so what?

QUANTUM mechanics begins as a theory of atomic structure. But it's far more than that. It explains, as Harvard physicist Sheldon Glashow says, ``the bulk properties of matter - that copper must be red and conduct electricity, that diamond is hard and brilliant, how water freezes, and why snowflakes are six-sided.'' So far-reaching is quantum mechanics, he adds, that ``almost everything we can see, smell, touch, feel, or hear can be reduced, in principle, to the quantum-mechanical interactions among lots of electrons and nuclei.''

Where, then, does it show up in our everyday lives? Just about everywhere, according to Fermilab director Leon Lederman. When he points out that ``almost [all of] our gross national product is based on the quantum theory,'' he may be exaggerating - but only slightly. The astonishing transformation of Western economies in recent decades - away from heavy industry into high-tech and services - owes much of its impulse to electronics. And electronics, these days, is squarely based on quantum theory.

Transistors, silicon chips, cathode-ray tubes, liquid-crystal displays, and a host of other devices have poured new products into domestic and commercial use. Personal computers, television sets, microwave ovens, digital watches, videocassette recorders, and anti-skid brakes for cars - not to mention CAT scanners in hospitals, superconducting magnets in experimental trains, phased-array radar in naval vessels, and heat-resistant plastics in manufacturing - all trace their development to an understanding of quantum mechanics.

And that, physicists say, is just the beginning. Take, for example, the question of global energy resources. Superconducting power lines, combined with superinsulating materials, could make transmission losses so negligible that objectionable power plants could be built far from population centers. More far-out is the speculation that new alloys manufactured with the aid of particle accelerators could help capture solar energy.

Technology, of course, could take a giant quantum step right past these current sources of energy. Nuclear fusion (which owes its development to quantum theory) is already capable of liberating about 4 million times the energy released when an equivalent amount of coal or oil is burned. Yet fusion, according to Einstein's basic equations, releases only about 1/500th of the amount of energy locked up in matter. In theory, the rest could be liberated by compacting the density of the nucleus - perhaps through high-velocity collisions, or proton decay, or the presence of a magnetic monopole.

What would be the result? If a chunk of matter could be ``organized in such a way that all its constituent nucleons were to undergo [such a] reaction,'' Dr. Lederman wrote in a 1984 Scientific American article, ``the energy needs of the world projected for the year 2000 could be met with a few tons of water.'' -30-{et