Purple Magazine
— The Cosmos Issue #32 F/W 2019

martin rees

astrophysics MARTIN REES

science is the one truly global culture. the planet needs more socially engaged scientists to raise public awareness about the looming ecological disaster. it’s time to force politicians to act

interview by HANS ULRICH OBRIST
portrait by OLA RINDAL

HANS ULRICH OBRIST — I was wondering if there was an epiphany, or a sudden revelation, that led you to cosmology and astrophysics. How did it all start?
MARTIN REES — No, I didn’t have any epiphany at all. I came rather gradually to astronomy. When I was at school, I specialized in science, more because I was bad at languages than for any other reason. I turned out to be good at mathematics, so it seemed natural to study that subject at university. But I quickly realized I was not cut out to be a mathematician and preferred a more “synoptic” subject, where I could apply my mathematical skills to some complex phenomena. I thought of becoming an economist, but for various reasons ended up doing astrophysics. This was in the 1960s — a particularly good time for a beginner because the subject was opening up with the first discovery of black holes, the first evidence of the Big Bang, etc.

HANS ULRICH OBRIST — What was your first breakthrough in terms of discoveries?
MARTIN REES — I did some early work on some puzzling phenomena related to quasars [an extremely active galactic nucleus]. When new objects are discovered, they often display some mysterious aspects that pose a puzzle, giving young scientists the chance to immediately make an impact.

HANS ULRICH OBRIST — The last couple of years have seen a growing interest from artists in your books, such as Our Final Century and From Here to Infinity, where you address the fragility of our current condition. As early as the ’60s, there was an awareness about the looming ecological disaster, but when did this enter
your work?
MARTIN REES — I think I first became concerned with the fragility of our global situation through concern about nuclear weapons during the latter part of the Cold War — especially in the 1980s. I involved myself in the Pugwash Conferences [on Science and World Affairs] and other activities of that kind. This led, later on, to a concern about how the advance in technology is generating new threats to the planet. These threats are of two kinds: firstly, our collective actions are depleting resources, disrupting ecosystems, and affecting the climate; then, there are novel risks stemming from the misuse (by error or terror) of ever more powerful technology by a few individuals. Ten years ago, I wrote Our Final Century, which was really an attempt to highlight the risks that may confront us later in this century. This is a theme I’ve continued to engage with in the subsequent years. I’m sometimes asked whether my being an astronomer brings anything special to this subject. I think there’s indeed one special perspective, which is an awareness of the huge future lying ahead. Most people who are familiar with Darwinism know that we are the outcome of about four billion years of evolution on Earth, starting from simple organisms and evolving toward our present biosphere and, of course, human beings. However, most people, I think, see us humans as the culmination of evolution. No astronomer could think that way. That’s because we’ve learned that the sun has five or six billion years to go before it flares up and dies: it’s less than halfway through its life! So, we should think of humans as just some intermediate stage in evolution. Much more wonderful creatures will emerge in the future here on Earth and far beyond. Indeed, that claim is strengthened because future evolution may be much faster — intelligently directed rather than natural selection, and perhaps eventually silicon-based rather
than organic. The reason we should be so concerned about what happens this century is that if we snuff out human life, it’s not just us and our immediate descendants who would be destroyed, but we would also destroy the potential for post-human life, which could extend for billions of years.

HANS ULRICH OBRIST — Do you believe in the possibility of life on other planets?
MARTIN REES — Of course, if humans can eventually escape from the Earth and produce self-sustaining colonies, our species would thereafter be less vulnerable to the kinds of disasters that could affect most of the Earth. I think that within a few centuries, there will be small communities living away from the Earth. They will be empowered by huge computer intelligence and an understanding of genetics, and they will use the knowledge of those fields to modify their progeny to adapt to that alien environment. At that stage, the post-human era will begin because they will adapt to a different environment to the extent that they would, within only a few centuries, become a different species.

HANS ULRICH OBRIST — What do you think about Elizabeth Kolbert’s concept, the “sixth extinction”? She says that over the past half-billion years, there have been five mass extinctions on Earth, when the diversity of life suddenly contracted. For her, what could happen now is actually the sixth and possibly most devastating.
MARTIN REES — As I said earlier, one class of threat for this century stems from the pressures we, as humans, are collectively imposing on the planet. There are more of us, and each of us is more demanding in terms of energy and resources — already about 40% of the biomass of the Earth is being used directly or indirectly by humans. Humans are very much the dominant species in the biosphere, and we are changing the biosphere, causing extinctions. Climate change could happen too fast for species to adjust, and that will be an aggravating factor.

HANS ULRICH OBRIST — Would you agree with Elizabeth Kolbert that the threat of the sixth extinction could lead to the biggest extinction since the dinosaurs?
MARTIN REES — How big it is will depend on how humanity controls its development in the coming century. Obviously, if global warming became very acute, or if we destroyed entire ecosystems, then this may indeed be serious, so certainly this could happen. I wouldn’t want to comment on how likely it is, nor be too alarmist, because the outcome depends on many uncertainties: how humanity’s technology will develop, how the population will evolve after mid-century, and many other imponderables. Of course, one doomsday scenario is runaway ecological catastrophe, which would lead to mass extinctions — but which scenario actually turns into reality will depend on choices that we and the next one or two generations make.

HANS ULRICH OBRIST — As an astronomer, what is your relationship to science fiction?
MARTIN REES — I certainly encourage people to read science fiction. Indeed, I tell my students it’s better to read first-rate science fiction than second-rate science. Imagination can be nourished by the best science fiction. I hugely admire the classics like H.G. Wells. But a special favorite is Olaf Stapledon, who wrote two classic books in the 1930s: one called Star Maker, which was a pioneer’s speculation about how universes might be created, and another, Last and First Men, which was one of the first books to actually explore the very, very distant future. As regards more recent science fiction, I’m not an avid reader of it, but I would strongly recommend a wonderful book called Evolving the Alien by Jack Cohen and Ian Stewart, where they in fact condense the plots of a lot of science fiction books.

HANS ULRICH OBRIST — What’s your dream for the 21st century in science?
MARTIN REES — The first is to unify the physics of the very small, the quantum world, with the physics of the very large — the domain where Einstein’s theory of gravity holds sway. Normally we get on very well without this unification because if you’re a chemist, you have to apply quantum theory, but you don’t need to worry about the gravitational force between two atoms in a molecule because it’s very small. On the other hand, if you’re an astronomer, you need to consider gravity, but you don’t need to worry about the quantum fuzziness in the orbits of stars and planets because that effect is tiny since the masses are so large. But to really understand the beginning of the universe, a time when the entire universe was squeezed to microscopic size, clearly we need a theory that can relate gravity to quantum effects, a so-called unified theory. Until we have such a theory, we won’t really be able to understand why the universe is expanding the way it is and why it’s got the properties and “mix” of ingredients that it has. Even if we some day discover this unified theory, it won’t be of any direct help to 99% of scientists because they’re engaged with studying very complicated things: things that are neither very small nor very large, but which have layer upon layer of structure — in particular, living organisms. Of course, we humans are the most complicated things we know about in the universe, and it’s an unending challenge to understand that complexity. So, it really is the biologists who face the toughest challenge — not particle physicists, not astronomers. A familiar analogy I’d like to give is with a game of chess. Suppose you’d never seen a game of chess being played before. By watching people play, you could figure out what the rules are — that the knight moves in a jagged way, bishops move diagonally, and so on. But learning how the pieces move in chess is just a trivial preliminary to the absorbing progression from being a novice to being a grand master. Learning the basic laws of physics is like knowing the rules by which matter and forces interact. But even when you understand those rules fully, even when we have a unified theory, that’s still just the beginning of understanding how those rules play out in the complex world of living things and the environment that we humans inhabit. So, the biggest challenge of all is to understand complexity.

HANS ULRICH OBRIST — In your book From Here to Infinity, you talk about the scientific citizen and about the necessity of collaboration between lay people and scientists. At the moment, we’re working on a solar airplane project with the artists Tino Sehgal and Olafur Eliasson using Danish solar technology by Frederik Ottesen, and this one problem needs a combination of aerodynamics, design, solar technology, inventors, and artists. I suppose for all big questions of the 21st century, it needs a bringing together or a pooling of disciplines, a pooling of knowledge.
MARTIN REES — To address many of the challenges, both intellectual and practical, we need to combine the expertise of different branches of science. One of the occupational risks of scientists is that they become so sharply focused on one particular topic that they don’t realize it’s part of some bigger picture. Something that’s extremely encouraging is a consequence of the computer revolution. It has done two things. First, it’s allowed us to do simulations, virtual experiments in the virtual world of a computer, which can supplement real experiments. Aeronautical engineers can now compute the flow of air over an airfoil without necessarily having to do an actual experiment in a wind tunnel. Astronomers, of course, can’t do experiments on stars and galaxies in the real universe, and therefore benefit hugely from doing “experiments” in the virtual world of computer simulations. Another by-product of the information technology age is the Internet, which has allowed far more people to participate in science. Before the Internet, there were a few sciences, like botany, where amateurs could make a contribution. But now anyone with a computer and access to the Internet can download huge data sets in astronomy, in environmental science, or in microbiology; they can analyze the data and look for patterns themselves. This mass effort by amateurs will surely speed up the development of science, and that’s necessary because the rate at which the information is being gathered is getting so intense that the few professionals can’t handle it all.

HANS ULRICH OBRIST — You conclude your book From Here to Infinity by saying, “In today’s runaway world, we can’t aspire to leave a monument lasting a thousand years, but it would surely be shameful if we persisted in policies that denied future generations a fair inheritance.” You were president of the Royal Society [the United Kingdom’s national science academy] until a few years ago — what do you think is that institution’s role in providing future generations “a fair inheritance”?
MARTIN REES — I think science is clearly going to be an important part of the solution to most social problems. To address most of this century’s challenges, we need to think internationally and also to think long-term. But that is a problem for most politicians, for whom the urgent always trumps the long-term, and the parochial always trumps the global. Politicians want to please their own electors — especially before the next election. This is a structural problem with all attempts to address the most serious problems — providing food and energy for the world and controlling technology. I think scientists make a special contribution because science and technology are crucial to meeting these challenges, and they’re more far-sighted than the average person regarding the implications of their work. Their crystal ball is still, however, very cloudy! Also, science is the one truly global culture. As I say in my book, protons and proteins are the same all over the world, and everyone looks up at the same sky wherever they are in the world — it’s universal. Scientists have a tradition of transcending political barriers — even in the depths of the Cold War, there was strong and often benign contact between the physicists in the Soviet Union and in the West — so scientists are a special international community, and this perhaps gives them a special opportunity to do what they can to address these problems. It’s crucially important that we’re prepared to think longer-term because issues like transforming to a low-carbon economy and feeding nine billion people sustainably will depend on science. But it will take more than 50 years to achieve these goals. We need to care about the long-term future. We’ve got to avoid any discrimination on the grounds of age: we should surely value the welfare of someone born today just as much as the welfare of someone who’s 50. It’s sad that even though we have much broader horizons in both space and time than our ancestors did, and we don’t have such immediate hazards to face, we’re reluctant to plan very far ahead. There’s, somewhat ironically, only one context where people think a long way ahead, and that’s in deciding how to dispose safely of radioactive waste, when they talk seriously about whether it will be in a repository that is safe for 10,000 years. But they won’t think seriously about how we are going to keep the lights on 50 years from now or whether we will avoid causing dangerous climate change. Scientists can perhaps be more active in campaigning to ensure that these long-term global issues don’t fall too low on the agenda. However, scientists have to be modest. They’ve got to realize that all these political questions have a scientific dimension, but they are not just scientific. They have to discuss these questions in terms of economics, ethics, and politics, and in those arenas scientists have no special expertise. So, what we need are socially engaged scientists who are prepared to raise public consciousness of long-term issues and who are prepared to engage with the public and the politicians. We all want to ensure that we navigate the century safely — but it’s going to be a bumpy ride because of the unpredictability of new technology.

END