Sara Seager: Search for Planets and Life Outside Our Solar System

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

00:00:03.280 | a planetary scientist at MIT,

00:00:05.600 | known for her work on the search for exoplanets,

00:00:09.280 | which are planets outside of our solar system.

00:00:11.960 | She's an author of two books on this fascinating topic.

00:00:15.760 | Plus, in a couple days, August 18th,

00:00:18.320 | her new book, a memoir,

00:00:20.280 | called "The Smallest Lights in the Universe" is coming out.

00:00:23.680 | I read it and I can recommend it highly,

00:00:26.000 | especially if you love space

00:00:27.520 | and are a bit of a romantic like me.

00:00:30.720 | It's beautifully written.

00:00:32.240 | She weaves the stories of the tragedies

00:00:34.560 | and the triumphs of her life

00:00:36.200 | with the stories of her love for

00:00:38.040 | and research on exoplanets,

00:00:40.640 | which represent our hope to find life

00:00:43.240 | out there in the universe.

00:00:45.280 | Quick summary of the ads.

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00:00:57.860 | As a quick side note, let me say that extraterrestrial life,

00:01:02.880 | aliens, I think represent our civilization longing

00:01:06.640 | to make contact with the unknown,

00:01:08.920 | with others like us,

00:01:10.560 | or maybe others that are very different from us,

00:01:13.280 | entities that might reveal something profound

00:01:16.160 | about why we're here.

00:01:18.760 | The possibility of this is both exciting

00:01:21.400 | and, at least to me, terrifying,

00:01:24.160 | which is exactly where we humans do our best work.

00:01:27.280 | If you enjoy this thing, subscribe on YouTube,

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00:01:34.200 | or connect with me on Twitter @LexFriedman.

00:01:37.280 | As usual, I'll do a few minutes of ads now,

00:01:39.440 | and never any ads in the middle

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00:01:43.120 | I try to make these ad reads interesting if you do listen,

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00:05:27.400 | And now here's my conversation with Sarah Seeger.

00:05:31.180 | When did you first fall in love with the stars?

00:05:35.000 | - I think I've always loved the stars.

00:05:37.160 | One of my first memory is of the moon.

00:05:39.800 | I remember watching the moon

00:05:41.400 | and I was in the car with my dad

00:05:42.680 | who my parents were divorced

00:05:44.040 | and he was driving me and my siblings

00:05:45.560 | to his house for the weekend

00:05:47.320 | and the moon was just following me.

00:05:49.040 | Just had no idea why that was.

00:05:50.880 | - Yeah, so like looking up at the sky

00:05:52.920 | and there's this glowing thing.

00:05:54.720 | How do you make sense of the moon at that age?

00:05:57.240 | - At that age, like age five,

00:05:58.320 | there's just no way you can.

00:05:59.980 | I think it's one of the great things about being a kid.

00:06:01.920 | It's just that curiosity that all kids have.

00:06:04.800 | - You know, I was thinking 'cause there's these

00:06:08.120 | almost out there ideas that our earth is flat

00:06:12.240 | floating about on the internet.

00:06:14.280 | And it made me think, you know,

00:06:16.360 | when did I first realize that the earth is like this ball

00:06:21.360 | that's flying through empty space?

00:06:25.820 | I mean, it's terrifying, it's awe-inspiring.

00:06:29.480 | I don't know how to make sense of it.

00:06:31.200 | - It's hard 'cause we live in our frame of reference

00:06:33.280 | here on this planet.

00:06:34.800 | It's nearly impossible.

00:06:35.720 | None of us are lucky to go to see the curvature of earth.

00:06:38.560 | - I mean, do you remember when you realized,

00:06:40.400 | understood like the physics,

00:06:42.760 | like the layout of the solar system?

00:06:44.620 | Was it like, did you first have to take physics

00:06:48.200 | to really, like high school physics to really take that in?

00:06:52.440 | - I think it's hard to say.

00:06:53.520 | I had this book when I was a child.

00:06:55.160 | It was in French.

00:06:56.180 | I grew up in Canada where French is supposedly taught

00:06:59.440 | to all of us English speaking Canadians.

00:07:01.600 | And it was this book in French,

00:07:02.960 | but it was about the solar system.

00:07:04.080 | And I just loved flipping through it.

00:07:06.040 | It's hard to say how much you or I understand

00:07:09.060 | when we're kids, but it was really a great book.

00:07:11.420 | - What about the stars?

00:07:12.960 | When'd you first learn about the stars?

00:07:14.480 | - I have like, I do have this very incredible

00:07:16.440 | distinctive memory.

00:07:17.840 | And again, it had to do with my dad.

00:07:19.120 | He took us camping.

00:07:20.080 | Now my dad was from the UK and he was the type

00:07:23.480 | who you'd find wearing a tie on weekends.

00:07:25.960 | So camping was not in his fear, his comfort zone.

00:07:29.200 | We had a babysitter.

00:07:30.040 | Every summer we got a baby,

00:07:31.600 | every summer we had a babysitter.

00:07:33.400 | And one summer we had Tom.

00:07:34.600 | He was barely older than we were.

00:07:36.320 | He was 14, my brother was 12.

00:07:37.840 | I would have been 11 or 10 maybe.

00:07:40.200 | And we went camping because Tom said camping's the thing.

00:07:42.920 | We should try it.

00:07:44.000 | And I just remember, I didn't aim to see the stars,

00:07:47.060 | but I walked out of my tent in the middle of the night

00:07:49.640 | and I looked up and wow, so many stars.

00:07:54.080 | The dark night sky and all those stars

00:07:57.280 | just like screaming at me.

00:07:59.040 | I just couldn't believe that.

00:08:00.920 | Honestly, like my first thought was this is so incredible.

00:08:03.380 | Mind-blowing.

00:08:04.520 | Like why wouldn't anyone have told me this existed?

00:08:07.200 | - Can anyone else see this?

00:08:08.800 | - Have you had an experience like that with anything?

00:08:12.240 | - Yeah, I've had that.

00:08:14.080 | I mean, I don't know if maybe you can tell me

00:08:16.480 | if it's the same.

00:08:17.600 | I've had that with robots.

00:08:19.800 | There's a few robots I've met

00:08:21.120 | where I just fell in love with this.

00:08:22.560 | Like is anyone else seeing this?

00:08:25.080 | Is anyone else seeing that here in a robot

00:08:30.400 | is our ability to engineer some intelligent beings,

00:08:35.400 | intelligent beings that we could love, that could love us,

00:08:38.940 | that we can interact with in some rich ways

00:08:41.460 | that we haven't yet discovered.

00:08:43.540 | Like almost like when you get a puppy instead of a dog

00:08:47.380 | and there's this immediate bond and love.

00:08:51.100 | And on top of that ability to engineer it,

00:08:55.260 | it was, I had to just pause and hold myself.

00:08:58.800 | I imagine, I don't have kids.

00:08:59.960 | I imagine there's a magic to that as well,

00:09:02.220 | where it's a totally new experience.

00:09:04.100 | It's like, what?

00:09:05.460 | - Well, yeah, the stars though, unlike kids or the puppy,

00:09:09.740 | it's only a good thing.

00:09:10.900 | (both laughing)

00:09:13.420 | - So you felt, you weren't terrified?

00:09:15.780 | Like to me, when I look at the stars,

00:09:18.820 | it's almost paralyzingly scary

00:09:21.380 | how little we know about the universe, how alone we are.

00:09:26.220 | I mean, somehow it feels alone.

00:09:28.140 | I'm not sure if it's just a matter of perspective,

00:09:31.060 | but it feels like, wow, there's billions of them out there

00:09:36.060 | and we know nothing about them.

00:09:39.180 | And then also immediately to me,

00:09:40.900 | somehow mortality comes into it.

00:09:42.960 | I mean, how did that make you feel at that time?

00:09:45.220 | - I think as a child without articulating it,

00:09:47.160 | I felt that same way.

00:09:48.680 | Just like, wow, this is terrifying.

00:09:50.400 | What's out there?

00:09:51.480 | Like, what is this?

00:09:52.520 | What does it mean about us here?

00:09:55.600 | - You're a scientist, an ex-world-class scientist,

00:09:58.700 | planetary scientist, astronomer.

00:10:02.080 | Now, I'm a bit of an idiot who likes to ask silly questions.

00:10:06.880 | So some questions are a little bit

00:10:08.440 | in the realm of speculation, almost philosophical,

00:10:12.440 | 'cause we know so little.

00:10:13.640 | And one of the awesome things about your work

00:10:16.520 | is you've actually put data and real science

00:10:18.620 | behind some of the biggest questions

00:10:20.080 | that we're all curious about.

00:10:21.460 | But nevertheless, many of the questions

00:10:23.280 | might be a little bit speculative.

00:10:25.520 | So on that topic, just in your sense,

00:10:29.040 | do you think we're alone in the universe, human beings?

00:10:34.040 | Do you think there's life out there?

00:10:36.720 | - Well, Lex, the funny thing is is that as a scientist,

00:10:39.160 | I so don't even wanna answer that.

00:10:40.680 | - You really? - No, I will answer it, though.

00:10:42.560 | But I just love to say-- - You resist it naturally?

00:10:44.800 | - Yeah, we naturally resist that

00:10:46.040 | because we want numbers and hard facts and not speculation.

00:10:49.720 | But I do love that question.

00:10:51.080 | It's a great question, and it's one we all wonder about.

00:10:53.820 | But I have to give you the scientist's answer first.

00:10:55.880 | - Yeah, sure. (laughs)

00:10:56.720 | - Which is we'll have the capability to answer that question.

00:11:00.240 | Soon, even, starting soon.

00:11:02.220 | - How do you define soon?

00:11:03.800 | - How do I define soon?

00:11:05.060 | - So much happened in the last 100 years.

00:11:07.000 | - Right, right, right, right.

00:11:08.220 | And there's a difference, right,

00:11:09.240 | if it's 10 years or 20 years or 100 years.

00:11:11.720 | Yeah, there's a difference in that.

00:11:13.880 | Well, soon could be a decade or two decades.

00:11:17.920 | - And the answer-- - By the way,

00:11:18.760 | journalists usually don't like that,

00:11:19.800 | or the people want tomorrow, they want the news.

00:11:23.080 | But what it's gonna take is telescopes, space telescopes,

00:11:27.040 | or very sophisticated ground or space-based telescopes

00:11:30.320 | to let us study the atmospheres of other planets far away

00:11:34.560 | and to look what's in the atmospheres

00:11:36.080 | and to look for water, which is needed for life as we know it

00:11:38.560 | to look for gases that don't belong

00:11:40.200 | that we might attribute to life.

00:11:41.960 | So we have to do some really nitty-gritty astronomy.

00:11:45.560 | - So the promising way to answer this question

00:11:48.560 | scientifically is to look for hints of life.

00:11:51.340 | That's where many of your ideas come in

00:11:53.640 | of what kind of hints might we actually see about this life.

00:11:57.120 | - Right, right, that's exactly what we need to do.

00:11:58.800 | And I like the word you chose, hint,

00:12:01.360 | because it's gonna be a hint.

00:12:02.440 | It's not gonna be a 100% yay, we found it.

00:12:05.280 | And then it will take future generations

00:12:07.560 | to do more careful work to hopefully even find a way

00:12:12.440 | to send a probe to these distant exoplanets

00:12:15.640 | and to really figure this out for us.

00:12:17.880 | - I mean, we'll talk about the details.

00:12:19.440 | Those are fun, but like--

00:12:21.540 | - Back to the speculation.

00:12:22.660 | - The zoomed out big picture speculation question.

00:12:24.500 | - The zoomed out big picture is yes,

00:12:25.820 | I believe absolutely there is life out there somewhere.

00:12:29.640 | Because the vastness of the universe is incredible.

00:12:33.620 | It's so breathtaking.

00:12:35.660 | When we look at the night sky,

00:12:36.840 | if you can go to that dark sky,

00:12:38.180 | you can see many, many hundred,

00:12:40.560 | or even if you have good eyesight

00:12:42.220 | and you're somewhere very dark,

00:12:43.260 | you could see thousands of stars.

00:12:45.360 | But in our galaxy, we have hundreds of billions of stars.

00:12:49.740 | And our universe has hundreds of billions of galaxies.

00:12:52.520 | So think about all those stars out there.

00:12:55.960 | And even if planets are rare, even if life is rare,

00:13:00.900 | just because the number of stars is so huge,

00:13:04.140 | things have to come together

00:13:05.280 | somewhere, someplace in our universe.

00:13:07.080 | - Yeah, it's so amazing to think that somebody

00:13:08.780 | might be looking up on another planet

00:13:13.060 | in a distant galaxy.

00:13:14.460 | - I have to interrupt your reverie and get back to,

00:13:18.440 | in our lifetime at least, the short term.

00:13:20.600 | We have to, we only have the nearest stars to look at.

00:13:24.640 | It's true that there are so many stars,

00:13:27.200 | so many hosts for planets that might have life.

00:13:29.820 | But in the practical question of will we find it,

00:13:33.600 | it has to be a star quite close to Earth.

00:13:35.960 | Like a few light years, tens of light years,

00:13:38.480 | maybe hundreds of light years.

00:13:40.000 | - And by the way, you've introduced me

00:13:41.560 | to a tool of Eyes on Exoplanets, I think,

00:13:45.240 | that NASA's put together.

00:13:47.840 | - Eyes on Exoplanets, it's a great software

00:13:50.040 | you can download. - That's so cool.

00:13:51.680 | But anyway, can you give a sense of who our neighbors are?

00:13:56.680 | You said hundreds of light years.

00:13:59.880 | Like how many stars are close by?

00:14:02.080 | What's our neighborhood like?

00:14:05.680 | We're talking about five, 10 stars

00:14:08.640 | that we might actually have a chance to zoom in on?

00:14:12.680 | - I'm talking about maybe a dozen or two dozen stars.

00:14:16.560 | - And those are-- - With planets that look

00:14:19.240 | suitable for us to follow up in detail.

00:14:22.840 | - For life, okay. - Right, but

00:14:24.960 | one thing that's really exciting in this field

00:14:27.100 | is that the very nearest star to Earth,

00:14:29.920 | called Proxima Centauri,

00:14:31.960 | it's part of the Alpha Centauri star system.

00:14:34.160 | - Cool name, by the way. - Yeah, Proxima.

00:14:35.560 | - Whoever names them. - Nearby.

00:14:37.480 | - Okay, but it sounds cool.

00:14:39.120 | - But Proxima Centauri appears to have a planet around it

00:14:44.000 | that's about an Earth-mass planet

00:14:46.000 | in the so-called habitable zone,

00:14:48.680 | or the Goldilocks zone of the host star.

00:14:51.000 | So think about how incredible that is.

00:14:52.400 | Like out of all the stars out there,

00:14:54.320 | even the very nearest star has planets

00:14:56.640 | and has a planet of huge interest to us.

00:14:59.440 | - Yeah, okay, so can we talk about that planet?

00:15:04.080 | What does it mean to be maybe possibly habitable?

00:15:09.080 | How does size come into play?

00:15:14.840 | How does, what we know about gases

00:15:19.840 | and what kind of things are necessary for life?

00:15:23.120 | What are the factors that make you think

00:15:25.320 | that it's habitable?

00:15:26.640 | And by the way, maybe one way to talk about that

00:15:29.440 | is people know about the Drake equation,

00:15:32.720 | which is a very high-level, almost framework

00:15:37.400 | to think about what is the probability that,

00:15:40.480 | correct me if I'm wrong, that there's life out there.

00:15:43.840 | And intelligent life, I think, I don't know.

00:15:47.040 | But then you have an equation named after you now,

00:15:49.980 | which I think nicely focuses on the more achievable

00:15:56.040 | and interesting part of that question,

00:15:59.160 | which is on whether there is habitable planets out there,

00:16:03.240 | or how many, I guess, habitable planets are.

00:16:05.800 | - So the funny thing is was one time I met Frank Drake

00:16:09.420 | and I asked if he minded if I took his equation

00:16:11.920 | and kind of revamped it for this new field

00:16:15.440 | of exoplanet astronomy.

00:16:17.240 | He was totally cool with it.

00:16:18.400 | He's totally cool with it.

00:16:19.240 | - He got total approval?

00:16:20.720 | Well, maybe, okay, so sorry.

00:16:22.240 | - I'm not sure if he'd actually read the stuff

00:16:23.660 | about my equation, but he was cool with it.

00:16:25.920 | He was cool with it. - He was cool with it?

00:16:27.760 | Okay, so I just said like 15 different things,

00:16:30.200 | but maybe, can you tell from your perspective

00:16:33.760 | what is the Drake equation,

00:16:35.280 | and what is, sorry, the Seeger equation?

00:16:37.840 | - Sure, well, the Drake equation,

00:16:39.320 | as you said, it's a framework.

00:16:41.580 | It's a description of the number of civilizations out there

00:16:46.580 | of intelligent beings that are able to communicate with us

00:16:50.800 | by radio waves.

00:16:51.840 | So if you think of the movie "Contact,"

00:16:55.240 | you've seen "Contact," right?

00:16:56.920 | We're hoping to get, we're listening in, actually.

00:16:59.040 | It's an active field of research,

00:17:00.360 | listening to other stars at radio wavelengths,

00:17:03.040 | hoping that some intelligent civilizations

00:17:05.340 | are sending us a message.

00:17:07.080 | And the Drake equation came like at the start

00:17:10.080 | of that whole field to put the factors down on paper

00:17:13.720 | to sort of illustrate what is involved

00:17:16.400 | to kind of estimating.

00:17:17.920 | And there's no real estimate or prediction

00:17:19.720 | of how many civilizations are out there,

00:17:21.600 | but it's a way to frame the question

00:17:22.880 | and show you each term that's involved.

00:17:25.600 | So I took the Drake equation

00:17:27.760 | and I called it a revised Drake equation.

00:17:29.960 | And I recast it for the search for planets

00:17:34.520 | by more traditional astronomy means.

00:17:37.800 | We're looking at stars, looking for planets,

00:17:39.880 | looking for rocky planets,

00:17:41.760 | looking for planets that are the right temperature for life,

00:17:44.720 | looking for planets that might have life

00:17:48.500 | that outputs gases that we might detect in the future.

00:17:51.920 | It's the same spirit of the Drake equation.

00:17:53.680 | It's not gonna give us any magic numbers.

00:17:56.280 | So I'm gonna say, "Hey, here's exactly what's out there."

00:17:58.520 | It's meant to kind of guide of where we're going.

00:18:01.200 | - Although the Drake equation did,

00:18:02.520 | I mean, the initial equation proposed actual numbers

00:18:06.180 | for those variables, right?

00:18:07.360 | - Oh, yes, the equation proposed numbers

00:18:09.800 | and you can still plug your own numbers in.

00:18:12.280 | And there's this really cute website that lets you,

00:18:14.520 | for both the Drake and my revised equation,

00:18:16.400 | plug in some numbers and see what you get.

00:18:18.080 | So yeah.

00:18:19.180 | - So, okay, so what are the variables,

00:18:22.920 | but maybe also what are the critical variables?

00:18:26.200 | - So in my equation, I set out to what are the numbers

00:18:30.640 | of inhabited planets that show signs of life

00:18:34.080 | by way of gases in the atmosphere

00:18:35.680 | that can be attributed to life.

00:18:37.520 | I could just walk through the terms, that's simpler.

00:18:39.440 | - Sure, that's probably easier.

00:18:40.280 | - So the first thing I say is,

00:18:41.100 | what are the number of stars available?

00:18:43.100 | And it's not that those trillions and trillions

00:18:46.520 | of stars everywhere.

00:18:47.600 | It's what are available to a specific search.

00:18:50.800 | And so for example, the MIT led NASA mission TESS

00:18:55.440 | is surveying the sky looking for all kinds of planets,

00:18:58.320 | but it can also, it also has stars.

00:19:01.560 | It has about 30,000 red dwarf stars.

00:19:04.680 | So we just take a number of stars

00:19:06.920 | that a given survey can access.

00:19:08.820 | So that's what the number of stars is.

00:19:10.940 | Then I wanted to know what kind of stars are quiet.

00:19:15.520 | A quiet, I called it fraction of those stars that is quiet.

00:19:19.040 | In the case of TESS, the way it's looking for planets

00:19:22.000 | is planets that transit the star.

00:19:23.560 | They go in front of the star as seen from the telescope.

00:19:26.800 | But it turns out that some stars are very active,

00:19:28.680 | they're variable, and they brighten and dim with time,

00:19:31.880 | and that interferes with our observation.

00:19:34.240 | - I apologize to interrupt.

00:19:35.360 | So the transiting planet,

00:19:37.160 | so you're really looking for a black blob,

00:19:39.560 | essentially, that blocks the light.

00:19:41.920 | - We're looking for a black blob that blocks the light.

00:19:44.360 | - And then trying to say something

00:19:45.640 | about the size of the planet,

00:19:47.880 | from the frequency of that black blob's appearance,

00:19:51.440 | and the size of that black blob, that kind of thing.

00:19:53.560 | - Yeah, but let's just say that out of all the stars

00:19:55.960 | there are accessible to whatever telescope,

00:19:58.400 | some of them are just bad.

00:19:59.560 | For whatever reason,

00:20:00.400 | you're not gonna be able to find planets around them.

00:20:02.540 | So I need to know the fraction of those that are good.

00:20:05.800 | So again, we have the number of stars,

00:20:07.720 | the fraction of them that we can actually

00:20:09.000 | find planets around.

00:20:10.040 | - And by the way, is our sun one such,

00:20:14.600 | is our sun quiet?

00:20:16.440 | - Our sun is quiet.

00:20:17.280 | - Okay, good to know.

00:20:18.120 | - So I have actually two terms.

00:20:20.120 | One describes how quiet they are,

00:20:21.700 | and one is if we can find a planet around that star.

00:20:25.400 | These transiting planets, for example,

00:20:27.720 | not all planets transit,

00:20:29.520 | because the planet would have to be orbiting that star

00:20:31.720 | in this kind of plane, as viewed from you.

00:20:35.080 | But if a star is, for example,

00:20:37.560 | orbiting in the plane of the sky, it will never transit.

00:20:40.280 | It will never go in front of the star.

00:20:42.880 | So in that case, we have to have a fraction

00:20:44.500 | that takes into account that kind of geometric factor.

00:20:48.560 | - And hopefully, I mean, you can assume

00:20:51.160 | that it's uniformly distributed, hopefully.

00:20:52.840 | - Yes, we can assume, and there's evidence

00:20:54.440 | that it's uniformly distributed, yes.

00:20:56.840 | So then the next, so all of these factors so far,

00:21:00.000 | number of stars accessible to whatever telescope

00:21:02.160 | you're thinking about, how many stars are quiet,

00:21:04.480 | fraction of stars that are quiet,

00:21:06.120 | fraction that are observable,

00:21:07.880 | in this case, for the geometric factor,

00:21:10.040 | those are all things we can measure.

00:21:11.640 | And there's one more term in the Seeger equation

00:21:13.480 | we can measure.

00:21:14.920 | I call it fraction of planets in the habitable zone.

00:21:18.320 | Because believe it or not, we have a handle on that

00:21:20.520 | for a certain set of stars.

00:21:23.640 | We know from the Kepler Space Telescope

00:21:26.320 | that operated for a number of years,

00:21:28.360 | we have estimates for how many planets

00:21:30.040 | are in the so-called habitable zone of the host star

00:21:31.920 | for a certain type of star.

00:21:33.280 | So all those we have measurable.

00:21:34.840 | And then like the Drake equation itself,

00:21:36.620 | there are some terms we can not measure.

00:21:38.840 | And those ones, I call them FL,

00:21:41.540 | fraction of all those planets that have life on them.

00:21:44.740 | 'Cause we don't know what that is.

00:21:47.280 | And FS, I called for spectroscopy.

00:21:50.840 | The fraction that have, we can use our telescope

00:21:54.580 | and instrument tools to look for light.

00:21:57.780 | Actually, FS was the ones that, the planets that,

00:22:00.840 | that have life that actually gives off a gas,

00:22:03.640 | useful gas that might accumulate in the atmosphere

00:22:06.640 | so we could eventually observe it.

00:22:09.720 | - How do the FL and FS interplay?

00:22:12.140 | So these are separate terms?

00:22:14.020 | - Separate terms.

00:22:14.860 | So for example, you could imagine,

00:22:19.400 | so for example, you could imagine life,

00:22:21.640 | like us humans, we breathe out carbon dioxide.

00:22:25.200 | But our planet Earth, we already have

00:22:28.080 | a lot of carbon dioxide on it.

00:22:29.740 | Well, we have hundreds of parts per million,

00:22:31.380 | but it has a really strong signal.

00:22:33.480 | So us humans breathing out carbon dioxide,

00:22:35.480 | it's not helpful for any intelligent beings

00:22:37.560 | that are looking back at Earth.

00:22:39.020 | 'Cause there's already a lot of,

00:22:40.200 | there's already enough carbon dioxide,

00:22:41.600 | we're not adding to it.

00:22:42.940 | So if there is life on a planet,

00:22:45.060 | and it's outputting a boring gas,

00:22:46.620 | that's not helpful for us to uniquely identify

00:22:49.580 | as being made by life versus just being there anyway,

00:22:54.160 | then it's not helpful.

00:22:55.280 | So I separated those two terms out.

00:22:57.680 | Soon, I think we'll have evidence

00:22:59.560 | that planets that can support life, at least, are common.

00:23:03.180 | - So, okay, this is such an awesome topic.

00:23:08.020 | I have a million questions.

00:23:09.360 | Okay, I know this is a little bit of speculation,

00:23:13.560 | but what's your sense about that, I think, FS,

00:23:17.120 | which is that life would produce interesting gases

00:23:22.120 | that we'd be able to detect?

00:23:24.700 | One, is there scientific evidence?

00:23:28.000 | And second, is there some intuition

00:23:30.560 | around life producing gases,

00:23:33.080 | detectable hints in terms of chemistry?

00:23:36.720 | - So interestingly enough, that entire question

00:23:39.120 | relates to, I'm gonna say almost my life's work,

00:23:43.520 | the work I'm doing now,

00:23:44.480 | and the work I'm doing for the next 20 years.

00:23:46.280 | And I wish I could give you a concrete number, like 1%.

00:23:49.080 | Like on the worst days, it's 1%, let's say, in my mind.

00:23:52.720 | You know, on the best days, it's like 80%.

00:23:54.440 | And I could actually go into a lot of detail here,

00:23:57.060 | but I'll just give you the simplest things.

00:23:59.820 | So first of all, we make an assumption that,

00:24:02.480 | like us and our life here on earth, life uses chemistry.

00:24:07.480 | So we use chemistry 'cause we eat food, we breathe air,

00:24:10.580 | and we have metabolism to break down food,

00:24:14.720 | to get energy, to store energy,

00:24:16.680 | and then ultimately to use it.

00:24:18.680 | And all life here has some kind of byproduct

00:24:20.720 | in doing all that, some kind of waste product

00:24:22.640 | that goes into the atmosphere.

00:24:24.280 | So I like to think that life everywhere uses chemistry.

00:24:28.560 | Some people have imagined, like,

00:24:30.960 | let's imagine like a windmill, like mechanical energy,

00:24:34.080 | just getting energy and using it without storing it.

00:24:37.020 | And if there was life like that,

00:24:38.200 | it might not need to output a gas.

00:24:40.720 | So we make this basic assumption of chemistry.

00:24:42.580 | That's the first thing.

00:24:43.960 | The second more complicated thing that I and my team work on

00:24:46.740 | is what happens to the gas once it is produced by life.

00:24:49.960 | It goes into the atmosphere.

00:24:51.860 | And a lot of gas is just destroyed immediately, actually,

00:24:55.660 | by ultraviolet radiation or by oxygen.

00:24:59.200 | Oxygen's incredibly destructive to a lot of gases.

00:25:03.480 | So the gas can be produced by life,

00:25:05.560 | but it could be just completely destroyed

00:25:07.000 | by its environment.

00:25:08.640 | - I guess we should pause on that,

00:25:10.540 | that you mentioned your life's work.

00:25:13.680 | This is just a beautiful idea

00:25:16.400 | that it's kind of paralyzing when you look out there

00:25:19.260 | and you wonder, is there life out there?

00:25:21.260 | It's the first paralyzing.

00:25:24.200 | Actually, before I encountered your work,

00:25:25.920 | I feel like an idiot.

00:25:27.100 | But it feels like there's no tool to answer that question.

00:25:32.100 | And then what you kind of provided is this cool idea

00:25:37.680 | that it might be possible to answer that

00:25:40.200 | by looking at the gases.

00:25:41.240 | I mean, that's a really interesting,

00:25:44.100 | that's a beautiful idea.

00:25:45.680 | Yeah, so we could just pause on that.

00:25:49.880 | That's a powerful tool, I think,

00:25:52.600 | to build the intuition around.

00:25:56.160 | - 'Cause I was totally clueless about it.

00:25:57.640 | And it's kind of exciting.

00:25:59.480 | I mean, I'm sure there's folks probably early on

00:26:02.800 | in your life who were very skeptical about this notion.

00:26:06.680 | Maybe I'm not sure, but generally,

00:26:10.640 | you would wanna be skeptical.

00:26:11.680 | It's like, well, all these kinds of other things

00:26:14.520 | could generate gases, all those kinds of things.

00:26:16.760 | - Oh, that's so true.

00:26:17.840 | And that's a big part of this growing field

00:26:20.480 | is how to make sure that this gas

00:26:22.760 | isn't produced by another effect.

00:26:24.600 | But I do wanna, again, pausing on that and going back a bit,

00:26:28.840 | it's incredible to think,

00:26:29.860 | but at least almost 100 years ago,

00:26:32.400 | there's a record of someone talking about

00:26:34.400 | the idea of a gas being an indicator of life elsewhere.

00:26:38.080 | - Oh, that idea was floating about somewhere.

00:26:39.960 | - Yes, it was totally floating about.

00:26:41.800 | And it comes down to oxygen,

00:26:43.520 | which on our planet fills our atmosphere to 20% by volume.

00:26:48.320 | And we rely on oxygen to breathe.

00:26:50.800 | When you hear about the people on Mount Everest

00:26:52.680 | running out of air, they're really running out of oxygen.

00:26:56.800 | 'Cause the air is getting thinner

00:26:58.600 | as they climb up the mountain.

00:27:01.480 | But without plants and bacteria,

00:27:05.040 | there's bacteria that also photosynthesizes

00:27:07.760 | and produces oxygen as a waste product.

00:27:09.600 | Without those, we would have virtually no oxygen.

00:27:12.040 | Our atmosphere would be devoid of oxygen.

00:27:15.400 | - So yeah, if you were to analyze Earth,

00:27:19.040 | is oxygen the strong indicator here?

00:27:21.560 | - Oxygen's a huge indicator.

00:27:22.800 | And that's what we're hoping,

00:27:23.640 | that there is an intelligent civilization

00:27:26.000 | not too far from here around a planet orbiting a nearby star

00:27:29.960 | with the kind of telescopes we're trying to build.

00:27:32.240 | And they're looking back at our sun

00:27:34.000 | and they've seen our Earth and they see oxygen.

00:27:36.600 | And they probably won't be like 100.0% sure

00:27:40.200 | that there's life making it.

00:27:41.480 | But if they go through all the possible scenarios,

00:27:43.600 | they'll be left with a pretty strong hint

00:27:45.840 | that there's life here.

00:27:48.000 | - Okay, but how do you detect that type of gases

00:27:51.520 | that are on the planet from a distance?

00:27:55.280 | - And that's, going back to that,

00:27:56.880 | that's what people were skeptical about.

00:27:58.960 | When I first started working on exoplanets, long time ago,

00:28:03.000 | people didn't believe we would ever, ever, ever study

00:28:06.520 | an exoplanet atmosphere of any kind.

00:28:08.400 | And now dozens of them are studied.

00:28:11.160 | There's a whole field of people,

00:28:12.360 | hundreds of people working on exoplanet atmospheres,

00:28:14.480 | actually.

00:28:15.360 | - Wow.

00:28:16.200 | So at first there was a point where people didn't

00:28:18.080 | even know there was exoplanets, right?

00:28:20.720 | When was the first exoplanet detected?

00:28:23.080 | - The first exoplanet around a sun-like star, anyway,

00:28:25.520 | was detected in the mid-1990s.

00:28:28.240 | - That was a big deal.

00:28:29.400 | Kind of vaguely remember that.

00:28:30.800 | - Well, at the time it was a big deal,

00:28:32.080 | but it was also incredibly controversial.

00:28:34.480 | Because in planets, we only had one example

00:28:39.000 | of a planetary system, our own solar system.

00:28:41.800 | And in our solar system, Jupiter, our big, massive planet,

00:28:45.920 | is really far from our star.

00:28:47.880 | And this first exoplanet around a sun-like star

00:28:50.280 | was incredibly close to its star.

00:28:52.800 | So close that people just couldn't believe

00:28:54.520 | it was a planet, actually.

00:28:56.080 | - So maybe zoom out, what the heck is an exoplanet?

00:29:00.000 | - An exoplanet is our name, is the name that we call

00:29:03.800 | a planet orbiting a star other than our sun.

00:29:06.760 | - Right.

00:29:07.600 | Extrasolar, I guess, is the--

00:29:09.200 | - You can call it extrasolar.

00:29:10.800 | Exoplanet is simpler.

00:29:12.120 | But I think it's worth pausing to remember

00:29:15.020 | that each one of those stars out there

00:29:17.080 | in our night sky is a sun.

00:29:19.320 | - Right.

00:29:20.160 | - And our sun has planets, Mercury, Venus, Earth, Mars,

00:29:21.960 | et cetera, and so for a long time, people have wondered,

00:29:26.080 | do those other stars or other suns have planets?

00:29:29.040 | And they do, and it appears that nearly every star

00:29:31.280 | has a planet we call exoplanet.

00:29:33.680 | And there are thousands of known exoplanets already.

00:29:36.920 | - So there's already, yeah, there's so many things

00:29:40.160 | about space that it's hard to put into one's brain

00:29:44.640 | because it starts filling it with awe.

00:29:47.400 | So yeah, if you visualize the fact that the stars

00:29:51.020 | that we see in the sky aren't just stars,

00:29:54.820 | they're like, they're suns.

00:29:57.020 | And they very likely, as you're saying,

00:30:00.380 | would have planets around them.

00:30:02.080 | There's all these planets roaming about

00:30:06.100 | in this dimly lit darkness with potentially life.

00:30:13.020 | I mean, it's just mind-blowing.

00:30:14.700 | But maybe can you give a brief history

00:30:19.380 | of discovering all the exoplanets?

00:30:23.020 | So there's no exoplanets in the '90s,

00:30:25.180 | and then there's a lot of exoplanets now.

00:30:28.380 | So how did that come about?

00:30:29.540 | - So many planets.

00:30:30.460 | How did it come about?

00:30:32.340 | Well--

00:30:33.540 | - Maybe another way to ask is what is the methodology

00:30:36.040 | that was used to discover them?

00:30:37.500 | - I can say that.

00:30:38.980 | But I'd like to just say something else first.

00:30:41.540 | So in exoplanets, the line between

00:30:44.220 | what is considered completely crazy

00:30:46.180 | and what is considered mainstream research,

00:30:49.220 | legit, is constantly shifting.

00:30:51.500 | - This is awesome, yeah.

00:30:52.740 | - So before, when I started out in exoplanets,

00:30:55.020 | it was still sketchy.

00:30:56.340 | Like it wasn't considered a career or a thing,

00:30:59.060 | a place where you should be investing.

00:31:01.140 | And right now, now, today,

00:31:03.540 | so many people are working in this field.

00:31:06.060 | A good, I don't know, at least 1,000, probably more.

00:31:09.020 | I don't know if that sounds like a lot to you,

00:31:10.060 | but it's a lot.

00:31:10.940 | - No, it's just a legitimate field of inquiry.

00:31:13.740 | - Yeah, legitimate field of inquiry.

00:31:14.820 | And what's helped us is everything

00:31:16.420 | that's helped everyone else.

00:31:17.900 | It's software, it's computers, it's hardware.

00:31:21.660 | It's like our phones.

00:31:22.500 | You have a fantastic detector in there.

00:31:24.180 | They didn't always have that.

00:31:25.140 | I don't know if you remember the so-called olden days.

00:31:27.980 | We didn't have digital cameras.

00:31:29.260 | We had film.

00:31:30.520 | You take a film camera, you send the film away,

00:31:32.340 | and eventually it comes back,

00:31:33.420 | and then you see your pictures.

00:31:34.820 | And they could all be horrible.

00:31:36.580 | Yeah.

00:31:37.420 | - So yeah, I mean, digital.

00:31:38.240 | It just changed everything.

00:31:39.080 | Data changed everything.

00:31:39.920 | - Yeah.

00:31:40.740 | So one thing that really helped exoplanets

00:31:42.580 | were detectors that were very sensitive,

00:31:45.700 | because when we're looking for the transiting planets,

00:31:49.780 | what we're doing is we're monitoring a star's brightness

00:31:52.060 | as a function of time.

00:31:53.680 | It's like click, taking a picture of the stars

00:31:55.740 | every few seconds or minutes.

00:31:58.460 | And we're measuring the brightness of a star,

00:32:01.180 | like every frame.

00:32:02.740 | And we're looking for a drop in brightness

00:32:04.920 | that's characteristic of a planet

00:32:06.460 | going in front of the star,

00:32:08.460 | and then finishing its so-called transit.

00:32:10.580 | And to make that measurement,

00:32:13.520 | we have to have precise detectors.

00:32:15.780 | - And the detectors that are making the measurement,

00:32:19.280 | can you do it from Earth?

00:32:20.920 | Is it, are they floating about in space?

00:32:24.100 | Like what kind of telescope?

00:32:25.800 | - So on the ground, people are using telescopes,

00:32:28.520 | small telescopes that are almost just like

00:32:30.340 | a glorified telephoto lens.

00:32:32.380 | And they're looking at big swaths of the sky.

00:32:35.000 | And from the ground, people can find giant planets

00:32:37.500 | like the size of Jupiter.

00:32:38.700 | So it's about 10 to 12 times the size of Earth.

00:32:41.620 | We can find big planets,

00:32:42.740 | 'cause we can reach about 1% precision.

00:32:46.180 | So not sure how much technical you wanna get, but.

00:32:48.500 | - Well, yeah, how many pixels are we talking about?

00:32:50.740 | Like what, you mentioned phones.

00:32:54.460 | There's a bunch of megapixels, I think.

00:32:56.700 | - So for exoplanets, you wanna think about it

00:32:59.380 | as like a pixel or less than a pixel.

00:33:01.140 | We're not getting any information.

00:33:02.820 | But to be more technical, our telescope, you know,

00:33:05.640 | spreads the light out over many pixels,

00:33:07.860 | but we're not getting information.

00:33:09.220 | We're not tiling the planet with pixels.

00:33:12.220 | It's just like a point of light,

00:33:13.400 | or in most cases, we don't even see the planet itself,

00:33:16.140 | just the planet's effect on the star.

00:33:17.740 | But another thing that really helped was computers,

00:33:20.240 | because transiting planets are actually quite rare.

00:33:22.980 | I mean, they don't all go in front of their star.

00:33:25.420 | And so to find transiting planets,

00:33:27.140 | we look at a big part of the sky at once,

00:33:29.460 | or we look at tens of thousands or hundreds of thousands,

00:33:32.300 | or even in some cases, millions of stars at one time.

00:33:35.380 | And so, you know, you're not gonna do this by hand,

00:33:37.260 | going through a million stars, counting up the brightness.

00:33:40.540 | So we have computer software and computer code

00:33:43.540 | that does the job for us and looks for a,

00:33:47.020 | you know, counts the brightness and looks for a signal

00:33:50.320 | that could be due to a transiting planet.

00:33:51.980 | And, you know, I just finished a job

00:33:54.060 | called deputy science director

00:33:56.260 | for the MIT-led NASA mission test.

00:33:59.340 | And it was my purview to make sure

00:34:02.460 | that we got the planet candidates,

00:34:05.260 | the transiting light curves, out to the community

00:34:07.580 | so people could follow them up

00:34:09.500 | and figure out if they're actual planets or false positives.

00:34:13.220 | - So publish the data so that people could just--

00:34:15.940 | - Yeah, publish the data.

00:34:16.980 | - All the data scientists out there could crunch

00:34:19.420 | and see if they can discover something.

00:34:21.020 | - They can discover something.

00:34:22.300 | And in fact, the NASA policy for this mission

00:34:24.780 | is that all the data becomes public as soon as possible.

00:34:28.220 | So anyone could, it's not as easy as it sounds, though,

00:34:30.620 | to download the data and look for planets.

00:34:33.480 | But there is a group called planethunters.org,

00:34:36.300 | and they take the data,

00:34:37.620 | and they actually crowdsource it out to people

00:34:39.360 | to look for planets.

00:34:40.220 | Yeah, and they often find signals

00:34:42.580 | that our computers and our team missed.

00:34:44.820 | - So we mentioned exoplanets.

00:34:46.780 | What about Earth-like, or I don't know

00:34:49.500 | what the right distinction is,

00:34:50.740 | if it is habitable or is it Earth-like planets,

00:34:53.820 | but what are those different categories,

00:34:55.340 | and how can we tell the difference and detect each?

00:34:58.100 | - Right, right.

00:34:58.940 | So we're not at Earth-like planets yet.

00:35:01.220 | All the planets we're finding are so different

00:35:03.640 | from what we have in our solar system.

00:35:06.560 | They're just easier planets to find, but like--

00:35:08.560 | - In which way?

00:35:09.400 | - For example, there could be a Jupiter-sized planet

00:35:12.320 | where an Earth should be.

00:35:13.560 | We find planets that are the same size as Earth,

00:35:18.640 | but are orbiting way closer to their star

00:35:21.240 | than Mercury is to our sun.

00:35:22.700 | And they're so close that,

00:35:25.320 | because close to a star means they also orbit faster.

00:35:29.020 | And some of these hot super-Earths, we call them,

00:35:32.240 | their year, their time to go around their star

00:35:34.360 | is less than a day.

00:35:35.440 | And they're heated so much by their star.

00:35:38.480 | They're heated so much by the star,

00:35:40.360 | we think the surface is hot enough to melt rock.

00:35:42.800 | So instead of running out by the bay or the river,

00:35:46.000 | you'll have like liquid lava.

00:35:47.420 | There'll be liquid lava lakes on these planets, we think.

00:35:51.120 | - And life can't survive--

00:35:53.440 | - Way too hot.

00:35:54.280 | The molecules for life would just be,

00:35:56.200 | molecules needed for life just wouldn't be able

00:35:58.240 | to survive those temperatures.

00:35:59.680 | We have some other planets.

00:36:01.200 | One of the most mysterious things out there,

00:36:03.920 | factoid, if you will,

00:36:05.600 | is that the most common type of planet we know about so far

00:36:09.280 | is a planet that's in between Earth and Neptune size.

00:36:12.760 | It's two to three times the size of Earth.

00:36:15.560 | And we have no solar system counterpart of that planet.

00:36:18.320 | That is like going outside to the forest

00:36:21.760 | and finding some kind of creature or animal

00:36:23.860 | that just no one has ever seen before,

00:36:25.720 | and then discovering that is the most common thing out there.

00:36:29.280 | And so we're not even sure what they are.

00:36:30.560 | We have a lot of thoughts

00:36:31.640 | as to the different types of planet it could be,

00:36:33.700 | but people don't really know.

00:36:35.520 | - I mean, what are your thoughts about what it could be?

00:36:37.840 | - Well, one thought,

00:36:38.680 | and this is more when we want to be rather than might be,

00:36:41.740 | is that these so-called mini Neptunes, we call them,

00:36:45.920 | that they are water worlds,

00:36:48.040 | that they could be scaled up versions

00:36:49.760 | of Jupiter's icy moons,

00:36:51.640 | such that they are planets that are made

00:36:54.280 | of more than half of water by mass.

00:36:56.640 | - So, yeah, and what's the connection between water and life

00:36:59.960 | and the possibility of seeing that from a gas perspective?

00:37:03.240 | - Okay, so all life on Earth needs liquid water.

00:37:07.480 | And so there's been this idea in astronomy or astrobiology

00:37:11.360 | for a long time called follow the water.

00:37:13.000 | Find water, that will give you a chance of finding life.

00:37:16.320 | But we could still zoom out,

00:37:17.580 | and the community consensus

00:37:21.040 | is that we need some kind of liquid for life

00:37:23.920 | to originate and to survive,

00:37:25.800 | because molecules have to react.

00:37:28.280 | You don't have a way that molecules

00:37:29.620 | can interact with each other.

00:37:31.460 | You can't really make anything.

00:37:32.660 | And so when we think of all the liquids out there,

00:37:35.880 | water is the most abundant liquid

00:37:38.020 | in terms of planetary materials.

00:37:39.520 | There really aren't that many liquids.

00:37:41.140 | Like I mentioned liquid rock, way too hot for life.

00:37:44.560 | We have some really cold liquids,

00:37:46.440 | like almost gasoline, like ethane and methane lakes

00:37:49.360 | that have been found on one of Saturn's moons, Titan.

00:37:52.700 | That's so cold, though.

00:37:53.840 | And for exoplanets, we can't study really cold planets

00:37:56.160 | 'cause they're just simply too dark and too cold.

00:37:59.300 | So we usually are just left with

00:38:02.080 | looking for planets with liquid water.

00:38:04.760 | And to your point,

00:38:07.440 | you remember we talked about how planets

00:38:11.200 | are less than a pixel, in that way to say.

00:38:14.000 | So we can't see oceans on a planet.

00:38:15.560 | We're not gonna see continents and oceans, not yet anyway.

00:38:18.440 | But we can see gases in the atmosphere.

00:38:20.840 | And if it's a small rocky planet,

00:38:22.980 | and this is going into some more detail,

00:38:24.980 | if we see a small rocky planet

00:38:27.920 | with water vapor in the atmosphere,

00:38:29.760 | we're pretty sure that means

00:38:31.100 | there has to be a liquid water reservoir.

00:38:33.200 | Because it's not intuitive in any way,

00:38:36.200 | but water is broken up by ultraviolet radiation

00:38:39.560 | from the star or from the sun.

00:38:42.080 | And on most planets, when water is broken up into H and O,

00:38:46.140 | the H, the hydrogen, will escape to space.

00:38:48.960 | 'Cause just like when you think of

00:38:50.280 | a child letting go of a helium-filled balloon,

00:38:52.520 | it floats upwards.

00:38:54.920 | And hydrogen's a light gas and will leave from the planet.

00:38:58.720 | So ultimately, if you have water,

00:39:00.560 | unless there's an ocean,

00:39:01.780 | like a way to keep replenishing

00:39:03.280 | water vapor in the atmosphere,

00:39:04.400 | that water vapor should be destroyed

00:39:06.900 | by ultraviolet radiation.

00:39:09.240 | - Got it, so there's a, okay,

00:39:11.040 | so there's a need for a liquid.

00:39:14.280 | I mean, I guess, is water essential or are there liquids?

00:39:18.720 | I mean, the chemistry here is probably super complicated.

00:39:20.600 | - Well, there's not, it does,

00:39:21.440 | but you know, there's not an infinite number of liquids.

00:39:24.080 | There's maybe like five liquids that can exist inside

00:39:26.760 | or on the surface of a planet.

00:39:28.560 | And water is the one that exists

00:39:30.280 | for the largest range of temperatures and pressures.

00:39:32.680 | And it's also the easiest type of planet

00:39:35.200 | for us to find and study is one with water vapor,

00:39:37.400 | rather than a cold planet that has ethane and methane lakes.

00:39:41.200 | - What's your personal, in terms of solar systems

00:39:45.680 | and planets, that you're most hopeful about,

00:39:48.800 | in terms of our closest neighbors,

00:39:51.440 | that you kind of have a sense

00:39:55.000 | that there might be somebody living over there,

00:39:59.600 | whether it's bacteria or somebody that looks like us?

00:40:02.880 | - I'm hopeful that every star nearby has a planet.

00:40:06.480 | - Has some life.

00:40:07.320 | - Because it almost has to for us to make progress.

00:40:09.720 | We have to have that dream condition.

00:40:12.480 | - So the dream condition is like,

00:40:14.040 | life is just super abundant out there.

00:40:17.000 | - Yeah, the dream, well, yes,

00:40:18.360 | the dream condition is that life is super abundant

00:40:20.680 | and it's based on the thought

00:40:22.720 | that if there is a planet with water and continents,

00:40:26.640 | that it also has the ingredients for life.

00:40:28.680 | And that the kind of base,

00:40:30.800 | the base kernel thought is that

00:40:35.680 | if the ingredients for life is there, life will form.

00:40:37.960 | - Life will form.

00:40:38.800 | - That's what we're holding on to.

00:40:39.640 | - With a relatively high probability.

00:40:42.280 | - Yes, that's it.

00:40:43.560 | - Okay, let's go into land of speculation.

00:40:46.440 | What about intelligent life?

00:40:49.440 | Us humans consider ourselves intelligent,

00:40:51.720 | surprisingly or unsurprisingly.

00:40:54.760 | Do you think about, from your perspective

00:40:58.680 | of looking at planets from a gas composition perspective

00:41:03.680 | and in general of how we might see intelligent life

00:41:07.840 | and your intuition about whether that life is even out there?

00:41:12.840 | - I think the life is out there somewhere.

00:41:14.520 | The huge numbers of stars and planets.

00:41:17.560 | I like to think that life had a chance to evolve

00:41:19.840 | to be intelligent.

00:41:21.520 | I'm not convinced the life is anywhere near here,

00:41:23.560 | only because if it's hard for intelligent life to evolve,

00:41:28.040 | then it will be far away by definition.

00:41:30.160 | - Well, the sad thing is,

00:41:32.040 | maybe from the artificial intelligence perspective is,

00:41:35.360 | it makes me sad there might be intelligent life out there

00:41:37.740 | that we're just not,

00:41:39.000 | like the pathways of evolution

00:41:43.240 | can go in all these different directions

00:41:44.920 | where we might not be able to communicate with it

00:41:47.480 | or even detect its intelligence

00:41:50.520 | or even comprehend its intelligence.

00:41:52.560 | I'm convinced cats are more intelligent than humans

00:41:56.320 | that we're just not able to comprehend

00:41:59.520 | the proper measures of their intelligence.

00:42:04.920 | - My dog is so funny.

00:42:05.960 | He's the golden doodle.

00:42:06.920 | His name's Leo.

00:42:08.200 | We joke that he's either a really dumb dog.

00:42:10.800 | And sorry, he's not here to defend himself,

00:42:12.360 | but he's either really dumb or he's a super genius,

00:42:14.840 | just pretending to be dumb.

00:42:16.960 | And it's possible he's a multi-dimensional projection

00:42:21.360 | of alien life here monitoring

00:42:24.320 | one of the top scientists in the world

00:42:28.800 | trying to find aliens,

00:42:30.040 | just to make sure that humans don't get out of hand.

00:42:34.480 | - That's funny.

00:42:35.400 | I'm definitely gonna go in and ask him about that.

00:42:38.160 | Ask him about that when I get home.

00:42:39.800 | - She's onto something, yeah.

00:42:41.680 | What might we look for

00:42:43.040 | in terms of signs of intelligent life?

00:42:46.000 | From your toolkit,

00:42:48.680 | do you think there are things that we should,

00:42:52.000 | we might be able to use

00:42:53.360 | or maybe in the next couple of decades discover

00:42:56.640 | that would be different than life that's like bacteria,

00:43:00.480 | that's primitive life?

00:43:01.600 | - I still love SETI,

00:43:03.800 | Search for Extraterrestrial Intelligence.

00:43:06.160 | I like to hope that if there is a civilization out there,

00:43:08.520 | they're trying to send us a message.

00:43:10.640 | I think, like, think about it.

00:43:12.320 | I don't know, what are your thoughts?

00:43:13.680 | If you think about our Earth,

00:43:15.600 | there's no structure we've built

00:43:17.080 | that intelligent civilizations could see from far away.

00:43:20.560 | There's literally nothing,

00:43:21.560 | not even the Great Wall of China.

00:43:23.520 | And so to think, like,

00:43:24.400 | why would this other civilization

00:43:26.120 | build a giant structure that we could see?

00:43:28.400 | - Yeah, so with SETI,

00:43:30.320 | the idea is that we're both trying to hear signals

00:43:32.880 | and send signals, right?

00:43:34.120 | - Well, we haven't sent,

00:43:34.960 | when they call that METI, messaging,

00:43:37.120 | and there's a big kind of fear over METI

00:43:40.040 | because do you wanna tell them you're here?

00:43:42.760 | It's kind of this, like, let's wait 'til they call us.

00:43:45.000 | - Yeah. (laughs)

00:43:45.840 | - And so, we should be-- - It's like a dating game.

00:43:48.440 | You have to, like, how many days do I wait

00:43:51.080 | before I call kind of thing.

00:43:52.600 | - Yes, it is, and so, but the funny thing is

00:43:54.120 | if no one's sending us a message,

00:43:55.680 | if everybody's only listening,

00:43:57.240 | how do you make progress?

00:43:58.480 | - That's right.

00:44:00.600 | And I mean, but there's also,

00:44:02.320 | there's the Voyager spacecraft.

00:44:03.920 | We have these little pixels of robots

00:44:07.840 | flying out all over the place.

00:44:09.800 | Some of them, like the Voyager, reach out really far,

00:44:13.080 | and they have some stuff on them.

00:44:15.040 | Okay, I just--

00:44:15.880 | - We do, we have the Voyager,

00:44:17.240 | but they're not really going anywhere in particular,

00:44:19.040 | and they're moving very, very slowly on a cosmic scale.

00:44:21.760 | - Yeah, and me saying they're far is kind of silly.

00:44:25.040 | - Yeah, it's all relative in astronomy.

00:44:26.760 | It's all relative, yeah.

00:44:27.960 | - Yeah, I just, so from a, if you look at Earth

00:44:31.960 | from an alien perspective,

00:44:33.560 | from visually and from gas composition,

00:44:38.240 | I wonder if it's possible to determine the degree

00:44:41.640 | of maybe productive energy use.

00:44:46.440 | I wonder if it's possible to tell

00:44:48.840 | like how busy these Earthlings are.

00:44:51.440 | - Well, let's zoom out again and think about oxygen.

00:44:55.560 | So when cyanobacteria arose like billions of years ago

00:44:58.800 | and figured out how to harness the energy of the sun

00:45:01.200 | for photosynthesis,

00:45:02.960 | they re-engineered the entire atmosphere.

00:45:05.600 | 20% of the atmosphere has oxygen now.

00:45:08.960 | Like that is a huge scale.

00:45:11.360 | You know, they almost poisoned everything else

00:45:13.120 | by making this what was apparently very poisonous

00:45:15.640 | to everything that was alive.

00:45:17.320 | But imagine, so are we doing anything at that scale?

00:45:19.400 | Like are we changing anything at like 20% of the Earth

00:45:21.820 | with a giant structure or 20% of this or 20% of that?

00:45:24.760 | Like we aren't actually.

00:45:25.960 | - Yeah, yeah, that's humbling to think

00:45:30.280 | that we're not actually having that much of an impact.

00:45:32.440 | - I know, but we are because in a way

00:45:34.040 | we're destroying our entire planet.

00:45:35.360 | But it's humbling to think that from far away

00:45:37.560 | people probably can't even tell.

00:45:40.280 | - But from the perspective of the planet,

00:45:43.120 | when we say we're destroying, you know,

00:45:44.720 | global warming, all that kind of stuff,

00:45:47.520 | what we really mean is we're destroying it

00:45:50.320 | for a bunch of different species, including humans.

00:45:53.920 | But like, I think the Earth will be okay.

00:45:55.800 | - Oh, the Earth will be, the Earth will remain.

00:45:58.680 | Whatever, whatever happens to us, the Earth will still be here.

00:46:01.080 | - And it'll still be difficult to detect any difference.

00:46:03.680 | Like it's sad to think that if humans destroy ourselves,

00:46:07.640 | except potentially with nuclear war,

00:46:09.800 | it would be hard to tell that anything even happened.

00:46:12.520 | - Yeah, it would be hard to tell from far away

00:46:14.080 | that anything happened.

00:46:15.680 | - What about, what are your thoughts,

00:46:17.400 | now this is really getting into speculation land.

00:46:21.040 | You've mentioned exoplanets were in the realm of,

00:46:26.040 | you know, there's this beautiful edge

00:46:27.880 | between science and science fiction

00:46:31.320 | that some of us, a rare few are brave enough to walk.

00:46:35.920 | I think in academia, you were brave enough to do that.

00:46:39.880 | I think in some sense, artificial intelligence

00:46:42.680 | sometimes walks that line a little bit.

00:46:45.520 | There is so much excitement about extraterrestrial life

00:46:50.600 | and aliens in this world.

00:46:52.880 | I mean, I don't know how to comprehend that excitement,

00:46:57.600 | but to me, it's great to see people curious

00:47:01.720 | 'cause to me, extraterrestrial life and aliens

00:47:04.680 | is at the core, a scientific question.

00:47:08.240 | And it's almost looks like people are excited about science.

00:47:11.120 | They're excited by discovery.

00:47:14.800 | - Discovery, right.

00:47:15.840 | - And then the possibility that there's alien life

00:47:18.400 | that visited Earth or is here on Earth now

00:47:22.600 | is excitement about discovery in your lifetime, essentially.

00:47:27.600 | I mean, what do you make of that?

00:47:32.960 | There's recent events where DARPA or DOD released footage

00:47:37.960 | of these unmanned aerial phenomena,

00:47:44.200 | they're calling them now, UAP.

00:47:46.200 | They got everybody like super excited,

00:47:48.040 | like maybe there is, like what's here on Earth?

00:47:52.160 | Do you follow this world of people

00:47:56.520 | who are thinking about aliens that are already here

00:47:59.440 | or have visited?

00:48:00.400 | - I don't really follow it.

00:48:01.240 | They follow me, I'd say.

00:48:03.160 | Because in this field, if you're a scientist of any kind,

00:48:06.560 | people contact us, me.

00:48:11.000 | There's a lot of them about,

00:48:12.600 | hey, I have stuff you should see.

00:48:14.340 | Hey, the aliens are already here.

00:48:15.820 | I need to tell you about it.

00:48:17.560 | And I know there are people out there who really believe.

00:48:21.240 | - There's a psychology to it.

00:48:22.520 | - There's a psychology to it.

00:48:23.720 | - And it's fascinating.

00:48:24.960 | But okay, so it's similar to artificial intelligence.

00:48:27.720 | - But like you, I'm still enamored

00:48:29.280 | with the point that it is out there

00:48:31.000 | and that people believe so strongly

00:48:32.480 | and that so many people out there believe.

00:48:35.760 | - Believe.

00:48:37.440 | And I don't know, I'm not as allergic to it

00:48:41.280 | as some scientists are because ultimately,

00:48:44.480 | if aliens showed up or do show up or have showed up,

00:48:49.800 | these are gonna be very difficult

00:48:51.320 | to study scientific phenomena.

00:48:53.140 | Like in fact, like going back to cats and dogs,

00:48:58.760 | I think we should be more open-minded

00:49:02.760 | about developing new tools

00:49:06.280 | and looking for intelligent life on Earth

00:49:08.480 | that we haven't yet found.

00:49:10.260 | Or even understanding the nature of our own intelligence

00:49:14.000 | 'cause it kind of is an alien life form,

00:49:16.560 | the thing that's living in our skull.

00:49:18.960 | - It's so true and we don't understand consciousness.

00:49:21.960 | It's true, we don't understand how.

00:49:24.320 | Biology's hard, unpacking it and working it all out,

00:49:28.120 | it's a stretch.

00:49:29.000 | And they say too that our thinking mind

00:49:31.420 | is like the tip of a pyramid

00:49:33.680 | and that everything else is happening under the hood.

00:49:35.720 | But what is happening?

00:49:37.520 | But the thing with, so the typical scientist's response to,

00:49:40.880 | are there aliens here?

00:49:42.600 | Is that we need to see major evidence,

00:49:46.700 | not like a sketchy picture of something.

00:49:48.960 | We need some cold hard evidence and we just don't have that.

00:49:53.360 | - That's exactly right.

00:49:54.640 | But from my perspective, I admire people that dream

00:49:58.600 | and I think that's beautiful.

00:50:00.000 | The thing I don't like, there's two sides of the folks

00:50:04.480 | that probably listen to this podcast,

00:50:06.760 | is those that dream I think is beautiful,

00:50:09.680 | that wander what's out there, what's here on Earth.

00:50:14.020 | And then the other ones who are very conspiratorial

00:50:16.820 | and thinking that stuff is being hidden.

00:50:19.360 | And it becomes about institutions.

00:50:21.740 | - Right, right, right.

00:50:22.580 | Okay, I have a funny thing to tell you about that.

00:50:23.780 | So one of my colleagues had a really good answer to that.

00:50:27.120 | And it's not me saying this so I can say this,

00:50:29.020 | but he said, look, he works with NASA, not at NASA.

00:50:32.260 | He works with government, not in the government.

00:50:35.020 | It's kind of mean, but he'd say, trust me,

00:50:36.380 | they couldn't hide it if they tried.

00:50:38.340 | Do you know what I'm saying?

00:50:39.180 | - Yeah, everybody I know.

00:50:40.540 | - We're not smart enough, we're good enough.

00:50:42.200 | Not we, or not me, or not you, but whoever to cover it up.

00:50:45.240 | It just, it's sort of a myth.

00:50:47.100 | - Yeah, it makes it sad because the people at NASA,

00:50:53.000 | the people at MIT, the people in academia,

00:50:56.960 | the people in these institutions, and yes,

00:50:59.220 | even in government, are often trying,

00:51:03.360 | they're like just curious descendants of apes.

00:51:06.160 | They're just, they wanna do good,

00:51:08.760 | they wanna discover stuff,

00:51:09.880 | they're not trying to hide stuff.

00:51:11.400 | In fact, most of them would, in terms of leaks,

00:51:15.180 | would love to discover this and release this kind of stuff.

00:51:19.340 | - Did you ever watch this show called The X-Files?

00:51:23.320 | - Yeah.

00:51:24.160 | - Scully and Mulder?

00:51:24.980 | - Yeah.

00:51:25.820 | - And what I love, actually,

00:51:26.760 | I used to put it up during my talks, my public talks.

00:51:29.780 | There's a picture of a UFO, or what looks like a UFO,

00:51:32.140 | and it says, I want to believe.

00:51:34.360 | So that's where I think a lot of us are coming from.

00:51:38.060 | I want to believe.

00:51:40.080 | And it's so great, and one time, I put that up,

00:51:43.560 | and this very, very nice couple approached me,

00:51:45.560 | really nervous afterwards, and they said,

00:51:46.880 | hey, can we take you out for lunch sometime?

00:51:49.640 | And I said, sure, and they were like the nicest people.

00:51:52.600 | And just one of many who has an alien abduction story.

00:51:56.180 | And the woman could never have kids.

00:51:59.880 | They were older, but they didn't have kids,

00:52:01.120 | which for them was a real source of regret,

00:52:02.920 | but it was because the aliens who had abducted her

00:52:04.620 | had made it so that she couldn't have kids.

00:52:07.080 | And she had apparently something implanted behind her ear,

00:52:10.840 | which was somehow unimplanted later.

00:52:12.880 | And they were just so sincere.

00:52:15.200 | And they're such a lovely couple.

00:52:17.720 | And they just wanted to share their story.

00:52:19.760 | - That's a real, whatever that is, that's a real thing.

00:52:23.500 | The mystery of the human mind is more powerful

00:52:26.280 | than any alien, or I mean, it's as interesting,

00:52:30.800 | I think, as the universe,

00:52:31.880 | and I think they're somehow intricately linked.

00:52:35.200 | Maybe getting a sense of numbers,

00:52:38.360 | how many stars are there in maybe,

00:52:41.360 | I don't know what the radius that's reasonable to think

00:52:47.280 | about, I don't know if the observable universe

00:52:49.600 | is like way too big to think about,

00:52:51.960 | but in terms of when we think about how many

00:52:53.680 | habitable planets there are,

00:52:55.560 | what are the numbers we're working with in your sense?

00:52:58.800 | What are the scale of-

00:52:59.640 | - Honestly, the numbers are probably like billions

00:53:02.100 | of trillions.

00:53:03.080 | - Of stars.

00:53:04.040 | - Yeah, you know, in the UK, I think,

00:53:05.760 | I don't know if we do that here,

00:53:06.600 | but they will call a billion trillion,

00:53:08.560 | where you put like one billion followed by a trillion.

00:53:11.560 | Yeah, it's kind of weird.

00:53:12.400 | But here, I don't even know how to say the number,

00:53:13.960 | 10 to the 20, like if you know what that is,

00:53:15.780 | that's one followed by 20 zeros, that's a big number.

00:53:18.520 | We don't even have a name for that number, there's so many.

00:53:21.840 | - Per star, I think we kind of mentioned this,

00:53:23.800 | is there a good sense, there's probably argument about this,

00:53:26.840 | but per star, how many planets are there?

00:53:31.840 | - We don't have that number yet, per se.

00:53:33.720 | We're not really there, but some people think

00:53:35.960 | that there's many planets per star.

00:53:38.120 | There's this analogy of filling the coffee cup.

00:53:41.920 | Like, you know, you don't usually just pour one drop,

00:53:44.600 | you fill it, and that planetary systems,

00:53:47.240 | we see stars being born that have a disk of gas and dust,

00:53:51.080 | and that ultimately forms planets.

00:53:53.160 | So the idea, this kind of concept is that planets,

00:53:56.580 | so many planets form too many,

00:53:58.840 | and eventually some get kicked out,

00:54:00.440 | and you're left with like a full planetary system,

00:54:02.560 | a dynamically full system, and so there have to be a lot,

00:54:05.040 | 'cause so many form, and a bunch survive.

00:54:07.120 | - I mean, that makes perfect intuitive sense, right?

00:54:11.000 | Like, why wouldn't that happen?

00:54:13.280 | - Right, well, there's other thoughts too, though.

00:54:16.180 | These big planets that are really close to the star,

00:54:18.760 | we think they formed far away from the star

00:54:21.080 | where there's enough material to form,

00:54:22.960 | and they migrated inwards.

00:54:25.080 | And some of these planets migrating inwards

00:54:26.900 | due to interaction with other planets,

00:54:28.400 | or with the disk itself, they may have cleared it out.

00:54:32.000 | Like, kicked other planets out of the system.

00:54:34.560 | So there's a lot of ideas floating around.

00:54:36.440 | We're not entirely sure.

00:54:37.740 | - And what about Earth-like planets?

00:54:40.840 | Is that, that's another level of uncertainty that--

00:54:43.600 | - It's a level of uncertainty.

00:54:44.740 | If we think of an Earth-like planet

00:54:46.480 | being an Earth around a sun in the same orbit,

00:54:50.100 | an Earth-like planet being an Earth-sized planet

00:54:53.480 | in an Earth-like orbit about a sun-like star,

00:54:55.700 | we're not there yet.

00:54:56.540 | You know, we're not able to detect enough of those

00:54:58.360 | to give you a hard number.

00:55:00.640 | Some people have extrapolated,

00:55:02.960 | and they will say as many as one in five stars like our sun

00:55:07.280 | could be hosting a true Earth-like planet.

00:55:09.440 | - Wow.

00:55:10.280 | On the topic of space exploration,

00:55:12.720 | there's been a lot of exciting developments with NASA,

00:55:15.200 | with SpaceX, with other companies

00:55:17.440 | successfully getting rockets into space with humans

00:55:23.640 | and getting them to land back, especially with SpaceX.

00:55:27.840 | What are your thoughts about Elon Musk and SpaceX,

00:55:31.000 | Crew Dragon, working with NASA to launch astronauts?

00:55:35.560 | What's your sense about these exciting new developments?

00:55:39.680 | - Well, SpaceX and other so-called commercial companies

00:55:43.360 | are only good news for my field

00:55:46.000 | because they're lowering the cost of getting to space.

00:55:49.160 | By having reusable rockets, it's just been, it's incredible,

00:55:52.200 | and we need cheaper access to space.

00:55:53.800 | So from a very practical viewpoint, it's all good.

00:55:56.600 | About getting people, there's this dream that we have

00:55:59.120 | to go to Mars, boots on Mars.

00:56:01.320 | - Boots on Mars. (laughs)

00:56:03.840 | What do you think about that?

00:56:04.880 | You mentioned probes.

00:56:05.880 | What's the value of humans?

00:56:07.560 | Is that interesting to you

00:56:10.920 | from both a scientific and a human perspective?

00:56:13.600 | - Human mostly.

00:56:14.440 | I think it's such in our desire to explore.

00:56:16.960 | It's part of what it means to be human.

00:56:19.280 | So wanting to go to another planet

00:56:20.800 | and be able to live there for some time,

00:56:23.320 | it's just what it means to be human.

00:56:26.440 | You know, oftentimes in science and engineering,

00:56:29.720 | big, huge discoveries are made when we didn't intend to.

00:56:33.560 | So often this kind of pure exploratory type of research

00:56:36.080 | or this pure exploration research,

00:56:37.680 | it can lead to something really important, like the laser.

00:56:40.200 | We couldn't really live without that now.

00:56:42.240 | At the grocery, you scan your foods.

00:56:43.800 | There's surgery that involves lasers.

00:56:46.000 | GPS, we all use our GPS.

00:56:48.200 | We don't have GPS 'cause someone thought,

00:56:49.480 | "Hey, it would be great to have a navigation system."

00:56:52.960 | And so I do support, I do.

00:56:55.640 | I just, but I really think it comes primarily

00:56:57.760 | just from the desire to explore.

00:56:59.960 | - Do you think something, there's a lot of criticism

00:57:02.800 | and a lot of excitement about Mars.

00:57:06.280 | Do you think there's value in trying to go to,

00:57:10.560 | put humans on Mars, first of all,

00:57:12.320 | and second of all, colonize Mars?

00:57:15.560 | Do you think there's something interesting

00:57:16.840 | that might come from there?

00:57:18.960 | - I'm convinced there will be something interesting.

00:57:20.680 | I just don't know what it is yet.

00:57:22.400 | But I don't think having some commercial value

00:57:25.400 | or value in the metric of something useful

00:57:27.440 | is really what's motivating us.

00:57:29.400 | - So really, you see exploration is a long-term investment

00:57:32.560 | into something awesome that eventually

00:57:34.080 | will be commercial value.

00:57:35.560 | - I do, actually.

00:57:36.400 | - Yeah.

00:57:37.240 | - I do.

00:57:38.080 | - So what about visiting?

00:57:39.160 | Okay, I apologize, but I mean, there's an exciting longing

00:57:45.320 | to visit Earth-like planets elsewhere.

00:57:51.000 | So what's the closest Earth-like planet

00:57:55.480 | you think is worth visiting, and how hard is it?

00:57:58.800 | - Wow, it is very hard.

00:58:01.520 | I mean, our nearest, call it Earth-mass planet,

00:58:04.020 | it's orbiting a star very different from our own sun,

00:58:06.240 | an M-dwarf star, a small red star, Proxima Centauri.

00:58:10.240 | It's over four light years away.

00:58:12.560 | And we can't travel at the speed of light.

00:58:15.200 | We can't even, I mean, it would take

00:58:16.880 | tens of thousands of years to get there

00:58:18.520 | with conventional methods.

00:58:19.400 | So you know the movies like--

00:58:20.240 | - Multi-generationally.

00:58:21.080 | - Multi-generationally.

00:58:22.120 | Yeah, this movie, "Passenger," have you seen that movie?

00:58:24.720 | "Passenger."

00:58:25.560 | - No.

00:58:26.400 | - It's about a big spaceship that is traveling

00:58:28.640 | to another planet, and everyone's hibernating.

00:58:30.400 | I won't give you the spoiler alert,

00:58:31.600 | 'cause one person wakes up, and then it's kind of a problem.

00:58:33.760 | - Okay, got it.

00:58:35.160 | - But yeah, the multi-generational ships,

00:58:37.200 | I mean, when you think about where we're headed

00:58:40.840 | as a species, maybe we don't send people.

00:58:43.980 | Maybe we end up sending raw biological materials

00:58:48.280 | and instructions to print out humans.

00:58:51.640 | It sounds kind of far-fetched, but already we're printing

00:58:54.680 | like liver cells in the lab and beating heart cells.

00:58:58.200 | We're starting to reconstruct body parts.

00:59:01.420 | I mean, the thing is, it is so hard to get to another planet

00:59:03.880 | that this thought of printing humans

00:59:06.540 | or printing life forms actually could be easier.

00:59:09.120 | - Yeah, that's somehow so sad to think of the idea

00:59:14.120 | that we would launch a successful spaceship

00:59:17.420 | that has multi-generational non-human life,

00:59:21.440 | and it's gonna reach other intelligent life,

00:59:25.280 | and by the time they figure out where it came from,

00:59:27.840 | human civilization would be extinct.

00:59:31.800 | - Wow, yeah, that is really suffering.

00:59:33.600 | - That's so, that's one.

00:59:35.560 | There's a tempting thing to think about.

00:59:36.920 | What are the possible trajectories?

00:59:38.320 | So, you know, Elon keeps talking about multi-planetary,

00:59:45.120 | us becoming multi-planetary species.

00:59:47.540 | I mean, sure, Mars is a part of that,

00:59:49.900 | but the dream is to really expand outside the solar system,

00:59:54.900 | and it's not clear, just like as you said,

01:00:00.340 | what the actual scientific engineering steps

01:00:02.900 | that are required to take.

01:00:05.300 | It seems like so daunting, so daunting.

01:00:08.340 | So, the smart thing seems to be to do the most achievable,

01:00:13.020 | near daunting task, even if there doesn't seem

01:00:16.380 | to be a commercial application,

01:00:18.180 | which I think is colonizing Mars,

01:00:21.140 | but like from your perspective,

01:00:22.740 | is there some Manhattan project style,

01:00:27.620 | huge project in space that we might wanna take on?

01:00:32.620 | And you've had roles, you had scientist hat roles,

01:00:36.700 | and then you also had roles in terms of being

01:00:38.940 | on like committees and stuff,

01:00:39.980 | determining where funding goes and so on.

01:00:42.900 | So, like, is there a huge, like multi-trillion,

01:00:46.780 | we've been throwing the T word around recently a lot,

01:00:49.580 | but these huge projects that we might wanna take on?

01:00:52.100 | - Well, first of all, we wanna find the planets

01:00:54.340 | like Earth first, like just even finding

01:00:56.140 | those Earth-like planets is a billion dollar endeavor,

01:00:58.580 | billions of dollars endeavor.

01:01:00.040 | And that's so hard because an Earth is so small,

01:01:04.160 | so less massive, and so faint compared to our sun.

01:01:07.980 | It's the proverbial needle in a haystack, but worse.

01:01:10.600 | And we need very sophisticated space-based telescopes

01:01:14.320 | to be able to find these planets and to look at them

01:01:16.780 | and see which ones have water

01:01:18.700 | and which ones have signs of life on them.

01:01:20.380 | - Yeah, the Starshade project that you're part of.

01:01:23.260 | - Starshade.

01:01:24.100 | - Starshade, yeah, it's probably the most

01:01:25.400 | bad-ass thing I've ever seen.

01:01:26.380 | - Right.

01:01:27.220 | (laughing)

01:01:28.040 | You know what's interesting?

01:01:28.880 | - Can you describe what it is first of all?

01:01:29.720 | - So, what's amazing about Starshade

01:01:31.360 | is it was first conceived of in the 1960s.

01:01:33.780 | Imagine that, and revisited every decade until now

01:01:37.280 | when we think we can actually build it.

01:01:38.680 | And Starshade is a giant specially-shaped screen.

01:01:42.720 | It is about, there's different versions of it,

01:01:45.040 | but think about 30 meters in diameter.

01:01:47.600 | - So, you're blocking out the sun.

01:01:49.520 | - You're effectively blocking out the star.

01:01:51.840 | - Yeah.

01:01:52.680 | - So that you can see the planet directly.

01:01:53.860 | And Starshade would have a spacecraft attached to it,

01:01:56.800 | and it would fly in space far away from Earth's gravity.

01:02:00.040 | And it would have to formation fly with a space telescope.

01:02:03.520 | So, the idea is that Starshade blocks out the starlight

01:02:05.920 | in a very careful way,

01:02:07.960 | and it has to block that starlight out

01:02:10.200 | so that the planet,

01:02:11.660 | that is 10 billion times fainter than the star,

01:02:14.160 | that only the planet light, goes to the telescope.

01:02:17.120 | - Yeah, so in formation, meaning the telescope flies in,

01:02:23.360 | you gave a presentation on this,

01:02:24.560 | but it would fly in,

01:02:27.880 | this is extremely high-precision endeavor.

01:02:31.140 | - Yeah, we had this analogy,

01:02:32.460 | like asking a friend to hold up a dime five miles away.

01:02:35.880 | - Yeah.

01:02:36.720 | - And you would see it directly,

01:02:37.540 | like at the perfect line of sight with you.

01:02:38.960 | - Yeah.

01:02:39.800 | (laughs)

01:02:40.620 | And the shape of it is pretty cool.

01:02:41.720 | I mean, I don't know exactly what the physics of that,

01:02:44.480 | like what the optics are that require that shape.

01:02:47.240 | - I can tell you.

01:02:48.080 | It turns out that if you block out a star,

01:02:49.980 | imagine blocking out a star with a circularly

01:02:52.720 | or a square-shaped screen,

01:02:54.700 | you wouldn't actually be blocking it.

01:02:56.980 | Because the star acts like a wave,

01:02:58.800 | the starlight can act like a wave,

01:03:00.100 | and it would actually bend around the edges of the screen.

01:03:03.480 | And so instead of blocking out the light,

01:03:05.120 | you're expecting to see nothing,

01:03:06.280 | you would see ripples.

01:03:07.360 | And the analogy that I love to give,

01:03:10.120 | it's like throwing a pebble in a pond.

01:03:12.320 | You get those ripples,

01:03:13.300 | you get these concentric ripples and they go out,

01:03:16.220 | and light would do something quite similar.

01:03:18.540 | You'd actually see ripples of light.

01:03:20.360 | And those ripples of light,

01:03:22.520 | they're actually way brighter

01:03:23.880 | than the planet we'd be looking for.

01:03:25.280 | (laughs)

01:03:26.240 | So we can't--

01:03:27.080 | - So they would introduce this noise that's--

01:03:28.640 | - Yeah, noise.

01:03:29.480 | And so this star shade,

01:03:30.640 | it's like a mathematical solution

01:03:32.200 | to the problem of diffraction, it's called.

01:03:35.040 | And this is what the first person

01:03:37.440 | who thought about star shade in the 1960s worked out,

01:03:39.800 | the mathematical shape,

01:03:40.960 | or one family of solutions.

01:03:43.760 | And the idea is that when the star shade,

01:03:45.600 | this very special shape like a giant flower,

01:03:48.360 | with petals, when it blocks out the light,

01:03:50.460 | the light bends around the edges,

01:03:53.120 | but interacts with itself

01:03:54.400 | in a way to give you a very, very dark image.

01:03:57.160 | It would be like throwing a pebble in a pond.

01:04:00.120 | And instead of getting ripples,

01:04:01.840 | the pond would be perfectly smooth,

01:04:03.480 | like incredibly smooth to one part in 10 billion.

01:04:06.480 | And all the waves would be on the outer edges,

01:04:09.040 | far away from where you drop that pebble.

01:04:11.040 | - And so this camera would be able to,

01:04:13.880 | oh, this camera, this telescope would be able to

01:04:16.920 | get some signal from the planet then.

01:04:19.800 | - Yes, and it would be hard 'cause the planet is so faint.

01:04:21.920 | But with the star out of the way,

01:04:23.280 | the glare of that bright, bright, bright star,

01:04:25.680 | with that out of the way,

01:04:27.280 | then it becomes a much more manageable task.

01:04:30.440 | - So how do we get that thing out there?

01:04:32.360 | We're still working with unlimited money.

01:04:34.120 | - Okay, we're working with unlimited money.

01:04:35.680 | We have some more engineering problems to solve,

01:04:38.160 | but not too many more.

01:04:39.040 | We've been burning down our so-called tall pole list.

01:04:42.400 | - What kind of list?

01:04:43.680 | - We call it technology tall pole.

01:04:47.240 | It's the phrase where you have to figure out

01:04:49.760 | what are your hardest problems,

01:04:51.360 | and then break those down to solve.

01:04:52.960 | So the star shade, one of the really hard problems

01:04:55.600 | was how to formation fly at tens of thousands of kilometers.

01:04:59.680 | It's like, wow, that is insane.

01:05:01.960 | And the team broke that down, actually,

01:05:03.720 | into a sensing problem.

01:05:05.440 | Because of the star shade,

01:05:06.640 | how do you see the star shade precisely enough

01:05:09.040 | to control it?

01:05:10.400 | 'Cause if you're shining a flashlight,

01:05:11.640 | you know the beam spreads out.

01:05:13.640 | So if the star shade has a beacon, an LED or a laser,

01:05:16.160 | it's gonna spread out so much

01:05:17.880 | by the time it gets to the telescope.

01:05:19.880 | The problem wasn't how do you tell the star shade

01:05:21.920 | how to move around fast enough to stay in a straight line.

01:05:24.520 | The problem was how are you able to sense it well enough?

01:05:27.640 | So problems like that were broken down,

01:05:29.760 | and money that came from NASA to solve problems

01:05:32.640 | is put towards solving it.

01:05:34.360 | So we've got through most of the hard problems right now.

01:05:36.840 | Another one was that star shade,

01:05:39.280 | even though it's looking at a star,

01:05:40.920 | light from our own sun could hit the edges of the star shade

01:05:44.720 | and bounce off into the telescope, believe it or not.

01:05:47.440 | And that would actually ruin it,

01:05:50.560 | because we're trying to see this tiny, tiny signal.

01:05:52.880 | So then the question is, how do you make a razor-thin edge?

01:05:55.520 | Like those petal edges would have to be like a razor.

01:05:58.480 | And what materials can you use?

01:05:59.560 | So there's a series of problems like that.

01:06:01.600 | - Wow, so there's a materials problem in there?

01:06:03.800 | - Some of them, mm-hmm, materials problem.

01:06:06.480 | And there's one.

01:06:07.320 | So we almost finished solving all those problems,

01:06:10.160 | and then it's just a matter of building one

01:06:12.880 | and testing it in a full-scale size facility.

01:06:15.340 | And then building the telescope,

01:06:18.040 | it's just a matter of time to build everything

01:06:19.840 | and get it up for launch.

01:06:22.120 | - So this is an engineering--

01:06:23.720 | - Close, engineering, yeah, it's close.

01:06:24.560 | - This is an engineering project.

01:06:26.440 | - It's a real engineering project, mm-hmm.

01:06:28.280 | - I actually can tell you about two other projects

01:06:30.120 | that are not mine.

01:06:31.000 | I like to call Starshade mine,

01:06:34.100 | because it was my project that I helped make it mainstream,

01:06:38.920 | where that line is constantly shifting.

01:06:40.720 | When I started, when I got this leadership role

01:06:42.640 | on Starshade, I remember telling people about it,

01:06:45.480 | and it was definitely not on the mainstream okay line.

01:06:47.800 | It was on the giggle factor side of the line.

01:06:49.560 | - The giggle factor.

01:06:50.640 | - And people would just laugh, like, that's dead.

01:06:52.320 | Like, you can never formation fly.

01:06:54.240 | Or they'd say, why are you working on that?

01:06:55.680 | That's just so not, it's not possible.

01:06:57.360 | - That's so awesome.

01:06:58.200 | There's a few things you've done in your life,

01:07:00.320 | and that's when I first saw Starshade,

01:07:02.120 | I was like, what, really?

01:07:04.400 | And then, like, it sinks in.

01:07:07.080 | I mean, it's the same thing I felt with, like, Elon Musk,

01:07:09.880 | or certain people who do crazy stuff.

01:07:12.340 | And then, and they actually make it work.

01:07:16.280 | I mean, if you get Starshade information flying together,

01:07:21.280 | I mean, how awesome is that,

01:07:23.560 | if you actually make that happen?

01:07:25.660 | Even, like, from a, sorry, from the robotics perspective,

01:07:29.200 | even if it doesn't give us good data,

01:07:30.800 | that's just, like, a cool thing to get out there.

01:07:33.240 | I mean, it's really exciting.

01:07:34.440 | - Really cool.

01:07:35.520 | So there's two other topics that aren't mine,

01:07:37.280 | but I still love them.

01:07:39.180 | One of them, let's just talk about it briefly,

01:07:41.240 | 'cause it's not a probe,

01:07:42.080 | but it's the idea to send a telescope very far away,

01:07:45.240 | to 500 times the Earth-Sun distance.

01:07:47.720 | And this is way farther than the Voyager spacecrafts

01:07:49.960 | are right now.

01:07:50.880 | And to use our sun as a gravitational lens,

01:07:54.840 | to use our sun to magnify something that's behind it.

01:07:57.440 | It's gotta sink in for a minute.

01:08:00.320 | - Yeah, exactly.

01:08:01.840 | I mean, I don't know what the physics of that is,

01:08:04.080 | like, how to use the sun.

01:08:05.320 | - In astronomy, and Einstein thought about this initially,

01:08:08.520 | we can use massive objects, bend space.

01:08:12.000 | And so light that should be traveling, like, straight,

01:08:14.240 | it actually travels around the warped space.

01:08:17.280 | - And somehow, you figure out a way

01:08:20.360 | to use that for magnification.

01:08:22.840 | - You have a way to use that for magnification,

01:08:25.080 | that's right.

01:08:25.920 | There are galaxies that are lensed,

01:08:29.160 | so-called gravitational lens,

01:08:30.320 | by intervening galaxy clusters, actually.

01:08:33.600 | And there are microlensing events,

01:08:37.240 | where stars get magnified,

01:08:39.140 | as an unseen gravitational lens star

01:08:41.000 | passes in between us and that very distant star.

01:08:43.480 | It's actually a real tool in astronomy.

01:08:45.980 | Yeah, using gravitational lensing to magnify,

01:08:48.200 | because it bends more rays towards you

01:08:49.880 | than you'd normally see.

01:08:51.960 | - And again, we're trying to get more higher resolution

01:08:56.360 | images that are basically boiled down to light.

01:09:00.000 | - Well, it boils down to light, exactly.

01:09:01.600 | - And then you can maybe get more information about.

01:09:04.680 | - Well, in this case, you would ask me,

01:09:07.640 | let's say, if this thing could get built,

01:09:10.380 | it would take something, like,

01:09:12.440 | they like to say 25 years to get from here to there,

01:09:15.240 | 25 years, and then it could send

01:09:16.680 | some information back to us.

01:09:18.080 | And then you'd say, "So, Sarah, how many pixels?"

01:09:20.480 | And I wouldn't say one or less than one,

01:09:21.860 | I'd say, you know, it could be like 10 by 10 pixels.

01:09:25.080 | Could be 100 pixels, which would be awesome.

01:09:27.400 | - I mean, it's still crazy that we can get

01:09:28.960 | a lot of information from that.

01:09:30.680 | - Crazy, right, and it's crazy for a lot of other reasons,

01:09:32.800 | because again, you have to line up the sun and your target.

01:09:35.600 | You'd only have one telescope per target,

01:09:38.000 | 'cause every star is behind the sun in a different way.

01:09:40.800 | So, it's a lot of complicated things.

01:09:43.960 | - Well, what about the second?

01:09:44.920 | - The second one, it's called Starshot.

01:09:48.520 | You know, Starshot means, like, big dreams.

01:09:51.600 | And it's an initiative by the Breakthrough Foundation.

01:09:54.320 | And Starshot is the concept to send thousands

01:09:59.640 | of little tiny spacecraft, which they now call Starchip.

01:10:03.840 | So, instead of Starship, it's Starchip.

01:10:06.480 | And there's a little chip, and the Starchip,

01:10:10.520 | so, like thousands of little turtles being born,

01:10:14.140 | they're not all gonna make it.

01:10:15.720 | There's used to send lots of them.

01:10:17.480 | And each of these Starchips, once they're launched

01:10:20.680 | into, I guess, low Earth orbit,

01:10:23.000 | they will deploy a solar sail

01:10:25.600 | that's a few meters in diameter.

01:10:27.600 | And the idea is that on Earth, we would have a bank of,

01:10:31.420 | this one is still a bit on the other side of the line,

01:10:34.880 | but we'd have a bank of telescopes with lasers.

01:10:39.880 | They'd be like a gigawatt power.

01:10:41.720 | And these lasers would momentarily shine upwards

01:10:46.160 | and accelerate, they'd hit these sails.

01:10:49.260 | They'd be like a power source for the sail.

01:10:51.760 | And would accelerate the sails to travel

01:10:54.440 | at about a 20th the speed of light.

01:10:56.200 | - Is that as crazy as it sounds?

01:10:59.760 | - Well, like any good engineering project,

01:11:03.000 | it has to be broken down into the crazy parts.

01:11:05.600 | And the Breakthrough Initiative, to their huge credit,

01:11:08.320 | is sponsoring getting over these,

01:11:12.640 | actually, initially, they listed 19 challenges.

01:11:15.840 | This is broken down into concrete things.

01:11:17.800 | Like one of them is, well, you have to buy the land

01:11:19.680 | and make sure the airspace is okay

01:11:21.320 | with you sending up that much power overhead.

01:11:23.760 | Another one is, you have to have material on the sail

01:11:27.000 | where the lasers won't just vaporize it.

01:11:30.080 | So there's a lot of issues.

01:11:31.440 | But anyway, these sails would be accelerated

01:11:32.880 | to 20th the speed of light.

01:11:34.400 | And their journey to the nearest star

01:11:36.000 | would no longer be tens of thousands of years,

01:11:38.900 | but could be 20 years.

01:11:40.480 | Okay, 20, so it's not as bad as tens of thousands.

01:11:45.600 | And these thousands or however many make it,

01:11:50.600 | they'll go by the nearest star system

01:11:52.200 | and snap some images and radio the information back to Earth

01:11:56.560 | because they're traveling so fast they can't slow down.

01:11:58.440 | But they'll zoom by, take some photos, send it back.

01:12:01.160 | - I res.

01:12:02.000 | - Yeah, but see, just what I want you to pause on

01:12:03.960 | for a second is that just by making that a real concept,

01:12:07.600 | and the money given won't make it happen,

01:12:10.120 | but what it's done is it's planted the seed.

01:12:12.720 | And it's shifted that line from what is crazy

01:12:14.680 | to what is a real project.

01:12:15.880 | It's shifted it just ever so slightly enough, I think,

01:12:18.120 | to plant the seed that we have to find a way

01:12:20.640 | to somehow find a way to get there.

01:12:23.240 | - That is, again, to stay on that, that is so powerful.

01:12:26.240 | Take a big crazy idea and break it down

01:12:30.280 | into smaller crazy ideas, order it in a list,

01:12:34.440 | and knock it out one at a time.

01:12:37.180 | I don't know, I've never heard anything more inspiring

01:12:41.960 | from an engineering perspective

01:12:43.640 | 'cause that's how you solve the impossible things.

01:12:46.000 | So you open your new book discussing rogue planet,

01:12:51.000 | PSO J318, I never said this out loud, .522.

01:12:56.360 | So a rogue planet, which is just this poetic,

01:13:00.600 | beautiful vision of a planet that, as you write,

01:13:05.600 | lurches across the galaxy like a rudderless ship

01:13:09.320 | wrapped in perpetual darkness.

01:13:11.840 | Its surface swept by constant storms,

01:13:14.880 | its black skies raining molten iron.

01:13:18.360 | Just like the vision of that, the scary, the darkness,

01:13:23.360 | just how not pleasant it is for human life,

01:13:28.900 | just the intensity of that metaphor, I don't know.

01:13:32.500 | And the reason you use that is to paint

01:13:36.640 | a feeling of loneliness, I think.

01:13:41.400 | - And despair.

01:13:42.240 | - And despair.

01:13:43.440 | And why, maybe on the planet side,

01:13:48.440 | why does it feel, maybe it's just me,

01:13:53.200 | why does it feel so profoundly lonely

01:13:56.120 | on that kind of planet?

01:13:57.600 | - I think it's because we all wanna be a part of something,

01:14:04.220 | a part of a family or a part of a community

01:14:07.200 | or a part of something.

01:14:10.440 | And so our solar system, and by the way,

01:14:12.680 | I only, it's sort of like when you treat yourself

01:14:17.040 | to eating an entire tub of ice cream.

01:14:20.080 | Like I sometimes treat myself to imagine things like this

01:14:22.960 | and not just be so cut and dried.

01:14:25.040 | But when you imagine that, this planet's not,

01:14:27.520 | 'cause I don't wanna give emotions to a planet per se,

01:14:29.120 | but the planet's not part of anything.

01:14:31.360 | It's somehow, it's just all on its own,

01:14:34.120 | just kind of out there without that warm energy

01:14:37.400 | from its sun, it's just all alone out there.

01:14:40.900 | To me, it was this little discovery

01:14:43.380 | that I actually feel pretty good

01:14:45.260 | being part of this solar system.

01:14:47.540 | It felt like we have a sun, we have like a little family.

01:14:50.780 | And it felt like it sucked for the rogue planet

01:14:54.820 | to just floating about, not floating, flying rudderless.

01:14:59.820 | By the way, how many rogue planets are there in your sun?

01:15:04.620 | - We don't know totally.

01:15:05.580 | I mean, there's some rogue planets

01:15:07.460 | that are just born on their own.

01:15:08.540 | I know that sounds really weird

01:15:09.660 | to be how can you be born an orphan, but they just are.

01:15:13.580 | Because most planets are born out of a disc of gas

01:15:16.940 | and dust around a star.

01:15:19.060 | But some of these small planets are like totally failed stars

01:15:21.500 | they're so failed, they're just small planets on their own.

01:15:24.460 | But we think that there's probably honestly,

01:15:27.260 | there's another path to a rogue planet.

01:15:28.860 | That's one that's been kicked out of its star system

01:15:31.260 | by other planets, like a game of billiard balls.

01:15:33.700 | Something just gets kicked out.

01:15:35.500 | We actually think there's probably

01:15:37.140 | as many rogue planets as stars.

01:15:39.700 | - No flying out there, fundamentally alone.

01:15:44.500 | So the book is a memoir, is about your life.

01:15:49.500 | And it weaves both your fascination

01:15:55.060 | with planets outside the solar system

01:15:59.100 | and the path of your life.

01:16:02.420 | And you lost your husband,

01:16:04.860 | which is a kind of central part of the book

01:16:09.340 | that created a feeling of the rogue planet.

01:16:15.540 | By the way, what's the name of the book?

01:16:17.380 | - The name of the book is

01:16:18.660 | "The Smallest Lights in the Universe."

01:16:21.340 | - What's up with the title?

01:16:22.620 | What's the meaning?

01:16:23.460 | - Well, the title has a double meaning.

01:16:25.060 | On the face of it, it's the search for other earths.

01:16:27.580 | Earths are so dim compared to the big,

01:16:30.380 | bright massive star beside them.

01:16:32.580 | Searching for the earths is like searching

01:16:35.540 | for the smallest lights in the universe.

01:16:37.900 | It has this other meaning too.

01:16:42.340 | I really hope that you or the other people listening

01:16:44.900 | never get to the place where you're just,

01:16:48.700 | you've fallen off the cliff

01:16:50.220 | into this horrible place of huge despair.

01:16:55.060 | And once in a while you get a glimmer of a better life,

01:16:59.020 | of some kind of hope.

01:17:01.020 | And those are also the smallest lights in the universe.

01:17:03.700 | - Well, maybe we can tell the full story

01:17:06.380 | before we talk about the glimmer of hope.

01:17:11.500 | What did it feel like to first find out

01:17:15.460 | that your husband, Mike, was sick?

01:17:17.940 | - It was incredibly frustrating.

01:17:19.900 | Like lots of us have had some kind of problem

01:17:23.100 | that the doctors completely ignore.

01:17:24.980 | And so they kept blowing him off.

01:17:27.260 | It's nothing.

01:17:28.820 | Are they paid to just say it's nothing?

01:17:30.900 | I mean, it's just insane.

01:17:32.380 | I was just so angry.

01:17:34.460 | And we finally got to a point where he was really sick.

01:17:36.980 | He was like in bed, not able to move basically.

01:17:41.580 | And it turned out all the things they ignored

01:17:43.140 | and not done any tests,

01:17:44.340 | he had like a 100% blockage in his intestine, like 100%.

01:17:49.340 | Like nothing could get out, nothing could get in.

01:17:52.540 | And it was pretty, pretty shocking

01:17:55.380 | to even hear then that it could be nothing.

01:17:58.420 | - What was the progression of it

01:18:00.260 | in the context of maybe the medical system, the doctors?

01:18:03.180 | I mean, what did it feel like?

01:18:05.260 | Did you feel like a human being?

01:18:07.220 | - I felt like a child.

01:18:11.100 | Like the doctors were trying to

01:18:12.620 | water down the real diagnosis

01:18:17.020 | or treat us like we couldn't know the truth

01:18:19.940 | or they didn't know.

01:18:20.980 | You know, I felt mixed.

01:18:22.100 | Like it's not a good situation

01:18:23.940 | if you think the doctor either has no idea

01:18:25.660 | what he or she is doing

01:18:27.100 | or if the doctor's purposely,

01:18:28.960 | let's just say lying to you to sugarcoat it.

01:18:30.940 | Like I didn't know which one of it was,

01:18:32.300 | but I knew it was one of those.

01:18:34.220 | - What were the things he was suffering from?

01:18:37.940 | - Well, initially he just had a random stomachache.

01:18:39.860 | I hate to say that out loud

01:18:41.180 | because I know a lot of people

01:18:42.540 | will have a random stomachache.

01:18:44.580 | But so he just had a bad stomachache

01:18:46.140 | and then, hmm, this is weird.

01:18:47.740 | A few days later, another bad stomachache,

01:18:49.260 | it kind of gets worse,

01:18:50.260 | might go away for a few weeks, might come back.

01:18:52.820 | And at the time, all I knew was my dad

01:18:54.900 | had had that same thing.

01:18:56.580 | Not the same identical system,

01:18:57.980 | but he had these really weird pains

01:18:59.460 | and he ended up having the worst diagnosis.

01:19:03.500 | One of the worst diagnoses you can get

01:19:05.240 | from a random stomachache is pancreatic cancer.

01:19:07.980 | Because the time, the pancreas,

01:19:09.900 | like you can't feel anything,

01:19:10.860 | so by the time you feel pain,

01:19:12.220 | it's too late, it's spread already.

01:19:14.220 | So I was just like, beside myself,

01:19:15.980 | I'm like, this is like, wow,

01:19:18.300 | this guy, he's got a random stomachache.

01:19:19.860 | All I know is another man I loved

01:19:21.340 | had a random stomachache and it didn't end well.

01:19:23.980 | - How did you deal with it

01:19:25.620 | emotionally, psychologically, intellectually,

01:19:28.660 | as a scientist?

01:19:30.260 | What was that like?

01:19:31.540 | That whole, 'cause it's not immediate,

01:19:33.500 | it's a long journey.

01:19:35.180 | - It's a long journey and you don't know

01:19:37.340 | where the diagnosis is going.

01:19:38.820 | So anyone who's suffered from a major illness,

01:19:41.820 | there's like always branches in the road.

01:19:43.940 | So, you know, he had this intestinal blockage.

01:19:47.660 | I can't imagine someone in their 40s

01:19:49.140 | having that and that be normal.

01:19:50.460 | But the doctor's like, it could be nothing,

01:19:53.460 | could just cut it out.

01:19:54.440 | You don't need most of your intestine,

01:19:55.660 | it's a repeating pattern, just cut that out,

01:19:57.220 | it could be fine.

01:19:58.060 | But it ended up not being fine

01:19:58.980 | and he was diagnosed as being terminally ill.

01:20:01.900 | Well, it really changed my life in a huge way.

01:20:03.820 | First of all, I remember immediately one summer,

01:20:07.460 | the summer when this happened,

01:20:09.140 | I started asking everyone I knew, I would ask you,

01:20:11.820 | I don't know if it's my job to put you on the spot,

01:20:13.620 | I'd say, you have one year to live, or two or three.

01:20:17.200 | What will you do differently about your life now?

01:20:21.300 | Lex, you have one year to live, what would you do?

01:20:24.440 | - I mean, it's hard.

01:20:27.160 | I don't know if you wanna answer that.

01:20:28.520 | - No, no, no, I think about it a lot.

01:20:30.440 | I mean, that's a really good thing to meditate on.

01:20:33.520 | We can talk about maybe how, why you bring that up,

01:20:38.520 | if it is or not a heavy question.

01:20:41.160 | - It's very heavy.

01:20:42.000 | - But I get, I think about mortality a lot

01:20:46.440 | and for me, it feels like a really good way

01:20:52.760 | to focus in on is what you're doing today,

01:20:55.700 | the people you have around you, the family you have,

01:20:58.480 | does it bring you joy?

01:21:03.780 | Does it bring you fulfillment?

01:21:05.880 | And basically, for me, long ago,

01:21:12.020 | tried to be ready to die any day.

01:21:19.340 | So today, I kind of woke up looking for,

01:21:23.720 | I was nervous about talking to you.

01:21:25.480 | I really admire your work and the book is very good

01:21:29.980 | and it's super exciting topic.

01:21:31.580 | But then there's this also feeling like,

01:21:36.020 | if this is the last conversation I have in my life,

01:21:39.020 | if I die today, will this be the right,

01:21:43.100 | like am I glad today happened?

01:21:44.820 | And it is, and I am glad today happened.

01:21:48.560 | So that's the way--

01:21:49.400 | - And that's so unique,

01:21:50.540 | I never got that answer from a single person.

01:21:52.740 | - The busyness of life, there's goals, there's dreams,

01:21:58.540 | there's like planning, plans.

01:22:00.220 | - Very few people make it happen.

01:22:02.740 | That's what I learned.

01:22:04.140 | And so a lot of these people--

01:22:05.620 | - Oh, like you run out of time.

01:22:07.300 | - It's not so much you run out of time,

01:22:08.180 | but I'd come back later and be like,

01:22:09.540 | okay, why don't you do that?

01:22:11.220 | If that's what you would do,

01:22:12.860 | if you're gonna die a year from now,

01:22:13.940 | why don't you make it real?

01:22:16.380 | Simple things, spend more time with family.

01:22:19.040 | Like why don't you do that?

01:22:20.120 | And no one had an answer, it turns out,

01:22:21.680 | unless you usually, unless you have,

01:22:24.400 | you really do have a pressing end of life,

01:22:26.560 | people don't do their bucket list

01:22:28.880 | or try to change their career.

01:22:30.240 | And some people can't, so we can't,

01:22:31.840 | like for a lot of people,

01:22:32.720 | they can't do anything about it and that's fine.

01:22:34.800 | But the ones who can take action for some reason never do.

01:22:38.000 | And that was one of the ways that Mike's death,

01:22:41.920 | or at the time his impending death,

01:22:43.720 | really, really affected me.

01:22:45.840 | 'Cause you know, for these sick people,

01:22:47.340 | what I learned, he had a bucket list

01:22:48.780 | and he was able to do some of the bucket list.

01:22:50.260 | It was awesome.

01:22:51.780 | But he got sick pretty quickly.

01:22:54.260 | So if you do only have a year to live,

01:22:55.820 | it's ironic 'cause you can't do the things you wanted to do

01:22:59.340 | because you get too sick too fast.

01:23:01.260 | - What were the bucket list things for you

01:23:03.380 | that you realized like, what am I doing with my life?

01:23:06.380 | - That was the major concept.

01:23:07.940 | Of him, after he died, I didn't know.

01:23:09.740 | Like I was just lost.

01:23:12.140 | Because when something that profound happens,

01:23:15.020 | all the things I was doing,

01:23:17.180 | most of the things I was doing were just meaningless.

01:23:19.900 | Was so tough to find an answer for that.

01:23:23.900 | And that's when I settled on,

01:23:25.220 | I'm gonna devote the rest of my life

01:23:27.940 | to trying to find another earth

01:23:30.180 | and to find out, to find that we're not alone.

01:23:35.180 | - What is that longing for connection with others?

01:23:40.340 | What's that about?

01:23:43.500 | What do you think, why is that so full of meaning?

01:23:45.500 | - I don't know why.

01:23:46.340 | I mean, I think it's how we're hardwired.

01:23:48.220 | Like one of my friends some time ago,

01:23:50.220 | actually when my dad died,

01:23:52.260 | he never heard someone say this before,

01:23:54.780 | but he's like, Sarah, you know,

01:23:57.140 | why are we evolved to take death so harshly?

01:24:01.740 | Like what kind of society would we be

01:24:03.240 | if we just didn't care people died?

01:24:05.660 | That would be a very different type of world.

01:24:07.220 | How would we as a species have got to where we are?

01:24:11.380 | So I think that is tied hand in hand

01:24:13.600 | with why do we seek connection?

01:24:16.000 | It's just that what we were talking about before,

01:24:18.180 | that subconsciousness that we don't understand.

01:24:20.800 | - Yeah, coupled, you know, the other side,

01:24:24.460 | the flip side of the coin of connection and love

01:24:27.740 | is a fear of loss.

01:24:30.860 | It's like that was, again, I don't know.

01:24:33.660 | It's what makes you appreciate the moment

01:24:36.300 | is that the thing ends.

01:24:38.180 | - Yeah, that's definitely a hard one.

01:24:39.980 | - The thing ends, but, and it's hard to not,

01:24:42.860 | you wouldn't want to limit, like it's,

01:24:45.900 | like my dog who I love so much, I'll start to cry.

01:24:49.120 | Like I can't think about the end.

01:24:50.420 | I know he'll age much faster than I will,

01:24:52.620 | and someday it will end, right?

01:24:54.040 | But it's too sad to think of.

01:24:55.900 | But should I not have got a dog?

01:24:57.700 | - Right.

01:24:58.540 | - Should I have not brought this sort of joy into my life

01:25:00.680 | because I know it won't be forever?

01:25:02.180 | It's-

01:25:03.420 | - Well, there's a philosopher, Ernest Becker,

01:25:06.860 | who wrote a book, "Denial of Death."

01:25:08.980 | I just, and "Warm of the Cores" is another book,

01:25:12.940 | talks about terror management theory.

01:25:15.100 | Sheldon Solomon, I just talked to him a few weeks ago.

01:25:18.740 | He's a brilliant philosopher, psychologist,

01:25:21.540 | that their theory, whatever you make of it,

01:25:24.900 | is that the fear of death is at the core of everything,

01:25:29.900 | everything we do.

01:25:31.920 | So like you're, that you think you don't think

01:25:36.540 | about the mortality of your dog, but you do.

01:25:40.020 | And that's what makes the experience rich.

01:25:42.180 | Like there's this kind of, like in the shadows

01:25:45.380 | lurks the knowledge that this won't last forever.

01:25:50.380 | And that makes every moment just special

01:25:55.380 | in some kind of a weird way

01:25:57.180 | that the moments are special for us humans.

01:26:02.200 | - I mean, sorry to use romantic terms like love,

01:26:07.200 | but what do you make, what did you learn about love

01:26:12.880 | from losing it, from losing your husband?

01:26:16.940 | - Well, I learned to love the things I have more.

01:26:21.080 | I learned to love the people that I have more

01:26:24.200 | and to not let the little things bother me as much.

01:26:30.560 | - What about the rediscovery or like the discovery

01:26:35.560 | of the little lights in the darkness?

01:26:41.440 | So the book, I think you've brilliantly described

01:26:46.440 | the dark parts of your journey,

01:26:50.860 | but maybe can you talk about how you were able

01:26:57.160 | to rediscover the lights?

01:27:00.240 | - They came in many ways.

01:27:02.200 | And the way like to think about it is like grief is an ocean.

01:27:06.020 | It was tiny islands of the little,

01:27:09.960 | like the little lights and eventually that ocean

01:27:12.800 | gets smaller and smaller and the islands

01:27:14.480 | like become continents with lakes.

01:27:16.160 | So initially it'd be like the children laughing one day

01:27:20.600 | or my colleagues at work who rallied around me

01:27:22.920 | and would take me away from my darkness

01:27:25.640 | to work on a project.

01:27:28.320 | Later on, it turned out to be a group of women my age,

01:27:31.840 | all widows, all with children in my town.

01:27:34.220 | And it would be, even though it was a bit morose

01:27:37.120 | getting together, still very joyful at the same time.

01:27:40.980 | - What was the journey of rediscovering love like for you?

01:27:47.080 | So refinding, I mean, is there some, by way of advice

01:27:51.960 | or insight about how to rediscover the light?

01:27:57.640 | How to rediscover the beauty of life?

01:28:00.240 | - Of life, it's a hard one.

01:28:02.400 | I think you just have to stay open to being positive

01:28:07.000 | and just to get out there.

01:28:08.300 | - Do you still think about your own mortality?

01:28:13.720 | So you mentioned that that was a thing

01:28:15.320 | that you would meditate on as a question

01:28:17.600 | when it was right there in front of you,

01:28:22.320 | but do you still think about it?

01:28:24.040 | - I think I will after talking to you.

01:28:25.940 | (laughing)

01:28:26.880 | No, it's not really something I think about.

01:28:28.680 | I mean, I do think about the search for another earth

01:28:31.320 | and will I get there?

01:28:33.520 | Will I be able to conclude my search and is there one?

01:28:38.520 | I guess time goes by, that window to solve that problem

01:28:42.680 | gets smaller.

01:28:43.580 | - What would bring you, again, I apologize if this

01:28:49.240 | makes concrete the fact that life is finite,

01:28:52.080 | but what would bring you joy if we discovered

01:28:56.680 | while you're still here?

01:28:58.200 | - What would bring me joy?

01:28:59.080 | Finding another earth, an earth like planet

01:29:02.220 | around a sun like star, knowing that there's at least one

01:29:05.080 | or more out there, being able to see water,

01:29:07.680 | that it has signs of water and being able to see some gases

01:29:11.120 | that don't belong.

01:29:12.340 | So I know that the search will continue after I'm gone,

01:29:16.200 | enough to fuel the next generation.

01:29:18.000 | - So just like opening the door

01:29:21.080 | and there's like this glimmer of hope.

01:29:22.980 | What do you think it will take to realize that?

01:29:25.800 | I mean, we've talked about all these interesting projects,

01:29:27.920 | Starshade especially, but is there something

01:29:30.320 | that you're particularly kind of hopeful about

01:29:34.360 | in the next 10, 20 years that might give us

01:29:37.440 | that exact glimmer of hope

01:29:41.520 | that there's earth like planets out there?

01:29:43.800 | - I have to, I stand behind Starshade in all cases.

01:29:47.240 | But there is this other kind of field

01:29:49.320 | that everyone is involved in because Starshade is hard.

01:29:53.100 | Earths are hard.

01:29:55.000 | But there's another category of planet star type

01:29:57.960 | that's easier.

01:29:58.800 | And these are planets orbiting small red dwarf stars.

01:30:03.000 | They're not earth like at all.

01:30:03.960 | Think like earth cousin instead of earth twin.

01:30:06.560 | But there's a chance that we might establish

01:30:08.140 | that some of those have water and signs of life on them.

01:30:11.300 | That's nearer term than Starshade

01:30:12.760 | and we're all working hard on that too.

01:30:15.400 | - Let me ask by way of recommendations,

01:30:18.180 | I think a lot of people are curious

01:30:19.720 | about this kind of stuff.

01:30:20.960 | What three books, technical or fiction

01:30:24.120 | or philosophical or anything really

01:30:26.640 | had an impact on your life

01:30:28.880 | and or you would recommend besides of course your book?

01:30:33.880 | - There's one book I wish everyone could read.

01:30:38.680 | I'm not sure if you've read it.

01:30:39.660 | It's actually a children's book, like a young adult book.

01:30:42.160 | It's called "The Giver."

01:30:43.540 | - Yes.

01:30:45.280 | - And it is the book that kids in school read now.

01:30:48.520 | And I only--

01:30:49.640 | - Sorry.

01:30:50.940 | That's wow.

01:30:52.820 | 'Cause I forgot.

01:30:53.660 | (laughs)

01:30:54.480 | Sorry, that caught me off guard.

01:30:56.380 | So when I first came to this country, I didn't speak much.

01:30:59.460 | It's really what made me,

01:31:01.120 | it had a profound impact on my life.

01:31:04.100 | - Wow.

01:31:04.940 | - And at a really important moment

01:31:06.020 | 'cause they give it to kids.

01:31:07.580 | Like I think--

01:31:08.420 | - It's like middle school I think or maybe elementary.

01:31:09.260 | - Eighth grade, yeah, something like that.

01:31:10.620 | - Well, I'm so surprised you've even heard of this book.

01:31:12.460 | - Yeah, so they give it.

01:31:13.740 | But like it's the value of giving the right book

01:31:16.060 | to a person at the right time.

01:31:17.660 | - Wow.

01:31:18.500 | - 'Cause it's very accessible.

01:31:22.180 | - Do we wanna share what the story is without spoiling it?

01:31:24.980 | - Yeah, you can without spoiling, right?

01:31:28.020 | - Well, it follows this boy in this very utopic society

01:31:32.060 | that's like perfect.

01:31:32.900 | It's been all clean cut and made perfect actually.

01:31:35.540 | And as he kind of comes of age,

01:31:37.660 | he starts realizing something's wrong with his world.

01:31:40.260 | And so it's part of that question,

01:31:42.540 | are we gonna evolve as he,

01:31:43.700 | I mean, this isn't what's there,

01:31:44.540 | but it made me wonder,

01:31:45.620 | are we evolving to a better place?

01:31:47.540 | Is there a day when we can eliminate poverty and hunger

01:31:50.500 | and crime and sickness?

01:31:53.020 | In this book, they pretty much have

01:31:54.300 | in a society that the boy's in.

01:31:56.260 | And it sort of follows him.

01:31:58.140 | And he becomes a chosen one to be like a receiver,

01:32:01.740 | the giver's the old wise man

01:32:03.140 | who retains some of the harshness of the outside world

01:32:06.580 | so that he can advise the people.

01:32:08.460 | And as this sort of boy comes of age

01:32:09.820 | and is chosen for this special role,

01:32:11.220 | he finds the world isn't what he expects.

01:32:13.740 | And I don't know about you,

01:32:14.580 | but it was so profound for me

01:32:15.940 | because it jolts you out of reality.

01:32:18.220 | It's like, oh my God, what am I doing here?

01:32:19.980 | I'm just going with the flow with my society.

01:32:22.740 | How do I think outside the box

01:32:24.420 | and the confines of my society,

01:32:25.820 | which surely carries negative things with it

01:32:27.460 | that we don't realize today.

01:32:29.460 | - Yeah, and also in the flip side of that is

01:32:32.300 | if you do take a step outside the box on occasion,

01:32:36.140 | what's the psychological burden of that?

01:32:39.180 | Like, is that a step you wanna take?

01:32:42.260 | Is that a journey you wanna take?

01:32:44.780 | What is that life like?

01:32:46.100 | - I don't know.

01:32:46.940 | I felt like from the book, you have to take it.

01:32:48.180 | I found from the book.

01:32:49.820 | I never thought, like, now that you're saying it,

01:32:51.660 | I see what you're saying.

01:32:52.780 | The burden is huge, but I always felt like the answer is yes.

01:32:55.340 | You absolutely want to know what's outside,

01:32:58.220 | but you can't do that if you're very,

01:32:59.580 | it's hard to be objective about your own reality.

01:33:02.260 | - Yeah, I mean, it's a very human instinct,

01:33:04.180 | but it also, the book kind of shows that

01:33:08.500 | it has an effect on you.

01:33:09.780 | And it's a really interesting question

01:33:13.140 | about our society and taking a step out.

01:33:16.180 | It's by Lois Lowry, I think is how you pronounce it.

01:33:20.180 | I really do hope everyone can read it.

01:33:21.860 | And it is a young adult book, but it's still,

01:33:24.020 | it's incredibly, I'm really glad.

01:33:25.340 | I only read it 'cause my kids got it for school.

01:33:27.660 | I just thought, okay, well,

01:33:28.620 | why don't I just see what this is about?

01:33:29.740 | And I just, wow.

01:33:31.220 | - Yeah, yeah, I think it's also the value of education.

01:33:35.180 | I think, I'm surprised you mentioned it.

01:33:37.140 | I've never really mentioned to anybody.

01:33:38.940 | I'm sure a lot of people had similar experience like me

01:33:42.340 | and maybe--

01:33:43.180 | - It's a generational thing, though,

01:33:44.180 | because the book came out, I think, in the '90s.

01:33:46.220 | So if you're older than like me,

01:33:48.940 | that book didn't exist when we were in middle school.

01:33:50.860 | So I just do think a lot of people won't have heard of it.

01:33:53.620 | - But it's an interesting question of those books.

01:33:56.940 | I mean, I'm reminded often,

01:33:59.940 | I suppose the same is true with other subjects,

01:34:02.300 | but books are special.

01:34:04.380 | At early age, middle school, maybe early high school,

01:34:08.580 | those can change the direction of your life.

01:34:11.660 | And also certainly teachers,

01:34:15.300 | they can change completely the direction of your life.

01:34:17.820 | There's so many stories about teachers of mathematics,

01:34:20.940 | teachers of physics, of any kind of subjects,

01:34:24.740 | basically changing the direction of a human's life.

01:34:27.420 | That's like, not to get into the whole,

01:34:32.420 | almost like a political thing,

01:34:34.140 | but we undervalue teachers.

01:34:38.780 | It's a special position that they hold.

01:34:42.460 | - That's so true, yeah.

01:34:43.780 | Well, I do have two other books, or two other things.

01:34:46.580 | One is something I came across just a few days ago, actually.

01:34:49.900 | It's actually a film called "Picture a Scientist."

01:34:53.380 | And when you picture a scientist,

01:34:55.900 | you probably don't picture the women

01:34:58.940 | and women of color in this film.

01:35:01.020 | And it is a way to get outside your box.

01:35:03.900 | I really think everyone interested in science,

01:35:06.820 | even just peripherally, should watch this,

01:35:08.660 | because it is shocking and sobering at the same time.

01:35:12.460 | And it talks about how,

01:35:14.540 | well, I think one of the messages across is,

01:35:17.380 | we really are, like,

01:35:19.340 | I don't know if we're hardwired

01:35:20.380 | to just like people like ourselves,

01:35:22.380 | but we're excluding a lot of people,

01:35:23.660 | and therefore a lot of great ideas,

01:35:25.980 | by not being able to think outside

01:35:27.540 | of how we're all stereotyping each other.

01:35:29.580 | So it's hard to kind of convey that.

01:35:32.740 | And you can just say, "Oh yeah, I wanna be more diverse.

01:35:34.700 | I wanna be more open."

01:35:35.700 | But it's a nearly impossible problem to solve.

01:35:38.460 | And the movie really helps open people's eyes to it.

01:35:42.260 | This book I put third, because unlike "The Giver,"

01:35:45.540 | people may not wanna read it.

01:35:46.620 | It's not as relevant.

01:35:47.540 | But when I was in my early 20s,

01:35:50.340 | I went to this big,

01:35:51.860 | this like 800-people large conference

01:35:54.580 | run by the Wilderness Canoe Association

01:35:58.220 | in my hometown of Toronto.

01:36:00.180 | And there was a family friend there who I met.

01:36:03.140 | And he said, "Read this book. It'll change your life."

01:36:05.860 | And it actually changed my life.

01:36:08.060 | And it was a book called "Sleeping Island"

01:36:10.740 | by an author, P.G. Downs,

01:36:12.300 | who just coincidentally lived in this area,

01:36:14.620 | lived in the Boston area.

01:36:15.940 | And he was a teacher, I think at a private school.

01:36:18.100 | And every summer he would go to Canada

01:36:20.820 | with a canoe, often by himself.

01:36:23.340 | And he wrote this book, maybe in the 40s or 50s,

01:36:25.900 | about a trip he took in the late 1930s.

01:36:28.940 | And I was just shocked that even at that time,

01:36:31.220 | although that was a long time ago,

01:36:32.500 | there were large parts of Canada

01:36:34.620 | that were untouched by white people.

01:36:37.420 | And he went up there and interacted with the natives.

01:36:40.340 | He called the book, it had a subtitle that was called,

01:36:44.660 | it was something like "Journey in the Barren Lands."

01:36:47.300 | And when you go up north in Canada, you pass the tree line.

01:36:49.820 | Just like on a mountain, if you hike up a mountain,

01:36:51.340 | you get so far north there aren't any trees.

01:36:53.420 | And he wrote eloquently about the land

01:36:55.260 | and about being out there.

01:36:56.500 | There weren't even any maps of the region in that time.

01:37:00.380 | And I just thought to myself, wow,

01:37:02.620 | that you could just take the summer off

01:37:04.060 | and explore by canoe and go and see what's out there.

01:37:07.340 | And it led to me just doing that, that very thing.

01:37:10.540 | Of course, it's different now,

01:37:12.180 | but going out to where the road ends

01:37:14.260 | and putting the canoe in the water and just,

01:37:15.900 | well, we had to have a plan.

01:37:16.740 | We didn't just explore, but go down this river,

01:37:19.260 | rivers with rapids and travel over lakes and portages

01:37:22.460 | and just really live.

01:37:23.620 | - So just really explore, screw it.

01:37:27.420 | That doesn't, like it doesn't.

01:37:29.380 | - Or just use from a topo map,

01:37:30.700 | from a topographical map from the library.

01:37:33.140 | - That's scary.

01:37:33.980 | - There were scary elements about it, out of it,

01:37:37.700 | but part of the excitement or the joy or the desire

01:37:42.060 | was to be scared.

01:37:43.340 | Like it was to go out there and have, live on the edge.

01:37:45.860 | - And persevere, yeah.

01:37:47.220 | - And persevere, yeah.

01:37:48.320 | - Do you have advice that you would give

01:37:51.780 | to a young person today that would like to help you

01:37:56.780 | maybe on the planetary science side,

01:37:59.860 | discover exoplanets or maybe bigger picture,

01:38:02.900 | just succeed in life?

01:38:04.620 | - I do have some advice just to succeed.

01:38:06.220 | It's tough advice in a way,

01:38:07.860 | but it is to find something that you love doing

01:38:11.020 | that you're also very good at.

01:38:12.660 | And in some ways the stars have to align

01:38:15.980 | because you've got to find that thing you're good at

01:38:17.780 | or the range of things.

01:38:19.580 | And it actually has to overlap with something

01:38:21.260 | that actually you love doing every day.

01:38:23.220 | So it's not a tedious job.

01:38:25.000 | That's the best way to succeed.

01:38:27.380 | - What were the signals that in your own life

01:38:31.180 | were there to make you realize you're good at something?

01:38:34.020 | You're like, what were you good at

01:38:37.660 | that made you pursue a PhD

01:38:41.220 | and it made you pursue the search?

01:38:44.160 | - I mean, that was the one sentence version.

01:38:46.900 | In my case, it was a long slog

01:38:48.740 | and there were a lot of things I wasn't good at initially.

01:38:51.140 | But so initially, I was good at high school math.

01:38:53.460 | I was good at high school science.

01:38:55.220 | I loved astronomy.

01:38:56.780 | And I realized those could all fit together.

01:38:58.460 | Like the day I realized you could be an astronomer

01:39:00.600 | for a job, it has to be one of my top days of my life.

01:39:04.140 | I didn't know that you could be that for a job.

01:39:06.700 | And I was good at all those things.

01:39:08.260 | And although my dad wanted me to do something more practical

01:39:10.580 | where he could be guaranteed I could support myself

01:39:13.100 | was another option.

01:39:14.740 | But initially I wasn't that good at physics.

01:39:16.740 | It was a slog to just get through school and grad school.

01:39:18.980 | It was a very, very long time.

01:39:20.940 | But ultimately when faced with a choice

01:39:23.760 | and I had the luxury of choosing,

01:39:25.840 | knowing that I was good at something and also loved it,

01:39:27.740 | it really carried me through.

01:39:29.580 | - Now I asked some of the smartest people in the world

01:39:32.520 | the most ridiculous question.

01:39:34.320 | We already talked about it a little bit,

01:39:35.820 | but let me ask again, why are we here?

01:39:40.240 | So I think you've raised this question

01:39:44.000 | in one of your presentations as like one of the things

01:39:47.120 | that we kind of as humans long to answer

01:39:50.360 | and the search for exoplanets is kind of part of that.

01:39:53.480 | But what do you think is the meaning of it all, of life?

01:39:57.260 | - I wish I had a good answer for you.

01:39:59.160 | (laughing)

01:40:01.400 | - I think you're the first person ever

01:40:05.160 | who refused to answer the question.

01:40:07.560 | - It's not so much refusing, I just, yeah,

01:40:09.320 | I mean, I wish I had a better answer.

01:40:11.360 | - It's-- - Why we're here.

01:40:12.760 | - It's almost like the meaning is,

01:40:14.460 | wishing there was a meaning, wishing we knew.

01:40:20.560 | - I love that, that's a great way to say it.

01:40:24.800 | - Sarah, like I said, the book is excellent.

01:40:27.160 | I admired your work from afar for a while

01:40:30.000 | and I think you're one of the great stars at MIT

01:40:34.280 | and makes me proud to be part of the community.

01:40:37.240 | So thank you so much for your work.

01:40:40.100 | Thank you for inspiring all of us.

01:40:41.320 | Thanks for talking today.

01:40:42.680 | - Thank you so much, Links.

01:40:44.040 | - Thanks for listening to this conversation

01:40:46.360 | with Sarah Seeger and thank you to our sponsors,

01:40:49.600 | Public Goods, PowerDot and Cash App.

01:40:52.920 | Click the links in the description to get a discount.

01:40:55.640 | It's the best way to support this podcast.

01:40:57.800 | If you enjoy this thing, subscribe on YouTube,

01:41:00.120 | review it with Firestarz on Apple Podcast,

01:41:02.320 | support it on Patreon or connect with me on Twitter,

01:41:05.480 | Alex Friedman, spelled, I'm not sure how.

01:41:08.760 | Just keep typing stuff in until you get to the guy

01:41:12.340 | with the tie in the thumbnail.

01:41:14.640 | And now let me leave you with some words from Carl Sagan.

01:41:18.240 | Somewhere, something incredible is waiting to be known.

01:41:22.800 | Thank you for listening and hope to see you next time.

01:41:25.880 | (upbeat music)

01:41:28.460 | (upbeat music)

01:41:31.040 | [BLANK_AUDIO]

Sara Seager: Search for Planets and Life Outside Our Solar System | Lex Fridman Podcast #116

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