Sara Seager: Life beyond Earth

Sara Seager: Life beyond Earth

Sara is an astronomer and planetary scientist known for her pioneering work on the vast and unknown world of exoplanets, and the search for life beyond Earth.

Sara is an astronomer and planetary scientist known for her pioneering work on the vast and unknown world of exoplanets, and the search for extraterrestrial life.

We discuss:

  • The prospects for finding alien life in our solar system

  • The possibility that there is life on Venus

  • The infamous fermi paradox

  • Exoplanets

  • The beauty of the night sky 

… and other topics.

Watch on YouTube. Listen on Spotify, Apple Podcasts, or any other podcast platform. Read the full transcript here. Follow me on LinkedIn or Twitter/X for episodes and infrequent social commentary.

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Episode links

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  • Website:


0:00 Intro: Where are they?

5:35 Is there life on Venus?

13:25 Venus Life Finder mission

17:15 Non-biological life?

20:15 How might aliens discover life on Earth?

23:17 Should we broadcast our existence?

28:30 Consensus view - is there life outside of Earth?

31:05 Fermi Paradox - where are they?

34:50 Exoplanets

48:20 Starshade mission

54:11 Beauty and awe in physics

1:03:50 Book recommendations

1:11:23 Behind the scenes / backstory

Introduction: Where are they?

The question of whether there is life outside of Earth was once thought of as an esoteric and largely philosophical question, rather than scientific. 

However, our growing understanding of science and the cosmos has shifted this question from abstract philosophical pondering to something more tangible and scientifically motivated. And interestingly, the progress we’ve made in many different areas of science all seem to suggest that the emergence of life in the universe should be much more common than we once thought.

For example, in physics, over the past few hundred years, and again in the past few decades, we’ve experienced several paradigm shifts suggesting that our place in the universe is not quite as special as we once thought.

There was the Copernican Revolution of the 16th century, where we learned that the Earth is not the centre of the universe, but rather that the Earth orbits our Sun, along with the other planets in our solar system. Not long after that, Newton developed his universal laws of gravitation that explained how all of this works, and these laws work the same for all massive bodies - they don’t have anything special to say about Earth specifically.

In more recent times, we’ve learned that our Sun is just one of over 200 billion stars in our Milky Way galaxy, many of which have their own planets, and that our galaxy is just one of something like a trillion others in the observable part of the universe.

All of this suggests that Earth-like planets should be in no short supply.

We find a similar story in chemistry and biology. In chemistry we’ve learned that the building blocks of life as we find it on earth are composed of a relatively small set of organic molecules called amino acids, which are themselves made up of just a handful of elements. These elements are all in abundant supply in the universe, and in fact scientists have already found many full-fledged amino acids in outer space.

And in biology, Darwin’s theory of evolution by natural selection, which applies not just to living creatures, but also to cells, and even to molecules, has given us an end-to-end account for how even the most complex life forms can emerge over time from the very simplest building blocks of life.

We’ve also learned of extremophile organisms that can survive in the harshest of conditions on Earth, such as in acid hot springs, and in icy polar regions. Finding life in such extreme conditions expands the potential habitats where life beyond Earth might exist.

All these examples and many, many others suggest that life has probably emerged many times all over the universe. And this poses a very serious conundrum, and perhaps even a call to action, because despite life’s apparent abundance outside of Earth, we’ve not yet found any direct evidence of it. We don’t even have direct evidence for simple forms of life such as bacteria, let alone complex forms of life, such as a technologically advanced civilisation.

As Sara and I discuss in today’s conversation, there are several possible explanations for this, and unfortunately most of them are not very comforting.

One particularly concerning possibility is that complex life simply doesn’t tend to last for very long, and that any technologically advanced civilisations we might have encountered have been wiped out or self destructed before we’ve had the chance to meet them. This could be via nuclear self-destruction, or planets being bombarded by asteroid collisions before civilisations become space faring, or something far more pedestrian. Whatever the case may be, this does not bode well for the long term survival and flourishing of life. 

Not too long ago, this line of thought could justifiably have been considered nothing more than an entertaining thought experiment. But things are different now. If we take a rational, clear-eyed account of the science of life and the cosmos as we know it, then the intellectually honest and defensible position is to take this possibility seriously.

And this is all the more reason to take the idea of existential risk seriously, and to have serious discussions about how we can prevent ourselves from being destroyed, whether by self-destruction or otherwise. I’m looking forward to bringing you more conversations with the people at the forefront of these topics. And this conversation is the perfect introduction.

And now I bring you, Sara Seager.

Thank you for reading Paradigm. This post is public so feel free to share it.



This transcript is AI-generated and may contain errors. It will be corrected and annotated with links and citations over time.

[00:05:31] Matt: I'm here with Sara Seager. Sara, thank you for joining me.

[00:05:33] Sara: Thanks for having me.

[00:05:35] Matt: Sara, I'd love to have a conversation about the search for extraterrestrial life, which you're very well known for, both within our solar system and far beyond. Um, but let's start very close to home with the second planet from our sun, Venus.

And I'll put it straight to you. Do you believe that there is life on Venus or do you think there is life on Venus?

[00:05:54] Sara: Well, that's a great question. And I do hate to start out with the word believe, but if

[00:06:00] Matt: Yeah.

[00:06:01] Sara: I may say instead that Yes, I think it's a possibility.

[00:06:05] Matt: And, uh, what, what makes you, what makes you say that?

[00:06:08] Sara: Well, it's something very, very specific and very, very new. And it might take a few minutes to unpack this, My team decided to work on laboratory studies of sulfuric acid. Now, you may or may not be aware that the Venus clouds are made of acid.

And it's a very, very nasty, horrible chemical that destroys our life. But the clouds, if there is life on Venus, we think it has to be in the cloud layers. Because the surface of Venus is too hot for life event. The surface of Venus is scorching. It is unbelievably hot. It's over 700 Kelvin. Almost certainly too hot for life of any kind.

But just like here on Earth, if you hike up a mountain, or take an airplane, you know, it gets colder and colder above the surface, and so too on Venus. And in the cloud layers about 50 kilometers above the surface, it is a good temperature for life. It's actually like the temperature we have here at Earth's surface.

So if you hiked a mountain, I don't know if you're into hiking or you've ever been up a mountain,

[00:07:08] Matt: Yeah.

[00:07:09] Sara: And do you know how it gets colder? Like, have you ever been on a mountain where it's just a really nice day at the base, and then the top is frigid winter?

[00:07:15] Matt: Yeah. Yeah, definitely.

[00:07:16] Sara: Like, where? Where's that?

[00:07:18] Matt: I, I mean, a bunch of stuff. So I've done, um, okay, well, this is not too high in the UK, Ben Nevis. It's, it's not all, it's not all that high, but, uh, yeah, my, my family has done Kilimanjaro. I've, I've

[00:07:29] Sara: Did you go on Kilimanjaro?

[00:07:30] Matt: I, I personally didn't, but I've, I've seen the photos. I've seen the snow at the top and the, and the tropical sort of, uh, look down below.


[00:07:37] Sara: Right, right. So think about that for a minute. So hot on the surface of Venus, but way up in the clouds, just the right temperature. Now, we have life in our clouds. On Earth, there's bacteria that gets swept up from the surface, and it goes into the clouds, and it stays there for a while before it gets rained out.

So, why not life in Venus clouds? But this acid, you know, the clouds aren't made of water. They're made of a horrible, nasty substance. And, don't do this at home, but if someone accidentally puts an ant into sulfuric acid, it immediately has a seizure and turns to black goo instantly, before you can almost blink an eye.

So it's bad for our life, but we have started some experiments in sulfuric acid and we started to put some chemicals, biological chemicals, in sulfuric acid and we're finding they're stable. You know, I can give you some examples now or a bit later, but who would have thought that maybe some other kind of life, not our life, but a life that uses slightly different molecules than our life does.

Um, I mean, this is a, it's astonishing. It's not really well known. We're kind of, We're not advertising this work right now, because we're, it's so exciting, we're just trying to own the field.

[00:08:49] Matt: Yeah, I mean, there is a sense though, in which, like if we were to find life out there, perhaps you would expect it to be very close to home because, you know, it was sort of proof that. at least this little region of, of space, this pocket of space can facilitate life. And so there, there is a sense in, yeah.

[00:09:05] Sara: do. I like that kind of thought. That if life is everywhere, we have to also be able to find it in your home.

[00:09:09] Matt: Yeah, and even probably more likely to find it in your home.

in some sense, because we've kind of got proof that, you know, our solar system at least, uh, you know, allows it. Um, but why, why specifically Venus, you know, why, why are we not talking about, um, Mars or any of the other planets? Why specifically Venus for you?

[00:09:28] Sara: Well, I would, okay, there's several answers to this, but one is why not all planets? You know, if we had infinite time and infinite resources, yes, we should explore everywhere and anywhere for life.

Mars, we're all hoping, has life beneath the surface. Just beneath the surface in a pocket that's got a bit of water, hopefully.

[00:09:45] Matt: Hmm.

[00:09:45] Sara: just got obsessed with Venus. Everyone votes for the underdog. No, because, it's like, You have a family, maybe you've had siblings growing up. You know how one sibling gets all the attention, and then another sibling always gets ignored?


[00:10:00] Matt: Yeah.

[00:10:01] Sara: not sure which one you were.

[00:10:02] Matt: Oh, I'll keep that. I'll keep that to myself.

[00:10:05] Sara: Well, Mars is like the sibling that gets all the attention.

[00:10:09] Matt: Hmm.

[00:10:10] Sara: that make sense? Mm hmm. Venus is like the ignored sibling. I mean, the former Soviet Union sent many probes to Venus that went in the atmosphere, that measured things, and they did a phenomenal job. If something didn't work quite right on one, the next one fixed it.

They sent two balloons to Venus. Each lasted about 48 hours on battery supply and radioed information back to Earth. NASA sent a probe to Venus, Pioneer Venus, that separated out into four separate things that... And these were all nearly 40 years ago. So why haven't we sent probes back to Venus? It's amazing, but it turns out there are a lot of interesting things about Venus that were shelved.

Really interesting things that people found that just could put on the shelf. Atmosphere anomalies, we call them. Very unusual bits of chemistry in the atmosphere that aren't explained yet.

[00:11:00] Matt: But why, why is that? I mean, you know, if, if people are, have been historically uncovering interesting things, you would expect, uh, You know, follow-ups and, and this

[00:11:10] Sara: You would, you would. I'm not sure. I mean, I really don't know why Venus got out of favor. I do know, I'm new to the Venus research, but the Venus community has been trying to get a mission to Venus for a very long time. And now there are a few missions slated. The European Space Agency has a mission. NASA has planned for two missions.

Other countries want to go to Venus as well.

[00:11:31] Matt: can. you tell me a little bit about the Venus Life Finder mission? Um, I've read the, I've read the report that you are,

[00:11:36] Sara: Right, right. Well,

[00:11:37] Matt: sort of lead investigator

[00:11:38] Sara: emoted by phosphine, I initiated a study group and it morphed into, we used to call ourselves the Venus Lifefinder Team. We've changed our name now. We call ourselves, we're an international consortium and we call ourselves the Morning Star Missions to Venus. Because Venus is very bright in the morning sky sometimes.

And right now as we're speaking, I'm not sure if you've seen it in the mornings, it's incredible.

[00:12:03] Matt: Yeah,

[00:12:04] Sara: So bright, right? And so high up in the sky. So we, Morningstar, we feel like it's an evocative term, like something new, something rising. So we call ourselves the Morningstar Missions to Venus, and we're aiming for a series of missions, astrobiology focused missions, to search for signs of life and perhaps even find life.

So that's what we're doing. And our first mission in the series is called the Rocket Lab Mission to Venus. And we have teamed up with Rocket Lab to send a small, focused, low cost mission to Venus. And not sure if you've touched on at any time this kind of, um, the revolution CubeSat.

I don't know if you know what the word CubeSat is. There's this kind of flurry of activity of making small focus missions for space, both commercially and just for research teams. Well, we're aiming to do that for interplanetary as well. So that instead of waiting a decade or more for countries to get together or for the USA to have many instruments on a big mission that satisfies a lot of people to have a small focus mission of lower cost to get to Venus and try to answer focus questions.

[00:13:27] Matt: Yeah, this, um, this sort of emergence of privately funded missions is very interesting. Um, in the, in the report you write, um, uh, well, I don't know if you wrote this, somebody wrote in the report, as we write, the world is poised on the brink of revolution in space science, privately funded missions to Mars and Venus and perhaps beyond.

Are becoming a reality and I find this very, very interesting, um, you know, from a research perspective. Um, well firstly, am I correct in understanding that, you know, if this mission with Rocket Lab was to go ahead, this would be the first privately funded research mission to Venus?

[00:13:59] Sara: It would. And we do soften that a bit. We call it the first largely privately funded mission to Venus. So, yes, it would be the first. I

[00:14:08] Matt: And how, how does the, how does the like incentive mechanism work there? Why, why would, um, a private company fund a research mission like

[00:14:16] Sara: mean, that's a good question, and you'll have to ask if there's some way you can ask the private company, because I don't have the answers to why they would, why they've done that. But one fact I can tell you is that, to my knowledge, If you want your rocket, if you want to get a NASA contract or, you know, get a civilian space science research project, you know, on to another planet, you have to be qualified to go there. But how do you, it's a chicken and egg problem. How do you get qualified if you haven't sent a rocket to another, another planet?

So one incentive is if you can get a rocket to Venus and drop the payload into the orbit as planned,

now you can get to Venus, and you're another player in that space. But there may not be, you know, that's why we love science. You know, a lot of what we're driven to do, it's not driven by... Like a distinctive application or purpose. And so I don't know if we can really see like a giant future in privately funded space missions only because of what you said.

[00:15:19] Matt: Yeah, and if this, um, if this mission sort of all goes to plan and goes ahead, what are you, what are you hoping to find? What do you expect to find, uh, on this mission?

[00:15:27] Sara: Well, this mission is very simple and it's very cheap, low cost mission. Sometimes someone on the team, it wasn't me, joked, it's like throwing a rocket Venus because you're just sending a probe that's dropping down through the atmosphere. Well, we have a single instrument we call. The autofluorescence nephelometer.

And this instrument is going to shine a laser, a blue laser, through a window. And the thing we're really excited to look for is fluorescence. We are sending the light out to the cloud particles. And if they light up, do you know what fluorescence is? Like if you ever go to like a nightclub or like a kids fun house and the lights are off so it's supposed to be dark but then if you're wearing something white it just lights up like fluorescence.

And it, some very, a set of interesting molecules fluoresce. And if we see fluorescence, it could indicate that there's organic material in these droplets. So that they're not pure sulfuric acid with nothing interesting in them. Now, it won't prove there's life. That's not what we're setting out to do. But all life needs organic material.

So it'll be a clue that there's something very interesting happening in these droplets. The other thing we're going to try to do, is answer some lingering questions about the cloud droplets themselves. If the droplets are just pure sulfuric acid, like sterile, with nothing interesting going on, they're going to be spherical at the conditions they're at.

But the Pioneer Venus had a similar instrument, it couldn't look for fluorescence. But they actually found some of the particles appeared to be non spherical and not pure sulfuric acid, and those go hand in hand. So we're going to go back and try to constrain the composition of those particles, because we're also going to measure the backscattered radiation from these particles, and that has some encoded information about what the particles are made of.

[00:17:16] Matt: You mentioned that, um, you know, organic molecules being sort of necessary for, for life. I want to dig into that point just briefly. Um, you know, obviously on, on our planet, uh, all life that we know of is, is based on organic molecules, but what's your sense of, to whether that's true more generally? You know, is, is this a very constrained view of.

what could comprise life?

Or do we feel this is a fairly comprehensive view? You know, I would almost say, like, close to a necessary condition for life.

[00:17:46] Sara: I'd say so. I'm not an expert in And no one understands what could be a possible biochemistry elsewhere, but the sheer flexibility of carbon and hydrogen and how they work together and other atoms. Nothing really comes close.

[00:18:02] Matt: And, uh, to what, to what extent is, or how close is it to a sufficient condition? You know, if we, if we were to find many organic molecules, some similar to, to what we have here on earth, how much confidence should we, would we, should we glean from that?

[00:18:14] Sara: in general, or the Rocket Lab mission specifically?

[00:18:17] Matt: Uh, in general, but,

[00:18:19] Sara: general, yeah, because our mission will just only indicate whether something's interesting there, and whether it deserves, we deserve to go back and take a closer look. Well, life is about complexity. And when you think about complex molecules, you can ask yourself, do they come out of volcanoes?

Are they just littering the surface? You know, or is there a unique, or is there a set of molecules that we just don't expect to be floating around in the clouds? And so seeing a lot of complex molecules would definitely be an indicator that there's something extremely intriguing there. But before we get ahead of ourselves.

In this mission series, we've envisioned three missions, or maybe four, so we have our first mission to demonstrate we can go there and to find out whether these cloud particles are different from pure sulfuric acid. And if all of that is the case, it's like a green light for us to pursue our second mission where we would try to answer your question.

What is the range of molecules there? What is, what are some of the molecules if there are indeed complex organic molecules in the cloud droplets? There may be another mission, but what we ultimately want to see happen is a sample return from the clouds of Venus. And you may be aware that we're planning, we meaning NASA, is planning for a sample return from Mars.

And so, sample return, it's like, new trend, new trend, extremely difficult, very challenging. But some of the work will be done, not by us, but by NASA, when they figure out how to bring samples back. You know, we just had part of an asteroid brought back to Earth by NASA, and the Japanese have brought back part of an asteroid.

So many of the elements we know how to do. And we have spent some time working on what the mission might look like. But can you imagine, we have pieces of clouds of Venus, and we subject those to our very best instruments here on Earth, things we couldn't bring to Venus and couldn't float around in the atmosphere and do analysis with there.

[00:20:12] Matt: Yeah. It's absolutely incredible. It does pose the question, like, looking more generally at the search for extraterrestrial life, you know, whether in our solar system or not, um, on the methods, so, you know, if we could extract samples from Venus or Mars and analyze them, uh, obviously that's sort of, um, you know, one of the best indicators that we could do, but, um, you know, I think People generally think a lot about the question, how Should we, or how could we detect extraterrestrial life?

Um, I'm interested in your thoughts if we turn the question around and imagine ourselves as the extraterrestrial life to some advanced civilization out there, wherever it may be, and imagine that they were, you know, playing the same game and, and searching for life out in the stars. How would this hypothetical civilization likely find us?

You know, what, what would they see? That indicates that there.

is life here on Earth.

[00:21:06] Sara: Yeah, I love that question. And if we think about, if they're at our level of technology right now, they wouldn't be able to find us at all. They wouldn't even be able to find our specific planet, actually. So that's maybe something we want to talk about a bit later, but we actually have real experiments on this.

We have spacecraft that have been on their way to Mars, or on their way to someone else, that we've had look back at Earth and pretend like Earth was an exoplanet. And one of the really interesting ones was a mission went to Jupiter in the 1990s called Galileo. And it had to do a gravity slingshot of Earth, and there's a paper actually by Carl Sagan where they turned on the camera, looked at Earth, and did like a double blind experiment, just like you're asking.

Like, if we take this data, what does it tell us? And it wasn't, maybe, I don't know what your, I don't know what your expectations are. It wasn't conclusive that there's life here. You know, they could see oxygen, a gas that is, um, that's our favorite sign of life, by the way. Oxygen is made by plants and photosynthetic bacteria.

And our atmosphere here on earth has 20 percent by volume oxygen. But without life and photosynthetic bacteria, it would virtually have no oxygen. Oxygen is very reactive and has to be continually produced to be in the atmosphere. So if there's aliens looking at us from afar and they see oxygen, you know, they might be really suspicious that there might be life here.

On the other hand, you know, they might not. They might say, that's a terrible planet. It has so much oxygen. Oxygen is bad, right? It helps, it can cause fires. And they might look at our planet if they had super sophisticated technology and say, what a terrible planet. It has large raging fires covering big areas, like at any given time.

You know, they could have a list of why they don't like our planet. So it's really not clear. You know, that's, that's a very good question. They could see that our atmosphere has things going on that are suspicious, but they might. quite attribute those suspicious things to life.

[00:23:16] Matt: Well, what about, um, you know, there are some more active measures that people on Earth are taking to kind of broadcast our, uh, existence out there, you know? Things like submitting pulses, representing prime numbers, and those sorts of things. Um, I mean, suppose there were a civilization out there. Would that be something that would be detectable, or is this, uh, is this a bit of a farce?

[00:23:39] Sara: know, every once in a while, someone gets very enthusiastic about this idea and wants to start a group and wants to send a message. But what are your thoughts on that? The general consensus is not to do that. People are not wanting to broadcast our existence. What do you think about that?

Like, do you think we should go, yay, we're here, come in, come and find us?

[00:23:59] Matt: I'm not sure. I'm really not sure. I think it's a, I think probably, probably not. Probably not. I think that if you just look at the, the risk reward on that, I think we're erring too much towards the risk and not enough towards reward. Um, but it is intriguing and, and I do, I can imagine. That there would be civilizations who would have a different risk calculus and, and would choose to broadcast themselves,

[00:24:20] Sara: that's a really

[00:24:21] Matt: not sure.

[00:24:21] Sara: thing, right, because we're listening. We are spending a lot of money to listen, and if everyone feels like us, if everybody's listening and no one's sending that message, then it seems like it might dead end for us.

[00:24:33] Matt: Yeah, yeah, exactly. I mean, what are your thoughts? Like, should we be broadcasting, broadcasting our existence?

[00:24:39] Sara: I think, I'm not worried personally, I feel like any super Power aliens that could harm us probably already know we're here and so that's one thing the thing I like more That's concept. I like a lot more though is I like this thing. I like this concept about the ants I don't know if you ever get like a break in of ants to wherever you live, but you know, they're really clever They do reconnaissance So they'll come and look around a few of them like look around your kitchen and if they find something like if you've a chunk Of cat food on your counter, I don't this happens to you But then all of a sudden there's a steady stream of them and they're like coming

[00:25:18] Matt: I live in, I live in Australia. This is a sort of a daily occurrence.

[00:25:21] Sara: see. So, imagine that the stream of ants is coming by. You can like wipe out their trail and then they get confused for a while. But imagine if you wanted to talk to them. Tell them about your podcast. Like, how would you frame that to these ants?

[00:25:38] Matt: Yeah, it's uh, it's quite a conundrum, there is no overlap in our communication.

[00:25:44] Sara: what if we're the ants? And there's some super civilization out there. And they know we're here. I mean, you know the ants are there. Do the ants know you're there? I mean, probably. They must know somehow that you're there, but do they care? Like, maybe you're just so far... You can certainly wipe them all out, right?

You can poison them, you can do bad things to them, but... I don't know if they're really that aware. I'm just saying, like, I always wonder if we're the ants and the civilization out there knows we're here, but there's just no reason for them to want to contact us.

[00:26:14] Matt: Yeah, no, I think about that as well, and also if we are just searching for the completely wrong types of things, you know, um, you know, if you imagine the space of possible things we might call life or intelligence is.

very wide and The, the sort of biological forms of it are very, it's a very narrow sliver and we're sort of razor sharp focused on this, on this sliver and missing something larger.

[00:26:37] Sara: Well, dolphins are really smart. My dog is smart. We used to think my dog was the dumbest creature ever. But we learned that he's so smart he acts dumb and he had us fooled for like five years.

[00:26:50] Matt: yeah, I think it, I do think it's true. We definitely project a very narrow view of intelligence onto the world.

[00:26:56] Sara: I was just reading that roosters are smart. I read this article saying that one definition of smart is self awareness. Like if you look in a mirror and know that it's you and not someone else. And they did this test for roosters because they'll crow if there's danger. They alert other roosters. So they put a mirror in so the rooster sees itself and then they put a danger like a bird or some other kind of animal.

And the roosters didn't crow at themselves. But if the roosters get a one way window, so they can't smell or sense the other rooster, but they see the other rooster, then they will crow and warn it.

[00:27:28] Matt: Oh, very interesting. I mean, I've heard of versions of that where they would take a, an animal and put a mark somewhere on its

[00:27:35] Sara: Yeah, primate.

[00:27:35] Matt: and show, Yeah.

and, and the, actually the levels of self awareness seem to be pretty variable. There aren't that many

[00:27:41] Sara: Right. But this new study was saying you can put a mark on a rooster, but it doesn't really care. It's not aware of the mark, but it's self aware that when it looks in the mirror, it knows that it's looking at itself. And so they had to do a different test that made more sense for the rooster. So I'm just supporting your thought about how we're not defining, we're just defining intelligence differently.

I mean, imagine if we. I mean, dogs admittedly aren't as intelligent as we are, but imagine if you just had dolphins that became super intelligent, but they just live in the water and couldn't build a big telescope to broadcast.

[00:28:13] Matt: Yeah, exactly. I spoke to Michael Levin a little while ago, who's a, um, a very interesting sort of biologist, regenerative medicine guy, and, um, he made the point that every time we try to judge the intelligence of something, we're really taking an intelligence test ourselves, because it's a non trivial thing to do.

[00:28:30] Sara: right.

[00:28:30] Matt: Um, I'm interested in the mainstream view, or the consensus view, if there is any, among astrophysicists today on, um, How likely it is that there is life outside of Earth, maybe generally outside of Earth, and then within our solar system. My experience, um, and it'll be much more limited than yours, is, um, you know, if we were to go back, um, well, when I was younger, it seemed that more people were open to the idea that there was not, and now basically everyone I speak to Feels like there is and I'm not sure what has changed.

So, uh, what is, what is your, what is the, what is the mainstream view among astrophysicists today?

[00:29:07] Sara: Well, the mainstream view captures how vast our universe is. I mean, there are hundreds of billions of stars in our Milky Way galaxy, and we think there are hundreds of billions of galaxies out there. Our evidence right now says that most stars have planets. So if we have hundreds of billions of stars, and there are trillions of planets in our galaxy alone, we see the ingredients for life everywhere.

I mean, surely there has to be life somewhere other than here. So we feel fairly safe just saying that because the numbers are so vast. The harder question is, Is there life nearby, not just in our solar system per se, but around the nearby stars that our telescopes can access? And you might find some debate there.

But, what I love to say is, you know what? We don't have to speculate right now, because we've made big strides. We have, we all of us, we have found exoplanets and shown they're common. We have shown that rocky worlds exist, planets that are predominantly rocky like Earth is. And we have found that planets that are the right distance from the star, so as they're heated by the star, they have some chance of being the right temperature to host life.

Our next step, which we're doing right now, is we're trying to work towards finding water vapor. In the atmospheres of planets in their habitable zone so that we can say, you know, rocky planets, they only have water vapor in the atmosphere if they have a reservoir, a water ocean to get a water cycle and keep that water vapor in the atmosphere.

So we're just doing one thing at a time. And, you know, so we, we're making strides toward, so let's say that the rock, so we know rocky planets are coming. That's great. You know, I mean, if there weren't rocky planets everywhere. Would be harder. So we're just hoping we get lucky in that there is life everywhere and there is water everywhere.

And so we can then speculate or have a better answer for you.

[00:31:04] Matt: Part of me is, is very excited by this and then part of me actually starts to worry a little bit because, you know, reflecting back on the old Fermi paradox, um, you.

know, Fermi. Famously looked around it and asked the question, where are they? And I guess in the face of all this mounting evidence of, you know, the universe is, is bigger.

Um, there are more exoplanets out there, more spaces where life could emerge, you know, all these things that make it seem more likely that it should be there and we'll find it. I guess the question, where are they becomes a little bit. More difficult to answer or I guess the, this, the, the answers to that become a bit more constrained.

Um, and so maybe we'd love to pose the question to you. How do you, how do you think about the, the Fermi paradox and the question, where are they?

[00:31:49] Sara: Well, lots of things. My first one I love is the ant story. Where they're out there, but why are they going to come here? There's really no reason. The one I really do like though, and I know this is not in the spirit of the Fermi Paradox, but that it just takes so much energy to get anywhere. And that You know, society would have to use up a lot of their resources to go somewhere else, and maybe I just don't see why they would.

The one I don't like, but that I'm scared is true, is that intelligent civilizations self destruct, accidentally self destruct. I mean, we just have to look around at what's happening on our planet today. War, climate change, overpopulation, there's a lot of things going on. And so it worries me that that's the answer.

[00:32:35] Matt: Yeah, that's, that's what I was getting at. That worries me as well in the face of, it seems like there's increasing evidence that there will be life out there. And you would imagine, I don't know, maybe you have views here. You would imagine that a lot of them would go down this pathway of getting increasingly...

intelligent and, um, you know, where, where is, where is the filter,

[00:32:54] Sara: Where's the filter

[00:32:55] Matt: and is that, is that your, is that your, I mean, is there a, is there any, is there any sort of consensus or mainstream view as to where those filters are likely to be?

[00:33:04] Sara: No, no, I don't think so. But just one other thought, this is a bit of an aside and it's sort of, you know, maybe there are planets where intelligent life doesn't evolve. I once heard this amazing talk, I wish I could remember the details, and this evolutionary biologist was trying to convince us that we had five chances for life, intelligent life to rise on earth on five continents.

And he showed this really amazing thing. So wait, where did you say you were? Wait, where are you from originally? Okay. Okay.

[00:33:35] Matt: Oh, it's a complicated question. Originally from South Africa. but I've spent many times, a lot of time in lots of countries.

[00:33:41] Sara: Okay. That's why I couldn't tell where you were from, but this, um, evolutionary biologists started to explain how on each continent, there can be very different animals that fill the same niche.

Like let's take Australia, for example, they have marsupials. We don't have, as far as I know, I'm not a biologist, so I don't want to get out of my Zone of information, but usually like we have anteaters and they would have something else that still did that. And he was trying to say, you know, if every niche is filled, um, I'm not even a hundred percent sure I buy this, but if every niche is filled, there's no really need for anything else to evolve, you know, cause things just sort of move along and that was his opinion that we had five chances and life of intelligent life came out of one continent and he was pretty confident about that and.

was just trying to use that as a sort of help the answer along here. But we'd still have intelligent life if it was that easy. We'd still have it somewhere, but what if there was a planet where it just never got that? And you just had your local populations getting overpopulated and crashing and stuff.

[00:34:43] Matt: Yeah. Yeah, certainly, certainly worrying. Um, okay, well, let's, let's maybe then zoom out even further. So we started talking about our own solar system and you know, in Venus in particular, um, but zooming out further, you mentioned exoplanets. I think this is another topic you're very well known for. Um, and I think most people now.

would understand the concept of exoplanets. I think maybe what is not as well understood is just how recent this, um, how recently this came into the mainstream science. You know, as, as early as the 1990s, it was debated whether there were even exoplanets out there. And then, um, you know, the first few were discovered in the early nineties and I checked NASA's latest exoplanet archive before this conversation.

Apparently there are now over 5, 500 known exoplanets and Uh, about an equal amount of, of yet to be confirmed ones, which is roughly a new exoplanet discovered every second day since, uh, since the early nineties, which I find remarkable. Um, you've obviously been one of the, one of the key figures in, in this process.

Have you seen the field develop since the early days of skepticism about exoplanets until today where it's, it's completely mainstream?

[00:35:51] Sara: It is so crazy how it has evolved in just such a, yeah, as you pointed out, a relatively short time. In the early days, people, there were people who were violently against this. You know, you'd go to a conference and people were just angry. And, you know, planets are so small compared to the star, so low mass, so dim.

That it's very hard to find and many, you know, the first ways we find planets are indirectly on the influence of the host star. And not only that, it is really unfortunate in science when you build an entire theory over just one single example, our solar system. People were expecting to find giant planets like Jupiter far from the star.

Meanwhile, the first set of exoplanets were extremely close to the star, way closer than Mercury is to our sun, and they were giant planets like Jupiter. And we know from observations of star forming, there's not enough material to make a big planet right next to the star. So there's sort of layer upon layer of craziness there.

Just, you know, didn't make sense. people just didn't believe it. Peer, uh, other, I was a student when I started working on this. I was always a risk taker, and I had the chance to work on exoplanets, and I just decided to do it. And I wasn't even sure they were real, okay? I mean, my advisor, and my PhD, and another professor who was close to my topic, they believed.

I just thought, you know, if these turn out not to be real... I'll still be able to get a job somewhere. And even if I wanted to become an astronomer, I'd still have the skill set. Because the work I was doing on atmospheres involved complicated, we call it radiative transfer, how photons move through an atmosphere.

So I knew I had a skill, and I learned, was learning how to computer program. but wow, it was pretty shaky back then. And I was working on exoplanet atmospheres. And I remember, um, someone on my thesis committee would be like, well, we can barely find these exoplanets. How are we ever going to study their atmospheres?

And why was I considering clouds in the atmospheres? Because if we ever could, if we ever could discover an atmosphere or study them, there's no way we could discern if clouds were there well today, we've not only measured dozens and dozens of exoplanet atmospheres, but cloud, you can have an entire PhD thesis on clouds on exoplanets.

So as time went by, as time went by. Exoplanets became legit because more and more of them were discovered. And as they were discovered further and further from the star, the effects couldn't be explained away by like star variability or just some other random thing going on in the star. And there was really a pivotal moment when, um, two tech, two different techniques were able to be used on the same planet system.

And there was just no way that, that it could be anything other than a planet. So now you might be thinking, well, okay, great, that sounds happy. But no. And people were still against it because they thought the field would dead end. That because of our detectors and our ability to find planets, that we would kind of, you know, exhaust all the limited numbers of planets that we could uncover.

Um, and the reason is just because the star is always there. It's always big, it's always bright, it's, it's always massive, and it's just really hard to get around that elephant in the room, you know, almost like it's, it's just always there and you have to have techniques to work indirectly. So people didn't really think that, you know, people in the early days...

Um, never thought the field would get this big, especially this whole atmosphere thing. I remember when I was looking for a permanent, a faculty job. So you become a grad student, you get your PhD, you may be a postdoc for a while, it's sort of like post PhD training, you have to like prove yourself on your own, and then you look for a job as a professor.

And no one would hire me, that was just too scary. You know, they would say things like, There's this, there's a new technique called transiting planets that I was involved with. And that's when some planets and stars are so perfectly aligned, that the planet goes in front of the star as seen from our viewpoint.

If it's not aligned that way, the planet orbits the star, like in the plane of the sky, and it will never transit. Well, at that time, we had a couple of transiting planets, and one of the many things I did early on, because no one was working in the field, I was like able to pioneer many things. And one of the things that I invented was how to study atmospheres of planets.

When the planet goes in front of the star, some of the starlight shines through the atmosphere. And we can look at a star by itself. And we can look at a star when the planet's in front of that star. And we can look at the difference there. Think of like shining a flashlight through a fog. Some light makes it through, some light gets blocked.

And by looking at what light gets blocked at different colors, we can Yeah, that's the main way we observe exoplanet atmospheres today. There are hundreds and hundreds of people working on this, maybe more, but at the time applying for a job Invented this method which had even been successfully used already and people are like no that's not that's a one object one method success Meaning wow cute idea it worked in one case But I doubt we'll ever have anything bright enough or suitable enough to do this again And so then the thought was sort of like this is cute.

This is real and it's really cute Really, really cute, kind of fun. But it can't be serious because our detectors, our telescopes are meh. They're not good enough to take this field the distance. So then, after that, um, that was a little tricky. And then after that, it started to change a little. I would go around giving talks, and you'd always have the people would come to me and be, you know, if I was young, if I was young, I would do this.

These sort of older professors, and so the sort of change where people got more and more intrigued, and so that love we see today, like, from the public and the scientific community and astronomers alike, this sort of intrigue, that's why we're here talking to each other, and that just grew, and then younger people, as you know, because it's uplifting.

We've all been young before. There are young people listening. You often do things without thinking, right? And so then more and more people wanted to go in the field. They wanted to work on exoplanets. And then we saw universities, even though the older faculty didn't want to, because the students wanted to, everyone sort of had to move there.

Then those students themselves grew up and became faculty, so now the whole field is just multiplying.

[00:42:07] Matt: Yeah, it's, it's, uh, it's fascinating. I'm really interested in the, in the whole intuition there, you know, you mentioned at the start, like two, two things that really intrigued me. Um, one was that there was the skepticism of, of the existence of exoplanets and the other one was skepticism about how far this field could progress and, you know, how, how much we could end up being able to research and measure and so on.

Um, and I think I find both of these intuitions interesting because, um, well, first on the existence of exoplanets for myself. It feels that Observing that there are planets in our own solar system and knowing that, it feels like if, if, if we have to take a representative example of anything, that feels like the right representative example and we know there are other stars so, my intuition would immediately say, there should be more our solar system like stuff out there.

And then the second one similarly on the progress of science, again, if we look at our experience through history. Um, you know, increasingly there haven't been problems that we haven't been able to sort of really tackle eventually, we just, we keep making progress. And again, based on that, my intuition says basically all the problems will at some point be solvable.

I would be very interested to know about your intuitions in those early days, if you, if you can recall how you thought about those two questions, um, and, and if you've got any insight as, as to why, uh, those intuitions might not have been shared by others.

[00:43:32] Sara: Sure. Well, I remember one very distinctly because I was working with another young postdoc on trying to find the first ever planet by the transit technique. So we had to look, take a wide field telescope, look at tens of thousands of stars simultaneously and search them all with the computer, looking for a tiny drop in brightness that signifies a planet might be there.

And then we'd have to do some follow up measurements to make sure it was a planet and not another star. We were working so hard on this. Meanwhile, I go out to interview for a faculty position at a top university in the United States. And the professor interviewing me just says, Ah, there will never be very many transiting planets.

Well, today, you know, most of those 5, 000 are transiting planets. I think it's so successful. We've had the Kepler Space Telescope. The MIT led NASA mission TESS is churning them out today. Ground Base. And the reason why I found that so irksome was because I was working on it, and I knew how close we were to finding, unleashing untold numbers of them.

My team, unfortunately, myself and my partner, we failed. We didn't make this. We found other stuff along the way, but... Because I was working in the trenches, I literally knew what had to be done, and we know they're out there, we did the math. It was just a matter of getting everything to work. I mean, there's a lot of things like we have day night, we have bad weather, and just the right strategy, the right software, we were so close.

So I already knew that was wrong, and that intuition was based on actually doing things. Um, so in that case, that was some intuition right there. Then, when I was, at the same time I was doing that project, I did have a really amazing, the person who ran it, I hesitate to say boss because he wanted us to be independent, and he was very enthusiastic.

He'd be like, you know, if you have a great idea that can be backed up by physics, that is doable sometime in your lifetime, it is worth pursuing. And sometimes too, it's not so much of an intuition as just like a, youthful, energetic naivete, you know, so there's a bit of everything mixed together basically.

But now I've really honed my intuition. That's why I'm so enthused about Venus. I honestly, the chemistry we're finding is absolutely astonishing. And anyone who works on this will agree. But people just are reluctant to. Now to your question about why were people so hesitant. Well, Exoplanets has had a really checkered past.

There was the famous planet, I'm blanking on the name, In the 60s and 70s that was, um, you know, people thought that, well, some people thought there was, there were planets found and it had to do with the photographic plates and instrumentation change and it was just, yeah, it's had a checkered past where people have claimed there were planets and they weren't.

And then there's another case that comes from my home country, Canada, where the Astronomers had done a brilliant thing. They found out how to make measurements, like, one or two orders of magnitude better. Like, think about that for a moment. Anything you do, can you make it ten or a hundred times better? A better flavor of ice cream, a better, a better, uh, computer.

I mean, it's really hard, but they man And I could give you some technical details about how they did that. And they wanted to find exoplanets. But their telescope allocation committee, the peers who give you telescope time for your proposal, they were very conservative, and they monitored 20 stars for 12 years, looking for Jupiter, because Jupiter takes 12 years to go around the sun.

20 stars, and they didn't find, excuse me, they didn't find anything they could report on. And, honestly, if they had had 40 stars, they would have found something. Because planets are pretty common. And the planets close to the star have a whopping big signal that is unmistakable. And looking back at their data, there were one or two planets there in the end that they just couldn't find because the star was very variable or instrumentation got better.

So there's sort of a lot of things like that. Some checkered past where promoted planets turned out to be completely wrong. You know, the studies showing that they're just not, not there. They're not around every star. And so there was just some hesitance. There's also a thing in science called the giggle factor.

If I say, hey, I'm working on this and someone laughs, it just had that giggle factor. Like, people just couldn't take it seriously. And sure, we're, we're with you. We agree with you that we see stars being born. They all have disks around them, the ones we can see. It's like the dust bunnies under your bed or couch.

Like, they're gonna form. The planets want to form. They want to form. There's dust, there's... leftover material. So no one disagreed that planets shouldn't be there. Just the thought of searching for something that was so impossible to do, just based on how many decimal places you had to go to to uncover something next to the big bright massive star, people just thought that was silly.

[00:48:08] Matt: Yeah, but I mean, the amount of technological progress we have made is, is quite outstanding.

[00:48:12] Sara: It's absolutely outstanding. We all have a phone of some kind. It's just incredible.

[00:48:16] Matt: Yeah.

exactly, exactly. I mean, I think, um, a lot of people would still have the image of an astronomer, you know, looking into a, a telescope up at the night sky and obviously. The actual picture of it is nothing like that, it's, you know, advanced technology and complicated computing and, um, but some of the technology that I do find really just amazing is what we actually send up into, into space.

And, and one in particular that I know you've been involved with, uh, is called Starshade. Uh, would you mind telling me a little bit about Starshade?

[00:48:50] Sara: Yes, Starshade is a futuristic telescope idea. It is a giant, specially shaped screen that is tens of meters in diameter. And it has its own spacecraft, and it would formation fly in outer space with a telescope, tens of thousands of kilometers away from the telescope. And Starshade would block out the starlight so we can see the planet directly.

So imagine like the bright star and the glare block out that light so only planet light enters the telescope. In the star shade it's like a giant sunflower. It's a huge, big, beautiful thing that was first conceived of in the 1960s by the same person who conceived of the Hubble Space Telescope. But Starshade is so big and you have to line it up so precisely with the telescope, it wasn't buildable back then.

And what's really fascinating is that Starshade, or some form of it, was picked up again every decade, and then shelved for one reason or the other. Until 2013, I was so excited to get to lead a Starshade study. And I only found out afterwards that one of the reasons the Starshade study was started was to, for lack of a better word, kill Starshade.

It's very helpful to know what works and what doesn't. And if you can study something carefully and say, it's not going to work, it's a really good to know that actually, because we have another way to block starlight. And instead of having the giant screen on the outside, we can put like a tiny little screen, if you will, on the inside of the telescope.

And so both ideas were being studied and it turned out we showed starshade is not only doable. We showed that starshade is not only good idea, a good idea worth promoting. But it's actually very doable and has heritage and large radio deployables that we put out there to listen down on Earth. So Starshade, um, is something that is quite mature.

There's been lab demonstrations. We're super excited about Starshade. But not everyone's excited about Starshade. And it hasn't been chosen to be like the thing to go forward at the present time.

[00:50:52] Matt: Do you feel that at some point it, it will,

[00:50:54] Sara: I feel like it

[00:50:55] Matt: built, it'll be sent up

[00:50:56] Sara: I'm, I do think, logically speaking, if you look at the numbers of how mature Starshade is in terms of its buildability, and this sort of very, and this very simple, clear idea of blocking out all the starlight before it hits the telescope, it has to happen.

[00:51:16] Matt: And so maybe let's just briefly talk about the, the physics of, of Starshade a bit because a lot of my listeners are really into physics. So the, the idea here as I'm understanding it is, you know, basically too much starlight blocks, you know, prevents you from being able to see a planet. have this very intricate, interesting design, um, which is actually very fine tuned for technical reasons to block starlight so you can see the planet.

Can you

[00:51:40] Sara: Well, yeah, let's back up. Let's back up a little bit because not everyone will have this experience and I'm not sure I don't think you live somewhere where this can happen now, but if you ever try to take a picture in winter, there's like a lot of snow, fresh, bright snow. You want to take a picture of your friend.

It's nearly impossible actually, because your friend would be very, very dark and the snow is so bright, overwhelming, you know, your detector and you could say, okay, well, I can, You know, you could really lengthen your exposure so the person won't be dark, but then the whole thing will get washed out from all the light from the snow.

So the planet Earth compared to our sun in reflected light. It is 10 billion times fainter. So it's not like the person in the snow, it's way, way, way worse. So if you were just to take that image of the, a picture of like the planet and star with a fancy space telescope, you know, the glare of the star would overwhelm the detector.

And you could say, well, why don't I just take a really fast exposure, not let, you know, the light from the star won't bleed all over my detector. But you wouldn't get any photons from the planet then. Because it's just so faint. So we have to block out the star because otherwise we can't get a signal from the planet.

It's just overwhelmed by the star. So that's the kind of bigger picture. But as to the shape of it, let's imagine we put a giant screen, a circular screen in space, and we block out a star, a point source of light. Well, unfortunately, the picture we take, or the image, won't be just dark, because we'll get an airy ring pattern.

The light can act like a wave, and it can bend around the edges of a circular screen, and there are ripples of light, just like if you dropped a pebble in a pond, there would be ripples. And those ripples of light are actually way brighter than the planet we'd be looking for. So, instead, people figured out that mathematically, you can just have a different shape.

Not a giant circle in space, but this flower like shape with these giant petals that have very, very long, sharp tips. And then, when the starlight bends around the edges in this very complicated pattern, it can interact with itself and cancel itself out. So in this case, that point source star, that would be like dropping a pebble in a pond.

And now the pond is perfectly smooth to one part in ten billion. And all the waves are pushed to the outer edges.

So just think about that for light. The light is bending around and it's cancelling out.

[00:54:10] Matt: this? It's phenomenal. Um, and I will, I will link a little video, um, to the starshade, um, sort of design into the show notes here. But I mean, when looking at it, I found it just absolutely amazing that for, you know, something that was designed for you know, very technical reasons, you know, it was for physical reasons that it was designed with this way.

It actually resulted in something that was outstandingly beautiful and, and did, did look like a flower. Um, and it actually made me think of the, of the concept of, you know, beauty and all that, that people get when they look at these things and look up into the sky. I think something most people can probably relate to whether scientifically inclined or not is.

This um, sense of beauty and mystery and awe one feels when looking at the stars on a clear night sky. Um, I would love to move to this, this topic and, and ask you, you know, after so many years in the field, uh, if you do imagine standing outside on a crystal clear night, looking at the stars, looking at the moon, um, what, what do you feel, how do you feel looking at, looking at the night sky?

[00:55:10] Sara: My heart beats fast.

[00:55:12] Matt: That's amazing.

[00:55:13] Sara: I love the night sky. I look it up at every time I step outside. I'm a really early riser, and I get to work super early, and it's dark now, unfortunately, when I leave my house, but I, the night sky is amazing. I see Orion in the morning. Venus is so bright in the sky. Sometimes I get to see, I love the crescent moon, you know, just before it's about to go to new moon or comes out of new moon, and it's amazing.

I get to, sometimes I get to see the Perseid meteor shower in August. And occasionally, just occasionally, I'm out west, in the western United States, where there are some areas that are incredibly dry. When you think of the Rocky Mountains, the eastern side is dry. So dry. And if you go there and at night time, I mean, just wow.

The sky is so clear and beautiful, and I feel humble. And I feel... I feel the vast awesomeness of the universe.

[00:56:06] Matt: Yeah, that's, that's beautiful. It's, um, it reminds me, Star Shade in particular as well, because of the flower shape, it reminds me of a famous reflection by Richard Feynman. I can't remember where it came from, but he talks about talking to an artist friend of his about the beauty of a flower. And, um. The friend says, you know, I can perceive the beauty in this flower, but you scientists, um, you know, you reduce it to, you know, equations and so on, and you don't see the beauty and Feynman has a visceral reaction to this and he says, um, you know, I see it only as additive.

I mean, I can, I can still perceive the beauty of the flower, but I also see different levels. I can think about the cells, I can think about the molecules that make it. I can think about, you know, the fact that flowers have color. And that insects are attracted to these colours means that insects can perceive something like a colour and that tells me something.

Um, and so I think, I think the exact quote of Gautier is that he says, Science knowledge only adds to the excitement, the mystery and the awe of a flower. It only adds, I don't see how it subtracts. Um, and I would love to, to ask you, you know, over, over the time if you reflect back on how you felt when looking at the night sky when you were younger, without all the scientific knowledge and experience you have now, versus today.

How, how has that evolved? Has there been a change there? Has it, is it enriched? Has it diminished? How has it changed?

[00:57:29] Sara: It's, uh, that's a, just such a wonderful question. I really have never thought of that. changed. I just go out to the sky and I still feel that same excitement and that same joy when I see the night sky. In one way it's changed though because I'm working hard to find another Earth and I do envision the day when we can all look at the night sky together and we can point to a star and say that star has a planet like Earth.

And now I know exactly what we need to get there, and that's a really huge desire on my part. But I do try to just enjoy the beauty without over analyzing when I get a chance to see the dark night sky.

[00:58:09] Matt: No, that's beautiful. And, and, um, I don't know if you have a ready answer to this, but when you think about it, you know, what, what are the most, the biggest mysteries, most beautiful truths out there, what comes to mind? What do you find to be the most Beautiful, almost mysterious aspect of, of what's out there.

[00:58:27] Sara: Well, so many things. The origin and evolution of life is one of them. Like, if you ever start to learn biology and chemistry, like I'm trying to do now, for Venus, like, you just can't imagine, like, how everything came together and made us. So that's one of them. How did life originate and how did it evolve?

When we have an astronomy that's not in everything I think about every day is dark matter and dark energy that make up so much of our universe, the fact that so much out there is so mysterious, we don't even know what it is, it's literally mind boggling. I just love the planet Earth and how everything works together synchronously.

And sometimes it comes into play when you hear about an invasive species that just starts to destroy things and you're like, wow, that's just so crazy. So I just think the whole way ecology and biology and everything works together to me is a big mystery, how it came to be.

[00:59:20] Matt: Yeah, I'm sure, I'm sure so many people listening will be feeling the same way. And I mean, being led by curiosity, there's so many things one could look at and one could study. Um, and I'm sure many would be interested in digging deeper into. The fields we've been, the topics we've been talking about. Um, and so maybe let's turn to the topic of advice for someone interested in this field.

Again, think of, it doesn't have to be.

a young person, but probably a young person, you know, exploring, looking to get into, um, a field similar to you, very generically, knowing what you know now, what advice would you have for somebody? Just starting to explore this space.

[00:59:56] Sara: Well, before we get there, I do have some advice I'd like to share. That is, whenever possible, find something you love doing that you're also very good at. If those two things coincide, you have a winning combination. And it's really important to try to pursue that. Now, not everyone has that. You don't always find the thing you love is also the thing you're really good at.

But it can happen.

[01:00:20] Matt: I love that advice. And if there is a third dimension of something that the world needs, and you can find a combination of all three, all the better,

[01:00:27] Sara: I would say, if you find something you're interested in, if you find something you're interested in, like space, find out what the skills are that you need and start working on those. So in astronomy today, you need to be good with computers. You don't need to be like the best ever computer programmer, but you need to have, you need to be comfortable using software and hopefully you can learn how to use Python, like at the minimum to manipulate code, to use like libraries that exist.

As we were talking about, that wasn't true back in the old days where in the old days you'd have to be really good with the telescope, go to the telescope, know how to use it, maybe build your own instrument. Today, the typical astronomer. You may go to the telescope, but it's very rare now. Your observations get planned as cue observing or with a space telescope.

You do kind of plan it, but a lot of it is done for you. So today's astronomer needs to know how to, how to use software and how to program is a really important skill. The other thing that's really important too, which may not be what you're expecting, but it's like to follow the thread of your curiosity.

So get that skill going there. So like, if you read something that just doesn't sound right, don't just go, Hmm, that's weird and shelve it. Like take the, pursue that, go look it up, go read it, find a way to get to the bottom of that. Because being a scientist, that's really key is, you know, a lot of things, a lot of things come across.

We find a lot of things, but knowing, building that intuition of what's interesting, what's unusual is really important as well. And then my, I have more, one more thread of advice, and that is to Peers and mentors who can support you. Don't work in isolation here. So find some friends. If you're joining an astronomy club, if you're older, if you're in school, find other people.

And along those same lines is build confidence. You know, you have to find a way to build confidence in yourself as you gain skill and experience so that you can hold on to your dream and make it real.

[01:02:26] Matt: does somebody come to mind for you as a sort of a friend or a mentor who has been particularly formative?

[01:02:33] Sara: Well, I have to say it was my dad. He was a very eccentric thinker, and this had to cause me to do a lot of research on my own. He believed in reincarnation, and especially that we were so close that we would be always together. We might come back as business partners or brothers or like husband and wife or something, but he was quite convinced of that.

So when I was 11 years old, I had to go to the library and read a ton of books on this. And I decided I just don't believe that. I just can't. So in a way he was really amazing because he was so eccentric that I had to check things on my own and I got used to sort of being my own scientist detective at an early age.

But he was a big believer in the power of positive thinking. And as a, as my, my dad, he wanted to make sure that I knew how to have a vision for my best self and how to make that real. That's something that has always, always stayed with me. He's not alive now, but, um, in terms of believing in yourself, you know, it's good to have someone believe in you, but ultimately you have to believe in yourself to make yourself, um, kind of happy, peaceful, and successful.

And so I'd say I, I'd say it was my dad who really instilled in me what I needed.

[01:03:47] Matt: Yeah, amazing. And, uh, you mentioned that, you know, based on, based on what you learned from him, you know, you spend a lot of time reading. And as we sort of bring this towards a close, we'd love to turn to the topic of books. Um, you're obviously a very well read person. You've also written several books, both, um, academic books, and you've written a very beautiful memoir, which I, which I have here.

And I'll just briefly flash up to the screen for a bit, smallest lights in the universe, uh, which, uh, was just beautiful. Um, Maybe let's turn then to the topic of books. One of the questions I love to ask my, uh, my guest towards the end of the podcast is, which books have you most gifted to other people and why?

[01:04:27] Sara: Oh, that's, that's actually a good question. Let me think about that.

Well, I'm having trouble remembering the last time I gave a book to someone. So let me, let me, I have favorite books for sure.

[01:04:36] Matt: Can be favorite books. That's a,

[01:04:38] Sara: Well, I would like to talk about one of my favorite books. So you remember being in school and assigned books, right? Well, there's a book that was assigned after I was already a grownup, but I had kids in school. And so I read some of their books. And this book is called The Giver. And it's by this author, her last name is Lowry or Lowry.

And if you haven't read it, you definitely should read it. It's about a utopian society, and

this book it follows the main character, a boy. Who comes of age and realizes he sees for himself that it's not actually and so this idea that we're all just in our own little world Just kind of getting through life just getting by sometimes right like sometimes you're literally just getting through the day you aren't able to step outside and see what's really there.

And so that book really hits at home I can't give you the spoiler because it's just mind bending and it's not too hard of a read because it's like a middle school book But I was just like, you know browsing my kids book and I got I just fell in love with that book in a huge, huge way. Love that book.

[01:05:50] Matt: amazing. Amazing. Yeah. Oh, we'll definitely link that one in the, in the notes. Um, and have you, have you ever been, have you ever been gifted a book by someone else that, uh, you know, was particularly memorable that really

[01:06:00] Sara: I definitely have one that changed my life. I have two, actually, that I'll tell you about. Um, so in Canada, there's a famous character in a book called Anne of Green Gables. She's an orphan and her, the author, Lucy Maud Montgomery wrote this book like well over a hundred years ago. But when I was about nine years old, I got a gift, like a holiday gift, like a Christmas gift.

And it had this bright yellow hard cover. And the book was a little bit beyond my ability. So like it was really hard to read. And I got this book from my step grandmother who I'd met for the first time. And the book just fell in love with this character and this character, Anne of Green Gables is famous all around in the world and people go to, she's a fictitious character, but, you know, she stood up for herself and she was vivacious and obnoxious.

You know, most girls were trained to be very obedient and not to rock the boat. And so her spirited existence, also being an orphan and getting to, you know, an actual family, it's just such a warm. spirited book. And so that book for children, for, you know, girls especially, it's just people all around the world love it.

And that, that would be one that definitely made a difference. Another book, which is sort of strange, is when I was in my early 20s, um, I definitely, I joined the outing club at my university, and I had always loved canoeing and canoe camping. I'm more into hiking now, and I've even tried some mountaineering, but where I lived in Canada was super flat, and there's a lot of lakes.

And there's a lot of rivers too in Whitewater. And I, my um, one of the physics professors told me I should go to this symposium he organizes called the Wilderness Canoe Association. And there like 800 people go, mostly armchair explorers. And I bumped, I want to say I, someone at that meeting, Said read this book.

Well, two books actually, but read these books. It will change your life. And one of the books was called Sleeping Island and it was this teacher who every summer would take off the entire summer bleeding into the fall and go exploring and he went to like parts of Canada where I don't know how and why, but there weren't even maps yet.

And this was like, it was like either, I think it was like in the 1950s. You know, how, how is that possible? How is there no map or maybe no maps accessible, but that idea of exploring and being able to go somewhere like under your own power and see the wilderness on your own. And I followed part of the root of that book the next summer with my, um, then canoe partner.

We went in this two month journey. Like in the wilderness and no other people for hundreds or even a thousand miles or more. So like that book, just the spirit of exploration and the fact that you can, not very easily, okay, it's definitely not easy, but you could get the skill and go somewhere new, like, and really truly explore.

[01:08:45] Matt: That's, that's just incredible. Um, yeah, we'll, we'll link those two as Well, Um, and I guess maybe that brings us very nicely to a final question. You know, you talk about exploring the unknown and, um, get back to the, the question of, uh, extraterrestrial beings and exploring out of space, a bit of a sidestep question, but imagine we were to, uh, to find an extraterrestrial advanced civilization out there, or we were to be visited by one.

Um, and we had to pick. One person from humanity the past the present to represent us to this extraterrestrial other who should we send?

[01:09:20] Sara: Well, I don't know who we should send specifically, but I know the kind of person I'd want to send. Um, I mean, I'm not thinking it should be anyone super famous or, you know, even very accomplished, but I'd want someone who represents, you know, the best we have to offer, in terms of being like a kind, generous, approachable, flexible person.

I'm actually thinking of my best friend, Melissa, who you've read about in the book. She's in the book and she's just so like, she's like a shining sun. And honestly, even if it, if you, if I had to like send an ambassador to meet even a stranger human or a strange alien, it would be Melissa or someone like Melissa, that person that is just so warm and well, I can't even, I want to like imitate her, but I can't, but just, it's just so you meet this person, everything about her is welcoming.

And I would want that. I'd want someone who, so the aliens know that we welcome you. But Melissa's smart enough to see through any BS too. So if like these aliens really wanted to nail us, like, she would know right away. So I'd want to send somebody like that.

[01:10:19] Matt: Yeah, that's great. It's great. I've had very few people like elect famous people or politicians or it's, it's, it's usually sort of the, the good things about humanity, gratitude and kindness. And so,

[01:10:31] Sara: that's really wonderful.

[01:10:33] Matt: so this has been a direct conversation. Is there any final thing that you would like to, to share anything that you'd want to send to the listeners or if people wanted to find you, where should they, where would you send them?

[01:10:43] Sara: Well, they can find me on Facebook, on Twitter, which is now X, or on threads and Instagram as well. But my, my advice to people is, you know, to just take a step, take a step. It's to, um, take a step back and to try to think about what really matters. And try to invest there and invest in yourself so that you can also give back to the world in some way.

[01:11:10] Matt: And I could not think of a better way.

to, uh, to wrap the conversation. Sarah, it's been an absolute pleasure. Thank you so much for making the time

[01:11:16] Sara: Well, it was really a great podcast and thank you so much for having me.

[01:11:23] Sara: That was amazing. It's one of definitely the better, yeah, one of the best podcasts I've been on. So how did you come on, how did you come into doing these?

[01:11:32] Matt: I have always, I mean, it goes a long story, I actually mentioned the story on, on another podcast that I was invited on, but, uh, I just had the great fortune of, you know, when I was much younger, I was born in, to not a very sort of privileged environment in South Africa. And then by a series of events, I found myself getting to study at some amazing places.

So I went, I did my master's at Oxford, um, and I didn't finish a PhD at Cambridge, but I remember finding myself. Exposed to some of the best academics in the world and just feeling like it's kind of, it's just by luck that I get to have these conversations and I would love more people to, to be able to be exposed to them.

[01:12:10] Sara: And is this your main job or do you have another job?

[01:12:12] Matt: no, no, no. So this is definitely not, no. So I, I, um, I work in, for tech startups. I, I, I'm head of operations at a global sort of clinical AI company, and this is very much a, an important side thing.

[01:12:24] Sara: Interesting. Well, you're very good at this. And it's, it seems like it's along those lines of something you love doing that you're very good at. So I just wanted to emphasize that.

[01:12:31] Matt: Thank you so much. I really appreciate that. Yeah, it's, it's, uh, sort of the, my, um, one of the most important things for me is that.

you know, if I think of what guest experience do I, do I want to generate, I want them to look back and say, that was sort of my favorite, um, that was my favorite interview.

[01:12:45] Sara: Well, you know what I'm doing, where do I find your podcast, because I'm definitely going to download a few for my weekend.

[01:12:51] Matt: Oh, appreciate it. Um, I'll, I'll email it to you after this. ​

Conversations with the world's deepest thinkers in philosophy, science, and technology. A global top 10% podcast by Matt Geleta.