In a nice piece on his Scientific American blog 'Cross-Check', John Horgan recently gave me some much appreciated praise, whilst provoking discussion on a contentious subject - whether or not big science as we've known it 'may be coming to an end' (John's words).
Wrapped into this assertion is the idea that fundamental physics and cosmology have done what they can and are, in some ways, increasingly data-poor and incapable of producing further revolutions (ouch). Also that a subject like the search for life in the universe is rife with probabilistic, philosophical speculation. So are we hitting a time of diminishing returns in science?
John refers to his book The End of Science, where he also describes what he sees as a split between 'inevitabilists' and 'anti-inevitabilists'. Either the universe and its detailed contents - including life - are the highly probable outcome of immutable laws, or there is a heck of a lot of randomness and chaos in the mix that just makes us improbable flukes. With just one reality to hand, and one set of known life, this could remain a stalemate.
Do I agree with all of this? Yes and no, but mostly no.
For example, despite my exhortations that we're on the cusp of learning how much life is out there in the cosmos, it remains the case that at present we just don't know. It might also be a while before data on exoplanetary biosignatures - or even technosignatures - is good enough to convince every single scientist. Even when that data is definitive, myriad new questions will emerge. In that sense there may not be a single magic reveal for this question, no equivalent of an elegant piece of mathematical physics that suddenly clears the air - the cusp of knowing is an astonishing turning point, but not a full conclusion. Although a positive detection from SETI might do it.
Another example is that there is no answer at this time for the question of life's origins - no single, simple, compelling and complete theory to explain how atoms and molecules assemble across millions or billions of years to make us. We certainly have some very big pieces of the answer - we see natural selection at work (in places like the Galapagos we see it in real time, year-to-year, with Darwin's finches), we know the molecular form of life's information storage on Earth, we examine the ocean of microbes, viruses, and prions that make our biosphere. We even have multiple ideas and experiments testing the transitions from 'simple' chemistry to the beginnings of bio-chemistry; from amino acid soups to inorganic templates and suggestive ion-gradients in inanimate hydrothermal, geophysical systems. And we certainly know in detailed terms how the universe builds heavy elements, and in broad terms how some of those turn into objects like planets with temperate environments.
But again, in all honesty, I don't think anyone can claim that there will be a sudden revelation, a crisp theory that fits everything and 'explains' life. Life on Earth is a complex and diverse phenomenon, it's likely to be even more so across the cosmos. And we of course lack the most critical data of all - what really happened some 4 billion years ago here on Earth?
So are we seeing the end of science as we've known it. Are we in a time of endlessly chasing the rabbit down the hole with no big revolutions to come?
I actually don't think so, although it's a valid question. In fact I think there are several critical things happening right now. The first is that we're still in the midst of an enormous shakedown of what we do and don't know about nature. I wrote about the situation in This Is What We Don't Know About The Universe on these pages a while ago. There my motivation was to counter some over-simplifications that were sloshing around the popular press and media, and to point out that it's the unknown that is always more exciting and important - and there's lots of unknown.
The simple fact is that our overall ignorance is still pretty astonishing. The universe is not in our pocket yet. But that's not just a counterpoint to the arguments about the 'end of science'. That's also a wake up call for any scientists who cluck about having sorted it all out, that physics (for instance) is homing in on the ultimate answers and that it'll all kind of fall into place any day (although I'm not sure anyone really thinks like that). The problem for some areas of physics is that we're at a stage where our reach really does exceed our grasp, where it's tough to find testable predictions with current technology.
The second thing that I think is happening is that big science itself is evolving. There is no rule book that says science has to stay the same, or that past revolutions will resemble future revolutions. While the core scientific method - question, hypothesis, tests, revision, theory - is not going anywhere, the ways in which we tackle each of those steps is necessarily adaptive.
I'm no philosopher (although feed me enough beer and I might be a lousy one) but there is clearly feedback between the tools we have at hand and the questions that we ask. From personal experience I know that as a student learning how to write computer code and to apply numerical methods to scientific questions, the way in which I observed the world changed. Instead of just gawping at fish swimming in unison in an aquarium I might wonder what the algorithm was that would reproduce this, and therefore reveal the fishy rules of conduct. A new way of thinking. My own tiny bit of scientific adaptation.
And of course this kind of evolution has been going on since ever. A far, far grander example was when Leibniz and Newton pinned down calculus; all future scientists would simply ask different questions and think in ways that they wouldn't have - couldn't have - before this breakthrough.
Right now we're increasingly inspired (or exasperated) by phenomena such as complexity and emergence, buoyed by tools like computers, sensors, and the dextrous manipulation of atoms, molecules, and organisms. It may not feel like the science we did fifty or a hundred years ago, but in my opinion that doesn't mean it's not just as 'big', and just as likely to overturn all that we thought we knew.