American Scientist

The Hole in the Universe: How Scientists Peered over the Edge of Emptiness and Found Everything. K. C. Cole. xiv + 274 pp. Harcourt, 2001. $24.

The Book of Nothing: Vacuums, Voids, and the Latest Ideas about the Origins of the Universe. John D. Barrow. xviii + 361 pp. Pantheon Books (originally published in Great Britain by Jonathan Cape, a division of Random House UK, in 2000). $27.50.

Scientists banter endlessly these days about The Mysterious Vacuum. Like aliens in a crackpot conspiracy theory, the vacuum seems to be connected to everything: dark energy, dark matter, the anthropic principle, parallel universes (or multiverses), the theory of everything, black holes, extra dimensions, gravitational waves, you name it. Everything is connected to Nothing is connected to Everything. The surreal wordplay of confusing jargon makes you wonder: Is there any There there?

Two recent books delve into Nothing from very different perspectives. In The Hole in the Universe, K. C. Cole, from the behind-the-scenes perspective of a science journalist, heads for the banter—the endlessly creative attempts of scientists to explain things to each other and to others in colorful and trenchant metaphors. In The Book of Nothing, J. D. Barrow explores, with meticulous scholarly attention to detail, thousands of years of philosophy, mathematics, physics and theology organized around the concept of Nothingness. Cole's breezy book rushes past ancient controversies to highlight the state of giddy confusion at the boundaries of knowledge, including personal commentary from an impressive array of distinguished scientists. Barrow delves deeply into both old and new facts and ideas: You can learn how ancient numbering systems actually worked, or how Albert A. Michelson's interferometers proved that space defines no absolute rest frame, or why we think the expansion of the universe is accelerating.

At their best, books like these can introduce readers to real intellectual adventure. For example, I was delighted to find that Barrow describes John Conway's elegantly simple and original system of defining numbers, based ultimately on the Empty Set, that allows one to make precise mathematical sense of such concepts as "infinity minus one." (No, in this system it is not the same thing as infinity.) Barrow inspired me to dust off my old copy of Conway's On Numbers and Games to recapture the sense of amazement at thoughts at once so imaginative and so precise.

Both of these books also serve up excellent fare for cocktail parties. Barrow's epigrams are not always relevant, but they are almost always entertaining—my favorite one also cropped up in a recent popular book on Buddhist philosophy (Q. What did the mystic say to the hot dog vendor? A. Make me one with everything!).

But one of the most important jobs of popular books in a frontier area like this is to help nonspecialists distinguish sense from nonsense. The subject of Nothing intrinsically lies on the boundary of what is understood—the stage on which the observable drama of the world unfolds. On this side of the boundary—that is, the scientific side—thrive frontier fields concerned with real issues, such as the nature of the physical vacuum, and concrete measurable effects, such as its gravitational influence on the expansion of the universe. In one respect, the physics in such a situation is relatively straightforward, even mundane: We perform experiments and explore the math, and hope that someday the "mystery" about it will disappear when somebody comes up with a set of rigorous formal rules to make the experiments intelligible.

Backstage, on the Mysterious side of the boundary, we find those thinkers who lose interest in anything as soon as it is possible to say something simple, concrete or meaningful about it. Barrow includes for amusement a couple of brief extracts from Jean-Paul Sartre's Being and Nothingness: "The Being by which Nothingness arrives in the world must nihilate Nothingness in its Being, and even so it still runs the risk of establishing Nothingness as a transcendent in the very heart of immanence unless it nihilates Nothingness in connection with its own being." It seems incredible that books full of language like this are still taken seriously (indeed, they are treated as exceptionally deep scholarship!). Wittgenstein really had it right when he said such matters are better passed over in silence.

We scientists blur the boundary of science in the popular imagination by shamelessly marketing our ideas with new names. A couple of decades ago, in a satirical essay titled "Is the Universe Full of Stuff?" about a new joke form of dark matter particles called stuffons, I offered prescient commentary about exciting possibilities such as Superstuff and even Superduperstuff, tested by experiments with the Superdupercollider, using calculations performed on superdupercomputers. Silly marketing, however, serves a purpose in organizing scientific activity: Although the nature of dark matter is still not known today, many candidates have been ruled out. So in spite of the persistent hype and enduring mystery, we actually know more about it than we did then. Serious experiments may soon detect directly the most viable dark matter candidates, new supersymmetric particles called neutralinos (not stuffinos, alas).

Today we are hyping dark energy—sometimes called quintessence or the cosmological constant—the energy of the vacuum. We have not yet found the connection of this new stuff with the rest of particle physics; at the moment, it is little more than a name and an empirical gravitational behavior. But the apparent paradoxes generate great grist for mystery mongers: Most of the mass-energy in the universe has repulsive gravity! Empty space is not really empty! And so on.

To readers who crave awe more than understanding, the scientists' hype feeds an unhealthy addiction. We frequently receive manuscripts describing "independent research," often including an ambitious new theory of everything or claiming to debunk Einstein's theories of relativity. These passionate and sincere creations are often full of carefully crafted jargon, but of course they are just nonsense. The authors painstakingly create mathematically decorated, Sartre-style worlds that make sense referred unto themselves but with only a superficial connection to the best "reality" we know, defined by the web of thoughts and experiments that constitutes real science. Their minds are adrift, untethered, seeking not knowledge but validation from the professional establishment.

These cases are neither harmless nor amusing. True story: I give a lecture on cosmology for a group of talented youth; afterward, a bright teen from the audience says portentously, "I don't have any questions for you . . . but I do have some answers." He then proceeds to discourse like a crackpot far beyond his years, spouting a variety of nonsense that he has clearly picked up from avidly reading popular books about the frontiers of science. Before me stands a child with an active and inquisitive mind just going to waste—not on drugs, but on junky ideas.