Late last spring, as I’ve mentioned in previous columns, I participated in a conference called How the Light Gets In, where I hung out with all kinds of professional reality-ponderers. One was physicist Carlo Rovelli, who has sought to find a “unified theory” that reconciles general relativity, Einstein’s theory of gravity, with quantum mechanics. I recently interviewed him by email.
Horgan: Why did you become a physicist?
Rovelli: I was young in the sixties and seventies, and shared the dream of my generation: changing the world and make it more just and gentle. We lost. I did not know what to do next. I found physics, where, instead, revolutions succeed. I fell in love with it. It has been a passion that hasn’t ended.
Horgan: Has physics lived up to your expectations?
Rovelli: It has been much better than I expected. Infinite fun and enthusiasm. Investigating the secrets of the world. Thinking things that nobody else has thought before. Great adventures in thinking. Great companions of travel. Fantastic.
Horgan: Do you ever think it’s time for physicists to abandon the quest for a unified theory? [Editor’s note: unified field theory, or the theory of everything, a term coned by Einstein, is an unsolved physics goal to describe every force in nature in a single theoretical framework]
Rovelli: The “quest for a unified theory” is a misconception. Physicists never really searched for it. They stumbled upon string theory, which to some appeared as a possible unification of everything, and, for lack of imagination, put too much energy into strings. When the enthusiasm for strings begun to fade, many felt lost. Now that supersymmetry is not showing up where string theorists expected it, it is a disarray.
Horgan: Can physics—or science in general—ever completely solve the mystery of the universe?
Rovelli: What is the “mystery of the universe”? There isn’t a “mystery of the universe.” There is an ocean of things we do not know. Many of them we’ll figure out, if we continue to be somewhat rational and do not kill one another first (which is well possible). There will always be plenty of things that we will not understand, I think, but what do I know? In any case, we are very, very, very far from any complete comprehension of everything we would like to know.
Horgan: Can science attain absolute truth?
Rovelli: I have no idea what “absolute truth” means. I think that science is the attitude of those who find funny the people saying they know something is absolute truth. Science is the awareness that our knowledge is constantly uncertain. What I know is that there are plenty of things that science does not understand yet. And science is the best tool found so far for reaching reasonably reliable knowledge.
Horgan: What’s your opinion of the recent philosophy-bashing by Stephen Hawking, Lawrence Krauss, and Neil deGrasse Tyson?
Rovelli: Seriously: I think they are stupid in this. I have admiration for them in other things, but here they have gone really wrong. Look: Einstein, Heisenberg, Newton, Bohr…. and many many others of the greatest scientists of all times, much greater than the names you mention, of course, read philosophy, learned from philosophy, and could have never done the great science they did without the input they got from philosophy, as they claimed repeatedly. You see: the scientists that talk philosophy down are simply superficial: they have a philosophy (usually some ill-digested mixture of Popper and Kuhn) and think that this is the “true” philosophy, and do not realize that this has limitations.
Here is an example: theoretical physics has not done great in the last decades. Why? Well, one of the reasons, I think, is that it got trapped in a wrong philosophy: the idea that you can make progress by guessing a new theory and disregarding the qualitative content of previous theories. This is the physics of the “why not?” Why not studying this theory, or the other? Why not another dimension, another field, another universe? Science has never advanced in this manner in the past. Science does not advance by guessing. It advances by new data or by a deep investigation of the content and the apparent contradictions of previous empirically successful theories. Quite remarkably, the best piece of physics done by the three people you mention is Hawking’s black-hole radiation, which is exactly this. But most of current theoretical physics is not of this sort. Why? Largely because of the philosophical superficiality of the current bunch of scientists.
Horgan: Do you think physicists—and scientists in general–have a moral responsibility to oppose militarism?
Rovelli: I think that we have a moral responsibility to oppose war as human beings, not as physicists or scientists. I think that the problem is that everybody “opposes the war” in words, but then many people are ready to make exceptions to serve their interests, defend their power and economical superiority. And these people hide this behind “feel good” words like “help people” or “fight terrorism”. I find this morally disgusting. I wish people were less religious and more moral.
John Horgan directs the Center for Science Writings, which belongs to the College of Arts & Letters. A longer version of this Q&A was originally published on his ScientificAmerican.com blog, “Cross-check.”
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