 | like you can represent the chemistry

01:33:33.500 | in an individual cell as a network.

01:33:35.740 | And then those networks,

01:33:37.540 | something my group has shown,

01:33:39.380 | actually scale with the same property.

01:33:42.540 | So ecosystems have the same properties

01:33:43.940 | as individuals as planetary scale.

01:33:46.100 | And then you could imagine

01:33:47.140 | if you had alien chemistry intermixed in there,

01:33:49.620 | that scaling would be broken.

01:33:50.980 | So if there's some robustness property

01:33:52.820 | or something associated to it,

01:33:54.620 | and you get alien chemistry in there,

01:33:56.060 | it just breaks everything.

01:33:57.180 | And you don't have a planetary ecosystem functioning

01:34:00.780 | and individuals functioning across all these scales.

01:34:04.620 | So I guess what I'm arguing

01:34:06.220 | is life is not a scale dependent phenomena.

01:34:08.460 | It's not just cellular life.

01:34:10.260 | So if you have a shadow biosphere,

01:34:11.540 | it has to be integrated with all of these other scales.

01:34:13.580 | - And that would lose the meaning

01:34:16.180 | of the word shadow biosphere, I guess.

01:34:17.460 | - I think so, yeah.

01:34:18.540 | So it's an open question, right?

01:34:21.260 | And I think it would tell us a lot.

01:34:23.180 | So there has been very minimal effort

01:34:25.540 | of people to look for a shadow biosphere.

01:34:28.180 | - But then the question,

01:34:29.180 | it could be possible that there's like sufficiently

01:34:33.260 | distinct planets within one planet,

01:34:37.180 | meaning like environments within one planet.

01:34:39.820 | Like, I don't know.

01:34:41.300 | I've been looking recently

01:34:44.220 | because of having a chat with Catherine DeCleer

01:34:47.620 | about Io, the moon of Jupiter,

01:34:49.260 | that's like all volcanoes and volcanoes are bad-ass.

01:34:51.620 | But like imagining-

01:34:53.180 | - Io's bad-ass.

01:34:54.020 | - Imagining life inside volcanoes, right?

01:34:58.780 | It seems like sufficiently chemically different

01:35:03.020 | like to be living in the darkness

01:35:05.500 | where there's a lot of heat

01:35:06.700 | and maybe you can have different Earths on a planet.

01:35:10.380 | - Yeah, or like if you go deep enough in the crust,

01:35:12.660 | maybe there's like a layer where there's no life

01:35:14.380 | and then there's suddenly life again.

01:35:15.860 | And maybe those lizard men or whatever

01:35:19.300 | that people dream about are really down there.

01:35:22.660 | I know that's a little flippant,

01:35:24.420 | but really like there could be like chemical cycles

01:35:26.780 | deep in the Earth's crust that might be alive

01:35:29.020 | and are completely distinct in chemical origin

01:35:31.660 | to surface life.

01:35:33.460 | - Right, that they wouldn't be interacting with each other.

01:35:35.420 | - Yeah, and that's one of the proposals

01:35:36.660 | for the shadow biosphere is like,

01:35:38.140 | sometimes people talk about it as being geologically

01:35:40.860 | or geographically distinct that it might be,

01:35:43.700 | you have no life for this region

01:35:45.220 | and then a different example.

01:35:46.740 | And then sometimes people talk about it

01:35:47.940 | being chemically distinct,

01:35:49.300 | that the chemistry is sufficiently different,

01:35:51.580 | that it's completely orthogonal

01:35:52.940 | or non-interacting with our chemistry.

01:35:54.420 | - It seems to me at least the chemistry

01:35:55.980 | is a more powerful boundary than geographic.

01:36:02.500 | It just seems like life finds a way literally to travel.

01:36:06.260 | What do you think about all these UFO sightings?

01:36:11.540 | So to me, it's really inspiring.

01:36:14.100 | It's yet another localized way to dream

01:36:18.220 | about the mysterious that is out there.

01:36:21.660 | - Yeah, so I've actually been more intrigued

01:36:24.660 | by the cultural phenomena UFOs

01:36:26.580 | than the phenomena UFOs themselves,

01:36:28.440 | because I think it's intriguing about how

01:36:32.140 | we are preparing ourselves mentally

01:36:35.500 | for understanding others

01:36:37.620 | and how we have thought about that historically

01:36:39.740 | and what the sort of modern incarnations of that are.

01:36:43.440 | It's more like, I want an explanation for us,

01:36:47.520 | that's my motivation.

01:36:48.720 | And having some streaks across the sky or something

01:36:52.180 | and saying that's aliens, it doesn't tell you anything.

01:36:55.780 | So unless you have a deeper explanation

01:36:57.620 | and you have more lines of,

01:37:00.740 | where is this gonna take us in the future?

01:37:02.740 | It's just not as interesting to me

01:37:04.780 | as the problem of understanding life itself

01:37:06.840 | and aliens as a more general phenomenon.

01:37:08.820 | - I do think it's just, as you said,

01:37:11.100 | a good way to psychologically and sociologically

01:37:14.020 | prepare ourselves to sort of like,

01:37:15.940 | what would that look like?

01:37:17.540 | And very importantly,

01:37:18.740 | which is what a lot of people talk about politically,

01:37:21.540 | sort of there's this idea from the,

01:37:24.580 | so I came from the Soviet Union of like the Cold War

01:37:27.720 | and we have to hide secrets.

01:37:30.140 | Some way in us searching for life on other planets

01:37:33.500 | or searching for life in general,

01:37:35.220 | the way we've done government in the past,

01:37:40.900 | we tend to think of all new things

01:37:43.340 | as potential military secrets, so we want to hide them.

01:37:47.140 | And one of the ways that people kind of look

01:37:49.260 | at UFO sightings is like,

01:37:51.940 | maybe we shouldn't hide this stuff.

01:37:53.540 | Like what is the government hiding?

01:37:55.100 | I think that's a really,

01:37:57.940 | in one sense it's a conspiratorial question,

01:38:00.140 | but I think in another,

01:38:02.460 | it's an inspiration to change the way we do government

01:38:07.380 | to where secrets don't,

01:38:10.020 | maybe there are times when you want to keep secrets

01:38:12.480 | as military secrets,

01:38:13.500 | but maybe we need to release a lot more stuff

01:38:15.980 | and see us as a human species

01:38:18.260 | as together in this whole search.

01:38:20.220 | - Yeah, the public engagement part there

01:38:21.740 | is really interesting.

01:38:23.180 | - And it's almost like a challenge

01:38:25.700 | to the way we've done stuff in the past

01:38:27.740 | in terms of keeping secrets.

01:38:29.620 | When they're not, so like the first step,

01:38:33.340 | if you don't know how something works,

01:38:36.620 | if there's a mysterious thing,

01:38:38.460 | the first instinct should not be like, let's hide it.

01:38:42.100 | Let's put it in the closet.

01:38:44.060 | So that the Chinese or the Russian government

01:38:46.060 | or whatever government doesn't find it.

01:38:48.900 | Maybe the first instinct should be, let's understand it.

01:38:53.140 | Perhaps let's understand it together.

01:38:54.860 | - No, I think that's good.

01:38:56.740 | And something I realized recently

01:38:58.820 | that I never thought was gonna be a problem,

01:39:00.220 | but I think this actually helps with quite a bit

01:39:02.740 | is because so many people nowadays

01:39:05.900 | believe we've already made contact

01:39:08.300 | that as an astrobiologist,

01:39:10.980 | if we actually wanna understand life and make contact,

01:39:14.740 | we kind of have to deconstruct the narratives

01:39:17.460 | we've already built from ourselves

01:39:18.740 | and kind of unteach ourselves

01:39:20.060 | that we've learned about aliens and then reteach ourselves.

01:39:22.780 | So there's this really interesting sort of dialogue there

01:39:26.180 | and making it open to the public

01:39:27.900 | that they actually have to think critically about it

01:39:29.620 | and they see the evidence for themselves,

01:39:30.980 | I think is really important for that process.

01:39:33.820 | - Yeah, the reteaching,

01:39:35.020 | that aliens might be way weirder than we can imagine.

01:39:38.220 | - Yes, yes.

01:39:39.820 | I'm pretty sure they're probably weirder

01:39:41.940 | than we can imagine.

01:39:42.940 | - Okay, we've in 2020 and still living through a pandemic,

01:39:49.140 | setting the political and all those kinds of things aside,

01:39:54.180 | I've always found viruses fascinating as dynamical systems.

01:39:59.180 | I was gonna say living systems,

01:40:03.180 | but I've always kind of thought of them as living,

01:40:07.140 | but that's a whole nother kind of discussion.

01:40:09.540 | Maybe it'd be great to put that on the table.

01:40:13.260 | One, do you find viruses beautiful/terrifying?

01:40:17.540 | And two, do you think they're living things?

01:40:21.540 | Or there's some aspect to them per our discussion of life

01:40:25.780 | that makes them living?

01:40:27.740 | - I mean, living in a pandemic,

01:40:29.020 | saying viruses are beautiful is probably a hard thing,

01:40:30.900 | but I do find them beautiful to a degree.

01:40:34.460 | I think even in the sense of mediating a global pandemic,

01:40:39.460 | there's something like deeply intriguing there

01:40:41.380 | because these are tiny, tiny little things, right?

01:40:46.140 | And yet they can essentially,

01:40:51.420 | like cause a seizure,

01:40:52.540 | like handicap an entire civilization at a global scale.

01:40:55.780 | So just that intersection between

01:40:58.500 | our perceived invincibility and our susceptibility to things

01:41:02.620 | and also the interaction across scales of those things

01:41:04.820 | is just a really amazing feature of our world.

01:41:09.260 | - Most technology, whether it's viruses or AI,

01:41:12.660 | that can scale in an exponential way,

01:41:16.420 | like kind of run,

01:41:20.300 | as opposed to like one thing makes another thing,

01:41:23.900 | makes another thing,

01:41:24.780 | it's one thing makes two things

01:41:26.500 | and those two things make four things.

01:41:28.700 | Like that kind of process

01:41:30.900 | also seems to be fundamental to life.

01:41:34.780 | - Yes.

01:41:35.620 | - And it's terrifying because in a matter of,

01:41:39.980 | in a very short timescale,

01:41:42.020 | if it's good at being life, whatever that is,

01:41:48.740 | it can quickly overtake the other competing forms of life.

01:41:52.500 | - Right.

01:41:53.540 | - And that's scary both for AI and for viruses.

01:41:57.700 | And it seems like understanding these processes

01:42:00.580 | that are underlying viruses.

01:42:02.060 | And I don't mean like on the virology or biology side,

01:42:05.300 | but on some kind of more computational physics perspective,

01:42:09.860 | as we've been talking about,

01:42:11.380 | seems to be really important

01:42:12.740 | to figure out how humans can survive.

01:42:19.100 | - Right.

01:42:20.540 | - Along with these kinds of,

01:42:22.900 | well, this kind of life

01:42:24.020 | and perhaps becoming a multi-planetary species

01:42:26.900 | is a part of that.

01:42:28.740 | Like there's no,

01:42:30.020 | maybe like we'll figure out from a physics perspective

01:42:32.940 | is like, there's no way any living system

01:42:37.940 | can be stable for a prolonged period of time

01:42:40.820 | and survive unless it expands exponentially throughout.

01:42:43.740 | Like we have to multiply.

01:42:46.260 | Otherwise, anything that doesn't multiply exponentially

01:42:49.940 | will die eventually.

01:42:50.860 | Maybe that's a fundamental law.

01:42:52.460 | - Maybe, I don't know.

01:42:56.020 | I always get really bothered by these Darwinian narratives

01:42:58.940 | that are like the fittest replicator wins and things.

01:43:01.740 | And I just don't feel like that's exactly what's going on.

01:43:04.740 | I think like the copying of information

01:43:06.460 | is sort of ancillary to this other process of creativity.

01:43:10.460 | Right, so like the drive is actually,

01:43:12.420 | the drive is creativity,

01:43:13.740 | but if you wanna keep the creativity

01:43:16.020 | that's existed in the past,

01:43:17.500 | it has to be copied into the future.

01:43:19.660 | So replication, like if you,

01:43:21.660 | so that for me is,

01:43:23.260 | so I had this set of arguments

01:43:25.300 | with Michael Lachman and Lee Cronin

01:43:26.820 | about the like life being about persistence.

01:43:29.540 | They thought it was about persistence

01:43:30.740 | and like survival of the fittest kind of thing.

01:43:32.340 | And I'm like, no, it's about existence.

01:43:33.820 | It's like, 'cause when you're talking about that,

01:43:36.660 | it's easy to say that in retrospect,

01:43:38.620 | you can post-select on the things that survived

01:43:40.820 | and then say why they survived,

01:43:43.060 | but you can't do that going forward.

01:43:46.260 | - That's really profound.

01:43:47.980 | That survival is just a nice little side effect feature

01:43:52.180 | of maximizing creativity,

01:43:54.980 | but it doesn't need to be there.

01:43:56.620 | - Yeah.

01:43:57.540 | - That's really beautiful. - I like that, yeah.

01:43:59.100 | - Yeah, that's really-- - Like I said,

01:44:00.060 | I like optimistic theories.

01:44:01.820 | - Well, I don't know if that's optimistic.

01:44:03.140 | That could be terrifying to people because,

01:44:05.220 | because a system that maximizes creativity

01:44:09.380 | may very quickly get rid of humans

01:44:12.420 | for some reason if it comes up with some other creative,

01:44:15.940 | I mean, forms of existence.

01:44:18.980 | - Yeah.

01:44:19.860 | - Right, this is the AI thing.

01:44:21.300 | It's like the moment you have an AI system

01:44:24.260 | that can flourish in the space of ideas

01:44:29.000 | or in some other space much more effectively than humans,

01:44:33.380 | and it's sufficiently integrated into the physical space

01:44:36.620 | to be able to modify the environment.

01:44:39.180 | - I think we'll just be like

01:44:40.300 | the core genetic architecture or something.

01:44:42.100 | We'll be like the DNA for AI, right?

01:44:44.460 | - Yeah. - It's like we haven't lost

01:44:45.500 | the past informational architectures on this planet.

01:44:47.740 | They're still there.

01:44:48.800 | - Yeah, so the AI will use our brains in some part

01:44:53.860 | to like ride, like it'll accelerate the exchange of ideas.

01:44:58.020 | That's the neural language dream is that,

01:45:00.980 | well, the humans will be still around

01:45:03.500 | 'cause you're saying architecture will still--

01:45:05.340 | - Yeah, but I don't even think they necessarily

01:45:07.060 | need to tap in our brains.

01:45:08.340 | I mean, just collectively, we do interesting things.

01:45:10.420 | What if they were just using like the patterns

01:45:12.220 | in our communication or something?

01:45:14.740 | - Oh, without controlling it, just observing?

01:45:18.100 | - Well, I don't know.

01:45:19.020 | In what sense do you control the chemistry

01:45:20.740 | happening in your body?

01:45:21.900 | - Hmm, yeah.

01:45:25.220 | - I mean, obviously I don't know.

01:45:27.500 | People look at AI and then they look at this thing

01:45:32.240 | that's bigger than us and is coming in the future

01:45:34.660 | and is smarter than us, and I think though

01:45:37.020 | that looking at the past history of life on the planet

01:45:39.780 | and what information has been doing

01:45:41.140 | for the last four billion years

01:45:42.300 | is probably very informative to asking questions

01:45:44.940 | about what's coming next.

01:45:46.240 | One is planetary scale transitions are really important

01:45:53.460 | for new phases, so the global internet

01:45:55.620 | and sort of global integration of our technology

01:45:57.340 | I think is an important thing.

01:45:58.540 | So that's again, life as a planetary scale phenomena,

01:46:01.120 | but we're an integrated component of that phenomena.

01:46:03.380 | I don't really see that the technology

01:46:04.980 | is gonna replace us in that way.

01:46:07.100 | It's just gonna keep scaffolding and building.

01:46:09.820 | And I also don't have an idea

01:46:11.300 | that we're gonna build AI in a box.

01:46:12.680 | I think AI is gonna emerge.

01:46:14.460 | AGI to me is a planetary scale phenomena

01:46:17.100 | that's gonna emerge from our technology.

01:46:19.860 | - Planetary scale phenomena.

01:46:22.220 | But do you think, and AGI is not distinct from humans.

01:46:26.100 | The whole package-- - The whole package, yeah.

01:46:28.300 | - Comes as a planetary scale phenomena.

01:46:30.060 | - And that goes back to the fact that

01:46:31.620 | you were asking questions about you as an individual.

01:46:34.860 | Like what are you as an individual?

01:46:36.100 | You're like a packet of information

01:46:38.020 | that exists in the particular physical thing that is you.

01:46:41.320 | We're all just packets of information

01:46:43.660 | and some of us are aggregates in certain ways,

01:46:45.620 | but it's all just kind of exchanging

01:46:47.060 | and propagating, right, and processing.

01:46:49.620 | - Is your packet of information

01:46:52.620 | that you've continually referred to as Sarah

01:46:56.020 | afraid of the dissipation of the death of that packet?

01:47:01.020 | Are you afraid of death?

01:47:02.980 | Do you ponder death?

01:47:04.660 | Does death have meaning in this process of creativity?

01:47:09.260 | - I think I have the natural biological urge

01:47:12.300 | that everyone has to fear death.

01:47:13.900 | I think the thing that I think is interesting

01:47:17.820 | is if I think about it rationally,

01:47:20.220 | I'm not necessarily afraid of death for me

01:47:22.060 | because I won't be aware of being dead.

01:47:25.260 | But I am afraid for my kids

01:47:26.740 | because it matters to them if I die.

01:47:28.800 | So again, I think death becomes more significant

01:47:33.740 | as a collective property, not as an individual one.

01:47:37.300 | - Yeah, but isn't there something to fear

01:47:39.300 | about the fact that the way,

01:47:41.700 | like the creative,

01:47:45.580 | the complexity of information

01:47:48.580 | that's been created in you,

01:47:50.980 | the fact that it kind of breaks apart and disappears.

01:47:57.100 | - It doesn't, but I don't think it disappears.

01:47:59.600 | It's just not me anymore.

01:48:02.260 | - Right, but that process of it being not you anymore,

01:48:07.100 | that doesn't scare you?

01:48:09.020 | - Of course it does.

01:48:09.940 | - The mystery of it.

01:48:10.780 | I mean the-- - Yeah.

01:48:11.860 | But I guess I'm heartened by the fact

01:48:13.380 | that there will be some imprints of the fact

01:48:15.060 | that I existed still in the universe after I leave it.

01:48:17.980 | - Yeah, but there'll be a, okay.

01:48:20.220 | - And also that has to do with my perception of time, right?

01:48:22.740 | So I perceive time as flowing,

01:48:24.780 | but that might not be the case.

01:48:26.340 | I mean, this is standard physicist comfort

01:48:30.380 | is every moment exists,

01:48:32.620 | and the flow of time is just our perception of us changing.

01:48:37.620 | - So you can travel back in time and that's comforting?

01:48:43.980 | Like from a physicist's--

01:48:45.460 | - No, no, no, I'm not talking about traveling back in time.

01:48:47.420 | I'm just saying that the moments in the past still exist.

01:48:50.980 | Now whether the moments in the future exist or not

01:48:53.180 | is a different question.

01:48:54.380 | - That's not comforting to me in terms of death.

01:48:56.780 | The flow of time is not, that does not--

01:48:59.580 | - I think there's no comfort in the face of death

01:49:04.140 | for what we are because we like existing.

01:49:07.900 | And I think it's especially true if you love life

01:49:11.620 | and you love what life is.

01:49:13.740 | - Do you think there's a certain sense in which

01:49:16.220 | the fear of death or the fear of non-existence,

01:49:19.180 | maybe fear is not the right word,

01:49:21.420 | is the actual very phenomena that gives birth to existence?

01:49:26.420 | Like death is fundamental.

01:49:28.780 | Like it just feels like freaking out,

01:49:31.340 | oh shit, this ride ends, is actually like,

01:49:35.900 | that's the thing that gives birth to this whole thing.

01:49:41.300 | It's constantly, it's matter constantly freaking out

01:49:47.940 | about the fact that it's gonna be--

01:49:49.380 | - No, I think things like to exist.

01:49:51.660 | I think they wanna exist.

01:49:52.500 | - Yeah, there's a desire or whatever to exist.

01:49:55.820 | - Yeah, there's a drive to exist

01:49:58.020 | and there's a drive for more things to exist.

01:50:00.100 | I guess, yeah, I like existing.

01:50:03.060 | I like it a lot.

01:50:04.980 | And I don't know it any other way.

01:50:08.000 | - See, I don't even know if I like existing.

01:50:12.020 | I think I really don't like not existing.

01:50:14.580 | - Yes, yeah, that too.

01:50:15.860 | (laughing)

01:50:17.540 | Yeah, maybe it's that.

01:50:19.820 | Some days I might like existing less than others.

01:50:23.420 | (laughing)

01:50:24.660 | - Yes, but I think those are like surface feelings.

01:50:27.620 | There is some, seems like there's something fundamental

01:50:29.900 | about wanting to exist.

01:50:31.260 | - No, I think that's right, but I think to your point

01:50:34.580 | that that might go back to the more fundamental idea

01:50:38.260 | that if life is the physics of existence

01:50:40.660 | and maximizing existence, individual organisms,

01:50:43.080 | of course, wanna maximize their existence

01:50:45.540 | and everything wants to exist.

01:50:48.040 | But I guess for me, the small comfort is

01:50:50.620 | my existence matters to future existence.

01:50:52.820 | - Speaking of future existence,

01:50:56.060 | is there advice you can give to future pockets of existences

01:51:00.900 | aka young people about life?

01:51:04.180 | You've had, you've worn many hats,

01:51:07.260 | you've taken on some of the biggest problems in the universe.

01:51:10.420 | Is there advice you can give to young people about life,

01:51:13.900 | about career, about existing?

01:51:17.300 | - Maybe not about the last one.

01:51:20.380 | A lot of people ask me this question

01:51:23.420 | about like working on such hard problems,

01:51:25.900 | like how can you make a successful career out of that?

01:51:28.180 | But I think for me, it couldn't be otherwise.

01:51:31.300 | Like I have to, to be fulfilled,

01:51:33.340 | you have to work on things you care about

01:51:35.260 | and that's always kind of driven me.

01:51:36.860 | And that's been discipline, department

01:51:39.740 | and sort of superficial level problem independent

01:51:44.940 | because I started at community college actually

01:51:48.420 | and I was taking a physics class

01:51:49.740 | and I learned about magnetic monopoles

01:51:53.100 | and we didn't know if they existed in the universe

01:51:55.500 | but we could predict them and we could go look for them.

01:51:57.940 | And I was so deeply intrigued by this idea

01:51:59.540 | that we had this mathematical formula

01:52:01.180 | to go look for things.

01:52:02.500 | And then I wanted to become a theoretical physicist

01:52:05.140 | because of that,

01:52:05.980 | but that actually wasn't my driving question.

01:52:07.700 | I realized my driving question is the nature

01:52:10.660 | of the correspondence between our minds

01:52:12.180 | and physical reality and what we are.

01:52:14.420 | And that question is very deep

01:52:16.500 | so you can work across a lot of fields doing that.

01:52:18.620 | But I think without that driving question,

01:52:20.100 | I never would have been able to do all the things

01:52:22.340 | that I've done.

01:52:23.180 | It's really the passion that drives it.

01:52:25.100 | And usually when students ask me these kinds of questions,

01:52:28.500 | I tell them like,

01:52:30.700 | you have to find something you really care about working on

01:52:33.300 | because if you don't really care about it,

01:52:35.500 | A, you're not gonna be your best at it

01:52:37.900 | and B, it's not gonna be worth your time.

01:52:39.860 | Why would you spend your time working on something

01:52:41.580 | you're not interested in?

01:52:43.060 | - So find the driving questions.

01:52:44.820 | - Yeah, find the driving question, find your passion.

01:52:47.500 | I mean, I think passion makes a huge difference

01:52:49.500 | in terms of creativity, talent and potential

01:52:52.740 | and also being able to tolerate all the hard things

01:52:55.060 | that come with any career or life.

01:52:57.900 | - Yeah, I've had a bunch of moments in my life

01:52:59.860 | where I've just been captivated by some beautiful phenomena

01:53:03.220 | and I guess being rigorous about it

01:53:06.100 | and asking what is the question underlying this phenomenon

01:53:09.580 | like robots bring a smile to my face

01:53:13.420 | and forming a question of like,

01:53:17.060 | why the hell is this so fascinating?

01:53:19.980 | Why is this specifically

01:53:21.620 | the human robot interaction question

01:53:24.820 | that something beautiful is brought to life

01:53:28.220 | when humans and robots interact,

01:53:30.740 | understanding that deeply.

01:53:32.620 | I was like, okay, so this is gonna be my life work then.

01:53:36.660 | I don't know what the hell it is,

01:53:37.780 | but that's what I wanna do.

01:53:39.220 | And doing that for whatever the hell gives you

01:53:43.020 | that kind of feeling, I guess is the point.

01:53:46.540 | Am I allowed to ask you a question?

01:53:47.940 | - Sure.

01:53:48.780 | - Okay, on that point,

01:53:50.940 | 'cause I had this colleague that suggests the idea

01:53:53.940 | that consciousness might be contagious

01:53:56.180 | and so interacting with things.

01:53:57.900 | - That's funny.

01:53:59.020 | No, yeah, yeah, it's a beautiful way of putting it.

01:53:59.860 | - It's an interesting idea, right?

01:54:01.060 | So I'm wondering the motivation there.

01:54:04.500 | Is it the motivation that you want more of the universe

01:54:08.660 | to appreciate things the way we do

01:54:11.340 | and appreciate those interactions

01:54:12.820 | or is it really more the enjoyment of the human

01:54:15.820 | in those interactions?

01:54:16.820 | Is it, do you know what I'm asking?

01:54:20.380 | - Yeah, yeah, yeah.

01:54:21.220 | See, I think consciousness is created

01:54:23.860 | in the interaction between things.

01:54:27.580 | - Yes, I agree.

01:54:28.420 | - So the joy is in the creation of consciousness.

01:54:31.140 | - I see.

01:54:31.980 | - I really like the idea that it doesn't just have to be

01:54:36.980 | two humans creating consciousness together.

01:54:40.140 | It could be humans and other entities.

01:54:43.420 | We talked offline about dogs and other pets and so on.

01:54:46.540 | There's a magic, I mean, I've been calling it love.

01:54:49.700 | There's beauty of the human experience that's created

01:54:54.340 | and it just feels like fascinating that you could do that

01:54:58.260 | with a robotic system.

01:55:00.460 | There's something really powerful at least to me

01:55:06.940 | about engineering systems that allow you to create

01:55:10.900 | some of the magic of the human experience

01:55:12.620 | 'cause then you get to understand what it takes,

01:55:15.460 | at least get inklings of what it takes

01:55:17.940 | to create consciousness.

01:55:21.380 | And I don't get this, you know,

01:55:24.300 | philosophers get really upset about this idea

01:55:26.260 | that sort of the illusion of consciousness is consciousness.

01:55:29.660 | But I really like the idea of engineering systems

01:55:33.700 | that fool you into thinking they're conscious.

01:55:37.260 | - Right.

01:55:38.100 | - Because that's sufficient to create

01:55:40.060 | the magical experience.

01:55:41.900 | - Right, because it's the interaction, yeah.

01:55:43.540 | - It's the interaction, yeah.

01:55:45.100 | And this is the Russian hat I wear,

01:55:47.620 | which is like, I think there's an ocean

01:55:50.260 | of loneliness in the world.

01:55:51.940 | I think we're deeply lonely.

01:55:53.460 | We're not even allowing ourselves to acknowledge that.

01:55:57.220 | And I kind of think that's what love is

01:55:59.220 | between romantic love and friendship

01:56:01.940 | is two people kind of getting a little bit

01:56:05.220 | alleviating for a brief moment.

01:56:11.420 | - That loneliness.

01:56:12.260 | - That loneliness, but we're not,

01:56:15.300 | it's not the full aspect of that loneliness.

01:56:17.940 | Like we're desperately alone,

01:56:19.380 | we're desperately afraid of non-existing.

01:56:22.580 | - Right.

01:56:23.420 | - I have that kind of sense,

01:56:24.560 | and I just wanna explore that ocean of loneliness more.

01:56:28.180 | - Right.

01:56:29.020 | - In engineering, like create a submarine

01:56:30.860 | that goes into the depth of that loneliness.

01:56:33.740 | So creating systems that can truly hear you.

01:56:36.580 | - Right.

01:56:37.420 | - And truly listen.

01:56:38.240 | - Make the universe a less lonely place.

01:56:39.780 | - Exactly.

01:56:40.980 | Let me ask you about the meaning.

01:56:43.180 | You've brought up why.

01:56:44.820 | - Yeah.

01:56:45.660 | - The physics of why.

01:56:46.480 | What do you think is the meaning of our particular planets,

01:56:51.100 | set of existences, and the universe in general?

01:56:54.600 | The meaning of life.

01:56:57.020 | - Yes, someone once told me as a physicist,

01:56:59.020 | I'm not allowed to ask why questions,

01:57:00.780 | but I don't believe that.

01:57:02.100 | I think what we are is the creative process

01:57:09.940 | in the universe, I think.

01:57:11.460 | And for me, that's the meaning.

01:57:13.200 | The ability to-- - Create.

01:57:15.140 | - Yeah, to create more possibilities

01:57:18.180 | and more things to exist.

01:57:19.540 | - What is, Odessiyevsky has the saying,

01:57:23.820 | "Beauty will save the world."

01:57:25.980 | Is there a connection between creation and beauty?

01:57:32.320 | - I think so.

01:57:34.220 | - So is that like, is beauty a correlate of creation?

01:57:39.080 | - It might be, I don't know.

01:57:41.260 | I mean, why is it, you know,

01:57:43.420 | a lot of people have asked these kind of questions,

01:57:44.860 | but like, why is it we have such an emotional response

01:57:47.300 | to intellectual activity or creativity?

01:57:49.460 | And that seems kind of a deep question to me.

01:57:52.540 | Like, it seems very intrinsic to what we are.

01:57:55.660 | So I do have an interest in the questions I ask

01:57:59.940 | because I think they're beautiful,

01:58:01.380 | and I think the universe is beautiful,

01:58:02.980 | and I'm just so deeply fascinated

01:58:06.480 | by the fact that I exist at all.

01:58:09.360 | And so maybe it's that, you know,

01:58:13.560 | that intrinsic feeling of beauty that's in part driving,

01:58:17.280 | you know, the physics of creating more things,

01:58:19.120 | so they could be deeply related in that way.

01:58:22.160 | - Well, I don't think there's a better way to end it.

01:58:24.760 | I think this conversation was beautiful.

01:58:27.200 | Thank you so much for wasting

01:58:29.840 | all your valuable time with me today.

01:58:32.000 | I really, really appreciate it, Sarah.

01:58:33.600 | This is an honor.

01:58:34.440 | I hope we get the chance to talk again.

01:58:36.080 | I hope, like I mentioned to you offline,

01:58:38.200 | we get a chance to talk with Lee.

01:58:39.640 | You guys have a beautiful, like, intellectual chemistry

01:58:44.640 | that's fascinating to listen to,

01:58:46.080 | so I'm a huge fan of both of you,

01:58:47.440 | and I can't wait to see what you do next.

01:58:49.760 | - Thanks so much.

01:58:50.600 | Great to be here.

01:58:51.600 | Bye. - Bye.

01:58:52.440 | - Thanks for listening to this conversation

01:58:54.720 | with Sarah Walker.

01:58:55.760 | A thank you to Athletic Greens, NetSuite,

01:58:59.040 | Blinkist, and Magic Spoon.

01:59:01.440 | Check them out in the description to support this podcast.

01:59:04.680 | And now let me leave you with some words from Robert Frost,

01:59:07.800 | one of my favorite poets.

01:59:09.800 | In three words,

01:59:10.640 | I can sum up everything I've learned about life.

01:59:13.880 | It goes on.

01:59:15.080 | Thank you for listening.

01:59:17.120 | I hope to see you next time.

01:59:18.920 | (upbeat music)

01:59:21.500 | (upbeat music)

01:59:24.080 | [BLANK_AUDIO]

Sara Walker: The Origin of Life on Earth and Alien Worlds | Lex Fridman Podcast #198

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