Science: Toward Unity

SCIENCE

While Albert Einstein was last week running his little sailboat aground in the Connecticut River, there appeared from his mighty pen a communication to The Physical Review which marked a milestone toward the goal to which the exiled German has promised to devote the rest of his life.

It was 34 years ago that another brainy German, Max Planck, discovered that atoms do not radiate light continuously or in indiscriminate amounts, but in separate pulses and uniform quantities which were subsequently called quanta. Planck’s constant, h, is equal to .00000000000000000000000000655 erg-seconds. For any sort of light the energy multiplied by the period of vibration is always equal to h. To a physicist grouping within the atom, h and the quantum mechanics which have grown up around it are as important as bait, hook & line to a fisherman.

Elucidating the great universe of stars and spiral nebulae and abysmal reaches of space, Dr. Einstein advanced in 1915 his General Theory of Relativity, which brought celestial performances into the four-dimensional theatre of space-time and made gravity an effect of space-time’s curvature. Today Relativity is as familiar a guide to astronomers as a radio beam to an aviator.

But as the quantum mechanics could not cope with the outer universe, so Relativity found itself stumped when it got down to ultimate particles. Protons and electrons have electric fields, and relativistic equations which tried to allow for the presence of such fields came out with ”singularities” (anomalies). Thus physicists found themselves dealing in effect with two separate universes, the invisible atom and the vast cosmos. To Dr. Einstein this seemed wrong. His powerful imagination saw Nature as an integrated whole. Beneath the quantum mechanics and Relativity, he was sure, the deepest wells of ultimate reality held the secret of a great unity. Few years ago he made a start toward a “Unified Field Theory,” abandoned it when irreconcilable flaws cropped up. Lately at the Institute for Advanced Study in Princeton he and Dr. Nathan Rosen, co-author of last week’s paper, started off on a new and better tack.

The two savants, following a suggestion from a third, found that the classic Relativity equations could be altered to take particles and electric fields into account with no more drastic change than a simple elimination of denominators. The solutions came out free of “singularities,” and they described a space radically different from the old four-dimensional continuum. The new space was a system of two identical “sheets” joined here & there by what Dr. Einstein and his associate deemed best to call “bridges.” The bridges turned out to be particles. The properties of one bridge identified it as a particle with mass but no electric charge, like the hypothetical neutrino or the familiar neutron. Another bridge indicated the existence of a totally unfamiliar particle, having electric charge but no mass whatever. Particles like protons and electrons, having both mass and charge, seemed to Einstein to represent “two-bridge problems”—two points of space connecting the two space-sheets. The gentle professor was relieved to find that his new mathematics dredged up no particles of less than zero mass.*

Thus did Albert Einstein fit atoms and their constituent particles into the framework of Relativity. But the Unified Field Theory is not yet in his hands. The mathematics is not yet sufficiently developed to deal with more than one “bridge” at a time. And nowhere does the new system deal with Planck’s invaluable constant h. But the system as it stands has no loose ends, and holds within itself the possibility, on further elaboration, of containing the quantum mechanics—and of yoking the spin of electrons in a glass of water to the sweep of Betelgeuse through space and time.

* A particle of negative mass would have been no more surprising mathematically than the argument of Britain’s brilliant young Paul A. M. Dirac that the existence of electrons occupying states of minus energy was theoretically called for. Yet later just such a particle as Dirac demanded was found in the laboratory when Caltech’s Carl David Anderson first identified the track of a positive electron.