All or Nothing
“If there was no empty space,” wrote Lucretius, “everything would be one solid mass.” In championing the concept of empty space, what the ancients called “the void,” Lucretius was going against the grain of mainstream Greco-Roman thinking; most scholars of the ancient Western world agreed with Aristotle that the very idea of nothingness was an abomination. Yet although this view held immense sway, the void has asserted a subtle power on human imagination ever since, constantly tugging, as Lucretius suggests, at our conceptual foundations. How can there be something unless there is nothing to stage it against? This search for nothing, for pure unalloyed emptiness, is the subject of “The Hole in the Universe,” L.A. Times science writer K.C. Cole’s latest book.
Initially most scientists also recoiled from the void; a God of plenitude, thought the great philosopher-physicists of the 17th century, would not have created a universe with gaps. Hence Decartes’ cosmos filled everywhere with swirling ether. It took Newton to make empty space acceptable, and then only because he filled it with the presence of God: Space might be empty of matter, he said, but it was teeming with divine spirit. Only in the parsimonious climate of the Enlightenment was the possibility of a genuine void taken up seriously when rationalist philosophers stripped the Newtonian universe of its theological cladding, paring it back to its mechanistic roots.
But the real lesson of Cole’s book, and one of the more interesting twists in the history of physics, is that Aristotelians have won the day: “[E]very time scientists and mathematicians think they have reached the ultimate void, new stuff appears,” Cole writes. True nothingness, it seems, is an illusion, a theoretical abstraction. Whether it is black holes, undulating spacetime, vibrating strings, extra dimensions, a repulsive anti-gravity force or “universes that breed like bunnies,” to use Cole’s whimsical phrase, the more closely physicists examine the void, the more complex and something-like it becomes. Much of Cole’s book is devoted to explicating the extraordinary picture of this nothing-that-is-something which has emerged out of post-Newtonian physics.
The seeds of this revolution were sown in the mid-19th century by Michael Faraday, a child of poverty, discoverer of electromagnetic induction and founder of the field concept, as in magnetic fields and gravitational fields. Initially viewed as crackpot nonsense, these fields have since become the foundation of modern physicists’ picture of reality. Space is not empty, Faraday asserted, it is filled everywhere with unseen but powerful influences of which magnetism serves as the most obvious exemplar. According to Faraday, magnetic fields are areas of stress within the “fabric” of space itself. In one of the book’s most fascinating chapters, Cole describes how Faraday imagined that every particle was like a tiny fountain gushing forth fields of force, not so much a thing in itself but rather a place where fields were concentrated. Surprisingly, Cole does not tell us that Faraday further believed that all the forces in the universe must be expressions of a single overarching force. The quest for this super-force or “unified field” has become the unofficial goal of theoretical physics, a program that over the last several decades has led to an awesomely complicated view of the void.
If Faraday filled the void with fields, Einstein did something even more radical: He gave it form. In Newtonian physics, empty space was infinite and formless. But this simple picture proved inadequate to explain the facts of the observable world, notably the behavior of electromagnetic fields. On close inspection, Einstein found that these fields demanded a new conception of space itself. Unlike Newtonian space, Einsteinian space has an architecture; it is sculpted and molded like a landscape. According to Einstein’s general theory of relativity, every star and planet warps the “membrane” of space, causing “depressions” in the local topology; these “depressions” are what we experience as the force, or field, of gravity. Here the gravitational field becomes in fact synonymous with space, for gravity becomes a byproduct of the curvature of space. In the relativistic universe, gravity is not a force imposed upon the void, in a very real sense gravity is the void.
Today physicists have come to believe that it must be possible to accomplish a similar feat for all the forces. In this new vision, the entire universe and everything in it become byproducts of empty space folded into patterns. Cole calls this “the origami universe.” Sculpted out of nothingness, we are not in space, we literally are space, with every particle making up our bodies just a local wrinkle in the spatial membrane that is the substance and substrate of all reality.
The latest phase in the search for this overarching synthesis is string theory with the most recently generalized version known as M-theory. According to string theory, both forces and particles can be explained in terms of microscopic strings vibrating within a multidimensional space. To make this all work, physicists find they have to propose not just the three spatial dimensions we normally see but a slew of unseen dimensions. At present 10 spatial dimensions look most likely. The topology of this 10-D void is fiendishly complex and the subject of much debate in theoretical physics today. But if the theoreticians can get it right, the rewards might be huge. By absorbing everything into the architecture of space, physicists hope to resolve some of the thorniest problems in their science: Why does the expansion of the universe appear to be accelerating? How do quarks, which make up protons and neutrons (and hence make atoms possible), hold together? Why is there so much more matter than antimatter in the universe? Why is there matter at all?
Further, as Cole notes, this multidimensional view of space may be akin to a new Copernican revolution. Just as Copernicus suggested that our world was not the center of the universe, M-theory suggests that our space may be just one of an infinite variety of cosmological spaces.
For those with a fair knowledge of physics, this will be compelling stuff; Cole’s book is packed with intriguing insights into the science of nothing. Those who don’t have some prior familiarity will find the going heavy, but it must be said that this is a problem from which most “popular” physics books suffer. No, reader, you are not a moron, even physicists find “imaginary time” daunting. Cole is a better writer than most and she has a wry way with words, but this is not a book for the faint-hearted. Moreover, there is little narrative on which to hang these difficult ideas. Particularly during the first half, the text flits from one interesting idea to another, never settling on any for long. It’s a bit like being immersed in a cloud of butterflies: The spectacle is snazzy, but one pines for continuity. Not until the second half does Cole settle into a narrative groove.
“Anybody who knows all about nothing knows everything,” one of Cole’s physicists opines. Far from being a zero, nothing turns out to be perhaps the most complex entity of all. This is the fourth book during the last year to come out on this fascinating subject (the other three being Robert Kaplan’s “The Nothing That Is: A Natural History of Zero,” Charles Seife’s “Zero: The Biography of a Dangerous Idea” and John Barrow’s forthcoming “The Book of Nothing”) and, given the concept’s importance to both physics and mathematics, I suspect it will not be the last.
