There's no reason to think that the ocean ends just beyond your horizon.
And likewise, there's no reason to think that the aftermath of our big bang
ends just at the boundary of what we can see.
Indeed, there are quite strong arguments that it probably goes on about 100 times further.
And it may even go on so much further that all combinatorials are replicated.
And there's another set of people like us sitting in a room like this.
The following is a conversation with Lord Martin Rees,
emeritus professor of cosmology and astrophysics at Cambridge University
and co-founder of the Center for the Study of Existential Risk.
This is the Lex Friedman podcast.
To support it, please check out our sponsors in the description.
And now, dear friends, here's Martin Rees.
In your 2020 Scientific American article, you write that, quote,
today we know that the universe is far bigger and stranger than anyone suspected.
So what do you think are the strangest, maybe the most beautiful,
or maybe even the most terrifying things lurking out there in the cosmos?
Well, of course, we're still groping for any detail understanding of the remote parts of the universe.
But of course, what we've learned in the last few decades
is really two things.
First, we've understood that the universe had an origin about 13.8 billion years ago
in a so-called Big Bang, a hot 10 states whose very beginnings are still shrouded in mystery.
And also, we've learned more about the extreme things in it,
of black holes, neutron stars, explosions of various kinds.
And one of the most potentially exciting discoveries in the last 20 years,
mainly in the last 10, has been the realization that most of the stars in the sky
are orbited by retinues of planets, just as the sun is orbited by the Earth
and the other familiar planets.
And this, of course, makes the night sky farmer interesting.
What you see up there aren't just points of light, but they're planetary systems.
And that raises a question, could there be life out there?
And so that is an exciting problem for the 21st century.
So when you see all those lights out there, you immediately imagine
all the planetary worlds that are around them.
And they potentially have all kinds of different lives,
living organisms, life forms, or different histories.
That we don't know at all.
We know that these planets are there.
We know that they have masses and orbits rather like the planets of our solar system.
But we don't know at all if there's any life on any of them.
I mean, it's entirely logically possible that life is unique to this Earth.
Doesn't exist anywhere.
On the other hand, it could be that the origin of life is something
which happens routinely given conditions like the young Earth,
in which case there could be literally billions of places in our galaxy
where some sort of biosphere has evolved.
And settling where the truth lies between those two extremes
is a challenge for the coming decades.
So certainly, we're either lucky to be here or very, very, very lucky to be here.
I guess that's the difference.
Where do you fall?
Your own estimate, your own guess on this question.
Are we alone in the universe?
Do you think?
I think we foolish to give any firm estimate because we just don't know.
And that's just an example of how we are depending on greater observations.
And also, incidentally, in the case of life,
we've got to take account of the fact that, as I always say to my scientific colleagues,
biology is a much harder subject than physics.
And most of the universe, as we know about, could be understood by physics.
But we've got to remember that even the smallest living organism,
an insect, is far more complicated with layer on layer complexity
than the most complicated star or galaxy.
You know, that's the funny thing about physics and biology.
The dream of physicists in the 20th century and maybe this century
is to discover the theory of everything.
And there's a sense that once you discover that theory,
you will understand everything.
If we unlock the mysteries of how the universe works,
would you be able to understand how life emerges
from that fabric of the universe that we understand?
I think the phrase theory of everything is very misleading
because it's used to describe a theory which unifies the three laws of micro physics,
electricity, magnetism, and weak interaction with gravity.
So it's an important step forward for particle physicists.
But the lack of such a theory doesn't hold up any other scientists.
Anyone doing biology or most of physics is not held up at all
through not understanding sub-nuclear physics.
They're held up because they're dealing with things that are very complicated.
And that's especially true of anything biological.
So what's holding up biologists is not a lack of the so-called theory of everything.
It's the inability to understand things which are very complicated.
What do you think we'll understand first?
How the universe works or how the human body works deeply?
Like from a fundamental, deep level?
Well, I think, and perhaps we can come back to it later,
that there are only limited prospects of ever being able to understand
with unedged human brains the most fundamental theories
linking together all the forces of nature.
I think that may be a limitation of the human brains.
But I also think that we can, perhaps aided by computer simulations,
understand a bit more of the complexity of nature.
But even understanding a simple organism from the atom up is very, very difficult.
And I think extreme reductionists have a very misleading perception.
They tend to think that in a sense we are all solutions to Freudian's equation.
But that isn't the way we'll ever understand anything.
It may be true that we are reductionists in a sense if we believe
that that's the case, we don't believe in any special life force in living things.
But nonetheless, no one thinks that we can understand a living thing
by solving Freudian's equation.
To take an example which isn't as complicated,
lots of people study the flow of fluids like water.
Why waves break, why flows go turbulent, things like that.
This is a serious branch of applied mathematics and engineering.
And in doing this, you have concepts of viscosity, turbulence, and things like that.
Now, you can understand quite a lot about how water behaves
and how waves break in terms of those concepts.
But the fact that any breaking wave is a solution of the problem
is a solution of Freudian's equation for tens of 30 particles.
Even if you could solve that, which you clearly can't,
would not give you any insight.
So the important thing is that every science has its own irreducible concepts
in which you get the best explanation.
So it may be in chemistry, things like balance, in biology,
or concepts in cell biology.
And in ecology, there are concepts like imprinting, et cetera.
And in psychology, there are other concepts.
So in a sense, the sciences are like a tall building
where you have basic physics most fundamental,
then the rest of physics, then chemistry, then cell biology, et cetera,
all the way up to the, I guess, economists in the penthouse and all that.
And we have that.
And that's true in a sense, but it's not true that it's like a building
in that it's made unstable by an unstable base.
Because if you're a chemist, biologist, or an economist,
you're facing challenging problems, but they're not made any worse
by uncertainty about sub-nuclear physics.
And at every level, just because you understand the rules of the game
and some understanding of the rules of the game
doesn't mean you know what kind of beautiful things that game creates.
Right.
So if you're interested in birds and how they fly,
then things like imprinting baby on the mother and all that
and things like that are what you need to understand.
You couldn't even, in principle, solve this physics equation
how an albatross wanders for thousands of miles to the southern ocean
and comes back and then coughs up food for its young.
That's something we can understand in a sense and predict the behavior.
But it's not because we can solve it on the atomic scale.
You mentioned that there might be some fundamental limitation to the human brain
that limits our ability to understand some aspect of how the universe works.
That's really interesting.
That's sad, actually, to the degree it's true, it's sad.
So what do you mean by that?
I would simply say that just as a monkey can't understand quantum theory
or even Newtonian physics, there's no particular reason
why the human brain should evolve to be well matched
to understanding a deepest aspect of reality.
And I suspect that there may be aspects that we are not even aware of
and couldn't really fully comprehend.
But as an intermediate step towards that,
one thing which I think is very interesting possibility
is the extent to which AI can help us.
I mean, I think if you take the example of so-called theories of everything,
one of which is string theory.
String theory involves very complicated geometry and structures in ten dimensions.
And it's certainly in my view on the cards that the physics of ten dimensions,
very complicated geometry, may be too hard for a human being to work through,
but could be worked through by an AI with the advantage of the huge processing power
which enables them to learn world championship chess within a few hours
despite watching games.
So there's every reason to expect that these machines could help us to solve these problems.
And of course, if that's the way we came to understand where the string theory was right,
it should be in a sense frustrating
because you wouldn't get the sort of ah-ha insight,
which is the greatest satisfaction from doing science.
But on the other hand, if a machine churns away a ten-dimensional geometry
figuring out all the possible origamis wound up in extra dimensions,
if it comes out at the end and spews out the correct mass of the electron,
the fact that there are three kinds of neutrinos, something like that,
you would know that there was some truth in the theory.
And so we may have a theory which we come to trust
because it does predict things that we can observe and check,
but we may never really understand the full workings of it
to the extent that we do more or less understand how most phenomena can be explained in a fundamental way.
Of course, in the case of quantum theory, many people would say,
understand if there's still some mystery if you don't quite understand why it works.
But there could be deeper mysteries when we get to these unified theories
where there's a big gap between what a computer can print out for us at the end
and what we can actually grasp and think through in our heads.
It's interesting that the idea that there could be things a computer could tell us that is true.
And maybe it can even help us understand why it's true a little bit.
But ultimately, it's still a long journey to really deeply understand the whys of it.
Yes, and that's the limitation of our brain.
We can try to sneak up to it in different ways, given the limitations of our brain.
Have you, I've gotten a chance to spend the day at Deep Mind,
Dr. Dennis Lasabes, his big dream is to apply AI to the questions of science,
certainly to the questions of physics.
Have you gotten a chance to interact with them?
Well, I've known quite well. He's one of my heroes, certainly.
I'm sure he would say the same.
I remember the first time I met him, he said that he was like me.
He wants to understand the universe.
But he thought the best thing to do was to try and develop AI.
And then with the help of AI, he'd stand more chance of understanding the universe.
And I think he's right about that.
And of course, although we're familiar with the way his computers play go and chess,
he's already made contributions to science through understanding protein folding
better than the best human chemists.
And so already he's on the path to showing ways in which computers have the power to learn
and do things by having ability to analyze enormous samples in a short time
to do better than humans.
And so I think he would resonate with what I just said,
that it may be that in these other fundamental questions, the computers will play a crucial role.
Yeah, and they're also doing quantum mechanical simulation of electrons.
They're doing control of high temperature plasmas fusion reactors.
Yes, that's a new thing, which is very interesting.
They can suppress the instabilities in these tokamaks better than any other way.
And it's just the march of progress by AIs and science is making big strides.
Do you think an AI system will win a Nobel Prize in the century?
What do you think?
Does that make you sad?
If I can digress and push in a plug for my next book,
it has a chapter saying why Nobel Prizes do more harm than good.
So on a quite separate subject, I think Nobel Prizes do greatly damage to the percept of the way science is done.
Of course, if you ask who or what deserves the credit for any scientific discovery,
it may be often someone who has an idea, a team of people who work a big experiment, etc.
And of course, it's the quality of the equipment, which is crucial.
And certainly in the subjects I do in astronomy, the huge advances we've had come not from us being more intelligent than Aristotle was,
but through us having far, far better data from powerful telescopes on the ground and in space.
And also, incidentally, we've benefited hugely in astronomy from computer simulations,
because if you are a subatomic physicist, then of course you crash together the particles in the big accelerator,
like the one at CERN, and see what happens.
But I can't crash together two galaxies or two stars and see what happens.
But you will have a computer, one can do simulations like that.
And the power of computers is such that these simulations can yield a phenomena and insights,
which we wouldn't have guessed beforehand.
And the way we can feel by making progress and trying to understand some of these phenomena,
why galaxies have the size and shape they do and all that,
is because we can do simulations tweaking different initial conditions,
and seeing which gives the best fit to what we actually observe.
And so that's a way in which we've made progress in using computers.
And incidentally, we also now need them to analyze data,
because one thinks of astronomy as being traditionally a rather data-poor subject,
but the European satellite called Gaia has just put online the speeds and colors and properties
of nearly two billion stars in the Milky Way,
which we can do fantastic analyses of,
and that, of course, could not be done at all without just the number-crusher-capacitors computers.
And the new methods of machine learning actually love raw data,
the kind that astronomy provides, organized, structured raw data.
Well, indeed, because the reason they really have a benefit over us
is that they can learn and think so much faster.
That's how they can learn to play chess and go.
That's how they can learn to diagnose lung cancer better than a radiologist,
because they can look at 100,000 scans in a few days,
whereas no human radiologist sees that many in lifetime.
Well, there's still a magic to the human intelligence,
to the intuition, to the common sense reasoning.
Well, we hope so.
For now. What is the new book that you mentioned?
The book I mentioned is called,
If Science is to Save Us, it's coming out in September,
and it's on the big challenges of science, climate, dealing with biosafety
and dealing with cyber safety,
and also it's got chapters on the way science is organized,
universities and academies, et cetera,
and the ethics of science and the education.
And the limits, yes.
Well, let me actually just stroll around the beautiful and the strange of the universe.
Over 20 years ago, you hypothesized that we would solve the mystery of dark matter by now.
So, unfortunately, we didn't quite yet.
First, what is dark matter, and why has it been so tough to figure out?
Well, I mean, we learned that galaxies and other large-scale structures,
which are moving around but prevented flying apart by gravity,
would be flying apart if they only contained the stuff we see,
or anything in the most shining.
And to understand how galaxies formed and why they do remain confined the same size,
one has to infer that there's about five times as much stuff producing gravitational forces
than the total amount of stuff in the gas and stars that we see,
and that stuff is called dark matter.
That's obviously the leading name.
It's not dark, it's just transparent, et cetera.
The most likely interpretation is that it's a swarm of microscopic particles,
which have no electric charge and very small cross-sections were hitting each other
and hitting anything else.
So, they swarm around and we can detect their collective effects.
And when we do computer simulations of how galaxies form and evolve
and how they emerge from the Big Bang,
we get a nice consistent picture if we put in five times as much mass
in the form of these mysterious dark particles.
And, for instance, it works better if we think they're not interacting particles
than if we think they're a gas, which would have shock waves and things.
So, we know something about the properties of these, but we don't know what they are.
And the disappointment compared to my guess 20 years ago
is that particles answering this description have not yet been found.
It was thought that the big accelerator, the Large Hadron Collider at CERN,
which is the world's biggest, might have found a new class of particles,
which would have been the obvious candidates, and it hasn't.
And some people say, well, dark matter can't be there, et cetera.
But what I would argue is that there's a huge amount of parameter space
that hasn't been explored.
There are other kinds of particles called axions,
which behave slightly differently, which are good candidates.
And there's a factor of 10 powers of 10
between the heaviest particles that could be created by the Large Hadron Collider
and the heaviest particles which, on theoretical grounds, could exist
without turning into black holes.
So, there's a huge amount of possible particles which could be out there
as remnants of the Big Bang, which we wouldn't be able to detect so easily.
So, the fact that we've got new constraints on what a dark matter could be
doesn't diminish my belief that it's there in the form of particles
because we've only explored a small fraction of parameter space.
So, there's this search.
You're literally, upon an unintended, are searching in the dark
here in this giant parameter space of possible particles.
You're searching for, I mean, there could be all kinds of particles.
There could be, and there's some which may be very, very hard to detect,
but I think we can hope for some new theoretical ideas
because one point which perhaps you'd like to discuss more
is about the very early stage of the Big Bang.
And the situation now is that we have an outlined picture
for how the universe has evolved from the time when it was expanding
in just a nanosecond, right up to the present.
And we could do that because after nanosecond,
the physics of the material is in the same range that we can test in the lab.
After a nanosecond, the particles move around like those in the Large Hadron Collider.
If you wait for one second, they're rather like in the centers of the hottest stars
and nuclear actions produce hydrogen, helium, etc., which fit today.
So we can, with confidence, extrapolate back to when the universe was a nanosecond old.
Indeed, I think we can do it with as much confidence as anything a geologist tells you
about the early history of the Earth.
And that's huge progress in the last 50 years.
But any progress puts in sharper focus new mysteries.
And of course, the new mysteries in this context are,
why is the universe expanding the way it is?
Why does it contain this mixture of atoms and dark matter and radiation?
And why does it have the properties which allow galaxies to form,
being fairly smooth but not completely smooth?
And the answer to those questions are generally believed to lie
in a much, much earlier stage of the universe when conditions were much more extreme
and therefore far beyond the stage where we had the foothold in experiments, very theoretical.
And so we don't have a convincing theory.
We just have ideas until we have something like string theory
or some other clues to the ultra-early universe.
That's going to remain speculative.
So there's a big gap.
And to say how big the gap is, if we take the observable universe,
a bit more than 10 billion light years, then when the universe was a nanosecond old,
that would have been squeezed down to the size of our solar system or compressed into that volume.
But the times we're talking about when the key properties of the universe were first imprinted
were times when that entire universe was squeezed down to the size of a tennis ball
or baseball, if you prefer, and it emerged from something microscopic.
It was extrapolation and it's not surprising that since it's so far from our experimental range of detectability,
we are still groping for ideas.
But you think first theory will reach into that place
and then experiment will perhaps one day catch up?
Well, I think in a sense it's a combination.
I think what we hope for is that there'll be a theory which applies to the early universe,
but which also has consequences which we can test in our present day universe,
like discovering my new tree does exist or things like that.
And that's the thing which, as I mentioned, we may perhaps need a bit of AI to help us to calculate.
But I think the hope would be that we will have a theory which applies
under the very, very extreme early stages of the universe, which gains credibility and gains confidence,
because it also manages to account for otherwise unexplained features of the New England world
and what people call a standard model of particle physics, where there are lots of undetermined numbers.
So it may help with that.
So we're dancing between physics and philosophy a little bit,
but what do you think happened before the Big Bang?
So this feels like something that's out of the reach of science.
It's out of the reach of present science, because science develops and as the front is advanced,
then new problems come into focus that couldn't be postulated before.
I mean, if I think of my own career, when I was a student, the evidence for the Big Bang was pretty weak,
whereas now it's extremely strong, but we are now thinking about the reason why the universe is the way it is and all that.
So I would put all these things we've just mentioned in the category of speculative science
and I don't see a bifurcation between that and philosophy, but of course, to answer your question,
if we do want to understand the very early universe,
then we've got to realize that it may involve even more counter-intuitive concepts than quantum theory does,
because it's a condition even further away from everyday world than quantum theory is.
I remember our lives, our brains evolved and haven't changed much since our ancestors roamed the African savannah
and looked at the everyday world and it's rather amazing that we've been able to make some sense of the quantum micro world and of the cosmos,
but there may be some things which are beyond us and certainly, as we implied,
there are things that we don't yet understand at all and of course, one concept we might have to jettison
is the idea of three dimensions of space and time just ticking away.
There are lots of ideas. I mean, I think Stephen Hawking had an idea that talking about what hasn't before the Big Bang,
it's like asking what happens if you go north from the North Pole.
It somehow closes off. That's just one idea.
I don't like that idea, but that's a possible one.
And so we just don't know what happened at the very beginning of the Big Bang,
whether many Big Bangs were other than one, etc.
And those are issues which we may be able to get some foothold on from some new theory,
but even then, we won't be able to directly test the theories.
I think it's a heresy to think you have to be able to test every prediction of a theory.
Let me give another example.
We take seriously what Einstein's theory says about the inside of black holes,
even though we can't observe them, because that theory has been vindicated in many other places
in cosmology and black holes, gravitational waves and all those things.
Likewise, if we had a theory which explains some things about the early history of our Big Bang
and the present universe, then we would take seriously the inference
if it predicted many Big Bangs, not one, even though we can't predict the other ones.
So the example is that we can take seriously a prediction
if it's the consequence of a theory that we believe on other grounds.
We don't need to be able to detect another Big Bang in order to take it seriously.
It may not be a proof, but it's a good indication that this is the direction where the truth lies.
Yeah, if the theory is getting confidence in other ways.
Yes.
Where do you sense? Do you think there's other universes besides our own?
There are sort of well-defined theories which make assumptions about the physics at the relevant time.
This time, incidentally, is 10 to the power minus 36 seconds or earlier than that.
So it's a tiny, sliver of time.
And there are some theories, famous one, due to Andrew Linday, the Russian cosmologist now at Stanford
called Eternal Inflation, which did predict an eternal production of new Big Bangs, as it were.
And that's based on specific assumptions about the physics.
But those assumptions, of course, are just hypotheses which aren't vindicated.
But there are other theories which only predict one Big Bang.
So I think we should be open-minded and not dogmatic about these options until we do understand the relevant physics.
But there are these different scenarios, very different ideas about this.
But I think all of them have the feature that physical reality is a lot more extensive
than what we can see through our telescope.
I think even most conservative astronomers would say that because we can see out with our telescopes to a sort of horizon,
which is about, depending on how you measure it, maybe 15 billion light-years away or something like that.
But that horizon of our observations is no more physical reality than the horizon around you, if you're in the ocean.
And looking out at your horizon, there's no reason to think that the ocean ends just beyond your horizon.
And likewise, there's no reason to think that the aftermath of our Big Bang ends just at the boundary of what we can see.
Indeed, there are quite strong arguments that it probably goes on about 100 times further.
It may even go on so much further that all combinatorials are replicated and there's another set of people like us sitting in a room like this.
Every possible combination of...
Yeah, that could happen.
That's not logically impossible.
But I think many people would accept that it does go on and contain probably a million times as much stuff as what we can see within our horizon.
The reason for that, incidentally, is that if we look as far as we can in one direction and in the opposite direction,
then the conditions don't differ by more than one part in 100,000.
So that means that if we're part of some finite structure, the gradient across the part we can see is very small.
And so that suggests that it probably does go on a lot further and the best estimates say it must go on at least 20 times further.
Is that exciting or terrifying to you? Just the spans of it all, the wide, everything that lies beyond the horizon.
That example doesn't even hold for Earth, so it goes way, way farther.
And on top of that, just to take your metaphor further on the ocean, while we're on top of this ocean, not only can we now see beyond the horizon,
we also don't know much about the depth of the ocean.
That's right.
Nor the actual mechanism of observation that's in our head.
Yes.
No, I think the Ruggles and the Houses is on those points you make.
Yes.
But I think even the solar system is pretty vast by human standards.
And so I don't think the perception of this utterly vast cosmos need have any deeper impact on us than just realizing that we are very small on the scale of the external world.
Yeah.
It's humbling though.
It's humbling in depending where your ego is.
It's humbling.
Well, if you start off very unhumble indeed, it may make a difference, but most of us, I don't think it makes much difference.
And well, there's a more general question, of course, about whether the human race as such is something which is very special,
or if on the other hand, it's just one of many such species elsewhere in the universe or indeed existing at different times in our universe.
To me, it feels almost obvious that the universe should be full of alien life, perhaps dead alien civilizations, but just the vastness of space.
Yes.
And it just feels wrong to think of Earth as somehow special.
It sure as heck doesn't look that special.
The more we learn, the less special it seems.
Well, I mean, I don't agree with that as far as life is concerned, because remember that we don't understand how life began here on Earth.
Yes.
And although we know there were any evolution of simple life to complex life, we don't understand what caused the transition between complex chemistry and the first replicating metabolizing entity we call alive.
Yes.
That's a mystery.
And serious physicists and chemists are now thinking about it, but we don't know.
So we therefore can't say, was it a rare fluke?
Yeah.
Which would not have happened anywhere else?
Or was it something which involves a process would have happened in any other planet where conditions were like they were on the young Earth?
So we can't say that now.
I think well, many of us would indeed bet that probably some kind of life exists elsewhere.
But even if you accept that, then there are many contingencies going from simple life to present day life.
And some biologists like Stephen Jay Gould thought that if you rerun evolution, you'd end up with something quite different and maybe not with an intelligent species.
So the contingencies in evolution may militate against the emergence of intelligence, even if life gets started in lots of places.
And I think these are still completely open questions.
And that's why it's such an exciting time now that we are starting to be able to address these.
I mean, I mentioned the fact that the origin of life is a question that we may be able to understand.
And serious people are working on it.
It's usually put in the sort of too difficult box ever knew was important, but they didn't know how to tackle it or what experiments to do.
But it's not like that now.
And that's partly because of clever experiments, but I think most importantly, because we are aware that we can look for life in other places, other places in our solar system.
And of course, on the exoplanets around other stars.
And within 10 or 20 years, I think two things could happen, which will be really, really important.
Right with the next big telescope, be able to image some of the Earth-like planets around other stars.
Image, right?
Get a picture?
Well, actually, let me caveat that.
It takes 50 years to get a resolved image, but to actually detect the light.
Because now, of course, these exoplanets are detected by their effects on the parent star.
They either cause their parent star to dim slightly when they transit across in front of it.
And so we see the dips or their gravitational pull makes the star wobble a bit.
So most of the 5,000 plus planets that have been found around other stars, they've been found indirectly by their effect in one of those two ways on the parent star.
You could still do a pretty good job of estimating size, all those kinds of things.
The size and the mass, you can estimate, but detecting the actual light from one of these exoplanets hasn't really been done yet, except in one or two very bright big planets.
So maybe like James Webb Telescope would be.
Well, James Webb may do this, but even better will be the European ground-based telescope called, on the magic of the Extremilars Telescope, which has a 39-meter diameter mirror.
39 meters.
And that will collect enough light from one of these exoplanets around a nearby star to be able to separate out its light from that of the star,
which is a million times brighter, and get the spectrum of the planet and see if it's got oxygen or chlorophyll and things in it.
So that will come. James Webb may make some steps there.
But I think we can look forward to learning quite a bit in the next 20 years, because I like to say, supposing that we're aliens looking at the solar system,
then they'd see the sun as an ordinary star, they'd see the Earth as, in Carl Sager's nice phrase, a pale blue dot.
Lying very close in the sky to its star, our sun, and much, much, much fainter.
But if they could observe that dot, they could learn quite a bit.
They could perhaps get the spectrum of the light and find the atmosphere.
They'd find the shade of blue is slightly different, depending on whether the Pacific Ocean or the land massivation was facing them.
So they could infer the length of the day and the ocean and continents, and maybe something about the seasons and the climate.
And that's the kind of calculation and inference we might be able to draw within the next 10 or 20 years about other exoplanets.
And evidence of some sort of biosphere on one of them would, of course, be crucial, and it would rule out the still logical possibilities that life is unique.
But there's another way in which this may happen in the next 20 years, people think there could be something swimming under the ice of Europa and Enceladus,
and probes are being sent to maybe not quite go under the ice but detect the spray coming out to see if there's evidence for organics in that.
And if we found any evidence for an origin of life that happened in either of those places,
that would immediately be important because if life has originated twice independently in one planetary system, the solar system,
that would tell us straight away it wasn't a rare accident and must have happened billions of times in the galaxy.
At the moment, we can't rule out it being unique.
And incidentally, if we found life on Mars, then that would still be ambiguous because people have realized that this early life could have got from Mars to Earth
or vice versa on meteorites.
So if you found life on Mars, then some skeptics could still say if it was a single origin.
But I think...
Europe is far enough...
That's far enough away, statistically because...
That's why that would be especially...
It's always the skeptics that ruin a good party, but...
But we need them, of course.
We need them at the party.
We need some skeptics at the party.
But boy, would that be so exciting to find life on one of the moons because it means that life is everywhere.
That would just be any kind of vegetation or life.
The question of the aliens of science fiction is a different matter.
Intelligence aliens.
Yeah, but if you have a good indication that there's life elsewhere in the solar system, that means life is everywhere.
I don't know if that's terrifying or what that is because if life is everywhere, why is intelligent life not everywhere?
You've talked about that most likely alien civilizations, if they are out there, they would likely be far ahead of us.
The ones that would actually communicate with us.
And that, again, one of those things that is both exciting and terrifying.
You've mentioned that they're likely not to be of biological nature.
Well, I think that's important.
Of course, again, it's a speculation.
But in speculating about intelligent life, I take the search seriously.
In fact, I chair the committee that the Russian American investor Yuri Milner supports looking for intelligent life.
He's putting $10 million a year into better equipment and getting time on telescopes to do this.
And so I think it's worthwhile, even though I don't hold my breath for success.
It's very exciting.
But that does lead me to wonder what might be detected.
And I think, well, we don't know, we've got to be able to mind about anything.
We've no idea what it would be.
And so any anomalous objects or even some strange shiny objects in the solar system or anything, we've got to keep our eyes open for.
But I think if we ask what about a planet like the Earth where evolution had taken more of the same track, then as you say, it wouldn't be synchronized.
If it had lagged behind, then, of course, it would not have got to advanced life.
But it may have had a head start.
It may have formed on a planet around an older star.
OK, but then let's ask what we would see.
It's taken nearly four billion years from the first life to us.
And we've now got this technological civilization, which could make itself detectable to any alien life, aliens out there.
But I think most people would say that this civilization of flesh and blood creatures and the collective civilization may not last more than a few hundred years more.
I think that some people would say it will kill itself off.
But I'm more optimistic, and I would say that what we're going to have in future is no longer the slow Darwinian selection.
But we're going to have what I call secular intelligence design, which will be humans designing their progeny to be better adapted
to where they are.
And if they go to Mars or somewhere, they're badly adapted and they want to adapt a lot.
And so they will adapt.
But there may be some limits to what could be done with flesh and blood.
And so they may become largely electronic, download their brains and be electronic entities.
And if they're electronic, then what's important is that they're near immortal.
And also they won't necessarily want to be on a planet with an atmosphere or gravity.
They may go off into the blue yonder.
And if they're near immortal, they won't be daunted by interstellar travel taking a long time.
And so if we looked at what would happen on the earth in the next millions of years, then there may be these electronic entities which have been sent out and are now far away from the earth,
but still sort of burping away in some fashion to be detected.
And so this therefore leads me to think that if there was another planet which had evolved like the earth and was ahead of us,
it wouldn't be synchronized.
So we wouldn't see a flesh and blood civilization, but we would see these electronic progeny as it were.
And then there's another question because there's the famous argument against there being lots of aliens out there,
which is that they would come and invade us and eat us or something like that.
That's a common idea, which is fairly attributed to have been the first to say.
And I think there's a escape clause to that because these entities would evolve by second intelligence design,
designed by their predecessors and then designed by us.
Whereas Darwinian selection requires two things.
It requires aggression and intelligence.
This future intelligence design may favor intelligence because that's what they were designed for,
but it may not favor aggression.
And so these future entities, they may be sitting deep thoughts and not being at all expansionist.
So they could be out there and we can't refute their existence in the way the Fermi paradox is supposed to refute their existence
because these would not be aggressive or expansionist.
Well, maybe evolution requires competition, not aggression.
And I wonder if competition can take forms that are non-expansionary.
So you can still have fun competing in the space of ideas, which may be primarily...
It'll be philosophers, perhaps, yeah.
In a way, right.
It's an intellectual exercise versus a sort of violent exercise.
So what does this civilization on Mars look like?
So do you think we would more and more maybe start with some genetic modification
and then move to basically cyborgs, increasing integration of electronic systems,
computational systems into our bodies and brains?
This is a theme of my other new book out this year, which is called The End of Astronauts.
Co-written with my old friend and colleague from Berkeley, Don Goldsmith.
And it's really about the role of human spaceflight versus sort of robotic spaceflight.
And just to summarize what it says, it argues that the practical case for sending humans into space
is getting weaker all the time as robots get better and more capable.
Robots 50 years ago couldn't do anything very much,
but now they could assemble big structures on space or in space or on the moon
and they could probably do exploration.
Well, present ones on Mars can't actually do the geology,
but future AI will be able to do the geology and already they can dig on Mars.
And so if you want to do exploration of Mars and of course even more of Enceladus
or Europa where you could never send humans, we depend on robots.
And they're far, far cheaper because to send a human to Mars requires feeding them
for 200 days on the journey there and bringing them back.
And neither of those are necessary for robots.
So the practical case for humans is getting very weak.
And if humans go, it's only as an adventure really.
And so the line in our book is that human spaceflight should not be pursued by NASA
or public funding agencies because it has no practical purpose,
but also because it's especially expensive if they do it
because they would have to be risk averse in launching civilians into space.
I can illustrate that by noting that the shuttle was launched 135 times
and it had two spectacular failures which each killed the seven people in the crew.
And it had been mistakenly presented as safe for civilians
and there was a woman's school teacher killed in one of them and it was a big national trauma
and they tried to make it safer still.
But if you launch into space just the kind of people prepared to accept that sort of risk
and of course test pilots and people who go hang gliding and go to the South Pole etc.
are prepared to accept a 2% risk at least for a big challenge, then of course you do it more cheaply.
And that's why I think human spaceflight should be left to the billionaires
and their sponsors because then the taxpayers aren't paying
and they can launch simply those people who are prepared to accept high risks.
Space adventure not space tourism and we should cheer them on.
And as regards where they would go then low earth orbit I suspect can be done quite cheaply in future.
But going to Mars which is very very expensive and dangerous for humans
the only people who would go would be these adventurers maybe on one way trip
like some of the early polar explorers and Magellan and people like that
and we would cheer them on.
And I expect and I very much hope that by the end of the century
there will be a small community of such people on Mars living very uncomfortably
far less comfortably than at the South Pole or the bottom of the ocean or the top of Everest
but they will be there and they won't have a return ticket but they'll be there.
Incidentally I think it's a dangerous illusion to think as Elon Musk has said
that we can have mass emigration from the earth to Mars to escape the earth's problems.
It's a dangerous illusion because it's far easier to deal with climate change on earth
than to terraform Mars to make it properly habitable to humans.
And so there's no planet beef or ordinary risk of earth people
but for these crazy adventurers then you can imagine that they would be trying to live on Mars
as great pioneers and by the end of the century
then there will be huge advances compared to the present in two things
first in understanding genetics so as to genetically redesign one's offspring
and secondly to use cyborg techniques to implant something in our brain
to indeed think about downloading etc.
And those techniques will, one hopes, be heavily regulated on earth
on prudentials and ethical grounds and of course we are pretty well adapted to the earth
so we don't have the incentive to do these things in the way they were there.
So our argument is that it'll be those crazy pioneers on Mars
using all these scientific advances which will be controlled here away from the regulators
they will transition into a new post-human species.
And so if they do that and if they transition into something which is electronic
eventually because there may be some limits to the capacity of flesh and blood brains anyway
then those electronic entities may not want to stay on a planet like Mars
and they want to go away and so they'll be the precursors of the future evolution
of life and intelligence coming from the earth.
And of course there's one point which perhaps astronomers are more aware of than most people
most people are aware that we are the outcome of four billion years of evolution
most of them nonetheless probably think that we humans are somehow the culmination
of the top of the tree. But no astronomers can believe that
because astronomers know that the earth is four and a half billion years old
the sun has been shining for that length of time
but the sun has got six billion years more to go before it flares up and engulfs the inner planet
so the sun isn't halfway through its life and the expanding universe goes on far longer still
maybe forever and I like to quote Woody Allen who said eternally is very long especially towards the end
so we shouldn't think of ourselves as maybe even a halfway stage in the emergence of cosmic complexity
and so these entities who are post-cursors they will go beyond the solar system
and of course even if there's nothing else out there already then they could populate the rest of the galaxy
and maybe eventually meet the others who are out there expanding as well
expanding and populating with expanded capacity for life and intelligence all those kinds of things
well they might but again all better off because I can't conceive what they'd be like
they won't be green men and women with eyes on stalks you know they'd be something quite different
we just don't know but there isn't anything to question actually which comes up when I sometimes
have spoken to audiences about this topic but the question of consciousness and self-awareness
because going back to philosophical questions whether an electronic robot would be a zombie
or would it be conscious and self-aware and I think there's no way of answering this empirically
and some people think that consciousness and self-awareness is an emergent property
in any sufficiently complicated networks that they would be
others say well maybe it's something special to the flesh and blood that we're made of
we don't know and in a sense this may not matter to the way things behave
because they could be zombies and still behave as though they were intelligent
but I remember after one of my talks someone came up and said wouldn't it be sad
if these future entities which were the main television universe had no self-awareness
so there was nothing which could appreciate the wonder and mystery of the universe
and the beauty of the universe in the way that we do
and so it does perhaps affect one's perspective of whether you welcome or deplore this possible future scenario
depending on whether you think the future post-human entities are conscious and have an aesthetic sense
or whether they're just zombies
and of course you have to be humble to realize that self-awareness may not be the highest form of being
that humans have a very strong ego and a very strong sense of identity
like personal identity connected to this particular brain
it's not so obvious to me that that is somehow the highest achievement of a life form
that maybe this kind of...
I think something collective would be
for example that well I think from an alien perspective when you look at Earth
it's not so obvious to me that individual humans are the atoms of intelligence
it could be the entire organism together, the collective intelligence
and so we humans think of ourselves as individuals
we dress up, we wear ties and suits and we give each other prizes
but in reality the intelligence, the things we create that are beautiful
just from our interaction with each other
and that may be where the intelligence is
ideas jumping from one person to another over generations
yes, but we have experiences where we can appreciate beauty and wonder and all that
and a zombie may not have those experiences
yeah, or it may have a very different...
we have a very black and white harsh description of zombies
like a philosophical zombie
that could be just a very different way to experience
and in terms of the explorers that colonize Mars
I mean there's several things I want to mention
one, it's just at a high level to me that's one of the most inspiring things humans can do
is reach out into the unknown
that's in the space of ideas, in the space of science
but also the explorers
and that inspires people here on earth
more... I mean it did
when going to the moon or going out to space in the 20th century
that inspired a generation of scientists
I think that also could be used to inspire a generation of new scientists
in the 21st century by reaching out towards Mars
so in that sense I think what Elon Musk and others are doing
is actually quite inspiring
I agree
it's not a recreational thing
it actually has a deep humanitarian purpose of really inspiring the world
and then on the other one to push back on your thought
I don't think Elon says we want to escape Earth's problems
it's more that we should allocate some small percentage of resources
to have a backup plan
because you yourself have spoken about and written about
all the ways we clever humans can destroy ourselves
and I'm not sure it does seem...
when you look at the long arc of human history
it seems almost obvious that we need to become a multi-planetary species
over a period if we are to survive many centuries
it seems that as we get clever and clever
with the ways we can destroy ourselves
Earth is going to become less and less safe
so in that sense this is one of the things
people talk about climate change
and that we need to respond to climate change
and that's a long-term investment we need to make
but it's not really long term, it's a span of decades
I think what Elon is doing is a really long-term investment
we should be working on multi-planetary colonization now
if we were to have it ready five centuries from now
and so taking those early steps
and then also there's something happens
when you go into the unknown and do this really difficult thing
you discover something very new
you discover something about robotics or materials engineering
or nutrition or neuroscience or human relations
or political systems that actually work well with humans
you discover all those things
so it's worth the effort to go out there
and try to become cyborgs
Yeah, I agree with that
I think the only different point I'd make is that
this is going to be very expensive
if it's done in a risk averse way
I think we should be grateful to the billionaires
if they're going to sort of foster these opportunities
for thrill-seeking risk takers who we can all admire
By the way, I should push back on the billionaires
because there's sometimes a negative connotation to the word billionaire
it's not a billionaire, it's a company versus government
because governments are billionaires and trillionaires
it's not the wealth, it's the capitalist imperative
which I think deserves a lot more praise than people are giving it
I'm troubled by this sort of criticism
like it's billionaires playing with toys for their own pleasure
I think what some of these companies
like SpaceX and Blue Origin are doing
is some of the most inspiring engineering
and even scientific work ever done in human history
No, I agree, I think the people who've made the greatest wealth
are people who've really been mega benefactors
I think some of them
Yes, some of them, but those who've founded Google and all that
and even Amazon, they're beneficiaries
they're in a quite different category in my view
from those who just shuffle around money
or crypto coins and things like that
Now you're really talking trash
But I think if they use their money in these ways that's fine
but I think it's true that the far more money is owned by us collectively as taxpayers
but I think the fact is, as in a democracy
there'd be big resistance to exposing human beings to very high risks
if in a sense we share responsibility for it
And that's the reason I think we've done much more cheaply by these private funders
That's an interesting hypothesis, but I have to push back
I don't know if it's obvious why NASA spends so much money
and takes such a long time to develop the things it was doing
so before Elon Musk came along
because I would love to live in a world where government actually uses taxpayer money
to get some of the best engineers and scientists in the world
and actually work across governments
Russia, China, United States, the European Union together to do some of these big projects
It's strange that Elon is able to do this much cheaper, much faster
It could have to do with risk aversion, you're right
I think it's that, it's that he had all the whole assembly within this one building
as it were rather than depending on a supply chain
But I think it's also that he had a Silicon Valley culture
and had younger people whereas the big aerospace companies
Boeing and Lockheed Martin, they had people who were left over from the Apollo program
in some cases and so they weren't quite so lively
and indeed quite apart from the controversial issues of the future of human spaceflight
in terms of the next generation of big rockets
then the one that Musk is going to launch for the first time this year
the huge one, is going to be far, far cheaper than the one that NASA's been working on
at the same time
and that's because it will have a reusable first stage
and it's going to be great, it can launch over 100 tons into Earth orbit
and it's going to make it feasible to do things that I used to think were crazy
like having solar energy from space, that's no longer so crazy
if you can do that, and also for science
because its nose cone could contain within it
something as big as the entire unfurled James Webb telescope mirror
and therefore you can have a big telescope much more cheaply
if you can launch it all in one piece
and so it's going to be hugely beneficial to science and to any practical use of space
to have these cheaper rockets that are far more completely reusable
than it was NASA had
Musk's are a tremendous service to space exploration and the whole space technology
through these rockets certainly
plus it's some big sexy rocket, it's just great engineering
of course, yeah
it's like looking at a beautiful big bridge
that humans are capable, us descendants of apes are capable to do something so majestic
and also the way they land coming down on this bar, that's amazing
it's both controls engineering, it's increasing sort of intelligence in these rockets
but also great propulsion engineering materials, entrepreneurship
and it just inspires so many people
No, I'm entirely with you on that
So would it be exciting to you to see a human being step foot on Mars in your lifetime?
Yes, I think it's unlikely in my lifetime since I'm so ancient
but I think this century is going to happen
and I think that will indeed be exciting
and I hope there will be a small community by the end of a century
but as I say, I think they may go with one way tickets or accepting the risk of no return
so they've got to be people like that
and I still think it's going to be hard to persuade the public to send people
when you say straight out that they may never come back
but of course the Apollo astronauts, they took a high risk
and in fact in my previous book I quote the speech that's been written for Nixon
to be read out if Neil Armstrong got stuck on the moon
and it was written by one of his advisors
and very eloquent speech about how they have come to a noble end etc
but of course there was a genuine risk at that time
but that may have been accepted
but clearly the crashes of the shuttle were not acceptable to the American public
even when they were told that this was only a 2% risk given how often they launched it
and so that's what leads me to think that it's got to be left to the kind of people
who are prepared to take these risks
and I think of an American adventure, there was a guy called Steve Fossa
who was an aviator who did all kinds of crazy things
and then a guy who fell supersonically with the parachutes from very high altitude
and all these people, we all share them all, they extend the bounds of humanity
but I don't think the public would be so happy to fund them
I mean I disagree with that, I think if we change the narrative we should change the story
You think so
I think there's a lot of people, because the public is happy to fund folks
in other domains that take bold, giant risks, first of all military for example
military
obviously yes
I think this is in the name of science, especially if it's sold correctly
I sure as hell would go up there with a risk, I would take a 40% chance risk of death
for something that's prepared
I might want to be even older than them now
but then I would go
I guess what I'm trying to communicate is there's a lot of people on earth that's the nice feature
and I'm sure there's going to be a significant percentage or some percentage of people that are
that take on the risk for the adventure
so and I particularly love that that risk of adventure when taking on inspires people
and just the ripple effect that has across the generation
especially among the young minds is perhaps immeasurable
but you're thinking that sending humans should be something we do less and less
than sending humans to space, that it should be primarily an effort
the work of space exploration should be done primarily by robots
well I think it can be done much more cheaply obviously on Mars
and no one's thinking of sending humans to Enceladus or Europa, the outer planets
and the point is we'll have much better robots
because let's take an example, you've seen the pictures of the moons of Saturn
and the picture of Pluto
and the comet taken by probes and Cassini spent 13 years going around Saturn
and its moons after seven-year voyage
and those are all based on 1990s technology
and if you think of how smartphones have advanced in 20 years since then
you just think how much better one could do instrumenting some very small sophisticated probe
and could send dozens of them to explore the outer planets
and that's the way to do that because no one thinks you could send humans that far
but I would apply the same argument to Mars
and if you want to assemble big structures like for instance radio astronomers
would like to have a big radio telescope on the far side of the moon
so it's away from the Earth's background, artificial radio waves
and that could be done by assembling, using robots without people
so on the moon and on Mars
I think everything that's useful can be done by machines much more cheaply than by humans
Do you know the movie 2001 A Space Odyssey?
Of course, yes, but you must be too young to have seen that when it came out obviously
I remember seeing it when it came out
You saw it when it came out?
Yeah, 50 years ago
When was it? In the 60s?
Yeah, it was still classic
It's still probably, for me, the greatest AI movie ever made
Yes, I agree
One of the great space movies ever made
Well, let me ask you a philosophical question since we're talking about robots exploring space
Do you think Hal 9000 is good or bad?
So for people who haven't watched, this computer system makes a decision
to basically prioritize the mission that the ship is on
over the humans that are part of the mission
Do you think Hal is good or evil?
Probably in that context, it was probably good
but I think you're raising what is of course very much an active issue in everyday life
about the extent to which we should entrust any important decision to a machine
and there again, I'm very worried because I think if you are recommended for an operation
or not given parole from prison or even denied credit by your bank
you feel you should be entitled to an explanation
It's not enough to be told that the machine has a more reliable record
on the whole than humans have of making these decisions
You think you should be given reasons you could understand
and that's why I think the presence of subtle trends to take away the humans
and leave us in the hands of decisions that we can't contest
is a very dangerous one, I think we've got to be very careful of the extent to which
AI which can handle lots of information actually makes the decisions without oversight
and I think we can use them as a supplement
but to take the case of radiology and cancer
I mean it's true that the radiologist hasn't seen as many x-rays of cancer lungs as the machine
so the machine can certainly help but you want the human to make the final decision
and I think that's true in most of these instances
but if we turn a bit to the short-term concerns with robotics
I think the big worry of course is the effect it has on people's self-respect and their labour market
and I think my solution will be that we should arrange to tax more heavily
the big international conglomerates which use the robots
and use that tax to fund decently paid dignified posts
of the kind where being a human being is important
above all carers for old people, teachers assistants for young, gardeners in public parks and things like that
and if the people who are now working in mind-numbing jobs
in Amazon warehouses or in telephone call centres are automated
but those same people are given jobs where being a human is an asset
then that's a plus-plus situation
and so that's the way I think that we should benefit from these technologies
take over the mind-numbing jobs and use machines to make them more efficient
but enable the people so displaced to do jobs where we do want a human being
I mean most people when they're old, they're rich people if they have the choice
they want human carers and all that, don't they?
They may want a robot to help with some things
MC to bedpans and things like that but they want real people
and certainly in this country I think it's worse in America
the care of old people is completely inadequate
and it needs just more human beings to help them cope with everyday life
and look after them when they're sick
and so that seems to be the way in which the money raised in tax from these big companies should be deployed
So that's in the short term but if you actually just look, the fact is
where we are today to long-term future in 100 years, it does seem that there is some significant chance
that the human species is coming to an end in its pure biological form
there's going to be greater and greater integration to genetic modification
than cyborg type of creatures
and so you have to think, alright, well we're going to have to get from here to there
and that process is going to be painful
and there's so many different trajectories that take us from one place to another
it does seem that we need to deeply respect humanness and humanity
basic human rights, human welfare, happiness and all that kind of stuff
Absolutely and that's why I think we ought to try and slow down the application of these human enhancement techniques
cyborg techniques for humans for just that reason
that's why I want to lead into the people on Mars
but there are people too, people on Mars are people too
I tend to, you know
but they are very poorly adapted to where they are
that's why they need this modification
whereas we're adapted to the earth quite well so we don't need these modifications
we're happy to be humans living in the environment where our ancestors lived
so we don't have the same motives
so I think there's a difference
but I agree we don't want drastic changes probably in our lifestyle
and that indeed is a worry because some things are changing so fast
but I think, I'd like to inject a note of caution
if you think of the way progess in one technology goes
it goes in a sort of spurt, it goes up very fast and then it levels off
let me give you two examples
one we've had already, human spaceflight
at the time of the Apollo program
it was only 12 years after Sputnik 1
I was alive then and I thought it would only be 10 or 20 years further
before the work would pretend Mars
but as we know for reasons we could all understand
that was and still remains the high point of human space exploration
and that's because it was funded for reason of superpower rivalry
at huge public expense
but let me give you another case, civil aviation
if you think of the change between 1919
when that was Alcock and Brown's first transatlantic fight
to 1979, the first flight to the jumbo jet
it was a big change
it's more than 50 years since 1969
and we still have jumbo jets more or less the same
so that's an example of something which developed fast
and to take another analogy
we've had huge developments in mobile phones
but I suspect the iPhone 24 may not be too different from the iPhone 13
they develop but then they saturate
and then maybe some new innovation takes over in stimulated economic growth
Yeah, so it's that we have to be cautious about being too optimistic
and we have to be cautious about being too cynical
I think that is the...
Optimistic is begging the question
do we want this to have a change?
Right, so first of all there's some degree to which technological advancement
is a force that can't be stopped
but the question is about directing it versus stopping it
or slowing it
Well, it can be sort of sloped or slow
but like human spaceflight
there could have been footprints on Mars
if America had gone on spending 4% of the federal budget
on the project after Apollo
But the reason...
There were very good reasons
and we could have had supersonic flight
but Concorde came and went during the 50 years
but the reason it didn't progress
is not because we realized it's not good for human society
the reason it didn't progress is because it couldn't make...
sort of from a capitalist perspective
it couldn't make...
there was no short term or long term way for it to make money
so for me...
But that's the same as saying it's not good for society
I don't think everything that makes money is good for society
and everything that doesn't make money is bad for society
that's a difficult...
that's a difficult thing we're always contending with
when we look at social networks
it's not obvious even though they make a tremendous amount of money
that they're good for society
especially how they're currently implemented
with advertisement and engagement maximization
so that's the constant struggle of...
I agree with you there's many innovations are damaging
Yes, yes
Well...
But I would have thought that the supersonic flight was
something that would benefit only a tiny elite
a huge expense and environmental damage
that was obviously something which they're very glad not to have in my opinion
Yeah, but perhaps there was a way to do it
where it could benefit the general populace
if you were to think about airplanes
wouldn't you think that in the early days
airplanes would have been seen as something that can
only benefit 1% at most of the population
as opposed to a much larger percentage
there's another aspect of capitalist system
that's able to drive down costs once you get the thing kind of going
so we get together maybe with taxpayer money
and get the thing going at first
and once it gets going companies step up
and drive down the cost
and actually make it so that blue collar folks
can actually start using the stuff
that does happen, that's good
Yeah, so that's again
the double-ish sort of human civilization
that some technology hurts us
some benefits us and we don't know ahead of time
we could just do our best
There's a gap between what could be done
and what we can actually decide to do
Yes
in a term you could push forward some developments
faster than we do
Let me ask you
in your book on the future prospects for humanity
you imagine a time machine that allows you to send a tweet-length
message to scientists in the past like to Newton
What tweet would you send?
It's an interesting thought experiment
what message would you send to Newton
about what we know today
Well I think he'd love to know that there were planets around other stars
He'd like to know that
That would really blow his mind
that everything was made of atoms
He'd like to know that if he looked a bit more carefully
through his prisms
and looked at light not just from the sun
but from some flames
he might get the idea that
different surfaces emitted light of different colors
and he might have been
twigged to discover some things
that had to wait two or three hundred years
I'm good at giving him those clues I think
It's fascinating to think to look back
at how little he understood
people at that time understood about our world
and how much we've...
And certainly about the cosmos
Well if we think about astronomy
then until about 1850
astronomy was a matter of
the positions of how the stars
and the planets moved around
Of course that goes back a long way
but Newton understood why the planets moved around
in ellipses
But he didn't understand
why the solar system was all in a plane
what we call the ecliptic
and he didn't understand it
and no one did until the mid 19th century
what the stars are made of
We thought we made of some fifth essence
not earth, air, power and water like everything else
and it was only after 1850
when people did use prisms
precisely to get spectra
that they realized that the sun
was made of the same stuff as the earth
and indeed the stars were
and it wasn't until 1930
that people knew about nuclear energy
and knew what kept the sun shining for so long
So it was quite late that some of these key ideas
came in which would completely transform Newton's views
and of course the entire scale of the solar
of the galaxy and the rest of the universe
Imagine what he would have thought about the Big Bang
or even just general relativity
Just gravity
Him and Einstein talking for a couple of weeks
Would he be able to make sense of space time
and the curvature of space time
Well I think given a quick course
I mean he was sort of
if one looks back he was really a unique intellect in a way
and he said that he
thought better than everyone else
by thinking on things continually
and thinking very deep thoughts
and so he was an utterly remarkable intellect obviously
But of course scientists aren't all like that
I think one thing that interests me
having spent a life among scientists
was a variety of mindsets and mental styles they have
and well just to contrast Newton and Darwin
Darwin said
and he's probably correct that he thought he just had
as much sort of a common sense and reasoning power
as he had with his lawyer
and that's probably true because his ability
was to sort of connect data and think through things deeply
That's a quite different kind of thinking
from what was involved in Newton or someone doing abstract mathematics
I think in the 20th century the coolest
Well there's the theory but
from an astronomy perspective
black holes is one of the most fascinating entities
to have been through theory and through experiment
to have emerged from
Obviously I agree it's an amazing story
Well of course what's interesting is Einstein's reaction
because as you know we now accept
this is one of the most remarkable predictions of Einstein's theory
he never took it seriously even believed it
although it was a consequence of
a source of his equations which someone discovered
just a year off his theory, Schwarzschild
but he never took it seriously and others did
but then of course
well this is something that I've been involved in
finding evidence for black holes and that's come in the last 50 years
so now there's pretty compelling evidence that they exist
as the remnants of stars or big ones in the center of galaxies
and we understand what's going on
we have ideas vaguely on how they form
and of course
gravitation waves have been detected
and that's an amazing piece of technology
LIGO is one of the most incredible engineering efforts of all time
That's an example where the engineers deserve the most of the credit
because the precision, as they said
it's like measuring the thickness of a hair
at the distance of Alpha Centauri
It's incredible
So maybe actually if we step back what are black holes
what do we humans understand about black holes
and what's still unknown
Einstein's theory extended by people like Roger Penrose
tells us that black holes are in a sense of other simple things
basically because they are
solutions of Einstein's equations
and the thing that was shown in the 1960s
by Roger Penrose in particular
and by a few other people
was that a black hole when it forms
and settles down is defined just by two quantities
it's mass and it's spin
so they're actually very standardised objects
it's amazing that objects as standardised as that
can be so big and can lurk in the vessel solar system
and so that's the situation for a ready formed black hole
but the way they form obviously is very messy and complicated
and one of the things that I've worked on a lot
is what the phenomena are
which are best attributed to black holes
and what may lead to them and all that
Can you explain to that?
So what are the different phenomena that lead to a black hole?
Let's talk about it
This is so cool
I think one thing that only became understood really
in the 1950s I suppose
and beyond was how stars evolved differently
depending on how heavy they are
This is the sun burns hydrogen and helium
and then when it's run out of that
it contracts to be a white dwarf
and we know how long that will take
about 10 billion years altogether
for its lifetime
but big stars burn up their fuel more quickly
and more interestingly
when they've turned hydrogen to helium
they then get even hotter
so they can fuse helium into carbon
and go up the periodic table
and then they eventually explode
when they have an energy crisis
and they blow out that process material
which as a digression is crucially important
because all the atoms inside our bodies
were synthesized inside a star
a star that lived and died more than 5 billion years ago
before our sources have formed
and so we each have inside us
atoms made in thousands of different stars
all over the Milky Way
and that's an amazing idea
and my predecessor Fred Hoyle in 1946
was the first person to suggest that idea
and that's been born out, that's a wonderful idea
so that's how massive stars explode
and they leave behind
something which is very exotic
and of two kinds
one possibility is a neutron star
which was first discovered in 1967-68
these are stars a bit heavier than the Sun
which are compressed to an amazing density
so the whole mass of more than the Sun's mass
is in something about 10 miles across
so they're extraordinarily dense
they're exotic physics
and they've been studied in immense detail
and they've been real laboratories
because the good thing about astronomy
apart from exploring what's out there
is to use the fact that the Cosmos has provided us with a lab
with far more extreme conditions
than we could ever simulate
and so we learn lots of basic physics
from looking at these objects
and that's been true of neutron stars
but for black holes, that's even more true
because the bigger stars
when they collapse
they leave something behind in the center
too big to be a stable white or four neutron star
becomes a black hole
and we know that there are lots of black holes
weighing about 10 or up to 50 times as much as the Sun
which are the remnants of stars
they were detected first 50 years ago
when a black hole was orbiting around another star
and grabbing material from the other star
which swirled into it
and gave us X-rays
which found these
objects
orbiting around an ordinary star
and emitting X-ray radiation
very intensely
varying out of a short time scale
so something very small and dense
was giving that radiation
that was the first evidence for black holes
but then the other thing that's happened
was realizing that there was a
different class of monster black holes
in the centers of galaxies
and
these are a response for what's called quasars
which is when
something in the center of a galaxy
is grabbing some fuel
and outshines all the
100 billion stars or so in the rest of the galaxy
giant beam
of light
and in many cases it should be
that's got to be the most
epic thing the universe produces
is quasars
well it's a debate about the most epic
but quasars maybe
or maybe gamma ray bursts or something
but they are remarkable
and they were a mystery for a long time
and they're one of the things I worked on
in my younger days
so even though they're so bright they're still a mystery
and but you can only see them
I think they're less of a mystery now
I think we do understand basically what's going on
how were quasars discovered?
well they were
discovered when astronomers found
things that looked like stars
and they were small enough to be a point like
not resolved by a telescope
but outshined
an entire galaxy
yeah and it's suspicious
yes but
but then they realized
what they were
they were
objects which you now know are black holes
and they were
black holes were
capturing gas
and that gas was getting very hot
but it was producing
more energy
than all the stars had it together
and it was the energy of the
black hole
that was lighting up all the gas in the galaxy
so you've got a spectrum of it
so
this was something which was realized
from the 1970s onwards
and as you say
the other thing we've learned is that they often
do produce these jets squirting out
which could be detected
in all wave bands
there's a giant black hole
generating jets
like in the center of most
galaxies
do we know
if every galaxy has one of these big
big boys
big black holes
most galaxies have big black holes
they vary in size the one in our galactic center
do we know much about ours?
we do yes
we know
it weighs about as much as four million
million suns
which is less than some
it's a several billion in other galaxies
but we know this
the one in our galactic center isn't
very bright or conspicuous
and that's because not much is falling
into it at the moment
if a black hole is isolated then of course it doesn't
radiate
all that radiates is gas
swirling into it
which is very hot or has magnetic fields
it's only radiating the thing it's murdering
or consuming
however you put it
so it's thought that
our galaxy may have been bright
at some time in the past
but now
that's when the black hole formed or grew
but now it's
not catching very much gas
and so it's rather
it's rather faint and only detected
indirectly and by a fairly
weak radio mission
and so I think the answer to your question
is that
we suspect that most galaxies
have a black hole in them
so that means that some stays in their lives
or maybe one or more stages
they went through a phase of being like a
quasar where that black hole
captured gas
and became very very bright
but for the rest of the lives
the black holes are fairly quiescent
because there's not much gas
falling into them
and so this universe of ours
sprinkled a bunch of galaxies
and giant black holes with
like
very large number of stars
orbiting
these black holes and then
planets orbiting
likely it seems like
planets orbiting almost every one of those
stars
and just this beautiful
universe of ours
so what happens when galaxies collide
when these two big black holes
collide
is that
what would happen is that
well and I should say
this is going to happen near us one day
but not for four billion years
because the Andromeda galaxy
which is the biggest galaxy
near to us which is about
three million light years away
which is a big disk galaxy
with a black hole in its heart
rather like our Milky Way
and that's
falling towards us
because they're both in a common gravitational
potential well
and that will collide
with our galaxy in about four billion years
but it'll be
maybe it'll be less a collision and more of a dance
because it'll be like a swirling situation
well it's a swirling but eventually
there'll be a merger
they'll go through each other and then merge
in fact the nice move
is to be made of this
computer simulations
to go through
and then
there's a black hole
in the sense of Andromeda and our galaxy
and the black holes
will
settle towards the center
then they will orbit around each other
very fast and then they will eventually merge
and that'll produce
a big burst of gravitational waves
a very big burst
that in alien civilization
where the LIGO-like detector will be able to detect
yes well in fact
we can detect these with
their lower frequencies
than the ways that
will be detected by LIGO
so there's a space interferometer
which can detect these
it's about one cycle per hour
rather than about a hundred cycles per second
it's the ones that are detected
but that
will happen but
thinking back to what will happen in four billion years
to any of our descendants
they'll be okay
because the
two disc galaxies will merge
it'll end up as a sort of amorphous elliptical galaxy
but
the stars won't be much closer together
than they are now
it'll still be
twice as many stars in a structure almost as big
and so
the chance of another star
colliding with our sun
will still be very small
because there's actually a lot of space between
stars and planets
the chance of a star getting close enough to
affect our solar system's orbit
is small and it won't change that very much
so you can be reassured
a heck of a starry sky though
what would that look like
well it won't make much difference even to that actually
it'll just be
wouldn't it look kind of beautiful when you're swirling
or because it's swirling so slow
yeah they're far away
so it'll be twice as many stars in the sky
yeah
the pattern changes
yeah the pattern will change a bit
and there won't be the Milky Way
because the Milky Way across the sky
is because we are looking in the disc of our galaxy
and you lose that
and because the disc
will be sort of disrupted
and it'll be also the spherical distribution
and of course many galaxies are like that
and that's probably because
they have been through mergers of this kind
if we survive four billion years
we would likely be able to survive
beyond that
what's the other thing
on the horizon for humans
in terms of the sun
burning out all those kinds of
interesting cosmological
threats to our
civilization
well I think only cosmological times
because it won't be humans
because even the
evolution's got no faster than Darwinian
and I would argue it will be faster
than Darwinian in the future
and we're thinking about
six billion years before the sun dies
so any entities
watching the death of the sun
if they're still around maybe it's different
much as we are from slime mold
or something you know
and far more different still if they become
electronic so on that time scale
we just can't predict anything
but I think going back to
the human time scale
then
we talked about whether there'll be people on Mars
by the end of the century
and even in these long
perspectives then
indeed this century is very special
because it may see the transition
between pure leaf flesh and blood
entities to those which are sort of cyborgs
and that'll be
an important transition
in
biology and complexity
in this century but of course the other importance
and this has been the theme of a couple of my older books
is that
this is the first century when one species
namely our species
has the future of the planet in its hands
and that's because of
two types of
concerns
one is that there are more of us
where more
demanding of energy and resources
and therefore we are for the first time
changing the whole planet
through climate change
loss of biodiversity and all those issues
this has never happened in the past
because having enough humans
so this is
an effect that's obviously
is high on everyone's agenda now
and rightly so because
we've got to ensure that we leave
a heritage that isn't
eroded or damaged
to future generations
and so that's one class of threats
but there's another
thing that worries me
perhaps more than
many people seem to worry
and that's the threat of
misuse of technology
and so this is
particularly because
technologies
empower even small groups
of malevolent people
or indeed
in careless people
to create some effect which could
cascade globally
and take an example
of a dangerous
pathogen or pandemic
I mean my worst nightmare
is that
there could be
some small group
that can engineer
a virus
to make it more virulent or more transmissible
than a natural virus
this is so called gain of function experiments
which were done on the flu virus 10 years ago
and can be done for others
and of course we now know
in 2019
that
our world is so interconnected
that a disaster in one part of the world
can't be confined to that part
and we spread globally
so it's possible for
a few dissidents
with expertise in biotech could
create a global catastrophe of that kind
and also I think
we need to worry about
very large scale disruption by cyber attacks
in fact
one of my books
a 2012 report
from the American Pentagon
about the
possibility of a state level
cyber attack on the electricity
grid in eastern United States
which as it could happen
and it says at the end
of this chapter that
this would merit a nuclear response
this is a pretty scary possibility
that was 10 years ago
and I think now
needed a state actor then
could be done perhaps by a small group
empowered by AI
and so there's obviously been
an arms race between
the cyber criminals
and the cyber security people
not clear which side is winning
but the main point is that
as we become more dependent
on more integrated
systems
then we get more vulnerable
and
as we have the knowledge
then the misuse of that knowledge
becomes
more and more of a threat and
bio and cyber are the two
biggest concerns
and if we depend too much
on AI and complex
systems then
just breakdowns it may be that
they break down and
even if it's an innocent breakdown
it may be pretty hard to mend it
and just think how much worse the pandemic
would be if we'd lost the internet
in the middle of it
more than ever
for communication and everything else
on the internet and zooms and all that
and if that had broken down
that would have made things far worse
and those are the kinds of
threats that we I think need to be
more energized
and politicians need to be more energized
to minimize
and one of the things I've been doing in the last year
through being a member
part of our parliament
is sort of a
help to instigate a committee to think more
on better preparedness for
extreme technological risks
and things like that so they're a big concern
in my mind
that we've got to make sure
that we can benefit
from these
advances
but safely because
the stakes are getting higher
and the benefits are getting great as we know
these benefits from computers
but also huge downsides as well
and one of the things this war
in Ukraine has shown
one of the most
terrifying things
outside of the humanitarian crisis
is that at least for me
I realized
that the human capacity
to initiate nuclear war
is
greater than I thought
I thought the lessons of the past
have been learned
it seems that we hang on the brink
of nuclear war
with this conflict like every single day
we're just one
mistake
or bad actor
or
the actual leaders of
particular nations launching a nuclear strike
and all hell broke
brakes loose so then
add into that picture cyber attacks and so on
that can
lead to confusion and chaos
and then out of that confusion
calculations are made such that
a nuclear
launch is
a nuclear weapon is launched
and then you're talking about
I mean
I don't direct
probably 60-70%
of humans on earth are dead
instantly and then the rest
I mean
it's basically
99% of the human population
is wiped out in the period of 5 years
well it may not be that bad but
it will be a devastation for civilization of course
and of course it will be quite right
that this could happen very quickly
because of
information coming in
and there's hardly
enough time for human
collected and
careful thought and there have been
recorded cases of
false alarms
where there have been
suspected attacks
from the other side and
fortunately there have been
false alarms soon enough but this
could happen and there's a new
class of threats actually which in our
center in Cambridge people are thinking about
which is that
the commander
control system
of the nuclear
weapons and the submarine
fleet and all that is now
more automated and
could be subject to cyberattacks
and that's a new threat which didn't
exist 30 years ago
and so I think
indeed it's
we're in a sort of scary
world I think
and it's because
things happen faster
and human beings aren't in such
direct and immediate control because so much
delegated to machines
and also because the world is so
much more interconnected
then some
local event can cascade
globally in a way it never could
in the past and much faster
yeah it's a double-edged sword
because the inter-connectedness
brings
brings a higher quality of life
across a lot of metrics
yeah it can do but of course
there again I mean if you think of supply
chains where we get stuff from
around the world then one lesson
we've learned is that there's a trade-off between
resilience and
efficiency and it's resilient
to have
an inventory and stock
and to depend on local supplies
whereas it's more efficient to have
long supply chains
but the
risk there is that
a break in one link in one chain
can screw up car production
as it already happened in the pandemic
so there's a trade-off
and there are examples I mean for instance
the other thing we learned was that
it may be efficient to
have 95% of your hospital
intensive care beds occupied all the time
which has been the UK situation
whereas to do what the Germans do
and always keep 20% of them free
for an emergency is really
a sensible precaution and so
I think
you've probably learned a lot of lessons
from COVID-19 and they
would include
rebalancing the trade-off between
resilience and
efficiency.
Boy, the fact that COVID-19
a pandemic that could have been a lot
a lot worse
brought the world to its knees anyway
it could be far worse in terms of
its fatality rate
fatality rate, yeah
so the fact that that
we build so many flaws
in our human institutions
and I think
I'm rather pessimistic because
I do worry about
the
bad actor or the small group
who can produce catastrophe
and
if you imagine someone
with access to the kind of equipment
that's available in university labs or industrial labs
and they could create
some dangerous pathogen
then even one such person
is too many
and how can we stop that because
it's true that you can
have regulations I mean academies
are having meetings etc about
how to regulate these
new biological experiments
etc make them safe but even
if you have all these regulations
then enforcing regulations
is
pretty hopeless we can't enforce the tax laws
globally we can't enforce
the drug laws globally and so
similarly we can't readily
enforce the
laws against people doing these
dangerous experiments even if
all the governments say they should be prohibited
and so my line
on this is that
all nations are going to face
a big trade-off between three things we value
freedom
security
and privacy
and I think
different nations
will make that choice differently
the Chinese
would give up privacy
and have more
certainly more security if not more liberty
but I think
in our countries
I think we're going to have to give up more privacy
in the same way
that's a really interesting trade-off
but
there's also something about human nature here
where I personally believe
that all humans are capable of good
and evil
and there's some aspect to which we can fight
this
by encouraging
people
incentivizing people
towards the better angels of their nature
so
in order for a small group of people to create
to engineer deadly pathogens
you have to have people
that
for whatever trajectory
took them in life wanting to do that kind of thing
and if we can
aggressively
work on a world
that sort of sees
the beauty
in everybody and encourages
the flourishing of everybody
in terms of mental health, in terms of meaning
in terms of all those kinds of things
that's one way
to fight the development
of weapons that can lead to atrocities.
Yes and I completely agree with that
and to reduce the
reason why people feel embittered
but of course
we've got a long way to go to do that
because if you look at the present world
nearly everyone
in Africa
has reason to feel embittered
because
their economic development is lagging behind
most of the rest of the world
and the prospects of getting out of
the poverty trap
is rather bleak especially if the population
grows because for instance
they can't develop like the eastern tigers
by cheap manufacturing
because robots are taking that over
so that they will naturally feel
embittered
by the inequality
and of course what we need to have
is some sort of mega version
of the Marshall Plan that helped Europe
in the post-World War II era
to enable
Africa to develop. That will be
not just an altruistic thing for Europe
to do but in our interest
because otherwise
those in Africa
will feel massively disaffected
and indeed
it's a manifestation of the excessive inequalities
the fact that the 2,000
richest people in the world
have enough money to double the income of the bottom
billion
and that's
an indictment of the ethics of the world
and this is where
my friend Stephen Pinker and I
have had some contact. We have joined articles
on
bio threats and all that
but
he writes these books being very optimistic
about quoting figures about
how
life expectancy has gone up
infant mortality has gone down
literacy has gone up with all those things
and he's quite right about that
and so he says the world is getting better
do you disagree with your friends, Stephen Pinker?
Well, I mean
I agree with those facts
but I think he misses out
part of the picture because
there's a new class of threats
which
hang over us now
which didn't hang over us in the past
and I would also question
whether we have collectively
improved our ethics at all because
let's think back to the Middle Ages
it's true that as Pinker says
the person was
in a more miserable state than they are today
on average
for all the reasons he quantifies
that's fine
but in the Middle Ages
there wasn't very much
there could have been none to improve
people's
lot in life because of lack of knowledge
and lack of science etc
so the gap between the way the world was
which is pretty miserable
and the way the world could have been
much better was fairly narrow
whereas now
the gap between the way the world is
and the way the world could be
is far, far wider
and therefore I think we are ethically
more
at fault
in allowing this gap to get wider
than it was in medieval times
and so I would very much question
and dispute the idea that
we are ethically
in advance of our predecessors
a lot of interesting hypotheses
in there
it's a fascinating question
of how much
is the size of that gap
between the way the world is and the way the world could be
is a reflection of our ethics
or maybe sometimes it's just
a reflection of a very large number of people
maybe it's
a technical challenge too
it's not just about political systems
political systems
and we're trying to figure this thing out
like there's a 20th century
tried this thing that sounded
really good on paper
of collective communism type of things
and it's like
turned out at least the way it was done there
that leads to atrocities
and the suffering and the murder
of tens of millions of people
okay so that didn't work let's try democracy
and that seems to have a lot of flaws
but it seems to be the best thing we got so far
so we're trying to figure this out
as our technology has become more and more powerful
have the capacity
to do a lot of good to the world
but also unfortunately have the capacity
to destroy the entirety
of the human civilization
and I think it's social media generally
which
makes it harder to get
a sort of moderate consensus
because in the old days
when people got their news
filtered through responsible journalists
in this country the BBC
and they made newspapers etc
and they would muffle the crazy extremes
whereas now of course
they're on the internet
and if you click on them you get to the war extreme
and so I think we are
seeing a sort of
dangerous polarization which
I think is going to make all countries harder to govern
and that's something which I'm pessimistic about
so to push back
it is true that
brilliant people like you highlighting the limitations of social media
is making you realize
the
the stakes and the failings
of social media companies but at the same time
they're revealing the division
it's not like they're creating it they're revealing it
in part
and so that puts a lot of
that puts the responsibility
into the hands of social media
and the opportunity in the hands of social media
to alleviate some of that division
so it could
in the long arc of human history
result so bringing some of those
divisions
and the anger and the hatred
to the surface so that we can
talk about it and as opposed to
disproportionately promoting it
actually just surfacing it so we can get over it
well you're assuming that the
fat cats are more public spirited
than the politicians and I'm not sure about that
I think there's a lot of money
to be made in being
publicly spirited
I think there's a lot of money to be
made in increasing the amount of
love in the world despite the sort of
public perception
that all
the social media companies heads are interested
in doing is making money
I think
that may be true
but I just personally believe
people being happy
is a hell of a good business model
and so making
as many people happy
helping them flourish in a long
term way that's a lot of way to make
that's a good way to make money
and I think guilt and shame
are good motives to make you behave better
in the future
from maybe in the political
perspective
but it does make sense
now that we can destroy ourselves
with nuclear weapons
with engineered
pandemics and so on
that the aliens would show up
that
if I was
the
leadership position
maybe as a scientist
or otherwise in an alien civilization
and I would
come upon earth
I would try to watch from a distance
do not interfere
and I would start interfering
when these life forms
start becoming
have the capacity to be destructive
it is an interesting question
when people talk about UFO sightings
and all those kinds of things
that at least
benign yes
I mean they
benign almost curious
almost
partially as with all curiosity
partially selfish
to try to observe is there something
interesting about this particular evolutionary
system
because I'm sure even to aliens
earth is a curiosity
where it is very special
stage
this century
is very special among the 45
million centuries the earth experienced already
so it is a very special time
where they should be specially interested
but I think going back
to the politics
the other problem is
getting people
who have short term concerns
to care about the long term
by the long term I now mean just
30 years or so ahead
I know people who have been
scientific advisors to governments
and things and they may
make these points but of course they don't have
much traction because as we know very
well any politician has
an urgent agenda of very worrying
things to deal with and so
they aren't going to prioritize
these issues which
are longer
term and less immediate and don't
just concern their constituents if they concern
distant parts of the world
and so I think
what we have to do
is to
enlist
charismatic individuals
to convert the public
because if the politician
know the public care about something
climate change
as an example
then they will
make decisions which
take cognizance of that
and I think for that to happen
then we do need
some public
individuals who are respected
by everyone
and to have a high profile and in the
climate context
I would say that I mentioned
four very disparate people
who have had such a big effect in the last few years
one is Pope Francis
the other is David Attenborough
the other is Bill Gates and the other is
Greater Thornburg and those four people
have certainly had a big shift
in public opinion
and
even changed the rhetoric of business
although how deep that is I don't know
and so
but politicians
can't let these issues
drop down off the agenda
if there's a public
clamor and it needs people like that
to keep the public clamor going
to push back a little bit so those four
are very interesting and I have deep respect
for them
they have, except David Attenborough
David Attenborough is a really
everybody loves him
but Bill Gates
and Greta
they also create a lot of division
and this is a big problem
so it's not just charismatic
I put that responsibility
actually on the scientific community
and the politicians
so we need
the
charismatic leaders
and they're rare
when you look at human history
those are the ones that make a difference
those are the ones that
not the ride
they inspire
the populace
to think long term
the JFK
we'll go to the moon in this decade
not because it's easy but because it is hard
there's no
discussion about
short term
political gains
or any of that kind of stuff
in the vision of going to the moon
or going to Mars
or taking on gigantic
projects
or taking on world hunger or climate change
or the education system
all those things that require
long term significant investment
that requires
it's hard to find those people
and incidentally I think another problem
which is
down side of social media
is that of younger people
I know
the number who would contemplate a political career
has gone down
because of the pressures
on them and their family
from social media
it's a hell of a job now
and so I think we are all losers
because the quality of people
who choose that path
is
really
dropping and as we see
by the quality of those who are in these
compositions. That said I think
the silver lining there
is the quality of the competition
actually is inspiring
because it shows
to you that there's a dire need
of leaders
which I think would be inspiring to young people
to step into the fold.
I mean great leaders are not afraid
of a little bit of
background social media
so if you have a 20 year old kid now
25 year old kid
is seeing how the world
responded to the pandemic
seeing the geopolitical division over the war in Ukraine
seeing the brewing war
between the West and China
we need great leaders
and there's a hunger for them
and the time will come
when they step up
I believe that
but also to add to your list of four
of credit I've been defending him in this conversation
Elon Musk
in terms of the fight and climate change
but he also has led
to a lot of division but
we need more David Edinburgh
I mean I'm a fan
definitely
I've heard him described as a 21st century
Brunel for his innovation
and that's true but
whether he's
an ethical inspiration I don't know
yeah he has a lot
of fun on Twitter well let me ask you
to put on your
wise sage hat
what advice would you give
to young people today
maybe their teenagers
in high school maybe early college
what advice would you give
to a career
or have a life they can be proud of
yes well I'd be very different
really about offering
any wisdom but
I think
they should
realise that
the choices they make
at that time are
important and
from the experience
I've had with many friends
many people don't realise that opportunities
are open until it's too late
they somehow think
that some opportunities are only open to a few privileged people
and they don't even try
and that they could
succeed but
if I focus on people
working in
some profession I know about
like science I would say
pick an area
to work in where new things
are happening
where you can
do something that the old guys never had
a chance to think about
don't go into a field that's fairly stagnant
because then
there's not much to do
or you'll be trying to tackle the problems
that the old guys got stuck on
and so I think in science
I can give people good advice
that they should
pick a subject where there are exciting
new developments
and also of course something which
suits their style because
even with in science which is just one profession
there's a big range of style
between the sort of solitary thinker
the person who does field work
whether you like computing
or mathematical thought etc
so pick some
subject that suits your style
and where things are happening fast
and be prepared to be flexible
that's what I'd say really
keep your eyes open for the opportunity
throughout like you said
go to a new field
go to a field where new cool stuff is happening
just keep your eyes open
yes that's platitudinous but I think
most of us
don't think it's too late
yeah I think
this applies way beyond science
what do you make of this fight knightness
of our life do you think
about death do you think about mortality
do you think about your mortality
and are you afraid of death
well I mean I'm not afraid
because I think I'm lucky
I feel lucky to have lasted as long as I have
and to have been
fairly lucky
in my life in many respects
compared to most people
so I feel very fortunate
this reminds me of this
current
emphasis on
living much longer
the so-called altos laboratories
which have been set up by
billionaires
there's one in San Francisco
one in
La Jolla I think
and one in Cambridge
they're funded by
these guys who when young
wanted to be rich and now they're rich
they want to be young again
they won't find that quite so easy
and do we want this I don't know
if there was some
elite that was able to live much longer than others
that would be a really fundamental kind
of inequality
and I think
if it happened to everyone
then that might be an improvement
it's not so obvious
but
I think
for my part
I think to have lived as long as most people
and had a fortunate life
is all I can
expect and a lot to be grateful for
those old past issues
I am incredibly
honored that you sit down with me today
I thank you so much for life
of exploring some of the deepest
mysteries of our universe
and of our humanity
and thinking about our future with existential
risks that are before us
it's a huge honor
Martin you sit with me and I really enjoyed it
well thank you Lex
I thought we couldn't go on for as long as this
but we could have gone on much longer I think
exactly thank you so much
thank you for listening
to this conversation with Martin Rees
to support this podcast please check out our sponsors
in the description
and now let me leave you with some words from Martin Rees
himself
I'd like to widen people's awareness
of the tremendous time span lying ahead
for our planet
and for life itself
most educated people are aware
there were the outcome of nearly 4 billion
years of Darwinian selection
but many tend to think
that humans are somehow the culmination
our son
however
is less than half way through his lifespan
it will not be humans who watch
the sun's demise
6 billion years from now
any creatures that then exist
will be as different from us
as we are from bacteria
or amoeba
thank you for listening
I hope to see you next time