We Are on the Verge of Discovering Aliens, According to These Scientists
A fascinating new book seriously tackles the
question of extraterrestrial life from the perspective of leading astronomers,
astrophysicists, geneticists, and neuroscientists.
c Theoretical physics may
be difficult and complicated, "but it does have sex appeal." So says
quantum physicist Jim Al-Khalili. "It's easy to find an audience for
popular science or for a TV documentary about the Big Bang or about black
holes," he recently told me. Al-Khalili's work in the field has led to the
fascinating new book Aliens: The World's Leading Scientists on the Search for Extraterrestrial
Life, which explores what he believes is the likely
possibility of alien life.
The Iraqi-born, UK-based
Al-Khalili's intro opens with an anecdote: The Nobel Prize–winning physicist
Enrico Fermi is jokingly discussing flying saucers with some colleagues at the
Los Alamos National Laboratory when he poses a simple question: "Where is
everybody?" His point, Al-Khalili writes, is that the universe is so
massive and contains so many planets, that it makes little sense for Earth to
be the only place where life blossomed, unless our planet is
"astonishingly and unjustifiably special."
Aliens, out this week from Picador, proceeds in the
way that one imagines that Fermi's conversation at Los Alamos might have:
serious scientists, in occasionally cheeky dialogue with one another,
acknowledging that the question they're pursuing—Is anybody out there?—has
long been pursued by kookier personalities, conspiracy theorists obsessed with
Area 51, and alien abductions. Instead, Al-Khalili's book offers
research-driven essays by prominent astronomers, astrophysicists, geneticists,
and neuroscientists, and their pieces offer a wide range of ways to think about
the question of extraterrestrial life. Several astrobiologists consider what life
requires and which planets and moons might have the right mix: neuroscientist
Anil Seth considers the "alien" intelligence of the octopus here on
Earth; cosmologist Martin Rees speculates on the possibility of humans merging
with machine intelligence and setting out to explore the universe as a new
cyborg species.
But for the most part,
these experts are weighing in on one fundamental question: Is life special, a
unique and almost impossible trick that happened here on Earth? Or is it easy,
almost inevitable, a spark that just arises where the conditions are right?
It's an age-old question, that, as Al-Khalili explains, we may finally have the
technology to answer.
VICE: What drew you to
the questions that the book addresses? Are you someone who has had a lifelong
interest in the idea of aliens?Jim Al-Khalili: It's not so much aliens, but more to do
with the question of what is special about life. Probably all scientists find
that topic fascinating. There are certain questions in science that we don't
have answers to, which we say, those are the big questions: What was there
before the universe, before the Big Bang? How did life begin on Earth? How did
chemistry turn into biology? What is the nature of consciousness? These are the
questions that transcend disciplines. If you get a chemist, a physicist, a
biologist, a computer scientist—all of them are going to be fascinated by this.
When I was young, I
suppose I was interested in aliens like anyone else. I'm a sci-fi fan. But, for
me, the question was really what is so special about life how did it start on
Earth and whether it is unique to Earth.
The book is serious,
but the interest in extraterrestrial life has a reputation for being pretty
quirky.Someone once told me
that half the internet is devoted to conspiracy theories to do with alien
abductions and UFOs. Half is probably too much, but there's so much out there,
from X-Files to science fiction in movies, that it is
surprising to think that scientists would treat the question of
extraterrestrial life seriously at all. And that's what made this so
refreshing. The book is highlighting the fact that there are lots of questions
that are of interest to scientists that you can actually treat seriously. If
you really want to know the possibility of whether there are little green men
out there, here are the serious scientific takes on it, from all angles. So,
it's meant to be of interest to the wider lay audience but dealt with in a
grown-up way.
You mention that there
has been a shift within the scientific community toward taking this seriously
and away from the era of imagining little green men. Do you have thoughts on
when and how that changed?
This shift has come about because of advances in astronomy and space exploration in the last decade or two. We have started to send probes to Mars, to the moons of the gas giants Saturn and Jupiter, and we are seriously starting to be able to study the places where there potentially could be life in our solar system. And at the same time, in the past decade, we have discovered planets around stars outside our solar system, exoplanets. Astronomy has been advancing so quickly that what was unthinkable a decade ago is now reality. We can now not only pinpoint which stars have planets going around them, but we can look at those planets and even tell whether they have an atmosphere. Just from the light passing through the atmosphere from the star that they are going around, we can study that light and that can tell us the chemical composition of the atmosphere and that can tell us what elements, what molecules, what compounds are in that atmosphere, and would they be there naturally or would there have to be life present to have made them. So, these advances in astronomy and space exploration suddenly mean that we can actually address this question. It's got to the point now where I'm quite optimistic that in my lifetime, it's likely that we will discover life elsewhere.
This shift has come about because of advances in astronomy and space exploration in the last decade or two. We have started to send probes to Mars, to the moons of the gas giants Saturn and Jupiter, and we are seriously starting to be able to study the places where there potentially could be life in our solar system. And at the same time, in the past decade, we have discovered planets around stars outside our solar system, exoplanets. Astronomy has been advancing so quickly that what was unthinkable a decade ago is now reality. We can now not only pinpoint which stars have planets going around them, but we can look at those planets and even tell whether they have an atmosphere. Just from the light passing through the atmosphere from the star that they are going around, we can study that light and that can tell us the chemical composition of the atmosphere and that can tell us what elements, what molecules, what compounds are in that atmosphere, and would they be there naturally or would there have to be life present to have made them. So, these advances in astronomy and space exploration suddenly mean that we can actually address this question. It's got to the point now where I'm quite optimistic that in my lifetime, it's likely that we will discover life elsewhere.
Wow.
Ten years ago, I
wouldn't have thought that. Now, all these things are coming together. One of
the contributors in the book, [professor of evolutionary biochemistry] Nick
Lane, talks about the building blocks of life. What do you need? Is there
anything magical? You get molecules getting more and more complicated, and then
eventually you get something that can make copies of itself, and that's the
first precursor of life. Well, until recently we thought there was a missing
step—"and then some magic happens"—and then you get biology from
chemistry! But there seems to be no magical steps necessary. I now reckon that
the consensus among most scientists is that it would be quite surprising if we
don't find life elsewhere, probably within our lifetime. It might not be
interesting life—it won't be men in flying saucers—it will be some form of
microbial life. But, hey, for scientists that will be enough.
"Astronomy has
been advancing so quickly that what was unthinkable a decade ago is now
reality. It's got to the point now where I'm quite optimistic that in my
lifetime, it's likely that we will discover life elsewhere."
So on the big question
in the book, which is something like "is life on Earth special and unique
or is it common?"—and there are great arguments posed for each side—where
do you fall on that spectrum personally?
There's a wide spectrum of opinion among informed scientists. So the fact that I sit somewhere in the middle is because I've been influenced by both sides. My kind of naïve view is that we only know of life happening somewhere: on Earth. We are beginning to see that the conditions on Earth are not unique. Forgive the metaphor, but a lot of stars have to have aligned for that—we have to be the right distance from the sun, we have to have an atmosphere, we have to have a moon that gives us tides, we have to have a big planet like Jupiter that is sucking up the debris so it doesn't bombard us. But there are so many other star systems; there are so many other exoplanets, just in our galaxy alone, that there must be millions, billions of other Earths that have the conditions necessary for life. So in that sense we know we are not unique.
But that doesn't mean
that we know how life got started, just because those conditions
exist. We know that life began on Earth very soon after Earth cooled down
enough for life to possibly exist, almost 4 billion years ago. Now, over 4
billion years ago, the Earth was just a ball of fire. It wasn't conducive to
anything. So, as soon as the conditions were right for life, life got started.
But it didn't develop into complex life until much, much later. So I'm of the
view that life as a simple single cellular form may well be not that difficult.
It may be almost ubiquitous in the universe. But multicellular life, life that
could then evolve into complex organisms, some of which could develop
consciousness and intelligence and civilizations—that actually may be the
harder step. How hard it is, we don't know yet.
I wonder if you can
talk a little bit about the role of human radio, TV, and satellite
communication and how that factors into the search for alien life. Why do
people assume that aliens would also use this same kind of signaling?
We're starting with the assumption with the idea that the laws of physics and the forces of nature are the same throughout the universe. We know of four of these forces. Two of them are active inside of atoms, the nuclear forces. And the only other ones are gravity and the electromagnetic force. Gravity is limited technologically, but the electromagnetic force is versatile: Light is the electromagnetic force, and radio waves are the electromagnetic force. So it's a means of sending information from one place to the other. So we're assuming that whatever form life takes elsewhere, even if its not carbon based—it could be something really beyond our imagination—we still think they will make use of electromagnetic forces. It is a potentially universal way of communicating.
So if we are announcing
our existence to the rest of the universe, then it may be that life elsewhere
that is doing the same thing. Which is why the whole SETI program is about
listening out into the universe to hear some electromagnetic signal that we
don't think could have just happened naturally. Of course, we've only been
announcing our existence to the world for about 100 years or so, when we first
developed radio. So our electromagnetic signals have only extended out to a
radius of 100 light years. And actually there aren't that many star systems
within 100 light years. The universe is vast—there's billions of stars in our
own galaxy—but there are only a handful within that range. Of course, an alien
civilization may have been announcing their existence to the universe millions
of years ago, for all we know, so those signals, if we do receive those
signals, they may have traveled across vast distances—it won't mean that we can
then say, "Hi, we're here," and then make contact with them. But just
the knowledge that there is life out there somewhere would be profound.
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