Nuclear Physics: In a Constants Restless Can Universe Vary

In what scientists sometimes call "the restless universe" are a few unchallenged constants that have become the bench marks of basic research. Among them are absolute zero, which represents cold so intense that there is no molecular movement, and the speed of light, which was written into Einstein's age-shaking equation, E = mc2. Constant too is the decay of radioactive materials at rates that cannot be altered by heat, cold, pressure, magnetism, or any other influence.*Such reliability means that ancient tombs can be dated by the decay of carbon 14; the age of the earth's most ancient rocks may be measured by decaying uranium.

Any suggestion that any of nature's constants can indeed be changed—however small the alteration—is always big news in science. And last week physicists at Westinghouse Research labs in Pittsburgh announced that they had turned the trick. Working with a radioactive substance, iron 57, they proved that they could influence the rate of radioactive decay.

Iron 57 exists in both an "excited" (radioactive) and an "unexcited" state. It decays from one to the other with the emission of gamma rays. When an F 57 atom in the unexcited state ab sorbs a gamma ray, it too becomes excited, then decays to the unexcited state again a brief instant later. Westinghouse's physicists surrounded excited F 57 atoms with a blanket of the same atoms in the unexcited state and recorded their behavior. As the excited atoms began to decay at the normal rate, some of the gamma rays they emitted were absorbed by unexcited atoms, which then became excited. As they in turn decayed, their gamma rays returned some of the atoms that had already decaved to the excited state once more. Then these atoms had to repeat the decaying process, thus lengthening the average radioactive life of the original group of excited atoms by as much as 3%—a startling violation of the rigid rule.

In the distant future, some similar system may conceivably put radioactivity to work by turning it on and off like water from a kitchen faucet, but at present the Westinghouse scientists, though delighted with their accomplishment, see no practical application. Said Dr. Lawrence M. Epstein: "The thrill was purely intellectual."