The Search for Life in the Universe with Adam Frank
ABBY ZABRODSKY: I am Abby Zabrodsky, a member of the Hajim class of 2014, and I completed my MBA at the Simon School in 2019. I am also a member of the alumni board, a group made up of 25 members representing each of the university schools with the purpose of engaging all alumni and students in a lifelong connection with one another and with the university. I would like to take a brief moment to thank everyone who participated in our 2023 Day of Giving yesterday.
Over 3,800 donors gave, with over $3 million raised. Every gift, no matter the size, makes a difference in the lives of students, patients, researchers, faculty, staff, artists, and musicians, and so many others around the world. Today's session is part of a series launched in April 2020 called Experience Rochester that exemplifies the university's commitment to lifelong learning. The series features topics and speakers unique to the university. Today, we are joined by renowned astrophysics professor Adam Frank, who will help us consider the potential for life in the universe. Adam Frank, Helen F. and Fred H. Gowan Professor
of Physics and Astronomy and LLE Distinguished Scientist, studies the processes that shape the formation and death of stars and has become a leading expert on the final stages of evolution for stars like the sun. Adam is a theoretical computational astrophysicist and heads a research group that is developing new tools for simulating the cosmos. Adam, who describes himself as an evangelist of science, is actively involved in science outreach as a popular writer.
He is the cofounder of Big Think's 13.8 blog, an occasional contributor to The New York Times, and a periodic guest to CNN, where he explains the latest developments in the world of science. Adam received the science-writing prize from the Solar Physics Division of the American Astronomical Society in 1999 and was awarded the 2021 Carl Sagan Medal for public communication for his sustained efforts to make science broadly accessible.
Adam's third and most recent book, Light of the Stars, Alien Worlds and the Fate of the Earth, explores a new vision for climate change and the human future by placing them both in their proper astrobiological context. He received his PhD in physics in 1992 from the University of Washington and joined the faculty of University of Rochester in 1996. At the end of his presentation, Adam will answer as many questions from our audience as time will allow.
You can put your questions in the Q&A box on your screen at any time. And now I will turn it over to Adam Frank. ADAM FRANK: Hello, everyone. Thank you very much for coming today. I'm really excited to have this chance to talk with you.
And what I'm going to be talking about with you is-- let me share the screen. This is going to be a little talk about aliens. And I'm going to be talking about the search for life in the universe, the scientific search for life in the universe. And in the end, I want to talk about why looking for other civilizations is really about the future of our own. So this is actually the topic of my new book, my fourth book, which is called The Little Book of Aliens, and that should be available at the end of the year, around November. Very excited about this.
It was super fun to write. So what are we going to talk about today? We're going to do, first, a brief history of aliens. What I mean by that is human beings thinking about aliens. And then we're going to consider something I call the three revolutions of astrobiology. Astrobiology is the field of thinking about life in the universe in a cosmic perspective rather than just focused on Earth.
Then we're going to talk about something called biosignatures, and then we're going to talk about something called technosignatures. These are both ways that we have to find life now using telescopes. That's the main thing I want you to come away from this talk, is we are now poised to find life in the universe. Like, it's game on now in a way that was never possible before. And then, finally, I'm going to conclude by just telling you why does this matter, what's important about this.
And I'm going to make the argument, which is what was my last book was about, about something called the astrobiology of the Anthropocene, which is really climate change, this global crisis we're facing, that we've changed the Earth's climate. So I want to talk a little bit how these ideas fit into that. So let's begin with a brief history of aliens. Now, this is interesting. The question about whether or not we're the only life in the universe is a very old one.
It goes all the way back, in fact-- it actually may be humanity's oldest question. And you can see the Greeks-- if you read the ancient Greeks, you can see them arguing with each other about it in their writings. So there was Aristotle, for example, who believed that the Earth was the center of the universe, and so, therefore, there was no other planet like Earth, and all the other planets that we saw orbiting-- or they didn't even know that the planets orbited the sun-- all the planets in our solar system were just lifeless worlds. They had nothing to do-- there is no way-- no possibility for life to form on them.
So Aristotle was what we might call an alien pessimist. He did not believe there could be any life anywhere else. But then there was Democritus, who said, "There are infinite worlds both like and unlike our own. And in all of these worlds, there are living creatures and plants and other things we see in this world."
So Democritus was a alien optimist. He believed that there was-- life would be-- there were going to be planets everywhere. We're going to see that's an open question, whether or not other stars have planets orbiting like them like the sun has many planets orbiting it.
So he believed there were many planets and that there were many-- that each of those planets-- or many of those planets would be inhabited. So the modern-- so people have been arguing about this forever. There's a whole long history we can go through-- the Middle Ages and into the Renaissance.
But the modern story of thinking about aliens begins with Enrico Fermi, who was a great scientist, Italian American scientist. And in 1950, Fermi and his friends were on their way at the Los Alamos National Laboratory, the nuclear weapons laboratory, to lunch, and they started talking about UFOs because, actually, this cartoon had shown up in The New Yorker magazine. UFOs were a new thing then, and the cartoon was-- this was an explanation of-- apparently, all of New York City's trash cans were disappearing.
So this cartoon blamed it on UFOs. But being scientists, the four friends, as they were walking to lunch, were asking about the possibilities for interstellar travel and working out some details in their heads. And then the conversation moved on. And then, about half an hour later, over lunch, Fermi says, but where are they? Where is everybody? That was his quote.
And really, what he was saying in that-- this was the beginning of what we call the Fermi paradox. What Fermi realized was that, look, if interstellar civilizations are common, that even if they travel at a fraction of the speed of light, they can hop from one star to the other and get across from one side of the galaxy to the other in about 600,000 years, which may sound like a long time, but the galaxy is 10 billion years old. So what Fermi realized, the question he was asking, look, if interstellar civilizations are common, then why aren't they here right now? Why haven't aliens landed on the White House lawn and announced themselves? So that's something that's going to be called the Fermi paradox. And we're going to come back to it because it's very important in the history of thinking, the modern history of thinking, about aliens. So here's, actually, a simulation that my group did. All the blue dots here, that's the galaxy.
The Milky Way galaxy is a pancake of stars. And right there is one civilization-- one civilization-- that's going to start sending out colony ships. And what you're going to see from this-- I'm going to run it.
And you can see the galaxy evolving. It's slowly rotating. And now, all of a sudden, you're going to get that one star, that one planet sending out colony ships. And what you see is, very quickly, it sweeps over the entire galaxy.
So let's run that again. So you got the whole galaxy. It takes about 250 million years for the galaxy to do one rotation. And what you can see is, in a fraction of the rotation, these ships have been able to spread across the entire galaxy. So that's the Fermi paradox. What's important about the Fermi paradox, it was the first modern, scientific question about aliens.
So what we see in the beginning of the 1950s, we begin to have the capacity to start asking questions that science can answer as opposed to just people yelling at each other with their opinions. We want to go beyond opinion and be able to answer this question about alien life scientifically. So the Fermi paradox was the first question that could at least be scientifically formulated. The next big step was 1958 through 1960, where a young Frank Drake-- that's him here-- he uses a radio telescope for the first search for signals from an extraterrestrial civilization.
So this project initiated what we now call SETI-- the search for extraterrestrial intelligence. The project, he called it, was Project Ozma. They looked at two different stars. They looked for about six months. They could not find anything.
So the search was unsuccessful in that way. But it launched the modern effort at looking for life in a direct, scientific search, searching for life in the universe. So people have-- so there's this other version of the Fermi paradox. So the first version of the Fermi paradox are why aren't they here right now.
Why haven't they-- why aren't the aliens already here in Washington, DC, in Paris announcing themselves? There's another version that people talk about, which is very much related to these radio telescopes, which is sometimes called the Great Silence. We have radio telescopes. People have been looking. Why haven't we found anything? Why haven't we been able to detect the signals from a distant intelligent civilization? And I'm going to give you the answer right now-- but we're going to come back to it-- is that there is no-- this version of the Fermi paradox is untrue. Because people have this idea that, every day, astronomers are looking through the sky for signals of extraterrestrial intelligence.
And that couldn't be farther from the truth. And we're going to see the reason why. But in a nutshell, we've never had the money to look. There's just been a few SETI searches here and there, once in a while. There's never been funding for it, so we haven't really looked.
So that's really the answer. Anybody who tells you that we have searched the sky for signals of intelligent civilizations and we haven't found them just doesn't know what they're talking about. It just hasn't happened.
And we're going to see, actually, one of the reasons why. Other important ideas if we're thinking about alien civilizations is-- and what I mean by important ideas, ideas that came up when this project was-- the modern project was started-- 1950s, 1960s, et cetera-- that we still use. One was this idea of alien megastructures. It was Freeman Dyson, a famous physicist, in 1960, who said, you know, if a civilization gets advanced enough, it's going to need more and more energy, and one thing it could do is try and capture all of the radiation coming from the sun, all the energy coming from the sun by building a giant megastructure, a huge piece of engineering which would basically be a sphere surrounding the sun, capturing all of its radiation.
And this is what's called a Dyson sphere. And it's an idea that, really, as we're going to see, comes up again and again-- and still comes up. Because one of the interesting things about this kind of megastructure is you would be able to see it from a great distance. If the sun-- if you're capturing all of the sunlight, that machine actually warms up. The Dyson sphere warms up. And by looking in infrared, you might be able to see it, even from across galaxies.
So the Dyson spheres are an important idea. Another important idea which has propagated over the decades was what's called the Kardashev scale. And Kardashev was a Russian physicist. And he argued that, just like with Dyson's idea, what you can imagine is that any civilization that is advancing technologically needs to harvest greater and greater amounts of energy. And you can think about the progression of civilizations in a very general way such that there is-- he had three different classes of civilization. What we might call a type I-- a type I civilization is a civilization that could harvest all the energy falling on the Earth at one time.
We literally have hundreds of atomic bombs worth of energy falling on the Earth every second. So if you could capture all that energy, imagine what you could do. That's a type I civilization.
A type II civilization would be like a civilization that could build a Dyson sphere, could capture all of the light coming from the star, not just the starlight that falls on a planet, but all of the starlight. A type III civilization would be able to capture all of the energy produced by all of the stars in a galaxy. And a galaxy is about, typically, 100 billion or 400 billion stars.
So this Kardashev scale is an idea that's really endured as well. And even now, we still use the Kardashev scale in our thinking, even as we try and push beyond it. So those are important ideas that exist or that started from this-- I'm going to call it the golden age of SETI, from 1950 to mid-1970s. It was a lot of excitement, a lot of enthusiasm. We even got to the point in the 1970s where people were proposing these enormous projects.
This was Project Cyclops, which was going to be 100 huge radio telescopes that was going to be so powerful it could detect very, very, very faint signals from alien civilizations. But then something happened which is really important to our story of thinking about aliens, and that was politics got involved. So, basically, SETI was killed by politics.
And it was politicians trying to use any funding for SETI as a way of getting their name in the press. So, for example, in 1978, Senator William Proxmire, he used to give this Golden Fleece Award to any project he thought was a waste of taxpayer dollars, and somehow he found out about SETI. So NASA was going to fund the SETI program-- a tiny amount of money, $2 million, which is chump change in the federal budget-- but Proxmire thought like, yeah, hooray, I can get in the press for this, and so he gave SETI the Golden Fleece Award and stopped Congress from funding any more SETI projects. Carl Sagan intervened and actually convinced him why SETI was important.
So Congress again funded it, later in the '80s. But then, in the '90s, it happened again, twice. NASA twice tried to fund SETI projects, and two congressmen, at different times, stood up and said, ha, ha, ha, I'm going to kill this project.
It's a waste of taxpayer money. We don't need any searches for little green men. I can go down to look at the National Enquirer and see pictures of little green men. So very much what we call the "giggle factor," very much associated with UFOs and all the nuttiness that goes on with UFOs, Hill was able to kill the scientific search for SETI. So from the 1990s, early 1990s onward, NASA wouldn't touch SETI. There has been no federal funding for SETI at all.
Nobody has money to use a radio telescope to search for-- so that's an important thing to understand to understand where we are right now. OK, so politics wanted to kill SETI, but nature and science had other plans. And we're not just talking about SETI now. Let's go beyond that. I'm interested in the search for any kind of life.
It doesn't have to be intelligent. Finding any example of another instance where life formed on another planet would be a game changer. We can talk about why in the end. But that would-- so we don't have to confine ourselves just to intelligent civilizations. Any planet that had a biosphere would be a remarkable, game-changing a discovery. So now I want to talk about something that happened in science, which was the three revolutions in astrobiology, this field of thinking about life in general-- not necessarily intelligent life, but life in general-- how much that changed things.
So the first of these revolutions was exoplanets. So I want to remind you that up until-- when the Greeks-- when we were talking about the Greeks talking about life in the universe, they didn't know whether there were any planets in the universe other than the ones in our solar system-- Mercury, Venus, Mars, et cetera. In fact, nobody knew whether there were any planets orbiting any other stars anywhere in the universe until 1995. It's just an incredibly hard problem. And it was really-- for a long time, we thought that, actually, planets were going to be super rare, like maybe only one in a trillion planets would be-- or stars would be able to form planets-- so that planets were just-- they never occurred. And then, starting in 1995, this is actually a movie of an actual data.
These are all-- these little dots here that are moving around-- that's a star at the center-- those are planets. This is an exosolar system. This is a solar system, an alien solar system. So starting at this kind of data, we started getting that proved to us, that planets, lots of planets, are out there. In fact, every star that you see in the sky has a family of planets. There are planets everywhere, and many of those planets are in the right place for life to form, meaning that they're in what we call the habitable zone, which is the band of orbits around a star where liquid water can form on the surface.
It's not so hot that the water would boil. You're not so close to the star that water would boil. And you're not so far away that water would freeze. We say that-- that's important to us because we believe that liquid water is going to be very important for life. And we can talk about this why later on.
But there's lots of reasons from biology to think that, really, any form of life is going to have to use water to get itself going. So we now know that every star in the sky has planets, and we know that one in every five stars has a planet in the right place for liquid water to form, which means that's a possibility for life to form. So there's lots and lots of possibilities out there. The second revolution was what we did in our own solar system, which is where we sent robots to every planet in the solar system, every kind of body in the solar system-- comets, asteroids, you name it. And we've gotten an incredible view of the evolution of planets.
So here's a picture. This picture could be Tunisia, right? This looks like this could be a picture in the deserts of Tunisia, or maybe even in the American Southwest, but this is Mars. This is a cliff on Mars, a picture taken by one of those amazing rovers that we've been landing on Mars. Mars is now a planet that's entirely inhabited by robots.
There's a lot of robots on Mars that either landed or are trundling around. Robot rovers. And there's going to be more in the future.
So we've learned so much about planets, about climate, about how planets evolve, volcanism-- all the things that go into the billions of years of evolution in a planet. And so, for example, one of things we know about Mars, right now, Mars is a frozen desert. It's a terrible place to live. But it used to look like that. There used to be water. We have conclusive evidence that Mars was a blue world.
It wasn't a red planet. It was a blue planet, much like Earth was, billions of years in the past. And we don't know why it lost its water.
So if you want to talk about climate change, that's climate change. Mars lost all of its water and lost its atmosphere. So yeah. So we've learned that this is the kind of thing that can happen with planets. The third revolution is encompassed in this picture. And I will ask you to look at this picture of these six planets and say which one of these is Earth.
So I'm going to take 10 seconds and allow you to look at that picture. Which one of these ones is Earth? The answer is all of them. Every one of these is Earth.
Earth has been many worlds in its 4 and 1/2 billion year history. When Earth started out, it was a lava world. Its surface was molten rock. Later on, another billion years later or so, there were no continents.
There were Australia-sized bodies, but it took the continents a while to grow. So Earth was a water world, an ocean world for a while. Earth has been through periods where it's been so hot, there's no snow, no glaciers anywhere, except maybe at the tops of mountains. So it's been a jungle world. Earth has also been so cold that it's been a snowball world.
It has been glaciated, probably, almost all the way down to the equator. And here's our beautiful version of the Earth now. And in the future, in less than a billion years, the Earth is going to be so hot that all the oceans are going to be boiled off, and it'll be uninhabitable. So what we've learned from the history of the Earth, from Earth's deep history, is we've learned how life and planets go together.
Life is not just some sort of green scruff sitting on the surface. Life hijacked the Earth. Life totally changed the history of the planet.
So once life forms, the planet is no longer on its own. It's now the planet and life coevolving. And so it's these three revolutions that have really changed our understanding of how planets-- of astrobiology, of how life and planets evolved together.
So, for example, there's something called the Great Oxidation Event. So this is a plot here of how much oxygen there was in the atmosphere as a function of time. So this is, right now, zero.
And if we go back 1 billion years, 2 billion years, 3 billion years, et cetera, this is the oxygen content here, in a log scale. So what you see is, 4 billion years ago, there was 1 million times less oxygen in the atmosphere than there is now. And this is where we are now. So here's what you-- we'll follow from 4 billion years ago.
There is literally no oxygen in the atmosphere. Then somewhere around 2 and 1/2 billion years, it shot up, and then stayed constant, and then increased again. What was it? Where did this oxygen come from? The answer is life.
It was a new form of photosynthesis, a new form of microorganisms that breathed out oxygen, that put all that oxygen into the atmosphere. So here you see an incredible example of a successful form of life utterly changing the history of a planet. And so now we have an oxygen-rich atmosphere, and that changes everything about the way the planet functions.
So that's an example of coevolution. OK. So what are these-- how do these exoplanet revolution change our understanding about aliens, about the possibility of SETI or thinking about alien life anywhere? Well, so, as I said, in 1994, we thought that there were zero potentially habitable planets. And now we know there are-- in the universe, there are 10 billion trillion potentially habitable planets. Every one of those planets is a place where the experiment on life and even civilizations got run, and so-- you know. So what the exoplanet revolution changes for SETI is that we now know exactly where to look.
Whereas when Frank Drake did his project in 1958, he would just-- he didn't know where-- where should I point my telescope? So he chose stars that looked like the sun. But he didn't know whether or not there were any Earth-like planets there. Now we know exactly where there are Earth-like planets or potentially habitable planets, and we'll know exactly where to look. And as I'm going to show you, we're going to know exactly how to look. So what are we going to look for using our telescopes, using telescopes like the James Webb? Well, one of the things we're going to look for are what are called biospheres.
So here is a animation of the Earth over time. This is over a few years. And this is real data. And watch what happens to the Earth over time. You see the ice coming and going.
But look at the green. That's life. Anything-- all the green you see there is-- that's algae and all kinds of material, basically plants growing and dying. The entire face of the planet is utterly changing, season to season. And the idea is this is so potent-- these changes are so potent that I could observe these from 20 light years away. I will be able to tell that this kind of thing is happening, that this planet is being changed by the life on its surface and in its oceans from 10 light years away.
And that is what we call a biosignature. We'll be able to see the effect of life on the planet. So the way we'll do this is-- one way we can observe planets orbiting other stars is through what are called transits. So if I have a planet that's orbiting a star-- the yellow thing here is the star-- when the planet passes in front of the star, it blots out a little bit of the light of the star. So if I was down here, this graph here is of the starlight that I would detect with a telescope.
And you'll see, when the star-- when the planet passes in front of the star, I get a little dip. And these are detectable. I can detect the dip.
But even more important, you see if there's an atmosphere around the planet. The starlight also has to pass through the atmosphere. And I'm going to be able to tell that what kind of gases are in the atmosphere when this happens, the starlight that passes through the planetary atmosphere, is actually going to have an imprint in it, a signature of the gas in the planetary atmosphere. And so I can look for gases that should only be there because of life.
So this is what we mean by a biosignature. So, for example, once again, here is a star. Here's a planet in front of it.
The black is the planet. And the white around here is an atmosphere. And as the light passes through that atmosphere-- if I take that light and I pass it through what's called a spectrometer, and I break the light into all of its different colors or frequencies, and I looked at it, what I would see is the light has these dips in it.
Look at the blue line here. There's going to be these big dips in the light where molecules in the atmosphere of the planet absorb that light. They're very good.
Like sponges, they soak up the light. And I'll be able to tell-- this is, to me, a scientific miracle. I can tell what kind of chemicals are in the atmosphere of this planet that could be 10, 100, 1,000 light years away. So a molecule is like methyl chloride, methyl bromide, isoprene, dimethyl sulfide. These are chemicals that would not be in the atmosphere if it wasn't for life on Earth.
So if I see these chemicals in the atmosphere of a distant planet, I could be pretty convinced that that planet has a biosphere pumping those chemicals into the atmosphere. And so we could not do this 10 years ago. We could not do this 20 years ago. We could not do this 30 years ago. We can do it now.
And so with the James Webb Space Telescope, we're just starting this. And now, with the telescopes, we're going to be putting-- over the next 10, 20 years, we're going to be able to do this. So the question of life in the universe, we are going to be able to answer it-- or at least get data relevant to it-- in the next decade, two three. So we're now-- the oldest question in the history of humanity, we are poised to answer. One of the interesting things about biosignatures is that they change over time. So these are the Earth at three different times.
This is the modern Earth down here. Up here is what we call the Archean Earth. That's about 3 and 1/2 billion years ago. And this is the Earth about 500 million years ago-- or more than that. But what you see is that, if you look at the spectra, the light, the imprint in the light, you see these wiggly lines are different depending on which one of these I look at.
So, for example, in the Archean Earth, I have a lot of things like methane-- CH4-- carbon dioxide-- CO2. But if I go down to the Proterozoic Earth, where oxygen is already being pumped into the atmosphere, you see something here that you don't see up here. You see something in the Proterozoic Earth that you don't see the Archean Earth, and that's a line of ozone-- oxygen three.
This big dip here only would be in the spectra because there was ozone in the atmosphere, and there's only ozone in the atmosphere because life put it there. Life put oxygen into the atmosphere. So we're also going to be able to-- as we look at different planets and take these spectra, we may not only be able to find life, but we might know where that life is in its own trajectory and its own evolution. OK. So biosignatures-- huge. If we could find them, game changer, right? But even more amazing would be able to find technosignatures-- not just signatures of life, but signatures of technological life.
And that is why this field of technosignatures is now replacing what we used to call SETI. So SETI was the search for extraterrestrial intelligence. It basically was all done with those radio telescopes. But now we don't need radio telescopes anymore.
We can use optical telescopes. We can use infrared telescopes. Because everything has changed, and so now we talk about technosignatures, not SETI. And what's amazing is, in 20-- remember, I said that NASA was not going to fund any studies involved with intelligent life.
But then, in 2018, Congress-- don't ask me why-- told NASA, you need to spend $10 million on technosignatures. And NASA was like, what? What does that mean? So they held a meeting in 2018, and they invited a bunch of us to come tell them, OK, we're going to get $10 million to study technosignatures, what should we do? And this was the most awesome meeting I was ever at. We were like kids in a candy store.
Like, oh, my god. Because NASA was like, if we gave you this money, what would you do? So we spent three days thinking about what would we do. And that was the birth of the modern technosignature.
The field has just been reborn, in some sense. So before I tell you about-- so I want to give you some examples of technosignatures we could look for. But the University of Rochester-- I'm the principal investigator on the first grant ever given for technosignatures. We put in a grant in 2019, and we got it. And it's a multiuniversity grant. But the University of Rochester leads it.
And this is the first time in decades that NASA's been willing to spend money to search for not just life, but intelligent life. So let me give you some examples of what might be a technosignature. So, if we go back here, remember I talked about transits.
When a planet passes in front of a star, you get this nice dip. But in 2018, there was this star called Boyajian's Star. That's the scientist who discovered it. The dips looked like this.
This is the same-- this is the brightness of the Boyajian Star. And it's not some-- you see that it looks like a dragon's smile, right? The light dipped, and then it came back. It dipped again, and then nothing happened. And then it dipped. And then it looks crazy.
And people are like, what is this? This is clearly not a planet. And one of the things that got proposed was it was a Dyson swarm. It was a collection of giant, mega-- alien megastructures that were passing in front of the star, each one causing a dip. So instead of a Dyson sphere that we talked about, this would be a swarm of large, planet-sized machines-- or not planet size, but large machines that were capturing starlight from the star. Now, it turned out this was not what happened. We actually figured out it's probably comets, a swarm of comets.
But the fact that they could write a paper and propose, include alien megastructures in their list of, oh, maybe this is what it is and nobody said, that's crazy, that also showed that we were entering a new realm, that now, thinking about life, thinking about intelligent life, yeah, it's a scientific endeavor. It's not some kind of weird-- there's no more giggle factor. Well, there is still some. But there's much less giggle factor.
Another possibility for a technosignature is if-- large-scale use of solar panels. If you-- on a planet or even a moon deploy lots and lots of solar panels, it turns out the light reflecting off the solar panel is going to actually imprint on it-- have an imprint on it. The reflected light is going to have a very sharp edge in it that you would be able to detect from a distance. So I won't go into this figure here. But you should know that if a species really, really wanted to go for solar panels, use solar panels either on its own world or maybe another world where it collected the energy, we would be able to see that from a distance. Finally, we may even-- well, I'm not going to go to the details of this-- but we may even be able to see city lights.
You've seen a picture of the Earth at night, you can see all the continents outlined by the cities and roads and the lights that are shining. And it may be possible with maybe the next generation of telescopes-- 10, 20 years from now-- to actually detect those city lights. So that's incredible as well. So technosignatures now, the game is on.
We now are figuring out how to find signatures of intelligent civilizations on other planets, and we have the capacity-- we're gaining the capacity to make those measurements. So that's my conclusion-- not for the whole talk. We're going to have-- we have maybe another 10 minutes. But the idea is we finally, after 2,500 years, we have the tools and the methods to find alien life. We are ready to go.
And what could be more exciting than that, right? But I do want to talk about-- oh, yeah. One thing I want to mention is, again, the Fermi paradox. Remember we said-- I said that, look, the Fermi paradox, the version of it where we've looked and we haven't found anything is wrong.
So my colleagues did a study of how much SETI has actually ever been done, how much searching have we done for intelligent civilizations. And if the stars are the ocean and we're looking for fish, how much of the ocean have we searched for? It turns out we've searched a hot tub. That's how much actual SETI has been done.
So if you had a hot tub's worth of ocean water, and you looked in it, and you didn't see any fish, would you be like, well, that's it. There's no fish in the ocean. That's where we are with looking for intelligent life. So there's just-- anybody who tells you that we've looked for intelligent life and hasn't found it, as I said, they don't know what they're talking about. We just haven't looked yet. But now we're ready to look, and we're going to look.
So there is no-- that kind of Fermi paradox, there is no Fermi paradox. So why does any of this matter? Let's just spend a couple of minutes on that. Why does it matter for us? There's lots of reasons, but I particularly want to point to the astrobiology of the Anthropocene, i.e. climate change. So we all know the problem, right? The Earth's climate is changing, and it's changing because of our activity.
At this point, that is-- we went through all these years of climate denial, which was ridiculous then, but now it's completely ridiculous because it's obvious that the planet, we're changing the climate. And the things we've seen-- the floods, and the fires, and the heatwaves-- what we've seen so far is the teaser trailer for climate change. You know when there's a trailer for a movie, but even before that comes out, they'll maybe do a 30-second teaser trailer.
That's what we're seeing now. You get down 10, 30, 100 years, yeah, there's going to be some pretty-- there could be some really significant changes in the planet. It's not going to be human extinction, but it could really stress human civilization.
So let's try and put that into the context of Earth history. So, here, the Earth is 4 and 1/2 billion years old. There's been all these different phases of life-- the Archean, the Mississippian, the Triassic, the Cretaceous, the la, la, la.
The Earth is currently in a geologic phase we call the Holocene. It's been the last 10,000 years. And it's a relatively mild-- it's been great for human civilization.
All of human civilization has been in the geologic epoch we call the Holocene. Temperatures have been mild. It's been relatively mild and relatively moist-- great for agriculture. But what we're doing now through human activity is we're pushing ourselves into what they call the Anthropocene. It's an entirely new geologic epoch where our activity is what's driving the changes in the planet-- or is forcing the changes in the planet. And we could go extinct tomorrow, and there would still be an Anthropocene.
We've already kicked the Earth into a new climate state. So all this thinking about other life, and other planets, and other civilizations and their history, how should it affect our understanding of the Anthropocene? So what I like to call the-- I like to think about the astrobiological question relative to this Anthropocene, this climate-change era. Are they common? Does every civilization have to go through an Anthropocene? Maybe it's a very general thing that any civilization that harvests huge amounts of energy and uses it to build their civilization, maybe they always feed back on their planet. So the question is, are Anthropocenes common? And if they are common, are they survivable? So what I mean by this is-- when we think about all the stuff the universe does, we know the universe makes black holes, and we know the universe makes comets, and we know the universe makes interstellar clouds. Are long-term, sustainable, energy-intensive civilizations on that list? Maybe there's lots of civilizations, but nobody makes it past 200 years in terms of-- they get to our stage, and nobody makes it more than 200 years.
So that's a question that my group, my research group, has been asking. And we've studied this. Let me just go back.
And we've actually-- one of the things we found was that, yes, it does look-- we modeled civilizations and planets evolving together, and what we found was, yeah, OK, sometimes. Sometimes you can get a long-term, sustainable civilization. But often, the civilization is not smart about what it does, and it drives itself into extinction. And by extinction, I mean the civilization can't hold together anymore. There may be individuals alive, but you can't hold this global thing that you call civilization together very much. So we've looked at that, and we're continuing to look at that.
So this is what I mean about the astrobiological perspective. How does that change our thinking about what's happening to us now? So that's what I'll spend the next five minutes talking about. So this really takes us beyond the Kardashev scale. Remember the Kardashev scale? Those different stages of civilization should be in? And remember, the scale I was when a planet harvests all the energy, solar energy, falling on it.
And by looking at what's happened to us, we can see that that's the wrong way of looking at it. The lesson of the Anthropocene is you can't just harvest all the energy on the planet. The biosphere will respond to that. If you try and harvest all that energy, you'll kick the planet, you'll kick the biosphere into a new state, and it'll just happily evolve past you. And it'll evolve into new conditions that are not going to be very useful for a civilization or could end the civilization. So, well, the first thing we learned is that Kardashev was kind of wrong.
Kardashev, you have to think not only about energy use, but you have to also think about energy consequences. Now, another thing that comes from this-- this is a little radical here, but it's that, when we think about climate change, we're not talking about saving the Earth. The Earth will be just fine, thank you very much. It's not a battle to save the planet. There have been five mass extinctions that we know about-- and we seem to be driving a sixth one. But each of those mass extinctions opened up niches for other creatures.
For example, this little critter here is your great great great great great great great-- et cetera, et cetera-- grandmother or grandfather. This was a little mammal that was alive during the time of the dinosaurs, and it was only losing the dinosaurs that allowed the mammals, the age of the mammals, to begin. So the Earth, the biosphere is just going to move on without us if we are not smart. So the question is not trying to save the planet. The planet's not a furry little bunny that we have to protect.
Well, we have to not-- our job is to not piss it off. The Earth is a god in some sense, or a goddess, if people looked at it that way, in terms of how much power it has. And you mess with it, and it'll shake you off like fleas on a dog, as George Carlin once said. So that's the real fight. So we need to know what the fight is.
And that fight, you only get from the-- knowing about it is from the astronomical perspective. Here is a-- I made this point in a New York Times op-ed, "Earth Will Survive, We May Not." And I got a lot of grief for this.
People accused me of being a shill for the oil companies. And in no way was I not saying that climate change is a real, super-dangerous transition, but we need to go past this kind of polarization that we usually get with thinking about it and understand what the real problem is. And so, if we're not smart, if we don't get rid of fossil fuels tomorrow, then, yeah, we may-- we're going to drive the planet into a state that is no longer-- that doesn't work for us. It's going to work for something else, but it won't work for us.
So it's really-- the astrobiology of the Anthropocene is about changing the questions that we ask and getting the right story. So the wrong story we often get when we talk about climate change is that we're a plague on the planet and it has to be saved from us. We're a virus. And that's the wrong story. The right story is we are what the biosphere is doing now, but the biosphere has done other things in the past-- for example, grass.
Grass was an evolutionary innervation of the biosphere. And the biosphere invented grasslands. And then there were prairies, and that changed the planet. And then the biosphere went on and invented new things like dinosaurs.
And a technological civilization is what the biosphere is doing now. But it doesn't mean that it's what it's going to be doing in a thousand years from now. The biosphere will be happy to take whatever effects we've had and just move on. So we're not a plague on the planet. We're actually a successful experiment that the biosphere has run.
But we don't have to-- that success is not guaranteed to continue. The other wrong question is-- which I often get when I have to fight with climate denialists-- is, did we change the climate? It's always like, did we change the climate, grrr? But from this perspective, the right question is, look, man, we built a world-girdling civilization that harvests huge amounts of energy, what did you expect to happen? Of course, we changed the climate. You can't use that much energy and not have an effect on the biosphere. So the question is we've got to figure out how to have the right effect on the biosphere, something that doesn't destroy the biosphere's ability to have us in it. So the astrobiological perspective tells us that Anthropocenes might not be rare, but what's happening with us-- climate change-- might be happening to any planet that develops life which then goes on to make a civilization and that triggering an Anthropocene marks a transition both for the planet and the civilization. Right now, we're like cosmic teenagers.
The planet's given us the keys to the planet. And the question is, are we going to drive responsibly, or are we going to drive the planet off a cliff? I love this line from a famous climate scientist. "Climate change is humanity's final exam." So sustainability and planetary intelligence, what we need to become-- from the astrobiological perspective, we can imagine there's lots of civilizations out there. Almost all of them go through some version of climate change. The smart ones make it through.
The smart ones gain an intelligence that includes the planet as a whole, and they're able to go on for thousands, tens of thousands, millions, billions of years. So it would be a cooperative, "all boats rise" relationship with the biosphere rather than our terribly crappy relationship with the biosphere now, where we think we can just take whatever we want out and just dump our garbage. So, on that note, people often ask me what I think about climate change because I do a lot of work in it, whether I'm hopeful. And my answer is always yes, because what's the alternative? But this is from a few years ago. These are U of R students who came to see Bill Nye talk about using science and engineering to save civilization, to change civilization so that it could be sustainable. And look at all these students.
These students are all ready to-- they're all there, and they are ready to do what they need to do to be able to allow us to become a long-term, sustainable civilization. Our job is just to get out of their way so that they can solve the problem. So I will end there, and I will be happy to take questions. OK.
Should I look at the questions that are available, or should I look in the chat? OK. All right, so I'm going to look in the chat. Actually, the first thing I'm going to start off with, though, are some questions that people mailed in, if you don't mind. So let me just find this. And I want to note, obviously, I did not talk about UFOs.
And lots of people love UFOs. And you might wonder why didn't I talk about UFOs. Because in my new book, I went back, and I looked at UFOs. So there's a couple of questions here about UFOs. Let me just give you my perspective on them.
Hold on a second. So, in this book, which will be available November 2023-- sorry for the shilling-- but I had to do a lot of research on UFOs. I personally am not impressed by the data around UFOs. In 2021, I wrote an op-ed for The New York Times with this title. And often, I don't like the titles that the editors give the pieces I write.
I have no control of them. But this nailed it. "I'm a Physicist Who Searches for Aliens, UFOs Don't Impress Me." So the problem with UFOs is that the data that we have for the UFOs, it's either people seeing things, which I can't really do much with in science-- if I told you I saw a ghost last week, and I tell you a great story, and it's hair-raising, that's great. But as a scientist, how can you prove that there was a ghost? How can you prove that it wasn't just I was hallucinating or it was a shadow that I hadn't seen? And in general, most of the data associated with UFOs is of that quality.
So there's lots of fuzzy blob pictures, radar readings, sometimes, that they didn't record the data. So, for example, let's talk about all the images-- you think about all the pictures, including those videos that were taken. Here is a picture that a pilot-- that's the Chinese spy balloon. And this is the picture that the pilot of the YouTube-- YouTube-- U-2 spy plane took of the Chinese spy balloon high above the Earth.
And he took it with a cell phone. And what you can see is-- so there's the balloon. And you can see the solar arrays on it. This is a very clear picture. I can see exactly what this is. How come with UFOs there's not hundreds, thousands of pictures this clear? Instead, they're almost all the pictures of UFOs are blurry.
They're blobby. They're out of focus. And it just makes no sense that, with all these cell phone cameras, why can't I get a picture like this of a UFO. And when you do see pictures like this, a little analysis almost always shows that's a hoax. You can see. Oh, that was a hoax.
So the UFO stuff that's going on now, I totally believe that there is something interesting happening. It's worth open, scientific discussion about it. But the idea that it's connected to aliens, that's just too large a leap. You're going to need really, really, really high-quality data, the same kind of data that I'm going to need if I want to say my telescopes have found evidence of life on a different world-- you need that kind of quality of data that will undergo that kind of scrutiny in order to tell whether or not there is-- in order to tell whether UFOs are aliens. So, right now, I would say it's probably a national defense issue. But let's study it.
Yeah, sure. Let's dedicate some money. Take it out of the defense budget, not out of NASA's budget, which is already small enough.
But I'm totally open to an open, and transparent, and nonbiased study of UFOs. But remember, if you do that, the point of that study is not to show that UFOs are aliens. That's not how science works. The point is, I'm seeing something in the sky, let me try and figure out what they are, not I'm seeing something in the sky, let me prove this bias that I have, this previous idea I have is that that's what's going on. So that's what a search would look like. OK.
So let me ask some questions-- let me take some questions from the chat. The search for alien intelligence seems to assume that aliens communicate in ways similar to the ways that we use on Earth. What if, for example, alien life cycles are so much faster or slower than our own? What should we be doing? That's a great question. And see, what's really interesting now is we're done with communications. We don't need aliens to send us a message. That was the old SETI.
Technosignatures just needs to look for-- we're going to basically be looking for aliens going about their business. We don't need them to send a message to us. So we're just going to look at the planets and see if we see any signature of energy being used in a way that would not be natural, any chemicals in the atmosphere that would not be there via natural processes. So that's why this is such an exciting change. We don't really need to care about whether or not they're trying to communicate with us anymore.
Biosignature tests presumes Earth-like life. What about others? Right. And again, we don't have to look-- biosignatures now, we're getting past the point in the science-- the science is maturing.
We're not going to look for Earth-like life. We're going to look for any kind of chemical compound that we don't think could be produced in a nonliving way. Biomolecules are often very complex, and they can't be assembled by just natural geological processes. So we can be agnostic about the biochemistry and still find markers in an atmosphere that show that life's creative activity, the ability of life to build bigger and more complex things, even on a molecular level, is what's operating.
So the big emphasis now is on agnostic biosignatures, meaning agnostic about the biochemistry. Professor Frank, thanks for leading today's discussion. I remember taking your astronomy class in 1998. Oh, my god. I'm so old.
[LAUGHS] I think I'd only been here two years then. My question is-- well, thank you. I hope the class was OK. I hope you got a good grade. Should there be further study of planetary moons? Yeah, absolutely.
So people are doing that. Because we know that the moons around Jupiter have subsurface oceans that are a hundred miles deep, and so who knows what's going on in those moons. So now we've come to recognize that, yeah, moons can just be-- "Star Wars" knew this, of course. Like, I don't know how many "Star Wars" movies have a moon that has a colony or settling on it. Dear Professor, thank you very much for your presentation.
Thank you. Can you please comment on recent corroborated military revelations about UAPs, et cetera, et cetera? So, yeah. Again, this thing with the military-- I mean, so what's interesting now-- and this is why I think, yes, let's-- the military, it's great that they've said to their pilots, report anything you see, rather than saying, oh, you know, nobody wants to mention what they see.
Because it's clear people are seeing things. Now, I think what we're going to find is it's going to end up being stuff associated with what people call peer-state adversaries. Even simple drones can be used in a way to mimic weird behavior. And because, of course, what you want to do if you're a peer-state adversary, you want the pilots to turn on all of those high-tech electronic imaging and sensor data because then you soak that all up. And you can be like, oh, that's what an F-17-- that's the electronic sweep that an F-17 has. We've done the exact same thing.
In the 1950s, the Russians had this giant radar array that they put up that we didn't know what its capacities was, so we faked a signal into it to get them to turn it up so that they would be able to-- so we could tell what their capacities were. So I've gone through all the data that they have, I've looked at it, and it's still-- it's not of the quality that you could say anything definite about it. Certainly, you're not in a position to say that this is nonhuman technology. You have to remember that, often-- like from those videos-- like those videos which everybody loves, remember, those videos, those have been processed.
We're not getting the full video. We're getting these little clips that somebody released. We don't know what else is on the video. We don't know anything about the instruments. Were they recently updated with new software that might have had issues? So we're just not getting-- if I tried to say that I discovered life on another world using that kind of quality of data, I'd get laughed out of the room. So that's why we've got to get more data.
So I certainly think-- I'm totally open to getting more data. But the idea that we've seen anything which should lead us to think that we're being visited by extraterrestrials, I just think there's just nothing there. We are not even one one-billionth close to that. But it's worth studying.
I mean, it's not like it's out of the question. It could be happening. But, to me, also, it's a little unlikely. It's less likely, let me put it that way. Let me put it this way, if you want to find Nebraskans, you want to find people from Nebraska, would you go look at a small mountaintop village in the Himalayas? Probably not. Why would there be Nebraskans in the Himalayas? You'd go to Nebraska.
So if you're looking for aliens, go look on alien planets, not some backwater world-- us, the Earth. You know? Why are they here? You can invent science-fiction stories about why they're here, but those are science-fiction stories. It's just much-- let's look where the aliens live, not where we're hoping that maybe they decided to visit for a weird vacation. OK. Let's take one or two more. How, if at all, has the discovery of lifeforms on Earth that we couldn't think of exist-- yes-- organisms that live at high temperatures or low temperatures and without sunlight informed our search for life on exoplanets? That is a great question.
These are what we call extremophiles. And what we've learned is that, yeah, life on Earth has a much larger range of possibilities, microbial life, than we thought. And those extremophiles really open up the possibility that maybe there's life still on Mars. Maybe below the surface of Mars, there's creatures that have been able to hang on for 4 billion years, living at a very low level. So yeah, that has really, totally changed our understanding of the potentials for life.
And it also means that you can even get what they call panspermia, where maybe life in rocks gets blown off by an asteroid impact and can travel through space, land somewhere else, and seed that life on that new planet. All right. Well, it's 12:59.
I have to go teach my astronomy course, which may be the same one that the person up here took. So I'm going to have to end now. But I thank you very much for your attention, and this was a lot of fun. Thank you. ABBY ZABRODSKY: Thank you, Adam, for that engaging and enlightening presentation. And thank you all for joining us today.
2023-05-09 18:03
