For theoretical physicist and best-selling author Paul Davies, it’s not a matter of proving or disproving the existence of extraterrestrial life, but rather asking how life happened in the first place. Did asteroid impacts propel rocks — and their cellular hitchhikers — between our planet and Mars, creating a vehicle for life’s earliest microbes? Did a chemical concoction billions of years ago curate life? Did something else altogether maroon cellular tidbits on the green planet?
These are the type of questions Davies explores in his research, but he’s also driven by larger, more fundamental mysteries in science. Davies works as director at the BEYOND Center for Fundamental Concepts in Science at Arizona State University, where he and other researchers approach these “big questions” and their philosophical implications across disciplines. Davies recently visited WID to give a public lecture for the Center for Complexity and Collective Computation (C4), a research center in the institute. He sat down with us to talk about how clashes of opinion and ideas also matter in the grander scheme of things.
You say the scientific community’s opinion on the possibility of life existing elsewhere in the universe has been swinging back and forth on a pendulum over the last 60 years. Where do you see yourself in comparison to your colleagues?
Davies: I’ve always been between disciplines, but also, I’m a contrarian. So if the herd is going this way, I’m going to say, ‘Hold on a minute, I’m going the other way.’ When I was a student in London in the 60s, the idea of searching for life beyond Earth wasn’t embraced — you might as well have said you were searching for fairies. People just thought this was completely crackpot. And at the time, SETI, the Search for Extra-Terrestrial Intelligence, was regarded as doubly nonsensical — people just made fun of our program. It’s very curious to me, because individuals I knew were derisory are now on the other side. So it’s not just a new generation of scientists who are more credulous or more open-minded or something, it’s that people really have changed their minds. And you might think, ‘Well, they’ve changed their minds because of some major scientific discoveries have taken place.’ But they haven’t. People will tell you that we now know there are all sorts of exoplanets –- well it’s true we didn’t know that in the 60s, but all astronomers assumed they were there. They just confirmed what was already believed, so that doesn’t count…
I went to a conference in London in 1996 on life on Mars, and I presented this theory — that life could have gotten to Earth from Mars or vice versa [via rocks from asteroid impacts]. One or two people there said, ‘Well yeah, it’s sort of obvious,’ but most participants said it was laughable… Well six months later, it all changed. And it all changed because of Bill Clinton. Bill stood on the White House lawn and announced to the world press that NASA had evidence of life on Mars in the form of a meteorite found in Antarctica. That evidence has slowly faded away (though not totally), but suddenly people were talking about: ‘Oh, well if rocks can come here from Mars with fossil microbes, maybe they can come with live microbes.’ And so suddenly, this whole idea became not only acceptable, but it became the party line. NASA has a planetary protection officer, and there is a strategy about sample returns, including whether microbes on rocks could bring back a killer plague and wipe us all out.
What do you think about life existing in the universe beyond Earth?
My feeling is that until we have positive evidence that there is life elsewhere in the universe that the default assumption is that there isn’t any. But I’m open-minded; I think one has to be an open-minded skeptic. I’m a strong supporter of SETI because my feeling about doing speculative science is that if it doesn’t cost much, you might as well do it anyway, Even if you don’t find the thing you’re looking for, you might find something else. I’ve tried to encourage people to broaden the search for extraterrestrial intelligence by looking not just for radio messages but any signature of intelligence, or any signature of technology, anywhere in the universe, near or far. You can look at the databases that are already there! I can give you one idea. It’s really crazy, and I’m not suggesting that it is likely, but we can do it. Instead of looking for messages in radio waves coming from space, why don’t we look for messages in genomes, because we’re sequencing genomes anyway? This would be ‘genomic’ SETI — maybe ET has put a message in the genomes of terrestrial organisms. So how could that be done? It seems like a difficult thing to do. Well, Craig Venter put his email address in a terrestrial organism, so if he could do it, maybe ET could too.
“When you look at the really major advancements in science, it’s usually that one set of ideas doesn’t marry up with another set of ideas, and that clash creates conflict. Not just technical conflict, but conceptual conflict. That’s where you get progress.”
How did you originally become interested in the origins of life, and how has that broadened your focus as a scientist?
I’ve always been interested in these deeper questions, what I call the fundamental questions in science. They seem to transcend traditional subject boundaries. But my particular interest is in what we now call astrobiology. Apart from reading popular articles about SETI when I was a teenager, I read Schrodinger’s book What is Life? as a student. And I thought, ‘life is weird.’ To a physicist it looks like a miracle. I asked myself, ‘What’s going on? How do these stupid atoms get together and do such clever things?’ So that was what originally possessed me. There was another influence, which was a little bit peripheral to astrobiology, but it got me thinking. When I was a student, my Ph.D. supervisor gave me a copy of a paper by Brandon Carter, which was the foundational paper of what is today called the anthropic principle. Carter had noted that if the laws of physics had been a bit different, there probably would have been no life in the universe. I thought that was a really intriguing set of ideas, and I in fact wrote a book about it in the 70s, well ahead of the herd, called The Accidental Universe. So, for me, the question of “What is life?” is important, but so also is the question, “Why is there life?” Why is it that the universe permits something of this nature? Not any old universe will do so.
Why is there a need for transdisciplinary centers like BEYOND and research institutes like WID?
They are really important in areas of crossover between physics, chemistry and biology and computing. We need a whole new way of thinking about such fields, particularly in biology, which is wide open to new conceptual frameworks. Most universities pay lip service to transdisciplinary research. Very few of them actually implement it. Arizona State University has made such a big impact in the last 10 years in part because the president, Michael Crow, really believes in transdisciplinarity. He does not just believe it is a good idea; he’s making it happen. Of course, some people don’t like it; they feel a little uncomfortable. However, it’s no longer necessary for people to say, ‘Well I’m really a physicist, so I belong in the physics department.’ There are new research programs opening up and new approaches, sometimes because of new technology, but sometimes because of deep new idea. Although I am a physicist by profession and temperament, I actually don’t care much about disciplines. I just care about problems, puzzles, mysteries. That’s me.
If there’s one thing you could leave behind at WID — kind of like violating the Prime Directive — what would it be?
I often quote John Wheeler. There’s an overarching theme he liked to cite that says progress in science is more often made by the clash of ideas than by the steady accumulation of facts. When you look at the really major advancements in science, it’s usually that one set of ideas doesn’t marry up with another set of ideas, and that clash creates conflict. Not just technical conflict, but conceptual conflict. That’s where you get progress. So we should go look for those clashes!
Interview conducted and edited by Marianne English