Marcelo Gleiser is the Appleton Professor of Natural Philosophy and a professor of physics and astronomy at Dartmouth College in New Hampshire. He obtained his PhD from King's College London in 1986 and has been a postdoctoral fellow at the Kavli Institute for Theoretical Physics at the University of California, Santa Barbara, and at Fermilab.

A theoretical physicist, Gleiser focuses his research on cosmology, field theory, complexity, and the origin of life. His contributions include advancing research on cosmological phase transitions and nonequilibrium field theory; he also codiscovered oscillons, a metastable state found in such physical systems as granular media and in many field-theory models of fundamental interactions and condensed-matter physics.

Gleiser received the 1994 NSF Presidential Faculty Fellows Award—the awards are chosen by the White House—in recognition of his teaching and research in theoretical physics. Believing that “science contributes in essential ways to our culture and worldview,” Gleiser participates frequently in TV documentaries and on radio programs, primarily in the US and in his birth country of Brazil. He cofounded the science and culture blog 13.7, which is hosted on NPR’s website. He has authored several popularizations; The Island of Knowledge: The Limits of Science and the Search for Meaning (Basic Books, 2014), is his fourth popularization in English. It was reviewed in this month’s issue.

Physics Today recently caught up with Gleiser to discuss The Island of Knowledge.

PT: Past philosophers have advanced the thesis that a Theory of Everything should not be the end goal of science. What motivated you to revisit that debate, and what does your book contribute that is not covered in previous works?

Gleiser: [My thesis] is not that a Theory of Everything shouldn't be the end goal of science. That impossibility is a consequence of the book's main thesis, which is to clarify how science works: as a series of better approximations to what we call “reality,” itself an evolving concept as we learn more about the world.

I'm interested in understanding how we make sense of physical reality through the use of tools and ideas—not a very common theme in science popularizations, which tend to focus mostly on the science. I developed the central metaphor of the book—the island of knowledge—independently and, I believe, quite beyond a few other thinkers that had similar ideas. As we learn more about the world, we become equipped to ask questions and build analogies we couldn't have considered before: for example, astronomy before and after the telescope, or nonlinear dynamics before and after computers. Science is a permanent work in progress.

PT: How do you respond to the reviewer’s conclusion that “only those who think that profound discoveries are possible will be motivated to try to make them”?

Gleiser: I understand where he is coming from, but I am not sure I agree. Many physicists make profound discoveries without being motivated to make them. Not everyone aspires to be Einstein, Newton, or Bohr. There are countless examples in the history of science of profound discoveries being made without this grand sense of purpose. Besides, profound discoveries are made in many fields, including those that do not ask fundamental questions about the structure of space, time, and matter. It is wrong to assume that one is being defeatist by not believing in unification or final answers. How awful would it be if one day we arrived at the end of fundamental physics? As I explain in the book, I'm glad that the very nature of science prevents us from getting there.

PT: In terms of attracting science funding, what do you see as the advantages of the final theories approach versus the iterative approach?

Gleiser: Final theories have the seductive appeal of “grand answers” and those are, of course, an important scientific pursuit: How far can we get simplifying our fundamental description of matter? But the real core of science is related not to such questions but to more concrete problems and technical challenges. For example, the possibility of life on Mars is an essential scientific question having nothing to do with final theories. I think a healthy scientific community would have a good balance of both, as long as “final theories” were properly renamed as fundamental theories. There are no final theories, only better ones.

PT: This is your fourth English popularization. What appeals to you about writing on scientific topics for a broad audience, and what have you found to be the most challenging aspect of that?

Gleiser: I find that we owe it to the general public explanations of what we do and how we do it. Not just because our funding is tax based, as is often said, but because I believe that science contributes in essential ways to our culture and worldview. We are pondering questions that are not just the province of science but of human inquiry. As such, I think some of us should engage with the public, sharing what's going on. Humans are storytellers, and science is the greatest of all stories. Plus, the children love it, and we need to motivate our future colleagues.

To balance content and quality of exposition and still make it appealing to a large number of people—that's the challenge. Scientists have a somewhat captive audience of science buffs that read the books we write. But branching out of this group is quite hard, as we see from the rare science popularization that makes it into the bestselling lists. We need to find ways to broaden the appeal of science.

PT: What’s the next book project for you?

Gleiser: My next book is the lightest I've written so far in English, a kind of travel journal combining my personal experiences as a traveling scientist and fly fisherman, exploring conferences and rivers around the world. [The estimated publication date is spring 2016.] The format gives me the freedom to explore topics in science and philosophy in a more approachable way than, say, The Island of Knowledge. It's an experiment in a new format of science popularization, somewhat reminiscent of Zen and the Art of Motorcycle Maintenance: An Inquiry Into Values (by Robert Pirsig, William Morrow Paperbacks, 2005), but with fly-fishing subbing for motorcycles—which, by the way, I also love.

PT: What books are you currently reading?

Gleiser: Nick Bostrom's Superintelligence: Paths, Dangers, Strategies (Oxford University Press, 2014) and Roberto Unger and Lee Smolin's The Singular Universe and the Reality of Time: A Proposal in Natural Philosophy (Cambridge University Press, 2014).