Science: When the World Began

One of the most profound questions that scientists can ask is: “How did the universe begin?” Last week British Radio-Astronomer A.C.B. Lovell of the University of Manchester predicted that within a few years the new giant radio telescopes, which enable man to probe far deeper into interstellar space than the biggest optical telescope, will provide some sort of an answer. Astronomer Lovell is director of the radio telescope at Jodrell Bank, England, whose massive, 250-ft. wire-dish antenna makes it the world’s biggest.

Hypothesis I. There are two major competing theories about the universe’s origin, he explained. “Evolutionary” theory holds that all the matter that now exists was once concentrated in a single mass that may have been no bigger than the earth’s orbit. This “primeval atom,” whose density must have been something like 2 billion tons per cubic inch, disintegrated 20 to 60 billion years ago. Its matter turned into hot, rapidly expanding gas, and stayed in this condition until about 9 billion years ago. Then the gas began to condense into the billions of galaxies, each containing billions of stars, that make up the present-day universe.

About the same time, a mysterious, repellent force—a kind of anti-gravity that works only when objects are separated by very great distances—took hold of the galaxies and made them fly away from one another. This is what they are doing still. The most distant ones that can be seen with the 200-in. Palomar Mountain telescope are moving away from the earth at 37,000 miles per second or about one-fifth the speed of light.

The evolutionary theory is generally credited to the Abbé Georges Lemaitre, a Belgian priest. “For him,” said Dr. Lovell, “and for all who associate their universe with God, the creation of the primeval atom was a divine act outside the limits of scientific knowledge and indeed of scientific investigation.” Some of Lemaitre’s nonreligious disciples think otherwise. Cosmographer George Gamov of the University of Colorado believes that the primeval atom was not an ultimate beginning but “merely a state of maximum contraction of a universe that had previously existed for an eternity of time.” A semi-mystical attitude is that not only space but also time itself began with the primeval atom; to ask what came before it is therefore pointless.

Hypothesis II. The second theory is known as “the steady state universe.” It holds that matter is still being mysteriously created in the form of hydrogen gas. Matter appears at the rate of a few atoms per year in each cubic mile of space. As the galaxies fly apart, new galaxies form out of fresh hydrogen in the widening gaps between them. These galaxies in turn grow old, fly apart and leave the space between them free for the formation of another generation.

By evolutionary theory, the universe should contain an unchanging amount of material. Consequently, it must be thinning out as it grows older and its galaxies fly farther and farther apart. The steady state universe will not thin out. Ten billion years ahead, it should look much as it does now. with galaxies sprinkled sparsely through space at the same average density.

The only way to determine how the universe is developing is to study how it has developed in the past. Astronomers look backward in time by looking outward in space. The best optical telescope can see galaxies that are 2 billion light-years away, i.e., with light that left them (at a travel speed of 186,300 miles per second) when they were 2 billion years younger than they are now. But 2 billion years is a comparatively short backward leap into the cosmic past, does not reveal enough evidence of change to prove or disprove either theory.

Radio Breakthrough. Radio astronomy, said Professor Lovell. promises to break this deadlock. Already the great radio telescopes can detect colliding galaxies (which give off powerful radio waves) at distances much greater than can be reached by an optical telescope. In a few years, improved vision should enable cosmographers to peer so far into space (or back into time) that they will be able to tell which kind of universe they are looking at.

The decision will be made by taking a galaxy census in a large chunk of space so distant that the galaxies in it are seen on earth as they were 5 or 6 billion years ago. If the galaxies prove to be crowded closer together than they are in the section of space near the earth, the primeval atom will have won the contest—since, according to the cosmic evolutionary theory, the universe was much smaller 6 billion years ago and its galaxies were therefore closer together.

But if the radio telescopes find that such remote galaxies are no more closely crowded together than those nearer and more recent than the earth, the proponents of the steady state universe will be proved right. For steady state theory holds that the universe’s matter was no more concentrated then than it is now. Its stars and galaxies change and develop, but the universe as a whole does not grow old. It had no beginning and will have no end, either in time or space.

Even the answer will leave a further mystery, Dr. Lovell admits. A universe that is still being created and that had no beginning is as hard to understand as one that “began” with a primeval atom. Creation, all at once or bit by bit, seems equally hard for scientific theory to handle. “Any cosmology,” Dr. Lovell says, “must eventually move over into metaphysics.”