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(Neil DeGrasse Tyson) Welcome, everyone, back to the American Museum of Natural History
on this auspicious day—10/10/2010. The day we’ve chosen to celebrate the 10th anniversary
of the opening of the Rose Center for Earth and Space. Some of you were here earlier with
the festivities. We had a huge cake. We had live entertainment. We had—we gave out awards
for the best video, we had a video contest. The best 2-minute expression of what science
has meant to you for the past 10 years. And so, if you go to the Rose Center website you
can see the award-wining videos. The runner-up video I like to characterize
as “Are you smarter than a 2-year-old?” Because, in it, there’s a 2-year-old reciting
all kinds of cosmic phenomenon and names of things and it’s a remarkable video, it’s
gone almost viral on the Net, so check that out when you get home.
This is a special, specially-inserted Asimov panel debate. Normally we meet in the spring
for this once a year. How many of you are regulars to the spring one? Excellent. And
who here is the first time you’ve ever been to an Asimov debate? My gosh. Where you been?
What, what? What? Welcome to this one. We’ll be doing this
again at our usually scheduled time in the spring, follow the news announcements for
that. For this occasion we thought we would involve a few more geologists and answer a
fascinating question that’s been on our minds for a long time—many people’s minds.
Is Earth unique? Is Earth unique? Now, we don’t mean exactly unique. Obviously,
any planet is unique down to its details. So we’re really asking, are the general
properties of Earth something we can expect to be common in the galaxy or rare? And that
question does not have an easy or well-understood answer at this point. Hence, we make it a
subject of this debate. And interestingly, what happened just a few days ago in the news?
An Earth-like planet, a Goldilocks planet around start Gleece-581. It is—well, the
star is Gleece-581. There’s several objects already known to orbit that star. The most
recent of which is a slightly-larger-than-Earth-size planet orbiting at just the right distance.
Which, if it had water under an atmosphere, it would remain liquid. Too close to your
host star, it evaporates. Too far, it freezes. So it’s Goldilocks temperature—just right.
And, on Earth, where there’s liquid water, there’s life. So water is a tantalizing
tag for us as we conduct our search for life in the universe. That’s the first of what
we expect to be many such planets in orbit around their habitable zone. We have a remarkable
selection of panelists. One of them, in fact, flew in from Europe. Another one came in from
California, landing just moments ago. And I’ll be introducing them in sequence. I
have first an astrophysicist—oh, by the way, all of the bios are in your schedules,
so I’m not going to read through all of them. They’ll be here for you to see. And
I want to get straight on to our panel discussion. Before I do, let me publicly acknowledge the
support of this program by the friends and family of Isaac Asimov, who was a long-time
friend of the American Museum of Natural History. He used our libraries to publish his 600-plus
books. One of the most prolific people in the history of book-writing. And on science
fiction, science, even wrote books on religion. Not a single subject was beyond his reach.
And much of his research that he conducted was here, in his backyard museum, the American
Museum of Natural History. So we’re indebted to the support that the loved ones and friends
of Isaac Asimov have provided for these past 10 years. And so first let me bring out onto
the stage right now Fred Adams, he’s a professor of physics at the University of Michigan.
Fred Adams, there you go. They will each begin with a minute or so of what it is that they
do and why and so we’ll wait till we get all five panelists out to discuss that. Come
on out Don Brownlee—he’s Professor of Astronomy, University of Washington in Seattle.
Don Brownlee. We have Paul Falkowski. He’s Professor of Geologic and Marine Science at
Rutgers University. I just realized, you’re a pretty cheap date, you just came across
the river here from New Jersey. (Paul Falkowski) I can charge more. (Neil DeGrasse Tyson) We’ll
have to invite you more often. And, where am I here? Who did I leave out? Yes, thank
you. (Chris McKay.) He’s a NASA scientist, working at Ames, NASA Ames Research Center
in Moffett Field, California. And we have Minik Rosing. He’s Professor of Geology,
University of Copenhagen. Minik. Just a half-hour ago we had a conversation in a room in the
back, because we all took a look at each other, said, oh, wow, we’re all guys. So this did
not go unnoticed by us and we’re going to check to see if we’ve had some inherent
bias over the years or what. So we’ll be checking on this in future Asimov debates,
yes. Just, while we’re in demographic statistics,
in the whole world of astrophysicists, 36 of them are black and one of them hosts this.
So, that’s just so you know. So we’re doing good on some counts here, I think. All
right. So, Fred. Why did I invite you to this panel? Who are you to us today? Just tell
me, remind me. (Fred Adams) Well, I work in theoretical astrophysics. I work primarily
as a theorist, so I do calculations more than observations. I spend my time primarily in
a physics department rather than an astronomy department, but I work in both camps, so I
kind of bring that to the table, I guess. I’ve spent most of my time working on star
and planet formation. About two-thirds of my papers are in that realm, which is relevant
to today’s discussion. And then I spend about the other third of my time working on
larger-scale things—cosmology and related issues, which kind of informs the big picture
of what we’re talking about. (Neil DeGrasse Tyson) So you think a lot about
the physics of the universe and how that shapes what the universe ultimately looks like. (Fred
Adams) Yes, exactly. (Neil DeGrasse Tyson) And is most of your work on computer or is
it just back—pencil and pad? (Fred Adams) The answer to that is yes. I’m one of the
old-school people that still do calculations on paper, but as you know, and most people
know, eventually you also put equations on computers, as well. So I go back and forth
between the two media. (Neil DeGrasse Tyson) Okay, excellent, thanks for that. Don Brownlee,
you’re an author of a book, Rare Earth. So you’re like the right guy to come in
here. But what else have you done lately? (Don Brownlee) So, I’m an astronomer. I
work in the solar system, planetary science. I was also head of the NASA Stardust mission
that brought comet samples back to Earth. And along with… (Neil DeGrasse Tyson) I
have to interrupt there. I remember a movie where they did that. Like, The Andromeda Strain.
Where they brought particles from space. I’m just…just…you were not worried about this?
(Don Brownlee) You would not believe it, but you look at the movie, the capsule they brought
back in that movie was almost identical in size and shape to the one we brought back
with comet dust… (Neil DeGrasse Tyson) I knew it! (Don Brownlee) And, and, the instruments
were very scientific in that movie. They used electromicroscopes, mass spectrometers very
similar to what we actually used on the comets, although it was many years later. Although,
JPL and Caltech were advisors on Andromeda Strain. But, yeah. I’m also an author with
Peter Ward, a paleontologist, on two books. One is called Rare Earth, which is—just
says the Earth is rare and is about the rare hypothesis, the idea that life may be common
in the universe, but like on Earth over its entire history, it’s mostly microbial and
it takes very special conditions to have animals like us. The second book was Life and Death
of Planet Earth, was amazingly the first book about the long-term future of our planet.
Some things that everyone should have learned in third grade and didn’t about future Earth
history. (Neil DeGrasse Tyson) Okay, so we’ll get back to you on that to find out if we
actually believe you that Earth is as rare as you suggest. So, Paul. Let me get your
name pronounced…Fulkowski. I tried. Fulkowski. Yeah, tell us what part of the universe you
come from. Paul Falkowski So, my interest here is the evolution and
origin of life broadly writ, but from a concrete point of view, I studied for many years the
origin of biogeochemistry, which is to all of us in this room, we’re breathing oxygen
that was created by organisms. It’s not a trace gas on the planet. So there’s an
oxygen cycle, there’s a carbon cycle, there’s a nitrogen cycle and I study how organisms
basically transform the planet. So it’s… (Neil DeGrasse Tyson) So you’re a biogeochemist.
(Paul Falkowski) That’s right. (Neil DeGrasse Tyson) You just stapled them all together.
(Paul Falkowski)Stapled them all together, that’s it. (Neil DeGrasse Tyson) Okay. And
this sounds like that’s an emergent field, because not that long ago our scientific professions
were pretty divided up department by department. So, are you a renegade or at least on the
frontier of a trend line that we should look forward to?(Paul Falkowski) Yeah, I’m trained
in biophysics and molecular biology and I’m in a geology department, so you could say
it’s trend line that’s a little weird. (Neil DeGrasse Tyson) So you’re a one-man
cross-pollinating machine. (Paul Falkowski) I try. (Neil DeGrasse Tyson) Okay. Chris McKay.
You flew in—you said you just flew in from California, but I don’t think so because
I think you just flew in from Mars. Mars is like your favorite planet and that’s all
you ever talk about. (Chris McKay) Well… (Neil DeGrasse Tyson) For example, you could
have breakfast with the guy and you’re drinking water and eating and he’ll say, “You know,
on Mars, this would … “ No matter what you say or do, he references back to Mars.
(Chris McKay) And it’s a good connection to Earth and the question of life. What I’m
interested in is is there life on other worlds and is that life different from life on Earth?
In a way, it’s asking the question “Is the story of the most important thing that
we see on this planet, what Paul studies—life and the biogeochemical cycles that it creates—is
that story repeated on other worlds? And, if it is, are the organisms that are doing
the biogeochemical cycling on other worlds similar to the life forms we have on Earth
or are they aliens?” (Neil DeGrasse Tyson) I’m going with the aliens. (Chris McKay)
I like the alien answer myself, yeah. (Neil DeGrasse Tyson) All right. Minik Rosing. I
have to tell everyone that you were born in Greenland. That is surely the first person
I have ever met born in Greenland. (Minik Rosing) [unintelligible] (Neil DeGrasse Tyson)
And how many people were in your hometown when you were born? (Minik Rosing) Well, there’s
not really a town. It was 7 people, so it was… (Neil DeGrasse Tyson) A town of 7…
(Minik Rosing) It’s about a… (Neil DeGrasse Tyson) We can’t even … (Minik Rosing)
… New York City, I guess. (Neil DeGrasse Tyson) … think that. We don’t even know
how to understand that, a town of 7 people. (Minik Rosing) Well, it seems quite busy at
times, actually. (Neil DeGrasse Tyson) So, what scares me a little is that you’re born
in Greenland and Greenland is the subject of your research specialty. And you’ve done
great, pioneer work there. It makes me worried, like, had you been born in the Bahamas or
something, you’d still be on the beach and we wouldn’t have learned what we have about
Greenland. (Minik Rosing) No, I think actually, had I been born in the Bahamas, I’d still
go to Greenland, because it’s the most interesting place on this planet and it’s a place where
I do what I’m best at. I’m a geologist and I have to warn you that geology is the
only science where your feet are more important than your head. So that’s the way people
use to walk across the fields and [unintelligible] rock the big hammers, so that’s kind of
the level of sophistication I operate at. (Neil DeGrasse Tyson) Okay, so let’s start
out with you. Let’s start our conversation—Oh, the way we, so many new hands had been raised.
The way we’re going to conduct this is, we’re not actually talking to you. We’re
having a conversation, like we’re a bar or something, among ourselves and you’re
eavesdropping on it, okay? That’s how these go. You got that? Okay, we’re just chilling
up here on the stage. So, Minik, we’re trying to understand whether or not Earth is unique,
but you work in Greenland. And there’s nothing more foreign that I can think of than Greenland,
especially since it’s mostly ice, so it’s like badly named to begin with. How could
studying Greenland possibly inform the rest of this conversation about Earth? (Minik Rosing)
Well, Greenland had preserved the oldest part of Earth, so rocks in Greenland have experienced
3.8 billion years, 3,800 million years of Earth history. And that actually is almost
one-third of the entire universe is recorded in these rocks. (Neil DeGrasse Tyson) Wait,
so why are your Greenland rocks older than somebody else’s rocks? (Minik Rosing) Well,
because we found it there. (Neil DeGrasse Tyson) Wait, wait. (Minik Rosing) There’s
no logical explanation, it’s just the way it happens to be. (Neil DeGrasse Tyson) No,
so is there some geological fact about Greenland that enabled it to keep older rocks compared
with some other place on Earth? (Minik Rosing) Not really, I think the magic point about
Greenland is that it has been glacierly polished within the last few thousand years, so that
means that the rocks are not covered by soil and plants and other [ugly] things, so you
can really see the geology and that allows you to get a much deeper insight into how
the geology of Greenland is put together and that allows you, again, to find the really
interesting rocks. (Neil DeGrasse Tyson) So when you say “glacially polished,” so
a glacier works its way—it’s very heavy and deep and it just sort of carves its way
over the surface. Then, if it retreats, it’s kind of a freshly-exposed. (Minik Rosing)
Exactly. If you tried to do that in Arizona or someplace like that, you see a lot of yellow
sand and more yellow sand and more yellow sand. Greenland have pristine rocks and they’re
just sitting there, waiting. So that’s the marvel of the place. (Neil DeGrasse Tyson)
Okay, I never knew that about it. Very good. And, actually, could you switch places? Sorry.
(Chris McKay) Good luck. (Neil DeGrasse Tyson) There you go, thank you. (Chris McKay) Ah,
this is much better. (Neil DeGrasse Tyson) So, Don, what are your best arguments for
whether or not Earth is unique? Are they philosophical or do you have real science behind these claims?
Because I read your books and you make some interesting points. And when you say “unique,”
is it rare because of the life that’s on it? Surely you agree that maybe other planets
have oceans. So where you comin’ from? (Don Brownlee) Well, the Earth is undoubtedly rare.
I mean, it’s rare in the solar system, it’s totally different than any other place in
the solar system. Look at this from an astronomical standpoint. (Neil DeGrasse Tyson) Wait, the
solar system is this big in a galaxy that’s this big and you’re asserting that it’s
rare. (Don Brownlee) Think if the universe as a whole, you can do that. A lot of people
like to think the universe as being a very friendly place. It’s almost an incredibly,
total hostile place. (Neil DeGrasse Tyson) I agree a hund...(Don Brownlee) And only a
couple of places where we could go and live. To me, Earth-like means, if I was there on
this other body, I’d feel at home. And I could go [breathes deeply] and breathe this
rich, oxygen atmosphere and be happy. Look out and see palm trees and beaches and people
running up and down the beach or something running up and down the beaches. And you know,
our neighbors in the solar system are vastly, vastly different than we are. I remember...
(Neil DeGrasse Tyson) You mean Mars and Venus, our adjacent planets. (Don Brownlee) The whole
rest of the works. I remember when the Huygens probe landed on Titan, a big moon around Saturn,
all the comments were, boy, this is really Earth-like! Because it has liquids, it has
land and a kind of… (Neil DeGrasse Tyson) It had coastlines, it had… (Don Brownlee)
It had coastline. It looked like Louisiana. You know, when you fly over Louisiana. But
it’s only a little bit warmer than liquid nitrogen. And you would not feel—you would
feel less at home in Titan than you would in Mars, which is a really un-Earthly-like
place. So, there are lots of places…(Neil DeGrasse Tyson) Be careful, because he’s
going to fight you if you talk bad about Mars. (Don Brownlee) So, anyway, the Earth is rare
to other places in the solar system and the Earth we live on now and think of our Earth
is actually not typical for the Earth throughout its entire history. Earth will last about
10 billion years and yet it took 4 billion years of geological and biological evolution
on our planet to get animals on it. So what is Earth like? Typically, in the past, you
land on Earth, you look around—Hey, nothing here, let’s zip off to Alpha Centauri or
something. Even though there was life on Earth for most of its lifetime, it was microbial.
It wasn’t animal life. And the Earth will spend at least half of its entire lifetime
as an ocean-free planet and most Earthlings right now, you look at that planet, you say,
god, that’s not an Earthly planet. There’s no ocean, can’t be like Earth. Well, it
is Earth. Earth has changed a lot over the past… (Neil DeGrasse Tyson) So, you’re
saying Earth isn’t even like Earth for most of Earth history. (Don Brownlee) Yeah, Earth
most likely when it was very young was a water world. Completely covered with water. I mean,
we don’t know what it takes to support life. We know what it takes to support us. And we
can’t live anywhere else in the solar system. We can’t live on Earth as we are right now
during most of Earth history. I mean, more than 2.4 billion years ago, there was no oxygen
in the atmosphere, so we would asphyxiate, just gasp, gone. (Neil DeGrasse Tyson) Although
the anaerobic microbes were doing just fine. (Don Brownlee) Microbes are tough, much tougher
than we are. But we’re smarter, so we … in the end, we may beat the microbes, believe
it or not. (Neil DeGrasse Tyson) So we tell ourselves constantly, that we’re smart.
(Don Brownlee) We live in an artificial environment… (Neil DeGrasse Tyson) I read the paper everyday,
that’s counter-evidence to… So, Paul. (Paul Falkowski) Yeah. (Neil DeGrasse Tyson)
One thing that I think is not widely appreciated by the public and perhaps even by other scientists
is how many cycles are going on simultaneously on this very Earth in which we live. And,
for me, what impressed me most I think was to realize that, if you’re going to look
for another planet out there in the galaxy, the urge is—well, let’s find a planet
that has a nitrogen-oxygen atmosphere, as we enjoy here on Earth. And then that’s
where we’ll pitch tent and live. As though that’s the kind of atmosphere that you just
might randomly find among planets. But of course life infuses the atmosphere with these
properties and life affects the oceans. So that we’re not just living on a planet,
we’re participant in the planet. So this—tell me about some of the cycles that either we
contribute to or that affect us directly? Just… (Paul Falkowski) So, life is made
up of six major elements—hydrogen, carbon, oxygen, nitrogen, sulphur and phosphorus.
And all of these cycle. And the cycles to first order are driven on this planet by tectonics,
because the Earth’s interior has uranium and thorium and potassium in it, there’s
radioactivity, and that allows the mantle to cycle. And it brings, for example, through
volcanoes, CO2 into the atmosphere, that’s why we have CO2. (Neil DeGrasse Tyson) So
we need our volcanoes, for the [sampling]. (Paul Falkowski) Absolutely. (Neil DeGrasse
Tyson) As bad and menacing as they are, they’re a fundamental part of these cycles. (Paul
Falkowski) Absolutely. First order fundamental part of the cycle. The carbon dioxide that’s
in the atmosphere absorbs water, makes carbonic acid, which is like seltzer. Seltzer rains
on igneous rocks, like granite. And the igneous rocks so-called “weather.” So magnesium
and calcium are taken out of those rocks by this weak acid and you form chalk. And so
that’s the first order, the carbon cycle. (Neil DeGrasse Tyson) So, chalk is a repository
of the carbon. (Paul Falkowski) Exactly. And so that cycle, which is dependent upon the
weathering of rocks and volcanism has maintained a carbon dioxide concentration that has not
led to a runaway greenhouse like on Venus or has not collapsed totally like on Mars.
So, the amazing thing about this planet is it’s a Goldilocks situation, where tectonics
stopped on Mars and it lost its atmosphere. And Venus, it’s incredibly, incredibly warm,
there’s huge amounts of CO2 and it’s much too hot for life to exist as we know it. And
Earth is the only one that is within the so-called habitable zone, where liquid water could exist,
where there is actually, physically water on the planet. And it’s nothing to do with
us. It has everything to do with just this volcanic activity and rock weathering. (Neil
DeGrasse Tyson) So when you say a cycling of the land, you’re talking about continental
drift, where the crust goes down, gets reheated and basically comes out of a volcano somewhere.
(Paul Falkowski) In this case, we’re talking about sedimentary materials from the oceans
primarily. You’re right, this is marine sediments, the marine crust, oceanic crust
going down, underneath, subducting, in this case, now, underneath the cratons, the continents
and coming back up in volcanic material, gases in the mid-ocean ridges and to some extent
on land. But the mid-ocean ridges, primarily. So that’s one cycle. And then there’s
the nitrogen cycle. The natural nitrogen cycle is dependent upon an oxygen cycle and the
oxygen cycle now is dependent on life. And all of these cycles are intertwined. So it’s
not as if one cycle operate freely. They all are related to each other like a network of
wires in a circuit diagram. And understanding the feedbacks here is not easy and it’s
one of those things that we really don’t understand very, very well, frankly, in science,
because we don’t have experimental planets where we could go out and say, oh, let’s
kill off all the nitrogen fixers and let’s see what happens. (Neil DeGrasse Tyson) We’re
already experimenting on Earth. That is our experimental planet. Last I checked… (Paul
Falkowski) Yeah, we’re experimenting with ourselves. So Don may say that, well, what
are we doing here? I would argue that what we do is carry e coli around from place to
place and deposit it in different planets, so we are basically a vector for e coli. (Neil
DeGrasse Tyson) We’re vessels for bacteria. (Paul Falkowski) Vessels for bacteria, that’s
it. (Neil DeGrasse Tyson) I once looked this one up. We have more bacteria living and working
in one centimeter of our lower colons than the total number of people who have ever been
born. (Paul Falkowski) Exactly, right. (Neil DeGrasse Tyson) So, in terms of who’s in
charge, they would have a different answer to that question than we would. (Paul Falkowski)
Right, exactly. Two-point-five kilograms, approximately, of each of us is bacteria.
(Neil DeGrasse Tyson) That’s just a nasty thought. We have bacteria on our skin and
in our digestive tract? (Paul Falkowski) Everywhere, right. You are not who you think you are.
(Neil DeGrasse Tyson) Creeping me out. Chris, Mr. Mars. Did you really just fly in from
Mars? (Chris McKay) No, no, I just came from JFK. (Neil DeGrasse Tyson) From JFK, okay.
Just had to clarify that. Let the records show. So, how does Mars fit into this? We’ve
all seen, perhaps, images of Mars and they’re tantalizing. You see dried river beds and
river deltas and flood plains and water clearly had a significant presence there. And we like
water, we think of life when we think of water. The place is bone-dry now. Something bad happened
on Mars. So do you—apart from your interest in finding life there maybe subterraneously,
is there some lesson that you can learn from Mars that will apply here to Earth? Because
I think we want to keep our water. (Chris McKay) Yeah, the general lesson of “take
care of your planet” is a good lesson. And we might learn that lesson by studying Earth,
obviously, but also including Mars in that study. But the more important question I think
we’re asking about Mars is the fundamental question about life. As everyone here has
been talking about life is all over on this planet. It’s done amazing things, it’s
continuing to do amazing things. We eat it for breakfast, lunch and dinner. It’s an
important part of everything we think about when we think about Earth. But we don’t
understand whether that phenomenon is unique to Earth or has occurred many times in many
different places. Mars is our first chance to really test that. To really go and look.
This planet had water. It had water for a long time. It was kind of like Earth. Did
it have life? And if the answer to that is “yes,” it had life—even if they’re
all dead—and that life turns out to be different than Earth life, what I call a second genesis,
that’s really cool. (Neil DeGrasse Tyson) Different as in no overlapping DNA or that
has DNA at all. (Chris McKay) Well, different if it has a separate origin. Even if it’s
got DNA. If we can deduce that it represents and independent origin of life so that right
here in our own little solar system life started twice, that’s telling us some amazing things
about the nature of the universe. (Neil DeGrasse Tyson) So that would say that life—that
Mars—that Earth in fact would not be unique, that one of our closest neighbors had these
properties in some time in its past, then we’re good to go. Water, a little bit of
atmosphere. (Chris McKay) Yep. It means the universe is full of life and that we have
every expectation that we find other worlds around other stars with water, even if they
don’t have all the plate tectonics and things that keep them active for a long time, they
still have a chance at life. Life becomes then a natural feature of the universe, not
a quirk of some odd little planet around this curious little star. (Neil DeGrasse Tyson)
I like that. Okay. Fred. You think about the formation of solar systems and of planets.
And of course you were never there so you have to sort of apply the known laws of physics,
look at examples in our galaxy where planets are forming. What have you concluded about
planet forming in general, but our solar system in particular? (Fred Adams) Well, there’s
a number of things you can say. One of the first things that we found circa 1984 is that,
when every star forms, it forms with a circumstellar disk around it. This was something that Kant
and Laplace had predicted 200 years ago, but no one had actually seen until the 80s. (Neil
DeGrasse Tyson) Circumstellar disk—you mean you make the star in the middle and there’s
extra stuff that forms a platter. (Fred Adams) There’s actually gas and dust surrounding
it, in orbit around it. And the remarkable thing about these disks that we found in the
80s was that they have the right mass and the right size to form solar systems. Before
these disks were discovered, people had done the exercise of taking the planets in our
solar system and augmenting them with extra mass, extra gas to make them have solar composition
so that they would have the same composition as the sun and then they would deduce the
properties of the nebulae that our planets formed out of. These disks have a range of
properties, but pretty much exactly what we would predicted. So, the birthplace of planets
were predicted and seen and measured in the 80s. Which argues that things are ripe, conditions
are ripe for planets to form. Then in the 90s we found planets around other stars. Right
now there’s anywhere from 400 to 800 planets, depending on how you do your accounting, that
we’ve discovered orbiting other stars. And the number changes every day. Since I haven’t
checked the Internet for a couple of hours, there’s probably more. In fact, at 10 o’clock
tonight there will be more preprints on the Astro PH preprints server, and probably announcement
of another planet. So there are planets everywhere. (Neil DeGrasse Tyson) Wait, wait. There is
an exoplanet app for the iPhone. (Fred Adams) Oh, there is. I have that app. (Neil DeGrasse
Tyson) Yes. Yes. Yes. And so it has all the properties of all the exoplanets and every
time you update it, it gives you the latest file on it and it shows you the orbit and
it’s pretty—just look it up. (Fred Adams) And it beeps you at 7 o’clock in the morning,
too. (Neil DeGrasse Tyson) What you say? (Fred Adams) [30:14] It beeps you at 7 o’clock
in the morning, tell you there’s a new planet. (Neil DeGrasse Tyson) I don’t mind that.
I’m cool with that. (Fred Adams) But, anyway, if you take the observed sample of extra-solar
planets—and you have to do a bit of an extrapolation because we haven’t looked at every solar
system for as long as we would have liked—but you can deduce what fraction of those solar
system have planets. And that projection gives you anywhere from 20% to 50%. What that means
is that anywhere from 20% to 50% of the stars out in our galaxy or at least in our solar
neighborhood, have planetary systems of some kind. So that bodes well for looking for earths.
(Neil DeGrasse Tyson) This is like the Drake equation where you look at the probability
of a star that has planets, that has a planet in the zone… (Fred Adams) Yeah, this is
exactly one part of the Drake equation. For those of you who don’t know, the Drake equation
asks the question, How many intelligent civilizations are there in a galaxy? And in order to get
up to an intelligent civilization, you have to have a number of factors. You have to have
stars, you have to have planets. You have to have the planet have life of some kind.
You have to have animal life, as we’ve seen. Then the animal life has to somehow become
intelligent, which may or may not have happened here. But then it also has to have technology
in the Drake equation. So we’re a long way from being able to predict the last of those
factors, but one of the things that’s I think very satisfying is that the astronomical
part of the Drake equation is rapidly becoming into focus. (Neil DeGrasse Tyson) Yeah, a
solved problem at that level. (Fred Adams) And it’s being solved in a positive direction.
Yes, there are solar systems, yes there are planets, yes there are places where life could
in principle arise. (Neil DeGrasse Tyson) I would go further than that, if I may. Because
let me get back to you, Paul. You gave a list of—both of the two of you sitting together
here, each would leave us to believe that what we see here on Earth, because of all
this interplay of cycles and conditions and circumstance, it’s though A has to go to
B to C to D and we’re like Z in this sequence. And, if you break any of these chains, something
bad happens and we don’t show up or something catastrophic happens to the planet. But let
me ask you: Practically every time we have imagined that something was a special condition,
upon further exploration in the universe, it hasn’t been. So, for example, even in
the Drake equation, where they talk about the habitable zone—before we call it the,
we would only later call it the Goldilocks Zone—the habitable zone, we have one of
the moons of Jupiter, Europa, kept warm not from the sun but from the gravitational stressing
of Jupiter and the surrounding moons themselves. So… (Fred Adams) In fact, there’s another
way to do it, as well. If you have a planet as big as the Earth that lives in the outer
solar system where the moons of Jupiter live, the natural radioactivity will keep liquid
water pockets. They won’t be on the surface, they’ll be beneath ice sheets. But there
will be some water. (Neil DeGrasse Tyson) So the undersea vents, that’s a source of
energy, nothing to do with the sun, life could just be doing the backstroke down there, won’t
even care what’s happening on the surface. (Fred Adams) Yeah, well, what we know for
sure, or what we think we know, is that there will be liquid water and there will be an
energy source. The rest is what we’re debating here. (Neil DeGrasse Tyson) So, what I worry
about is, couldn’t there be other combinations of cycles that would still work for some kind
of life that we might not have dreamt up yet. And, if that’s the case, you could say Earth
is unique for us, but unique for any kind of life at all, maybe not. Because you haven’t
thought of these other ways—because nature could be inventive at times. And is typically
more inventive than we ever are. So how do you address a criticism that you just haven’t
thought of other ways to sustain a planet that … to create a planet that could sustain
life? (Paul Falkowski) So, the way biologists have looked at it over the last 20 or 30 years
is they’ve looked at what’s called redox couples. That means the difference in energy
between, for example, hydrogen and oxygen. And that redox couple is very large and, obviously—everybody
in the room, let’s do the following experiment. Just [inhales deeply]. Take a breath. Okay,
so you just exchanged hydrogen from your body with the oxygen in the atmosphere and the
primary gas which resulted from that was water. Okay? So that’s a very, very high energy
gap which allows us to derive a huge amount of energy from that reaction. That reaction
is a relatively recent reaction, it only happened about 2.3 or so billion years ago. Before
that, the reaction was constrained to hydrogen sulfide or iron oxidation. So those reactions
have much, much lower free energy. And it doesn’t matter what planet you’re on.
You’re endowed with a certain number of redox couples. So, on Europa, the only reason
you could have life in the interior of Europa is either because some something is supplying
a redox couple from the interior of that moon or there’s a subduction of ice from the
surface into the interior and it cannot be a closed system. And all systems, ultimately,
have to be open systems. So, what I’m saying is, in our case, we only make bond energy,
new bond energy on this planet, it’s a first order, because the sun is shining and something
is taking water and splitting it—which we don’t do—splitting water and creating
energy gap and using that hydrogen, effectively, to reduce the CO2 in the atmosphere to sugars
that we eat. So, those are really common metabolisms… (Neil DeGrasse Tyson) So the fact that—correct
me if I’m wrong—the main engine of, on the space shuttle, but the big orange engine
is a hydrogen-oxygen reaction. (Paul Falkowski) Absolutely. (Neil DeGrasse Tyson) And so it’s
just making water as its exhaust. It’s exothermic and the thing takes off. (Paul Falkowski)
Right. You and I are fuel cells. We’re just a much more controlled rocket. (Minik Rosing)
I think you could also add that, if you go towards intelligent life, you’d say that
our brain uses a quarter of the energy that our entire body consumes. And that means that
you need a very intensive source of energy if you want to be intelligent. So, if you
should sustain yourself [with] the thermal energy inside of a moon someplace, there’s
no chance that you could organize higher organisms on that feeble amount of energy you have there,
to that level, I think. I think we’re so dependent on being able to convert the energy
from the sun into something that we can use to sustain a high level of activity that…
(Paul Falkowski) So there’s still more intelligence in Louisiana than on Titan, we can be sure
of that [prediction]. (Neil DeGrasse Tyson) He can pull off that joke here in New York,
but in Louisiana…. Just try that in Louisiana, I think … I think they just passed a law
that you have to carry a gun, so you’ll have a different reaction down there. What
do you have to say about what they just said? (Chris McKay) Well, I have a more optimistic
view. (Neil DeGrasse Tyson) That’s why I came to you. (Chris McKay) Yeah, I know. I
think we should look for strange things and hope to be surprised. And the strangest world
that I think is promising is Titan, because there there’s a liquid. And on Earth we
know that life is tied to liquid water. We don’t know if the critical thing is the
liquid or the water. And, on Titan, there’s a liquid. It’s the only world in the solar
system with a liquid on its surface besides the Earth. The liquid’s not water, it’s
liquid methane. But in many ways liquid methane is a nicer liquid for life than water. Water’s
aggressive, it tears molecules apart, it’s at high temperature. There’s a lot of drawbacks
to living in water. (Neil DeGrasse Tyson) But methane is the gas that comes out of my
stove. (Chris McKay) Yeah, but on Titan… (Neil DeGrasse Tyson) That I ignite and cook
my food with. (Chris McKay) That’s because we have a world that’s hot with oxygen.
On a suitable world, a world that’s really built for life, the temperature is very cold,
so things can move very slowly and methane is a liquid. It’ll look just like this,
clear and if this was Titan, it would be stable, it would be a liquid and you could imagine
a biochemistry based on that liquid. Finding that would be very, very interesting. (Neil
DeGrasse Tyson) This is way outside of any box that they’ve been talking about right
here. (Chris McKay) Exactly. It’s not just outside the box, it’s on the other side
of the street. And that’s what makes it so interesting. If we can find life that’s
that strange, then we know the universe is really full of interesting creatures. (Neil
DeGrasse Tyson) I had an incident. I was interviewed on Charlie Rose. This is now 15 years ago
when the Mars rock story hit. Remember that? The Alan Hills Mars rock. A meteorite on Earth
discovered to have come from Mars all by itself. It was studied for the chemistry in the nooks
and crannies and there was some curious properties of the material that was in there that was
suggestive that maybe it was life. Then they showed the picture that—that little, wormy-looking
thing, and that was not ever advanced as evidence for life, but it was just a curious photo.
In that interview, there’s a biologist piped in. And he sees the pictures—“That can’t
possibly be life.” I said, why not? And he said, that’s only one-tenth the size
of the smallest life on Earth. And I’m still waiting for him to give the reason why that
can’t be life—but that was his reason. And then I said, last I checked, this is from
Mars, so why is Earth your measure of this? And so I wonder whether biologists are—I’m
harping back to his point—I wonder if biologists are kind of stuck in their—in their sample
of one. And the sample of one is all life on Earth has common DNA. You don’t have
another example. (Paul Falkowski) No, that’s not the story. (Neil DeGrasse Tyson) What’s
the story? (Paul Falkowski) The story is that you have to—if you’re going to have life,
you have to have two properties. You have to have self-replication and you have to have
a metabolism. (Neil DeGrasse Tyson) How do you know this? (Paul Falkowski) Well, otherwise,
how do you define it? (Neil DeGrasse Tyson) That’s what… That’s not an answer to
what’s the definition of life. You give me that comment and then you say, well, otherwise,
how would you do it? I guess what… (Paul Falkowski) You went to Titan and you found—what
would you look for? If it’s not replicating and it has no metabolism, what is it? (Neil
DeGrasse Tyson) Okay, so now, if you define it that way and then you find something else
that’s not that, what do you do with it? (Minik Rosing) It’s called a mineral. (Neil
DeGrasse Tyson) Oh, called a mineral. Okay. It’s a rock, Jim. Okay. So we have words
for things that don’t do that already, is what you’re saying. (Paul Falkowski) Right.
I mean, I can plug my computer into a wall and it has a metabolism of a sort. There’s
an energy supply to it. It doesn’t replicate yet. (Neil DeGrasse Tyson) Stars. Stars have
a metabolism and they’re self-replicating. Is a star alive? (Chris McKay) No, they don’t
have a metabolism in a sense. (Neil DeGrasse Tyson) Yes, they do. They have an energy supply.
That’s an energy supply. (Chris McKay) They’re not Darwinian. They don’t reproduce, mutate
and then are selected by an environment. (Neil DeGrasse Tyson) That’s a very Earthbound
statement. (Chris McKay) Well, I think that’s a more general statement and that’s what
we’d be looking for on Titan. We wouldn’t be just looking for a reaction, because there’s
reactions there that aren’t biological. And we wouldn’t just be looking for replication
in the sense that a fire replicates or a cloud replicates or a star replicates. We’d be
looking for that unique biological process which we call Darwinian evolution which involves
replication with mutation and then selection from an environment. And that cycle is what
has created the complexity and diversity of life on Earth. That cycle I think could operate
on Titan. So, Paul’s right in the sense that there is some fundamental properties
that we can ascribe to life and we can look for them in other settings. (Neil DeGrasse
Tyson) Now, this bit about how much energy our brain uses, that’s fascinating. I think
most people don’t carry that knowledge with them, but that’s why they always say you
lose a lot of energy through your head and you wear a hat, this sort of—it’s related,
it’s a related phenomenon. My afro kept my head warm completely, I’ve never worn
a hat. And my head has never felt cold. Ever. (Minik Rosing) So that might mean that…
(Neil DeGrasse Tyson) They give me a hat, it’s like putting a hat on top of a hat.
It’s just a comment. So, but clearly, Paul and Don, you’d be happy if you found any
life at all, so we don’t need to put the requirement of intelligence as high on this
search for life. (Paul Falkowski) No, intelligence is very low on the search for life. (Neil
DeGrasse Tyson) Very low on the search, okay. (Paul Falkowski) To my mind, if you take a
look at life on Earth, it really is conducted by about 1,500 genes. That’s it. The rest
is the color of the car, the size of the windows—it’s trivia, it’s—we worship organisms in Darwinian
evolution. But in reality all you are is like a Patek Philippe watch. You’re just carrying
genes to give it on to the next generation. Ultimately, every microbe… (Neil DeGrasse
Tyson) We are what kind of watch? (Paul Falkowski) You basically hold—you’re a vessel of
genes. As an organism of humans, we’re just going to hand off those genes like a baton
to some other organism in the future. That’s what every microbe is. They’re a vessel
of genes. And only about 1,500 of them are really, really, really important. So they’re
the ones that make all the life on this planet really go. You know, in effect—it’s not
a joke, but it’s really true—that you and I are nothing but e coli that are organized
with brains and eyes and with a mouth and that’s it. We’re just the same.(Neil DeGrasse
Tyson) So we’re e coli brought to consciousness. (Paul Falkowski) Yes. (Don Brownlee) Oh, speak
for yourself. (Neil DeGrasse Tyson) Don, what was going on in the earliest time of Earth?
Because last I checked the numbers, life showed up pretty quickly on Earth. If you subtract
away the years where Earth is still accreting from its birth sac, the surface would be hostile
to complex chemistry. So subtract those years out, because that’s not fair to start the
clock. Wait for that to be done, start the clock—how long did life take? (Don Brownlee)
Well, in Earth history, you can see the earliest Earth’s history by looking at the moon.
Even with the naked eye, those huge craters. The biggest crater on the moon is on the back
side. It’s called the [Sal] Aitken basin, it’s almost 25 kilometers across. The Earth
got completely creamed in its first half-billion years of history. The heavy bombardment period
actually ended about 3.9 billion years ago. (Neil DeGrasse Tyson) And that period is called
the Heavy Bombardment period. Just want to make that clear. (Don Brownlee) It’s called
a variety of things. Any organisms lived here would have called it “Holy smo…” You
know? But, anyway, so there was a period of time which is envisioned by astrobiologists,
life may have formed again and again and again, but every great big impact that came sterilized
the planet. But when that was over, when the impact record ended on our neighboring moon,
which records this ancient history, right after that there’s chemical and isotopic
evidence that there was life on Earth. So that suggests that getting microbial life
may be easy. (Neil DeGrasse Tyson) Really easy. (Don Brownlee) Well, who knows? We only
got one—this is the challenge of astrobiology. How do we try to outsmart organisms we know
nothing about? Because we only know here, we’re our only data. But that it took so
long… (Neil DeGrasse Tyson) Well, but it’s not that we have no idea. If life formed almost
as quickly as it possibly could have, you’re allowed to say that at least nature found
it easy to make life. Aren’t you allowed to say that? (Minik Rosing) I think we have
one important piece of evidence, that is that we have no geologic record any part of Earth
history where there was no life. That means it’s not like we had a period where there’s
no life and then life came. So, all through the record we have presence of life. And I
actually tend to disagree a little bit with you about the 3.9 billion years ago. Because
3.8 billion years ago, life is already leaving very significant imprints on the planet. And
that would mean that that was not a very early type of life, but probably life 3.8 billion
years ago was already pretty sophisticated in a sense.(Don Brownlee) But no records.
(Minik Rosing) But there are no records of that prehistory, but it must have had a prehistory
to reach a level where it could really impact the planet already. (Neil DeGrasse Tyson)
What you’re saying, it wouldn’t have just been a tide pool over here. (Minik Rosing)
Yeah. (Neil DeGrasse Tyson) Given what you see in the geologic signature… (Minik Rosing)
You would have complex communities of microbes. You would have very efficient life that knew
how to… (Neil DeGrasse Tyson) Already by 3.8 billion years ago. (Minik Rosing) Yeah,
yeah. (Neil DeGrasse Tyson) So this happens quickly. So, if that’s the case—and let’s
accept the likelihood that nature does not have trouble making life. Let’s just accept
that for the moment. I don’t think that’s a stretch to make that claim. (Don Brownlee)
It is a stretch. (Minik Rosing) We don’t know. (Neil DeGrasse Tyson) I don’t think
it … it did it as soon as it could have. (Don Brownlee) We have 50,000 meteorites that
were much more carbon-rich, much more nitrogen-rich, much more water-rich than our planet. They
were warm and wet for a couple million years, early history of the solar system. No life.
So it can’t be totally trivial. I mean, these are from asteroids… (Neil DeGrasse
Tyson) So you’re comparing whether life formed on a planet versus an asteroid. (Don
Brownlee) Yeah, yeah. All the ingredients were there. If you were living inside that
asteroid, you wouldn’t know you weren’t living in [TALKOVER]. (Neil DeGrasse Tyson)
That’s true. You wouldn’t know whether… (Don Brownlee) …you’re surrounded by water,
there’s no sky to see. It’s like living in this room or something. But so there are
environment… (Neil DeGrasse Tyson) We can make a sky in this facility, just want you
to…(Don Brownlee) There’s no life on the moon other than the astronauts that we sent
there. So we do know a lot about the solar system and we know that there’s no life
in the meteorites or—some people think there is, but most people don’t. There’s no
life on the moon. The great thing about the solar system is that, unlike everything else
in the universe, it’s close. So we can in the coming years go to every single place
in the solar system and look for evidence of life. And even if we don’t know how to
define life, my guess is, once we see life on Titan or Europa or whatever, we will then
agree, yes, this is life. You know it when you see it. (Neil DeGrasse Tyson) Do your
solar systems that you create on the back of an envelope and occasionally with a computer,
do they resemble—what do they look like? Can you crank out the Earths in your models?
What *** do you have to turn so that either you make a lot of Earths or very few? (Fred
Adams) The surface density of solids. That’s the one *** that you need to turn to get
planets. (Neil DeGrasse Tyson) Surface dens… I don’t know what that … surface density
of solids. (Fred Adams) Perhaps I should define it. If you make a star and you have a disk
around it, there’s about 2%, in the case of the sun, 2% of that material is in the
form of things that are not hydrogen and helium, things that are not gas. We in astronomy call
that heavy metals. Heavy metals includes mostly carbon and lithium, not what you think of
as heavy metals. (Neil DeGrasse Tyson) They were heavy metals in astronomy before it was
a genre of rock music. (Fred Adams) Music. That is correct, yes. (Neil DeGrasse Tyson)
To clarify. (Fred Adams) Not Bon Jovi, right. So, the density of those solids is the single
most important variable that determines whether you can make planets, whether you can make
them quickly, whether you can make them in abundance in these theoretical calculations.
So, if you have a metal-rich system, which means that you have relatively more metals,
these heavy metals than we do in the sun, then it’s actually quite easy to form planets.
If you have a heavier disk—so even though you don’t have relatively higher abundance
of metals, but you have more gas in total, or more mass, rather, in total, then it’s
easier to form planets. So as long as you have one variable high enough, then everything’s
a go. (Neil DeGrasse Tyson) These would be solar systems made later in the history of
the galaxy, where you have much more of this enrichment to make your high surface density
of solids. (Fred Adams) Yes. Well, those are the ones that are—well... (Neil DeGrasse
Tyson) Because every generation of super nova, you’re cranking out heavy element, punching
them into the cloud… (Fred Adams) Yeah, but we don’t be lost in vagueness here.
The super novae that cause or create the heavy elements come from massive stars and massive
stars live and die on millions of years time scale. My point is that millions of years
is actually short compared to billions of years. So that you could have many generations
of massive stars producing metals and still have a solar system that’s quite old. The
extra-solar planets that we see now, the ones that are around these other stars, those stars
were targeted to be as much like the sun as possible, which includes the fact that those
are also 4 billion years old. These are not young stars that just formed. (Neil DeGrasse
Tyson) That just formed, right. (Fred Adams) So, even stars that old can have metals higher
than those of the sun. (Neil DeGrasse Tyson) So, maybe I’ll need you in the answer to
this, as well, when I ask this of Minsk, if in these models, if I have two identical Earths
in two different star systems, they’re basically identical, because you can make them way in
a model, and then you just step back and let events unfold, is there a chaotic regime in
what goes on so that in fact they could have divergent futures? (Minik Rosing) I think
that if we say, okay, they both develop life at some point in their history, I think they
will—they may start out being very identical, but they will take unique courses. Because
today the trajectory of the evolution of life is so determined in the inventions that the
life on Earth made basically, the type of metabolic inventions that life may determine
the way the planet functions today. We tend to see planet as a substrate to life, but
actually life is a product—Earth is a product of the life, basically, the way it looks.
You could make arguments that the continents that we live on are here due to the metabolic
activities of some type of microbes billions of years back in time. And the [completion
51:48] of the atmosphere we’re sure is controlled by the organisms that live here. (Neil DeGrasse
Tyson) Life feedback with… (Minik Rosing) That’s life feedback, and probably the stability
of climate on Earth is also coupled to the activity of life. So the fact that, if you
look back to the geologic history, it’s actually very boring. You go back and you
look at rocks that are 4 billion years old, almost, and they’ll look pretty much like
any rock that’s formed today in Hawaii. (Neil DeGrasse Tyson) I’ve always thought
rocks were boring, whether or not they…But that’s just me. Sorry. (Minik Rosing) No,
it is true, actually, I will reveal this little secret—rocks are really boring and Earth
is an extremely boring planet. Very little happens and even that would happen had it
not been for life. Life is only activity that’s really important on the planet and that’s
what process all the energy that drives the geochemical cycles today. That is life and
not Earth itself. (Neil DeGrasse Tyson) What happens to Earth when all our volcanoes stop?
Do we look like Mars? (Chris McKay) Eventually we will. Eventually, if we had no more CO2
coming out of the volcanoes, life and chemical precipitation would remove the CO2, the Earth
would lose its greenhouse effect and it would be, instead of plus-15 degrees Centigrade
average temperature, it would be minus-15 degrees Centigrade. (Neil DeGrasse Tyson)
We’d freeze Earth completely. (Chris McKay) Just like Mars. And in a sense, this is what
happens on Mars…happened on Mars. After several hundred million years, it lost its
recycling ability, its outgassing of CO2, lost its atmosphere and became cold and dry.
Earth could go that way if volcanoes were stopped. (Neil DeGrasse Tyson) So, Don, why
is Earth still warm and Mars isn’t? (Don Brownlee) I won’t say Goldilocks, but...
(Neil DeGrasse Tyson) No, no, I mean just why is—as a physical body, why is it still
warm? Because Mars has cooled down, right? There’s no heat source inside of Mars? (Don
Brownlee) We’re fortunate to be born closer to the sun. We have a much more—we’re
100 times more geologically active than Mars.(Neil DeGrasse Tyson) No, that’s my question.
(Don Brownlee) We have plate tectonics, which is unique to our planet. (Neil DeGrasse Tyson)
That’s my question. (Don Brownlee) The plate tectonics is one of the big factors in keeping
Earth habitable. (Neil DeGrasse Tyson) Wait, wait, just stop, I’m trying to understand.
Mars is dead and it has no plate tectonics. Earth has this energy source that has nothing
to do with the sun that’s driving plate tectonics. Why is that still happening on
Earth and it has stopped happening on Mars? That’s what I’m asking. (Don Brownlee)
Earth is Earth and Mars is Mars. There aren’t any plate tectonics… (Paul Falkowski) Mass.
(Chris McKay) Mass. (Neil DeGrasse Tyson) Such as mass. Come back over here. Mass, fine.
(Paul Falkowski) The answer is mass. Earth is 10 times bigger than Mars. (Chris McKay)
In mass, yeah. (Paul Falkowski) In mass. Ten times more mass. It’s the difference between
me and my cat in mass. My cat can do things that I can’t do. The cat can climb up a
wall. Mass, a factor of 10 in mass changes the physical properties. Earth, being 10 times
more massive than Mars, has a much more active internal heat flow and internal cycling. So
the difference between Earth and Mars, I think, is not so much that Mars is further from the
sun. It’s mass. (Chris McKay) Yeah. (Paul Falkowski) If Earth was where Mars is, it
would still be a nice place to live. (Neil DeGrasse Tyson) Well, then, how come Venus
looks so different when it has the same mass as Earth? (Paul Falkowski) Well, there, you’re
right. It’s too close to the sun. Sorry. It’s not all mass. Size matters, I learned
that on TV. (Minik Rosing) But, but I... (Paul Falkowski) But also distance to the sun matters,
too. (Neil DeGrasse Tyson) Okay, so it matters—distance to the sun matters between Venus and Earth,
but not between Earth and Mars. So you think you can sustain an Earth as Earth at the distance
to Mars? (Paul Falkowski) Right, right, yep. If Mars were the size of the Earth, we would
be having this meeting on Mars instead of on Earth. (Neil DeGrasse Tyson) And if Venus
were at the distance of the Earth…? (Paul Falkowski) It would probably be a nice place,
too. That’s right. You got it. Now… But I.... (Fred Adams) But if I can interject,
this internal energy source must be very, very—the details must be very, very sensitive
because the amount of energy you get from this internal radioactivity is 10,000 times
less than the energy you get from the sun. (Paul Falkowski) Absolutely. (Neil DeGrasse
Tyson) Oh. (Don Brownlee) That’s why it doesn’t drive the chemical reaction [TALKOVER].
(Fred Adams) So, one part in 10,000 makes a huge difference. (Minik Rosing) But there’s
a very important difference, also, and that is that we have the ocean that keeps hydrating
the ocean floor that goes back into the Earth and basically lubricates the machinery in
there. So, without the reflux of water into the interior of Earth, it would also stiffen
up. The Earth is soft inside. It is not a marshmallow or anything, but it’s soft due
to the presence of water that is being subducted with the ocean floor… (Neil DeGrasse Tyson)
So you’re saying Earth is like—it’s like oil in a car engine? (Minik Rosing) Yes,
something like that. And like Venus has lost its water and therefore cannot lubricate a
mantle and therefore the mantle works in different ways than it does—it doesn’t work in this
steady, smooth operation as Earth does. And you can also, again, argue that the stability
of the climate, the stability of the oceans which is maintained largely by life. So you
could say that the plate tectonics has been sustained on Earth for 4 billion years or
more, probably also due to the management of life, to some extent, or maybe to the full
extent. (Neil DeGrasse Tyson) Paul, something interesting here. (Paul Falkowski) Can I disagree
with Minik for a second? (Minik Rosing) No. (Neil DeGrasse Tyson) Sure. Wait, what about
it are you disagreeing with? (Paul Falkowski) Well, life is really important for disequilibria
of redox reactions. It takes and makes gases because it moves electrons around. But…
(Neil DeGrasse Tyson) But what you’re saying is inside a physical organism, we are highly
out of equilibrium. (Paul Falkowski) Right, exactly. (Neil DeGrasse Tyson) Okay. (Paul
Falkowski) But you would have a carbon cycle on this planet without life and we have three
or four oceans of water in the mantle below the ocean that we physically see. And that
would be there without life, also. So I think we over-ascribe this Gaia-esque world to—at
least you are… (Neil DeGrasse Tyson) But just briefly, “Gaia-esque”? Just tell
everyone what Gaia is. (Paul Falkowski) Well, Jim Lovelock hypothesized this kind of feedback
that life and the planet co-evolved, so that the planet’s surface conditions is always
made possible for the future of life by life itself. There’s a feature of life that makes
life more conducive for life. (Neil DeGrasse Tyson) So life is a stabilizing factor in
the dynamics of the planet. (Paul Falkowski) And as our mutual friend, Joe Kirschvink at
CalTech would say, well, if that was true, then we wouldn’t have had had Snowball Earth.
Snowball Earths were that period in time, starting at around 2.2 billion years ago,
shortly after we oxidized the atmosphere, where all the oceans appear to have frozen.
And they froze for maybe about a hundred, a hundred-and-fifty million years. We still
have [refugia] somehow for life, but certainly we stopped basically the hydrological cycle—this
planet became, the surface planet became very cold. And this happened apparently four times,
up until we got the Cambrian explosion. (Neil DeGrasse Tyson) But that notion got a lot
of play. (Paul Falkowski) It did. (Neil DeGrasse Tyson) It did. (Paul Falkowski) Yes. (Neil
DeGrasse Tyson) More than perhaps it deserved. (Paul Falkowski) I’m not sure. I think it’s
a very interesting thing of how can you get a planet so far out of its thermal zone, comfort
zone… (Neil DeGrasse Tyson) So that it never comes back. (Paul Falkowski) It never comes
back. (Chris McKay) It doesn’t never come back. It came back. (Paul Falkowski) It came
back because of tectonics. (Chris McKay) It came back because of volcanism persisting,
driven by tectonics. So as long as—volcanoes are a good thing. They’ll knock the Snowball
Earth eventually. (Neil DeGrasse Tyson) Okay, so what day will we lose our volcanoes? (Paul
Falkowski) We’ve got several billion years’ worth of radioactivity left in the interior.
(Minik Rosing) And we also have the liquid core that’s producing a lot of heat when
it’s solidifying. So we have two [engines 59:34], actually. Not only the radioactivity,
but we also have the liquid core which is releasing energy as it crystallizes. (Don
Brownlee) And we still have heat left over from our formation. (Minik Rosing) Yeah, that’s,
and the liquid core, exactly. (Neil DeGrasse Tyson) Okay, so we have heat from our formation.
You got heat from all this movement. I guess it’s friction down there. You had heat from
radioactivity. And you just said a moment ago, which I hadn’t heard this number, that
it’s what percent of the total energy budget of the Earth when you add in sunlight? (Paul
Falkowski) Well, it’s ten to the fourth? (Neil DeGrasse Tyson) One in 10,000. (Paul
Falkowski) Yeah. (Chris McKay) But that’s misleading. Because most of that sunlight
comes and hits the Earth and leaves. Whereas this geothermal heat is coming from deep below
the surface of the Earth and it’s driving the volcanoes and the tectonics… (Neil DeGrasse
Tyson) It’s actually getting busy. (Chris McKay) It’s doing something that that sunlight
isn’t doing. (Fred Adams) Well, in fact, it has to do something in order to get out.
That’s what it does. (Neil DeGrasse Tyson) It’s heat trying to get out. (Fred Adams)
No—yeah, because it has to…[TALKOVER] through the rock layers… (Paul Falkowski)
[TALKOVER] in the Mojave Desert at night, it’s got four tires touching the ground
and yet it’s radiatively more related to space than it is to the ground. It’s not
getting heat through the tires to keep it warm. It’s getting heat from the sun during
the day and it’s radiating it back at night. And that’s what most of the planetary surface
is doing. (Chris McKay) Surface. But the subsurface is what drives the volcanoes and that subsurface…
(Paul Falkowski) But the surface is where the light—where the light energy is transforming
molecules to make chemical bonds of light. And one more thing. You know, to me, discussing
the origins of life as being simple or not is like saying you can talk about the theory
of jazz and one day somebody like Thelonious Monk comes along and plays something, okay?
So, nature… (Neil DeGrasse Tyson) I didn’t make that…I didn’t get that connection.
(Paul Falkowski) No, nature was somewhere along the line a Thelonious Monk. It wasn’t
just a theoretician of learning jazz theory, it learned to play the piano. And it took
molecules and it made stuff. And it made stuff that replicated and it made bugs. And we can’t
do that. We haven’t been able to do that yet. So even the very simple redox reactions,
like water splitting, we don’t know how to do. We don’t know how to make nitrogen
into ammonium at room temperature… (Neil DeGrasse Tyson) But why should what we know
how to do be any measure of what was possible in the early universe? (Paul Falkowski) Because
we know the structures of those molecules at very high resolution. We talk about astrophysical
space that is phenomenal in terms of what a telescope can see. Well, conversely or obversely,
we have incredible resolution of molecules and we can go down to 1.1, 1.2 angstroms and
see how these molecules are structured. And yet we can’t replicate them. If I were to
change the world for our energy budget, I would invent a catalyst that splits water.
And if I could split water, I get hydrogen. The world changes instantly. Instantly. So
we have then an infinite source of energy for the rest of human civilization. (Neil
DeGrasse Tyson) So this brings up an interesting point. A pretty important chemical reaction
in the early Earth is photosynthesis. (Paul Falkowski) Absolutely. (Neil DeGrasse Tyson)
Okay. It’s nature figuring out a way to exploit the energy from the sun… (Paul Falkowski)
To make new bonds. (Neil DeGrasse Tyson) …because why not? It’s available to you. That reaction
is interesting—I remember learning about it in biology. But it wasn’t so complex
that I couldn’t imagine it happening naturally. Would that be something that you think might
be inevitable on any planetary surface? (Paul Falkowski) You know, it’s still a Darwinian
eyeball. It’s one of those things that occurs on Earth and yet we really don’t understand
how this thing came to be. So it occurs. I think every biologist that studies the reaction
believes in the evolution of this through some natural selection process. But we still
don’t know the very early blocks that allow the electrons to be moved because of photons.
(Neil DeGrasse Tyson) Why not? (Paul Falkowski) Well, to… (Neil DeGrasse Tyson) I got Fred
Adams over here claiming he knows how planets were born. You can’t figure out a molecule…?
(Paul Falkowski) Yeah, the trick of photosynthesis is the back reaction. So, if I take an electron
off a metal, like manganese, which is where the original electron comes from before it
oxidizes the water, and I put the electron somewhere, most cases it just goes back down.
And nothing happens. So, the magic of the photosynthetic reaction is you move the electron
and then we put it someplace where we stored it so it doesn’t go backwards. And that’s
been very, very, very hard to do for humans to mimic that. We almost can do it. In the
next 20 years, we probably will be able to do that pretty well. But it’s been one of
those… (Neil DeGrasse Tyson) Maybe biology is just still kind of in its infancy. I know
it’s hard to admit that as a biologist, but… (Paul Falkowski) No, not at all. (Neil
DeGrasse Tyson) Okay, so maybe it’s in its infancy and you need another century of this
effort before you can show that something that today is viewed as complex, in a hundred
years would be viewed as simple. We’ve been through this in physics. (Paul Falkowski)
Exactly. (Neil DeGrasse Tyson) We looked up at the night sky. Planets were going through
retrograde, nobody understood it. Newton comes along, writes down the equation of gravity.
It is trivial, you can do it on you iPod today. (Paul Falkowski) Well, exactly, the analogy
is exactly right. The beginning of the last century was the beginning of quantum mechanics
and the understanding of physical properties and the physicists ruled the 20th century
in science. I think this is the century of biology and biologists won’t rule in the
sense, but they’ll understand the rules of biology, which has been a very, very difficult
thing. (Neil DeGrasse Tyson) So, all right, so…(Fred Adams) Well, physics isn’t quite
done yet in the sense …(Chris McKay) …still things to do. (Fred Adams) No, but I actually
wanted to make an analogy, not a joke. One of the things that… (Neil DeGrasse Tyson)
Well, wait, just quick—this is that worm-y thing that was on the Mars rock, [Alan Hills
8401]. And we don’t know if it’s really a worm, or just intriguing. The photo was
published alongside the research paper that described it. So I don’t know, it was a
quick—these are just random wallpaper about life on Earth and elsewhere. So I interrupted,
sorry. (Fred Adams) Oh, I was just going to make the point that, just because we can’t
reproduce something in the lab doesn’t mean that nature can’t do it readily. (Neil DeGrasse
Tyson) Or easily. (Fred Adams) A good example of that is something called fusion. Every
star in the universe runs on nuclear fusion. In our physics labs we’ve been remarkably—well,
we found it remarkably difficult to produce a sustained… (Neil DeGrasse Tyson) Inept.
(Fred Adams) Yeah, that’s the word, inept. To produce a sustained, controlled—key word,
“controlled”—fusion reaction. It’s really easy to build a bomb that is an uncontrolled
fusion reaction. But it turns out to be really, really hard to have a controlled fusion reaction.
But that doesn’t mean that nature has any trouble with it. Nature does it billions and
millions of times in billions and millions of galaxies, so. (Neil DeGrasse Tyson) So,
let me ask. In the planets that we’re now adding to our inventory of—the exoplanets,
we have…Who here can tell us about the Kepler mission? Who’s the best among you to just
brief us on that? (Fred Adams) I can tell you. (Neil DeGrasse Tyson) Go ahead, the Kepler
mission. (Fred Adams) Well, just to lay the groundwork, before the Kepler mission, using
ground-based astronomy, we now have a database of approximately 400, 450 planets discovered
one at a time by telescope. The Kepler mission is a satellite that’s measuring the presence
of planets in a different way. There’s at least—well, there’s four different ways
to measure planets, but the two that have found the most fruit are what’s called the
radio velocity method, where you watch the star wobble back and forth in the sky and
then you deduce … (Neil DeGrasse Tyson) In reaction to the gravity… (Fred Adams)
In reaction to the gravity of the planet. And, from that signature, you can deduce the
properties of the planetary orbit, the mass of the planet and so on. The other way to
see planets is if you have a star and a planet goes in front of it, then the planet will
cast a shadow on the star and the star will appear dimmer for a little bit and then the
planet will pass the star and the brightness of the star will shoot back up. That’s called
a transit. So, the Kepler satellite measures transits. And it published a paper in June
where it gave partial discovery, or claimed partial discovery to 400 planets. Now, the
full story is that there are 800 planet candidates and, of those, they decided that 400 of them
were interesting and they didn’t want it released to the public, so they’re keeping
them in their drawers, as in their desk drawers. So that we can’t see them yet. And then
the 400 of them that they deemed less interesting they published as in “these are the planets,
these are the stars, these are their properties.” But what’s confusing about that is that
they haven’t figured out their false alarm rate correctly. So they’ve thrown out everything
they know is a false alarm, but they still figure that, of the planet candidates they
have, about a fourth of them are actually not really planets. So we have another 400
planets discovered as of June, although only 300 of them are real and what’s a little
bit frustrating is that we’re not sure which 300 are the real ones. (Neil DeGrasse Tyson)
No, but the takeaway here is that… (Fred Adams) The takeaway is that there will be
hundreds of planets. (Neil DeGrasse Tyson) It’s a mission tuned for finding Earthlike
planets. (Fred Adams) Yes. And we’re finding many smaller planets in this sample of 400
potential planets than we have in the sample of radio velocity planets. (Neil DeGrasse
Tyson) Because that one required that more massive planets… (Fred Adams) Yeah, it’s
easier to see... (Neil DeGrasse Tyson) …tug the host star. (Fred Adams) …these big planets
because they wiggle their stars more. (Neil DeGrasse Tyson) Right. So we’re going to
go to questions from the floor. We have two microphones set up. We’ll go in just a couple
of minutes. But just think about your question and feel free to come up. I just want to go
down the line here and I don’t know that we resolved anything, but let me just get
your take—yes or no, so is Earth unique? In whatever what the word “unique” means
to you. Is Earth unique? (Minik Rosing) I think it’s unique, yes. (Neil DeGrasse Tyson)
You think it’s unique. What do you think? Of course you say yes, okay. Paul. (Paul Falkowski)
I go with the odds, it’s not unique. (Neil DeGrasse Tyson) Not unique. (Paul Falkowski)
When you have 10 to the 11th stars in the Milky Way, in our galaxy, you have a 10 to
24th or some number like that in the universe, I think the odds of it being unique are incredibly
low. I mean, you just do the numbers, for the Drake equation, you just need the front
end. (Neil DeGrasse Tyson) Well, let me ask you this: Is it not unique in a neighborhood
of—in our little zone? Or do you have to really cross the galaxy to find one? (Paul
Falkowski) I would hope… (Neil DeGrasse Tyson) So, how unique is it? (Paul Falkowski)
Well, how unique is it? If we’re looking for life… (Neil DeGrasse Tyson) How pregnant
are you? How unique is it? (Paul Falkowski) I think the question, the seminal question
is, is this the only planet in the universe, for example… (Neil DeGrasse Tyson) A good
shot of Earth here now. (Paul Falkowski) …that supports life. And if I view life as something
that is far from thermodynamic equilibrium, that can self-replicate, then it leaves a
gas trace somewhere, it should leave a gas trace. And therefore long before there was
oxygen on this planet there was probably methane and nitrous oxide that co-existed. We could
have seen in that universe at that time, if we were sitting with a interferometer, for
example, evidence of life on this planet, even though humans were not here yet. (Neil
DeGrasse Tyson) The gaseous effluences of life thriving on its surface. (Paul Falkowski)
Right. We’re basically looking for reruns of Gilligan’s Island from—that’s what
search for intelligent life is doing, looking for reruns of Gilligan’s Island from some
planet’s 20, 30, 50 parsecs away. I’m not sure that we’ll ever find that. But
I certainly think that we’ll find disequilibrium gases. If you see methane and nitrous oxide
on a planet six parsecs away, game’s over. (Neil DeGrasse Tyson) But Gilligan’s Island
was a TV show in disequilibrium, right? Let us hope that that’s not our cultural emissary
that is first discovered by … Unique or not? (Chris McKay) Life is common in the universe,
so in that sense, Earth is not unique. (Neil DeGrasse Tyson) Wait, wait—you think life
is common in the universe. (Chris McKay) Right. (Neil DeGrasse Tyson) You didn’t say that.
You just said “life is common.” (Chris McKay) Well, I think— (Paul Falkowski) You
assert. (Chris McKay) I’m not from Roswell, New Mexico. I have no inside information to
share. (Neil DeGrasse Tyson) He is not authorized to … Fred, what have you got? (Fred Adams)
Well, I would say that Earthlike planets are common so, to be more specific, if you just
asked the question about the planetary properties, rocky bodies are easy to make. We see lots
of them already. We’re about to see one as small as Earth any day now, literally,
in the astronomical observations. And it’s only a matter of time before we find some
in the habitable zone. There might have been one discovered in the habitable zone a couple
of weeks ago, the one that you talked about in your introduction. So, the planetary properties,
the beds for forming life, if that’s what you consider an Earthlike planet, were there
already. The next question, is there life on them—well, I agree with the last two
colleagues here, that life is just a physical process, physical processes happen everywhere.
(Neil DeGrasse Tyson) Life is just complex chemistry, at some level. (Fred Adams) And
it would be remarkable if it were not at least life in some form common. I mean, everything
else that we’ve seen in astronomy—we’ve found black holes that have millions of solar
masses. Well, they’re not unique, there’s one in every galaxy. We found neutron stars
that are something like taking the whole mass of the sun, putting it into an 8-kilometer-sized
thing and spinning it a thousand times a second. Well, there’s millions of those. In every
galaxy and there’s billions of those galaxies. (Neil DeGrasse Tyson) By the way, this creates
a fundamental, philosophical rift between the astrophysicists and the biologists. Because
we get stumped practically weekly with cosmic phenomena that we never ordered. (Fred Adams)
And then we get millions and billions. So, from that point of view, or coming from that
point of view, I would have to place my bets (and I’m placing bets) that life is common.
(Neil DeGrasse Tyson) Don, I swung by you pretty quickly, so let me give you a chance
to speak. So, life unique or not? (Don Brownlee) Well, the real question is how abundant is
life? I mean, on our rare earth hypothesis, we suggested what I think most people believe
that microbial life is pretty common. But animals, how abundant are they. And it doesn’t
matter that they may be 10 to 22 stars. We will never know anything about that. We still
don’t know whether there’s life on Mars, even though it’s really in our backyard.
The real question is, of the nearest couple hundred or a thousand stars, is there something
like us on them that we can detect with telescopes in the next century or timescale? So, it doesn’t
make any difference if it’s another galaxy or on the other side of our galaxy. Is it
nearby that we could ever detect it with techniques from Earth? And the other question is, can
we ever go there or will they come…? (Neil DeGrasse Tyson) I go with Paul because if,
like he said, if life is a vessel that’s out of chemical equilibrium, otherwise it
couldn’t really survive. If you’re in equilibrium with your environment, the other
word we have for that is dead, okay? That’s … I’m not exaggerating. When you are at
equilibrium with your environment, you are the same temperature as your environment.
You are just simply dead. So, I agree that there would be a biomarker in the atmosphere
of these planets. So perhaps, while we’ll never visit them in any foreseeable technology
we have lined up, a carefully designed optical experiment, spectra of the atmosphere, we
can find chemistry that we know is out of equilibrium, that would tell you that there’s
disequilibrium chemistry going on on the surface and the best version of that we know of is
life. (Don Brownlee) Exactly. This is a tremendous… (Minik Rosing) I just say that this “unique”
business is—I mean, at what level of a discussion, it’s like “are you unique or…”? There’s
a billions, 6 billion people on the planet, so you could say humans are common, but you’re
still unique. And I think it’s the same, though, I think that Earth is unique is that
biology in its evolution is not deterministic. It is not meant to end with us—or not end
yet, but might end with us. (Neil DeGrasse Tyson) The roaches are waiting to take over
after we kill ourselves. (Minik Rosing) Yeah, yeah, so anyways… (Neil DeGrasse Tyson)
They’re going to have museums with humans. (Minik Rosing) So I think that we have, again…
(Neil DeGrasse Tyson) Like we have dinosaurs. (Minik Rosing) …that life is probably very
common, I agree with that, but I think that the chance of life would develop into us is
extremely unlikely and by that measure I think that our Earth is unique in having exactly
the makeup that we have. (Paul Falkowski) I think that there’s a confusion here, though.
So what we’re talking about is metabolic processes that seem to be common versus the
life forms that seem to be unique. (Minik Rosing) Yeah, exactly. (Paul Falkowski) Okay,
so evolution is not predictable in the sense that we can’t determine the outcome of evolution…
(Neil DeGrasse Tyson) Yeah, we’re not asking here is there another planet with dinosaurs
that went extinct with an asteroid and mammals rose to become…that’s not what we’re
talking about here.(Paul Falkowski) Right, exactly. (Neil DeGrasse Tyson) Just a system
that supports a thriving biota. (Paul Falkowski) Right. [TALKOVER] (Neil DeGrasse Tyson) So
you change your view. (Minik Rosing) Absolutely. (Neil DeGrasse Tyson) After four other people
disagreed with you, you just… (Minik Rosing) No, no, no… (Neil DeGrasse Tyson) …backpedaled
here, I just want you to know that’s what it looks like. (Minik Rosing) No, no, no.
(Neil DeGrasse Tyson) Between you and me, that’s okay. Let’s take a first question
from the floor here. (Speaker) I’d like to thank the panel and Dr. Tyson for tonight’s
debate. According to the app 492 exoplanets. (Neil DeGrasse Tyson) He’s the app! He’s
got the app. So the number’s 492? (Speaker) Four hundred ninety-two. (Neil DeGrasse Tyson)
So we should have a 500 party; that’ll be in an hour and a half. (Speaker) My question
goes to the engineering of actually determining the answer to this question. Given today’s
technology, how far away—what is the farthest you think we could be from Earth in order
to determine, using our technology, if there were life on Earth? (Neil DeGrasse Tyson)
That’s an excellent question. Let me go to you. Did anyone get the question. So the
question is, here we are on Earth and we know there’s life and we’re trying to determine
if there’s life on a distant planet. How far would we have to step away from Earth
before our current technologies would be able to see that there was life here as we know
it? That’s a good question. That’s a reality check on what hopes we have of finding Earth
on a distant planet. (Chris McKay) The most obvious signature of life on Earth is the
oxygen in the atmosphere and the ozone that’s produced from it. So the question, I would
rephrase your question as how far away from Earth could we still detect the oxygen, the
fact that the oxygen, that the Earth has an oxygen-rich atmosphere using telescopes like
we’re developing now? And I think the answer is it’s going to be pretty far away. I would
guess… (Neil DeGrasse Tyson) Could you be a little more quantitative than that, please?(Chris
McKay) I would guess… (Neil DeGrasse Tyson) We’ve got scientists here. “Pretty far.”
Oh, that’s how far away. (Chris McKay) I would guess as far away as this planet [Gliese]
20 parsecs, I’d say... (Neil DeGrasse Tyson) Twenty light-years. (Fred Adams) Twenty light-years.
(Chris McKay) Twenty light-years. (Fred Adams) No, more than that. (Chris McKay) Easily 20
light-years. (Speaker) GI581G is 20 light-years away. (Neil DeGrasse Tyson) Is that now what
I just said? I thought I just said that (Speaker) It’s also extremely close to its planet,
you’ll never resolve it. (Neil DeGrasse Tyson) I got a microphone, I just said that.
(Chris McKay) …if there was an Earthlike planet around that star. (Neil DeGrasse Tyson)
No, no, we were getting the distance to that star at 20 parsecs. What you’re thinking
we discovered much farther away than that. (Chris McKay) Twenty light-years. (Paul Falkowski)
You just have to stare at it. The photons coming from the object, if you can stare at
it long enough, it’s just time. (Neil DeGrasse Tyson) In fact, if you get starlight behind
it, you catch it in absorption and you have a much more sensitive detection. Okay, so
you’re thinking about that distance, you’re thinking. (Chris McKay) With telescopes we
have now which, for example, Gliese was not detected by direct imaging, it was detected
by, as Fred said, by velocity… (Neil DeGrasse Tyson) The Doppler shift. (Chris McKay) Right.
So it’s not obvious that we can map out the composition of those worlds even that
close—20 light-years. So I think 20 light-years would be a challenge, with current technology.
And we can imagine [farometers] in space and [conographs in space that could do much better
and could separate the planet from the star. We don’t have those in orbit right now.
(Neil DeGrasse Tyson) Nor will they be in the next 10 years, because I just served on
a decadal survey panel. (Chris McKay) Right, they’re not in the cards, but we know how
to do ‘em. So, if the question was how far could we see an Earth-like planet, say, in
the next—with the technology that we can imagine now and build in the next 20 years
in your professional lifetime, then I think the answer could be many, many times farther
than that 20 light-years. And, again, oxygen is the obvious fingerprint of life on Earth.
If you think of the Earth before the rise of oxygen, as Don said, there was a long of
period of time when Earth had life but no oxygen, then the fingerprints are much, more
subtle and I don’t see any prospect of detecting them more than a couple light-years, even
if we can even do that. (Neil DeGrasse Tyson) Excellent. Okay, next question right here.
(Speaker) This may for Chris McKay, also. How long will it be before we get rocks and
material back from Mars to tell if there was life there? And do we have to send people
to do that or will rovers and other things be able to do that? (Neil DeGrasse Tyson)
Did everyone catch that question? So, question is, do we go bring rocks back and study it
here to be sure whether or not there was life or do we send astronauts there? What’s the
plan for this going forward? (Speaker) How long? How long? (Chris McKay) How long? The
Academy, the National Academy will request that NASA bring back samples within the next
10 years. That’ll be part of the decadal survey. Will we be able to do it? Mars sample
return is kind of like fusion. It’s something that’s always there, we always want to do
it and we always think that in 10 years we’re going to do it and 10 years comes and we think,
okay, another 10 years and we’re going to do it.(Fred Adams) But it’s a little different
in that the fusion has some real techno….there’s instabilities and technological things we
don’t understand. We could probably do the Mars thing if we threw enough money at it.
The question is… (Neil DeGrasse Tyson) Yeah, good point. (Fred Adams) ...do we have the
budget for it? (Chris McKay) It’s a matter of money… (Neil DeGrasse Tyson) That’s
a cultural barrier not a technological barrier. (Fred Adams) There are some technological
issues, as well. But. (Chris McKay) But the answer’s the same. (Fred Adams) Yeah. (Neil
DeGrasse Tyson) He’s right, that’s why [I set up]. Right here, go ahead.(Speaker)
Okay, this one’s for Fred Adams. Now that we’ve found a Goldilocks planet, what’s
the probability, if you crank different parameters of the solar system to have that found, what’s
the statistical idea of finding, on the various different kinds of solar systems that are
possible, something with that kind of configuration? (Fred Adams) Well, the honest answer is that
we don’t have enough data to… (Neil DeGrasse Tyson) But just so I understand the question—are
you asking, now that we have one in the dataset, can we assign a probability to the frequency
of those among star systems? (Speaker) Depending on which way … depending on how you form
a star system. (Neil DeGrasse Tyson) Okay. (Fred Adams) Well, we can’t answer quite
the question you would like because we simply don’t know, we don’t have enough data.
I mean, what we do know is that we’ve discovered almost 500 planets… (Neil DeGrasse Tyson)
Four hundred and ninety-two, we already know. (Fred Adams) Four hundred ninety-two. (Neil
DeGrasse Tyson) Thank you. (Fred Adams) As of a moment ago. (Neil DeGrasse Tyson) We
can be precise when we got it, the man told you. (Fred Adams) That’s exactly right.
And of those 492, one is close to habitable, if not habitable. So you would naively think
that there’s kind of a 1 in 500 odds. What you need to realize is that, when you have
one event, the [error bars] on the odds are 100%. So I wouldn’t want to give you any
odds because they would basically have infinite… (Neil DeGrasse Tyson) Small number statistics.
(Fred Adams) Yeah, it’s what we call—we would just sum it up by saying it’s small
number statistics. So we definitely more data to answer your question, so we’ll get that
in the next, I would say five years, and then I’ll have something more intelligent to
say. The planet is... (Neil DeGrasse Tyson) Not that you haven’t been intelligent thus
far. (Fred Adams) Well, I’ve been trying. (Neil DeGrasse Tyson) Right, okay. (Speaker)
So then you could project that, based on certain stars, that these stars would generate a certain
number of different kinds of planetary systems and therefore one out of maybe a thousand
might have a combination of factors that would give you that kind of a planetary system.
(Fred Adams) Right, if we have enough data, we could start to answer those questions.
What we now have enough data to say is that something like 1 in 5 to 1 in 4 to 1 in 3
stars we expect will have planets of some kind. And then some fraction of those will
have what we call Earth-like planets, but we don’t have good enough statistics on
the… (Neil DeGrasse Tyson) Kepler should bring in enough planets to really make good
tabular statistics on this. (Fred Adams) It’s supposed to, that’s exactly why we funded
it. We just have to wait only maybe a year or two and we’ll know a whole lot more.
(Neil DeGrasse Tyson) Wait, who’s the “we” here? You said “we” funded it. You write
the equation on the back of an envelope, you didn’t fund a thing. (Fred Adams) I mean
“we” the country. (Neil DeGrasse Tyson) The country, good, good. (Speaker) It’s
called taxpayers. (Don Brownlee) So Gliese 581G is in the habitable zone. No one knows
[if it’s] habitable. We don’t know if it has an atmosphere, if it has an ocean.
It’s a very different world. If all the solar systems are like ours and if planets
are logarithmically-spaced, each one about 70% further, we expect the typical stars would
take—have a couple of planets in the habitable zone. So don’t call these habitable just
because they’re in the habitable zone. It means they have the chance of being habitable.
They also need atmospheres… (Neil DeGrasse Tyson) But that’s just semantic. Some irresponsible
journalist said that it was inhabited. But most of them got it right. That it’s…
Don Brownlee That was a scientist that said that, not a journalist. (Neil DeGrasse Tyson)
Oh… (Don Brownlee) Never mind, never mind. (Neil DeGrasse Tyson) Oh, was it actually
a correct quote of a misspoken statement from an actual scientist? (Don Brownlee) The key
word they said that “I believe.” And that’s a very important thing in this whole field,
is “belief.” A lot of this comes down—do you believe X, Y and Z? (Neil DeGrasse Tyson)
Are you saying one of our colleagues said that he believes Gliese 581G has life? (Don
Brownlee) Hundred percent chance of life. (Neil DeGrasse Tyson) Who said…? Who…?
(Don Brownlee) I don’t know, I forgot… (Chris McKay) First author on the paper. (Neil
DeGrasse Tyson) Oh, is that right? We’ll have to straighten him out. Yeah, as a scientist,
you never want to overstate… (Don Brownlee) Hundred percent, maybe 99, but not 100. (Neil
DeGrasse Tyson) You don’t want to overstate what your data allow you to say, otherwise
you compromise your integrity forever more. (Speaker) One other way that the Earth is
unique that no one’s addressed, and this is to the panel, is that in terms of the ratio
of a primary to its satellite, the Earth to the moon and the effect that the moon’s
formation has… (Neil DeGrasse Tyson) The ratio of the sizes. (Speaker) Right, right,
the ratio of the sizes, and the effect that the moon has had on the Earth over the billions
of years, for example, its formation caused the Earth to be tilted and we now have seasons
because of that. It created the tides, which churned up the basic oceans. It slowed the
Earth’s rotation down from 8 hours to 24 hours, which means we don’t have 200 mile
per hour prevailing winds. No one has addressed that and that—I’m not sure about Gliese,
but does it also have a large satellite to do those same things that would allow the
Earth to—this other Earth to evolve? (Neil DeGrasse Tyson) Don, I want you to handle
that. So, how important is the moon to everything we just discussed? (Fred Adams) Well, I think—you
mean Don or me? (Neil DeGrasse Tyson) Oh, sorry, called you Don? Sorry, sorry. Fred,
sorry. (Fred Adams) Well, I think Don actually knows the answer to that more than I do, but...
(Neil DeGrasse Tyson) Don, how important is the moon here? (Don Brownlee) The moon is
important, but it’s probably not a killer. If we didn’t have a moon, we could probably
surely still have life on Earth, but it would be different. I mean, one of the secrets of
Earth has been stable for billions of years. Mars hasn’t been stable. Venus hasn’t
been stable. One of the factors that kept… (Neil DeGrasse Tyson) Wait, Venus is stable
at 900 degrees. (Don Brownlee) Venus… (Neil DeGrasse Tyson) Just because you don’t like
it doesn’t mean it’s not stable. (Don Brownlee) Venus lost all of its old history.
The oldest things on the surface of Venus are only about 900 million years. It completely
turned itself inside-out. It’s a really, really… (Neil DeGrasse Tyson) It repaved
itself. (Don Brownlee) Not only is it [hellies] hot place, it turned its lid over. But, so
the moon has helped keep the Earth’s spin axis fairly constant, so we don’t melt the
poles and cause all kinds of catastrophes. (Neil DeGrasse Tyson) We just have a different
set of configurations and maybe a different trajectory that life would have taken. (Don
Brownlee) Yeah. (Neil DeGrasse Tyson) But you don’t think it is a deal-breaker. (Don
Brownlee) Well, it’s not … it would be a deal-breaker for us if the Earth started
spinning at 40 degrees to the 22 degrees. (Neil DeGrasse Tyson) In 2012, that’s what’s
going to happen [unintelligible]. I’m not authorized …no. So, I didn’t know that
myself. I mean, what measure of importance that would have been because, just to clarify,
the moon size relative to Earth is largest of all the planets. (Don Brownlee) The planet
Pluto also has a large moon. (Chris McKay) Yay for Pluto! (Neil DeGrasse Tyson) The dirty
ice ball in the outer solar system has a large moon, yes. (Speaker) You’ll never live it
down. You’ll never live it down. (Neil DeGrasse Tyson) Right here, yes. (Speaker) Yeah, hi.
So, quick comment about finding life on Mars. I think the reason we don’t know whether
there is or was life on Mars is because we don’t want to badly enough as a society.
But the technology’s there. We could send more robots, we could send people if we really
wanted to. But we haven’t done it because we don’t want to badly enough. But that’s
actually not my question, sorry. The question is… (Neil DeGrasse Tyson) That’s good
because it actually wasn’t a question. (Speaker) It wasn’t. That was an editorial. But the
question is, I think everyone would be really thrilled if we found microscopic life someplace,
but doesn’t everybody really want the next Asimov Debate have somebody from Arturis to
come in? What’s the probability of having multicellular life, much less intelligent,
technological life? Or can that even be estimated? (Neil DeGrasse Tyson) You want me to invite
a microbe as my next guest on…? No, I missed the thrust of the question. (Speaker) Can
you make any estimate of—most people are saying there’s probably life, but we’re
talking about microbes. Is there any way to make an estimate of what’s the probability
of multicellular life and ultimately technological life? (Paul Falkowski) What was the selection
pressure for multicellular life? (Chris McKay) You’re supposed to answer the question.
(Neil DeGrasse Tyson) Yeah, she’s—you’re the... (Speaker) The answer is “I don’t
know.” (Paul Falkowski) Okay, so we don’t know really, but we think it’s because we
ran out of certain nutrients and foraging behaviors and behavior in general became more
efficient. So if I were to take—at some point you are an energy-dissipating organism,
as Neil said, you’re not in equilibrium. (Neil DeGrasse Tyson) I used easier words
than that. (Paul Falkowski) Yeah, easier words. But if I were to take… (Neil DeGrasse Tyson)
Energy-dissipating organism, note, did not come out of my mouth. Okay. (Paul Falkowski)
If I were to take you or Neil or myself and dissolve us into our single cells, our individual
cells and put them out onto a petri dish, our individual cells would have a metabolism
about a thousand times greater than we have as an organism. So, multi-cellularity came
about as an energy conservation system. In places where you have lots and lots of energy,
there’s no selection pressure to ever have multi-cellularity. And this is one of those
things that I don’t think any biologist really understands why we developed this process,
why nature created multi-cellular organisms to begin with. They don’t diffuse materials
very well. They’re usually limited—you’re limited by oxygen right now, although you
may not realize it, so am I. We have major problems. Our reproductive rates are much
lower. It’s much better to be a microbe and stay that way for a long time, which is
why they persist. (Neil DeGrasse Tyson) I don’t want to be in somebody’s digestive
system, I’m sorry. I’m staying as human. (Paul Falkowski) Multi-cellularity is not
a necessary thing for life. (Neil DeGrasse Tyson) That’s a fascinating point about
the efficiency of [unintelligible 1:31:00), I didn’t know that, thanks. Next question,
here... (Speaker) Yes, pertaining… (Neil DeGrasse Tyson) I have to say, this is the
creator of the contest-winning video for the Rose Center. Turn around and wave to everybody.
[applause] We flew him in from Los Angeles and he’s here for the weekend with family,
so thanks for coming to this. And for your—his video was on the Large Hadron Collider. It’s
hilarious, it’s fun, it’s accurate and he was inspired by that as well as other science
topics, but that one particular brought him to create a video on it. So now that’s your
big preamble. So your question better really be good after this... (Speaker) I’ll do
my best. Pertaining to the Kepler mission, I wanted to know what factors led to the decision
for what patch of the sky that we pointed the telescope. Because correct me if I’m
wrong, but it’s only a small area of the sky that it’s pointing? (Neil DeGrasse Tyson)
Yeah, who can take that? (Fred Adams) I think you’d have to ask the Kepler team for details.
It’s always an optimization problem of, you know, do you look at the part of the sky
and you look deeper or do you look at more of the sky and you look… (Neil DeGrasse
Tyson) Is Kepler at L2 on the other side of the moon? (Fred Adams) I actually don’t
remember. (Chris McKay) No, no, it’s a drift-away orbit from Earth. (Neil DeGrasse Tyson) It’s
a what? (Chris McKay) It’s a 30-inch telescope, but it looks at 200,000 stars. And so it just—it
can’t look at the whole sky, it looks—it’s a miracle what it does. (Neil DeGrasse Tyson)
No, it’s science, but go on. (Chris McKay) No, no …. It has to measure the brightness
changes of 10 parts per million. And they proved they could do this by drilling little
holes in plate and putting little wires in front, shining a light through it and heating
the wires up by running a little current through and made it swell and block out the light.
People originally didn’t believe that you could do this with existing technology, but
this incredible [precision 1:32:55], it’s orders of magnitude higher than ever been
done before [to] measure star bright. So it is a miracle. (Neil DeGrasse Tyson) And so
maybe the point is, whatever is its field of view, 200,000 are getting monitored. And
keep in mind, you have to continue to watch them, because you’re looking at the light
dim and come back up again, it’s not just snapshots. Typically, in survey telescopes,
you take snapshots, you move the telescope, take another shot to get it. Here, you have
to keep at the stars to build your dataset. So we don’t have the luxury of doing that
for the whole sky, but 200,000 stars, that still feels pretty good. And that’ll all
be coming over in the next couple of years, once they get their understanding of their
uncertainties hammered out. Yes? Next question... (Speaker) This is a kind of, more separate
question to the other ones that have been asked, but if another Earth were discovered
and it had special uniqueness compared to this one, could we survive without the magnetic
field? (Neil DeGrasse Tyson) Magnetic field—we haven’t talked about magnetic field. How
important is the magnetic field? Mars doesn’t have one, right? (Chris McKay) Mars does not
have a magnetic field and a lot of people ask me about that. How could life on Mars
survive without a magnetic field? Well, Earth occasionally loses its magnetic field. We
can look back in Earth history and see times when our magnetic field flipped from north-pointing
to south-pointing and during the time in-between there would be no Dipole field. And so—and
those times in Earth history do not line up with extinctions. So I conclude from that
that a magnetic field is not essential for life and why you say—well, doesn’t magnetic
field shield us from radiation? It’s certainly true that a magnetic field steers solar radiation
toward the poles where it forms beautiful aurora. But even without the magnetic field,
that irradiation would be stopped by this thick atmosphere. So I think a magnetic field
is nice. It’s good for compasses, it’s good for aurora. (Neil DeGrasse Tyson) Compass?
You still use a compass? (Chris McKay) Yeah. (Neil DeGrasse Tyson) I’ll get you a GPS
thing after the show. (Chris McKay) I got a merit badge. But it’s not, without a magnetic
field, life is still possible. Complex life is still possible. And intelligent life is
still possible. (Neil DeGrasse Tyson) So people have made too much of the magnetic field,
I would say then, over the years. (Fred Adams) To be clear, the radiation that Chris is talking
about is what we call cosmic rays. So these are particles, charged particles, not photon
radiation. (Neil DeGrasse Tyson) Yes, thanks for that clarification. (Fred Adams) And the
other thing… (Chris McKay) Solar flares. (Fred Adams) That are caused by solar flares,
yes. But you could argue it the other way, if you wanted to, even though we don’t know,
and that is that the cosmic rays might cause mutations, which could lead to extinctions.
But they also just might cause evolution to work better. We don’t know. (Don Brownlee)
There’s also a worry that a lot of people have that if a planet doesn’t have a magnetic
field, when the star is young, they’re much more active, energetically active with all
these particles coming out would strip off the atmosphere. That may be one reason that
Mars has such a measly atmosphere. (Neil DeGrasse Tyson) Wait, but Minik, isn’t it true that
half the biomass of the Earth may be beneath the surface. So what goes on on the surface
might just be irrelevant to most of what’s going on? (Minik Rosing) No, I agree that
life at least could be shielded from the radiation, but I think the big question is could we tend
to lose the atmosphere by abrasion from the strong radiation that is otherwise deflected
around the planet? (Neil DeGrasse Tyson) What you’re saying is the high energy can actually
ablate the atmosphere off the planet? (Minik Rosing) Yeah. (Neil DeGrasse Tyson) That would
be a bad situation. (Paul Falkowski) Well, Venus also has no... (Chris McKay) Venus.
(Paul Falkowski) Venus has no magnetic field and it has an atmosphere. So this is what
is taught about and we’re taught—what the big, big, big deal is to keep an atmosphere
is size. (Don Brownlee) Doesn’t have a nice atmosphere, but a bad atmosphere. (Paul Falkowski)
But if you’re a big planet you can keep an atmosphere much better than if you’re
a little one. (Don Brownlee) Depends on lots of complicated factors. Magnetism is good.
(Chris McKay) I say down with magnetism. (Neil DeGrasse Tyson) We’re going to go five more
minutes and then we’ll break. By the way, I’ve convinced the panel to hang out afterwards.
We’re going to go into the Hall of Northwest Coast Indians and while several of them have
actually written books, none of them are here, but there are other books on Earth and the
cosmos that you can buy. And what people like to do is sometimes get them to sign their
program. So we’ll be hanging out in the corridor, if we don’t get to each one of
your questions. But I just want to have a definite ending time here, we’ll go another
five minutes. Go. And try to be quick so that we can get as many going on in five minutes
as possible. (Speaker) Yes, sir. Dr. Paul, I hail from New Orleans, Louisiana. [general
mayhem] And I have to defend my state and people of Louisiana. That there are plenty
of intelligent people in Louisiana, if only the Corps of Engineers would listen to us.
(Neil DeGrasse Tyson) There you go. (Speaker) So we definitely don’t want any Tony Hayward-esque
type of mentality that we love New Yorkers have towards Louisianans, please. And Dr.
Tyson, you may be confusing with the guns that Texas, not Louisiana. So, regarding,
you know, be sensitive. Y’all got Winton Marsalis, so, you know. We love y’all. I
was just kind of, I guess it’s more of a statement, as well. That I deal in the area
of science, but just on another level with medicine. And I love the banter back and forth.
But I think that, as long as what’s important for science in all fields, is that as long
as we keep open and that we don’t kind of close things off—because 50 years ago, we
would never have thought about marine life with bioluminescence or living near those
vent stacks down in the basins of the oceans or heart transplants… (Neil DeGrasse Tyson)
The most successful scientists are the ones that do have that open mind. (Speaker) Absolutely,
and who are willing to listen and not be so set in one path, but just kind of—I think
that’s where a lot of growth happens. (Neil DeGrasse Tyson) That’s why we try to get
the bleeding edge on the stage. (Speaker) Absolutely. Exactly, and you clarified when
you said “what is unique?” and that’s one of my thing is, well, what is “unique”?
Define “unique.” It may be different, because we may have another system looking
at us, discussing the same thing. But to them, what we do is totally off the charts. (Neil
DeGrasse Tyson) Out of their box, across the street, as we learned earlier. (Speaker) Absolutely.
(Neil DeGrasse Tyson) Okay, thanks for your comments. And thanks for coming up from Louisiana.
Okay, next question, sir. (Speaker) Putting aside the idea of methane-based life, oxygen
probably being the most possible, possibility, [club] for this museum, which has the red
band in iron—I work, by the way, in the Hall of Planet Earth… (Neil DeGrasse Tyson)
You’re a hall explainer there? (Speaker) I am a Hall of Planet Earth. And the idea
that biological affect is what’s going to keep the planet going. That is, as you probably
know, the red band of Earth hypothesizes that stromatolites , a kind of algae, developed
oxygen which then gave our planet a 20% oxygen rate.(Neil DeGrasse Tyson) These are the life
forms you’re referring to that were very, very far at the beginning. (Speaker) So the
point is then are life forms really needed for self-replication? I mean, that sounds
[contentious], but are they needed for self-replication? (Neil DeGrasse Tyson) Are life forms needed
for self-replication? (Speaker) Are the algae necessary, the oxygen that they produced necessary
for our replication? We wouldn’t be here if the oxygen—we have O3, by the way, would
stop the… (Neil DeGrasse Tyson) So what you’re saying we went through this whole
period of time in the history of Earth, no oxygen in the atmosphere. The algae’s make—I
guess the cyano bacteria, whichever it is—is cranking out the oxygen. And so up—what
I wonder is, if you were sucking away the oxygen while that was happening, would we
keep that bacteria and we would never arisen and that emergence of oxygen then, is that
what enabled the complexity of life? (Paul Falkowski) It enabled the evolution, we think,
of animal life. So, without oxygen, we would not have animal life. All animals require
a metabolism that is based on oxygen. But, to get to the point, there was probably between
a 600- or maybe even an 800 million year lag between the evolution of cyano bacteria and
the stromatolites, the guys that make the oxygen and the actual oxidation of the planet.
And that period—I mean, without tectonics, again, if we didn’t bury the carbon, we
would not have any oxygen on the planet. So, it’s not a simple thing. Just because you
make a bug that splits water and generates oxygen doesn’t mean you have any oxygen
on the planet. Right now we’re breathing oxygen, plants are making oxygen. The oxygen
concentration of the planet doesn’t change. It hasn’t changed substantially for hundreds
of millions of years. It’s in balance. There was a one tipping point at about 2.3 or so
billion years ago, we think, where they went from a world without oxygen to a world with
oxygen and we never went back again. And understanding that period of Earth’s history now is really
one of the more exciting areas of geochemistry. (Neil DeGrasse Tyson) And just to clarify,
when you said it’s in balance, there are two kinds of balance. One is a ball at the
top of a hill carefully placed. Another one is the ball at the bottom of the hill. They’re
both in balance, but one is stable. If you displace it one direction, it goes back. The
other one is unstable. You displace it, it rolls away. So you’re referring to a stable
kind of equilibrium here. (Paul Falkowski) Absolutely. (Neil DeGrasse Tyson) Yeah. Okay,
thank you, sir. Just a couple more questions here. Yes. (Speaker) Hi. First, I just wanted
to thank the panel for a fascinating talk. I teach high school in New Jersey and I’m
looking forward to telling the students about all this. My question is actually that somewhere
early in the talk I think it was our moderator who …(Neil DeGrasse Tyson) I didn’t do
it. (Speaker) … who was making an argument and said essentially, well, you’re just
talking about processes that we already know. Why can’t there be some processes that we
just don’t know anything about? (Neil DeGrasse Tyson) That was me. (Speaker) And what I want
to know is, qualitatively, how is that different from the people who say, oh, well, we thought
we couldn’t break the sound barrier and we did that, so why is light speed a limit?
Which is an argument that generally is pretty well rejected. Why is that argument any more
valid than the light speed argument? (Neil DeGrasse Tyson) Oh, okay, I can tell you that
the sound speed—those were just really ignorant people saying you’ll never break the sound
barrier, because at the time they made those statements rifle bullets went faster than
sound. The whip at the tip of the end of a bullwhip goes faster than sound. That’s
the crack of the whip. So to say “we’ll never go faster than sound”—they’re
making a technologically limiting statement, not a statement about the limits of nature.
To say we don’t go faster than light, that is not a technological statement. It’s a
statement of the laws of physics. So, you make an interesting point, is that do we know
biology well enough to assert that we know the limits of how you would have biology on
another planet? And is that the same kind of statement as when we say there’s a limit
to the speed of light? (Paul Falkowski) No, I think we know, if we base life on extracting
energy from some substrate, like a sun or from methane in the case of Titan, for example,
then there has to be something—if we’re going to oxidize methane, you can’t reduce
methane, methane is reduced as far as it’ll go—you’re going to oxidize it. Which is
the reaction that a life form would search for. Then what is going to be the electronic
sector? What are going to be the products? And that is really where I’m going from.
We can think about this in a very, very logical way. There are organisms on this Earth that
oxidize methane. They produce CO2 as a result of that. And so we should see in a planet
that has life, for example, carbon dioxide in a world in a sea of methane, if there’s
life forms. (Neil DeGrasse Tyson) So as long as life is based on chemistry, you have some
handle on what kind of byproducts it’ll make.(Paul Falkowski) Absolutely. (Neil DeGrasse
Tyson) And these laws of chemistry are pretty well understood? (Paul Falkowski) Yes. (Neil
DeGrasse Tyson) Yeah, so you think we got some handle on this. So the life wouldn’t
be sooo different—like the Blob or something, that it would throw you into a loop. (Paul
Falkowski) I wouldn’t know what the bug looks like, I wouldn’t know what the organism
looks like, but I could tell you basically there has to be some rules of the chemistry.
Yeah, that’s chemistry. (Neil DeGrasse Tyson) Okay, good. All right, just two questions,
just these last two here, okay? I’m sorry about that, but we’ll be at the tables,
you can come up to them. Go, sir. I didn’t do it. (Speaker) All right, quick comment.
Don, I think it was you that said the Earth has been different through most of its life,
so I don’t think it’s fair to compare other planets with what the Earth looks like
now, considering that we’re in the minority of the time. Maybe you should judge against
what we have been and could end up being. (Neil DeGrasse Tyson) I think that came up.
We agreed that even Earth hasn’t looked like Earth for most of Earth’s history.
(Speaker) Yeah, yeah, so we’re comparing to Earth-like planet as of Earth now. I just
don’t think it’s fair. And, two, we defined Earth or Earth-like as being, according to
Darwinian evolution—given a primordial ooze or the very early single-celled life forms
that abide by Darwinian evolution, isn’t more complex life eventually inevitable? (Paul
Falkowski) No. (Speaker) I mean, it’s something that no planet-killer…(Paul Falkowski) Everybody
invokes this concept of Darwinian evolution. And it is true, it operates to a very large
extent in selection. But there is another mode of evolution, it’s called neutral theory.
And I’ll give you an example. (Neil DeGrasse Tyson) Neutral theory? (Paul Falkowski) Neutral
theory. So you have blue eyes and these people in the room have blue eyes, people in the
room have brown eyes. Your visual acuity is totally independent of your eye color. There’s
no selection based upon your ability to see that brown-eyed people are going to have more
acuity or less acuity than a blue-eyed person. So tremendous amount of variation in nature
has no selective advantage and that’s just a totally non-Darwinian mode of evolution.
Okay? So you and I have a life form that we have two arms and five fingers on each hand
and so on and so forth. But we’re not really that different from many other organisms that
have similar modes of behavior. Okay? This is what makes us different, in a sense, is
a very funny thing, amongst very few mutations, we’re very, very, very close genetically
to chimpanzees from which we were diverged about 6 million years ago. So four—not even
four, three genes, I believe, three mutations, point mutations, in the FoxP2 gene cluster
on chromosome 7 in the human genome… (Neil DeGrasse Tyson) I thought it was chromosome
8, you know. (Paul Falkowski) …allowed us to speak. That gave us speech. Okay? So that
is a trivial, trivial number of mutations to give us the ability to communicate horizontally,
abstract thoughts with complex language. Now, that was a transformational mutation that
occurred once. A singularity in nature so far. And what is fascinating about evolution…
(Neil DeGrasse Tyson) Wait, you said it’s a simple mutation that had transformational
consequences. (Paul Falkowski) Absolutely. (Neil DeGrasse Tyson) Okay. (Paul Falkowski)
And those are the mutations that we really don’t understand what causes these singularities.
They’re random walks. And one or two mutations just changes the world. And that’s really
what the forefront of bioinformatics and molecular biology is at right now, trying to figure
out what were those key freak accidents, basically, that allowed those machines to change to change
the world. (Neil DeGrasse Tyson) So, very interesting that you can have a life form
with variation, but if it doesn’t have selective advantage, it’s just a variation. (Paul
Falkowski) Exactly. (Neil DeGrasse Tyson) And it’s happy being what it is for a billion
years. (Paul Falkowski) Right. So there are 20 million known genes out there sequenced.
And I told you, only about 1500 that make the world go round. The rest are colors of
the eye, the color of your hair, that’s the 99.9999% of the gene [unintelligible]
(Neil DeGrasse Tyson) We got to make this last question... (Speaker) Yes. (Neil DeGrasse
Tyson) It’s a quick question—but is the answer quick? That’s what really matters
here. Go. Right here, go... (Speaker) Yeah, so if we found any life on any exoplanet,
roughly how much time would it take for that microbial life to evolve into an intelligent
design? (Paul Falkowski) There’s no known answer. (Neil DeGrasse Tyson) How long would
it take? Minik. (Minik Rosing) I think that that would depend very much on the flow of
energy in that system. How much energy is available. (Neil DeGrasse Tyson) Let’s say
there’s a lot of energy.(Minik Rosing) So, if it has a lot of energy, that means that
you can make many attempts at doing things. You can make many organisms, many replications.
(Neil DeGrasse Tyson) An enhanced chemistry experiment going on. (Minik Rosing) Yes. So
I think that you cannot—I don’t think you can give a definitive answer to that question,
but you can say that, if you have a lot of energy flow in the system, it’ll probably
go fast. If you have very little energy flow in the system, it’ll be very slow. If that
helps anything. (Neil DeGrasse Tyson) And in your cold world on Titan, metabolic rates
go slower when they’re cold. Maybe even if it wanted to evolve something intelligent,
it would just take too long because it’s too cold. (Chris McKay) Yeah, I think Titan’s
not a favorable prospect because you don’t have the super-charged energy system available
to power large animals that we have on Earth with oxygen. So on Titan I think you would
never get beyond microbial life. On Mars, however… (Neil DeGrasse Tyson) Did I tell
you? I told you about this guy. (Chris McKay) You were warned. (Neil DeGrasse Tyson) I warned
you. (Chris McKay) Yeah, Mars, however, you could have had the buildup of oxygen very
early in Mars… (Neil DeGrasse Tyson) Is this Mars here? Is this Mars? (Chris McKay)
That’s—I don’t think that’s Mars, no.You could have had the buildup of oxygen
very quickly in conditions suitable for supporting large organisms. (Neil DeGrasse Tyson) Okay,
so … it’s quick Okay...(Speaker) You, somebody said before that life—I’m going
back to the beginning, not are we finding life, but how close are we to getting life.
And somebody said before it’s a very complex chemical reaction. How close are we? Is it
like controlled fusion? Are we that close or…? (Minik Rosing) To making it? (Speaker)
You know, how close are we to making this…? (Neil DeGrasse Tyson) To making life in the
laboratory... (Speaker) Right. (Paul Falkowski) Not close. (Neil DeGrasse Tyson) Not close.
(Paul Falkowski) Yeah. Let me put it to you…(Neil DeGrasse Tyson) Like his highly precise answers.
(Paul Falkowski) If I were to write a research proposal on the—I want to go and study the
origins of life, I want to try to make chemical reactions in the laboratory, because we don’t
have conditions that allow us to show the experiment can work conceptually, this is
like throwing darts at a board, right? So these are highly underfunded areas of research
and highly risky. One of my graduate students here is working on this, and sitting right
there, but the point I want to make is…(Neil DeGrasse Tyson)Not working on it right now.
Right, just. (Paul Falkowski) But the point I want to make is that this story, where we
came from, the origin of life, has been out there for a very, very long time and are we
alone has been out there for a very, very long time. I’m much more optimistic that,
in my lifetime, we’re going to know are we alone, than the origin of life. (Neil DeGrasse
Tyson) Is that right? (Paul Falkowski) I believe that. (Neil DeGrasse Tyson)Whoa. I wouldn’t
have guessed that. (Chris McKay) I agree. I agree. (Neil DeGrasse Tyson) And you agree?
(Chris McKay) Go Mars! (Neil DeGrasse Tyson) Whoa. Let’s all thank the panel once again.
Thank you.[applause]And thank you all for coming. We’ll see you in the spring. And
if you want to have—if you have more questions, you come out to the tables outside, we’ll
be there for you, okay? Drive safely. Thanks for coming.