The Island of Knowledge: The Limits of Science and the Search for Meaning, Marcelo Gleiser, Basic Books, 2014. $29.99 (335 pp.). ISBN 978-0-465-03171-9
A little while before his death in 1727, Isaac Newton is said to have remarked, “I seem to have been only like a boy playing on the sea-shore and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.” When I read this long ago, it occurred to me that as the island of scientific knowledge expands, the shoreline of ignorance also expands. That double metaphor is behind the title of theoretical physicist Marcelo Gleiser’s book, The Island of Knowledge: The Limits of Science and the Search for Meaning. Gleiser traces the metaphor to Friedrich Nietzsche, Victor Weisskopf, John Wheeler, and others.
Central to Gleiser’s new book—and also to his previous book, A Tear at the Edge of Creation: A Radical New Vision for Life in an Imperfect Universe (Free Press, 2010)—is the idea that we should not imagine the search for scientific knowledge could ever end with a Theory of Everything. Rather, the more we know, the more we know to ask. He argues that scientists should view that as optimistic, not defeatist.
But the future of science is not only up to scientists. Historians and sociologists of science have found that research in a given field of science or mathematics typically goes through a sigmoid growth pattern like that of a living organism, initially accelerating rapidly with new discoveries, growing steadily for a while, and finally slowing down as most of the relevant accessible knowledge has been discovered. But it then frequently happens that new discoveries or new techniques in a related field lead to another growth spurt, and then another. That is the explanation for the continuing exponential increases in the power of computers, in the equivalent beam energy in high-energy physics experiments, and in the reach of astrophysical observations. Those examples make it difficult to foresee any fundamental limitations to future growth of knowledge.
However, it is entirely possible that the unwillingness of government agencies to fund such growth could impose economic limits—especially on high-energy physics, astrophysics, and other areas where the research is primarily motivated by science and not by potential practical benefits. Moreover, scientific progress often depends on improving technological capabilities. So the real challenge for the future of science may well be to develop and exploit the new techniques that will advance knowledge while keeping people and governments interested in both scientific and practical questions.
In The Island of Knowledge, Gleiser also shows the human side of science through historical accounts and descriptions of his own career. He is a gifted writer, but I couldn’t help noticing some inaccuracies. For example, he is correct in saying that as space keeps stretching it will carry away the galaxies that are now within telescopic sight. However, he is not correct in saying current data place that event one or two trillion years from now: If the dark energy is a cosmological constant, all galaxies outside our Local Group of galaxies will disappear over the cosmic horizon in about 150 billion years.
What we have today in both particle physics and cosmology are standard models, theories with clear mathematical frameworks but with many parameters that have to be determined by measurement rather than from underlying theoretical principles. Of course, we want to find physical explanations for the structures of those theories and values of the parameters, and it is possible that new theoretical developments or experimental discoveries will point the way. I’m heartened that funding agencies have been willing to commit large sums to such research.
For Gleiser, the goal of physics should not be to find the Truth, but rather to make better and better approximations to reality. He regards the search for fundamental unifying concepts to be futile and says that it is a Platonist fallacy to believe that symmetries are an imprint of nature instead of an explanatory device we conceived to describe what we see and measure. Maybe he’s right. Perhaps new discoveries will only lead to a more accurate but still complex understanding of nature. Or maybe he’s not, and a new unification will emerge. But in science, the optimists always win: Only those who think that profound discoveries are possible will be motivated to try to make them.
Joel Primack is a Distinguished Professor of Physics at the University of California, Santa Cruz. He is coauthor, with Nancy Ellen Abrams, of The View from the Center of the Universe (Riverhead, 2006) and The New Universe and the Human Future (Yale University Press, 2011).
