The following is a conversation with Lord Professor Martin Rees, a leading cosmologist and
astrophysicist. He has conducted influential work on galaxy formation, cosmic jets, black holes,
gamma ray bursts, and speculative aspects of cosmology. Prof. Rees is the Astronomer Royal
and a Past President of the Royal Society. He is a prominent scientific spokesperson
and author of popular science books. In 2012 he co-founded the Centre for the Study of
Existential Risk, which is a research Centre at the University of Cambridge
intended to study possible extinction-level threats posed by present and future technology.
In this podcast we cover some of the aspects illustrated by professor Rees in his latest book
“On the Future”, where he talks about existential risks including nuclear warfare, climate change,
biotech, and artificial intelligence. Due to these challenges, he believes we will face
a growing tension between three things we want to preserve: privacy, security, and freedom.
I know that this is a polarizing topic and
please consider that this is not a debate but an opportunity to hear what one of the most prominent
scientists and policymakers has to say about global threats, including the current situation.
So whether you agree or disagree, please leave a comment below.
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And now, here is my conversation with Prof. Martin Rees.
Samuele Lilliu (SL). Good morning Professor Martin Rees. Martin Rees (MR). Good morning.
SL. I’d like to start our discussion with…
maybe if we could discuss a bit about… what was your major scientific contribution? And
if you had to pick up a paper, among your 500+ publications, which one would you choose?
Martin Rees (MR). Well, I find it difficult. I like to say really, that my
contribution has been to be involved in various debates over the last 40 or more years,
which have clarified how our universe began, and also clarified the nature of some of the
extreme objects in it. It obviously involved neutron stars, black holes, cosmic explosions,
etc. So I’ve written a lot on all those themes. SL. I was checking some projects online and
I found the IllustrisTNG project, which is a fascinating attempt to simulate galaxy formation
and evolution. These simulations basically start from collections of particles and the
laws of physics such as gravitational interactions and magneto hydro-dynamical interactions. So my
question is - I don’t know if this makes sense - but what would it take to simulate the emergence
of the laws of physics from the Big Bang? MR. Well, we don’t understand how the basic laws
originates, but we know that the expanding universe is governed by those laws.
We can trace the Big Bang, and its history right back to when the universe had been expanding for
about a nanosecond. Before a nanosecond it’s hard because the energy of a particle is higher
than the energy we can achieve in the Large Hadron Collider,
the biggest accelerator. So the physics is not well understood, for the first nanosecond.
But from that time onwards, we can understand how has the universe expanded and cooled,
the different processes that took place, we can understand how helium and deuterium were formed
when the universe was a few minutes old. We can understand how the radiation,
the thermal radiation, was produced in the early universe and it cooled down.
These obey the laws of physics that we understand.
It’s been quite easy to understand how a homogeneous universe, this uniform gas,
would behave. But, of course, what we want to do is to understand how structures emerge. We know
that the early universe wasn’t completely smooth, there were some places slightly denser than
average, some less dense than average. As the universe expanded, then the over dense regions,
lag behind their expansion and eventually condensed out.
This is how we believe galaxies formed. What was one of the great triumphs of
science in the last 25 years has been to observe the fluctuations in the universe
at an early epoch. This is done by looking at the background radiation over the sky and seeing these
non-uniformities and to put that in as initial conditions in a computer program and work forward.
The good news is that working forward you end up with a Universal rather like the one we live in.
This is done by putting into the calculation gravity and gas dynamics,
and maybe some other things. This has been great progress in the last 20
years because it needs good computer power. Until 20 years ago, it was not possible. Of course, more
generally, astronomy has benefited hugely from computer simulations, because if you’re a particle
physicist you can actually crash particles together and see how they behave. Whereas
we can’t actually crash real galaxies together, but we can, in the virtual world of our computer,
see what happens if two galaxies collide, where stars exploded, etc. That’s how we have been able
to see if our models do represent the real world. We now have a picture for how galaxies evolve,
which comes from simulations, but which is tested. In fact, we can tell it very
well because we look at galaxies now, but we have an advantage over paleontologists,
in that we can actually see the past. We can compare our simulations with the universe now,
the universe of billion years ago, 2 billion years ago, three million years ago, etc., by looking at
more and more distant galaxies, where the light set out earlier. So we have quite good evidence
that we understand the broad outlines of how cosmic structures evolved from amorphous the Big
Bang, which started out very hot and dense, with small fluctuations in it. But of course,
all progress in science leads to new questions, new mysteries, and what we’d like to know
is the crucial process that has happened right in the very first nanosecond, when the physics
is uncertain, because it’s those processes, which determine how the universe expands,
and the fact that it contains atoms, dark matter and radiation. And that’s still a challenge.
SL. In your books, you spoke about having a sort of “cosmic perspective”
towards the problems of the world. You became interested in topics related to
existential threats. You discuss these things in your book “On the Future”
and I’ve also read your other book “Our Final Hour”, where you talk about these issues. When
did you become interested in these topics? MR. Well, of course, that’s quite separate.
There’s a huge gulf between the cosmic scale and terrestrial scale, but I’ve always been
interested in politics since going back to student demonstrations for disarmament,
anti-Vietnam War and things like that, when I was a student. Later in my career, I got involved more
in disarmament through things like the Pugwash conferences, which are links between scientists
in the East and the West during the Cold War. So I got involved in that. But later in life, I had
more opportunity and more obligation, in fact, to engage in policy and politics because I spent five
years as president of our Royal Society, which is the UK National Academy of Sciences and that
of course covers all sciences and their policy implications. So during that period, and since
then, I’ve spent a fraction of my time on things which are not astronomy, but more general policy
related to what’s happening here on Earth now. SL. You’re also the Astronomer Royal. What’s
the role of the Astronomer Royal? MR. It’s just an old title. It used
to be the person who ran the observatory, the National observatory at Greenwich, near London.
But that became a museum when became possible to build telescopes on higher and drier locations,
Hawaii and Canary Islands, etc. But they kept the title but it’s just an honorary title.
SL. And you’re also the co-founder of the Center for the Study of Existential Risks here in
Cambridge. What’s the purpose of this centre? MR. Well, this is something which I become more
committed to over the years. In my early book, “Our Final Hour”, which you mentioned, I drew
attention to the fact that we were, in the world, becoming vulnerable to new classes of threats that
weren’t important in the past. In my new book “On the Future”, I explain this in more detail.
The main points that I make in these books, is that this century is special. The Earth’s been
around for 45 million centuries. But this is the first when one species, the human species,
has been numerous enough and empowered enough to actually determine the fate of the planet.
We can affect the Earth’s climate, the flora and fauna on it, and of course, we are interconnected
through air, travel, internet and all that. So for the first time, we run a risk of
catastrophes, which could cascade globally. This is something which is new. These are less
studied than more local conventional risks. I wrote quite a bit about that.
Our Center in Cambridge has a focus on these extreme high-consequence low-probability threats,
which are becoming more important and looming larger. Of course, the COVID-19 pandemic that
we are having this year has, of course, made people take these seriously because that in itself
shows how some unexpected threat can have global consequences. We clearly are learning that we need
to prepare more to cope with catastrophes of that kind and to minimize the chances they occur.
Pandemics are just one category. There are other things like a breakdown in the electric power grid
in a large region, either accidentally or [from] a cyber-attack, and other global catastrophes,
which could come about. So what our centre is doing, is collecting a group of people who will
focus on these and draw on the sort of convening power of the great universities like Cambridge to
bring more expertise to bear on these questions. SL. In terms of politics, does it cover the
full spectrum of politics? Is it a bipartisan organization?
MR. It’s not party politics, but it does include social scientists and economists of course,
that’s very important. But of course, we are experts who advise politicians
and, of course, we do engage with politicians, and participate in parliamentary affairs
and try and raise the profile of these issues on the agenda, compared to the way they were. So this
something which we think is important because politicians obviously have a crowded agenda,
they tend to focus on the immediate and the local, what happens before the next election.
The COVID-19 pandemic is a wakeup call, because this is a crisis, which they never prepared for
properly and it indicates what can happen. What we need to do is to make sure that governments do
prioritize these. There’s an important maxim, which I like to quote, is “the unfamiliar is not
the same as the improbable”. Because these things never happened before, that doesn’t mean that it
won’t happen. A pandemic, in retrospect, wasn’t all that improbable and there have been others
a bit like it in the last 20 years. So we need to prepare more for these things.
Of course, there are the class of threats, which are caused collectively by our heavy footprints
on the planet. This is because of climate change. We know that is going to have severe consequences.
But the political problem of dealing with that, prioritizing that, is that the main effects
are going to be a few decades in the future, they are not immediate. It’s not like the COVID-19,
which has immediate effects. So we’re rather like the, the frog in the pot of water that’s being
heated, which doesn’t realize that it’s going to boil until it’s too late to save itself. We’ve
got to think further ahead to do this. Of course the problem with politicians is that they tend to
focus on the more immediate concerns and also on the concerns for their constituents. Of course,
climate change is going to have a bigger effect in parts of Africa that does here. So
to get politicians to prioritize what happens in Africa 30 years from now, is hard. The only way
this can be done is if the public cares, and so they respond to public pressures.
That’s why raising the agenda on these long term issues among the wider public is very important.
SL. Do you guys also collaborate with SAGE, which is the Scientific
Advisory Group for Emergencies here in the UK? MR. Not directly, there’s some overlap, obviously,
and there is a parliamentary committee at the moment, which is going to discuss
better ways in which this country can prepare itself for these different kinds of threats.
So, we have, obviously, in a University, in all of science trying to be useful when you can,
and, clearly, these extreme threats are now being taken more seriously.
SL. So when we talk about the threats from space, I mean, we have threats from comets, asteroids,
solar flares, I mean, for those things, there isn’t much we can do at the moment,
maybe in the future, we could think about changing the path of meteor or a comet or
whatever. So I guess the only option now is building underground bunkers, or Faraday cages,
have you built one under your home? MR. No, but because
asteroid impacts don’t keep me awake at night. The reason for that is that we understand their
probability, we understand, I mean, asteroids, etc. And we know its possibility with a low
probability. We know that that probability is no higher now than it was 10,000 years ago or
10 million years ago. It’s so small and indeed, as you say, we might be able to do something
to protect against some within the next century, so it’s important to try and map out the
orbits of all asteroids that come here. But is not top priority.
What is more worrying, are the classes of threats, which are getting more probable year by year,
like a pandemic, cyber-attacks, and things like that. I’d worry far more about those
and about engineered pandemics, things of that kind. They’re the big worry.
Solar flares are in a slightly different category because they’re natural phenomena, but they had no
effect on life on Earth until 150 years ago when we had electricity. But they do, of course, now
have a potentially serious effects. So they are something which we want to predict a bit better
by observing the sun carefully and also, of course, to mitigate the effects of by the way
we construct the electricity grid, and also the way we harden the electronics of spacecraft.
SL. And also we have plans in place in case something happens, which is
taking all the government or Her Majesty the Queen to the bunkers. They have similar programs
in the US, where they have this emergency plans, which were from the Cold War, I guess,
when there was a threat of nuclear war. MR. Yes, well, certainly there have been
those threats. The key question is to decide what is the appropriate response
to any kind of catastrophe. Of course, we know the problems of hospitals being overwhelmed
by a severe pandemic, we know that if electricity failed for a few days over a large area
that would lead to complete social breakdown. The lights going out is the least of our problems,
all the electronics and everything would fail. So we need to absolutely minimize the likelihood of
those things happening and also have emergency plans in operation to deal with them.
Thank you for listening to this conversation with Prof. Martin Rees.
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