Science: Hanging the Universe on Strings

Like members of a family, the four basic forces of nature are all distinct personalities, with their separate quirks, abilities and housekeeping chores. Electromagnetism makes it possible for elevators to rise, light bulbs to glow and lightning to snake across the sky. Gravity holds chairs to the floor and planets in their orbital paths. The strong force binds together the protons and neutrons in an atomic nucleus. The weak force causes subatomic particles to shoot out of the nuclei of atoms during the radioactive decay of such unstable elements as uranium.

Despite these apparent differences, physicists have long believed that a sort of common blood unites the four forces. They are convinced that at the moment of the Big Bang, the violent birth of the universe, only a single, all-powerful force existed, and that not until a fraction of a second afterward did this force split into four. Like knights in pursuit of a visionary grail, scientists for decades have sought what they call--with a bit of tongue in cheek--a Theory of Everything (TOE), a single mathematical model that would describe the fundamental unity of the forces. So far, however, they have met with only some partial successes and many failures.

That is, perhaps, until now. These days physicists are astir with a concept that just may be their ultimate TOE. The theory, developed by Physicists John Schwarz of Caltech and Michael Green of Queen Mary College in London, is known by the unlikely name of superstrings. It explains the forces not as interacting pointlike particles--the conventional approach--but as infinitesimally small, winding, curling, one-dimensional strings. By manipulating the highly intricate mathematics of the string theory, physicists believe they can avoid many of the troubling discrepancies that have dogged all other TOEs. Some scientists are already comparing the idea of superstrings with the genesis of quantum physics, or even with the revolutionary work of Albert Einstein. Says Princeton Physicist Edward Witten: "It's probably going to lead to a new understanding of what space and time really are, the most dramatic [understanding] since general relativity."

Judging by the flurry of activity in the field, others apparently agree. Since the fall of 1984, scientific papers about superstrings have been streaming forth at an ever increasing rate that now averages 100 per month, and conferences centered around strings are becoming commonplace. Upon hearing of Schwarz and Green's latest breakthrough in string theory, says Steven Weinberg, a physicist at the University of Texas, "I dropped everything I was doing, including several books I was working on, and started learning everything I could about string theory." That task is far from trivial. "The mathematics," he concedes, "is very difficult."

The modern quest for a Theory of Everything began not long after Einstein published his theory of general relativity in 1915. Eager to continue breaking new ground, the great scientist next attempted to link his pet force, gravity, to electromagnetism. He pursued this quest without success until his death in 1955.