End to Explosion?

Is the universe exploding--expanding swiftly into the uttermost reaches of space? Scientists have been puzzling over the startling speculation ever since the 1920s, when Mount Wilson Astronomers Edwin Hubble and Milton Humason discovered that the glow from distant galaxies was of a longer wave length than normal. Since light from a receding source shifts toward the red (long wave length) end of the spectrum, the Hubble-Humason observations seemed to suggest that far-out galaxies are all speeding away from the earth and from each other.

Though many a cosmologist was bothered by the bizarre idea of a swiftly expanding universe, no one yet has been able to prove it wrong. But last week in the British journal Nature, Physicist Alastair Ward of Glasgow's Royal College of Science and Technology suggested a possible way to squelch the big explosion and bring the universe back into a steady state of vast but stable dimensions. Colliding light beams may lose some of their energy, says Ward, as photons (particles of light) carom off other photons. The loss of energy might cause a lengthening of wave length, and in light-drenched space such energy-diminishing collisions are highly probable. They could explain the Hubble-Humason red shift.

Other physicists have toyed with the same notion, but Ward describes an actual experiment to test this theory. The Moessbauer Effect, discovery of which won German Physicist Rudolph Moessbauer a Nobel Prize (TIME, Nov. 10), allows gamma rays from certain radioactive isotopes to be used for measurements of extreme precision. Since gamma rays are closely akin to light, Physicist Ward suggests shooting them across an intense light beam and measuring any loss of energy due to photon-photon collisions.

Such an experiment will be both expensive and difficult, and if it succeeds in bringing the theoretically expanding universe to a theoretical halt, it will raise an additional problem of its own: what happens to the energy lost in photon-photon collisions? Dr. Ward does not favor the suggestion that the lost energy turns into the radio waves that permeate space. He prefers the more startling notion that the energy is transformed, in some unexplained manner, into fresh, new hydrogen that provides an eternal source of nuclear fuel for the hydrogen-burning stars.

This file is automatically generated by a robot program, so reader's discretion is required.