(2 of 8)
Interstellar Stuff. Even before they first met, Hoyle and Lyttleton had spotted independently what they both considered a key bit of new information: that the major part of the matter in the universe is not in the stars but in the thin stuff between them. On a clear night a man can see, even with the naked eye clouds of "interstellar matter." They look like black holes punched in the Milky Way. With a telescope the astronomer can see long dark filaments and great round blobs, some so huge that it takes light 100 years (at 186,000 miles per second) to flash across their diameters. Made chiefly of hydrogen, mixed in places with dust of heavier elements, they are thinner than the finest laboratory "vacuum " but they outweigh all the stars scattered through and among them.
Many astronomers had agreed that the stars are probably condensations formed from interstellar gas. Hoyle and Lyttleton went further: they concluded, after long mathematical labor, that a star's "fate" (what happens to it during its life of many billions of years) is determined by how much interstellar gas and dust it has managed to gather. It may capture only a small amount, and so remain a commonplace star, like the sun. It may capture a lot, become unstable and eventually blow up.
Under the Desk. About the time Hoyle and Lyttleton reached this point of their reasoning, World War II put cosmology i ice. Both young mathematicians went into war work—Lyttleton into the War Office in London as a technical adviser and Hoyle into radar development All through the blitz and the buzz-bombs Lyttleton kept publishing small, abstruse papers. Hoyle, by his own account, worked on cosmology "under the desk" like a schoolboy reading comics instead of doing his arithmetic.
After the war both went back to Cambridge. There they found two kindred souls, Hermann Bondi and Thomas Gold Trinity College, also mathematicians, who had approached the problem of the universe from a more philosophical angle and were reaching similar conclusions. In eager discussions that sometimes developed into mathematical brawls, the four men began to hammer out their theories.
Genesis of Galaxies. The Hoyle-Lyttleton-Bondi-Gold universe has no beginning and no end, no middle and no circumference in either time or space It is hard to start describing such an endless, begmnmgless object. One way is to imagine all of space filled uniformly with very thin hydrogen, simplest and lightest of the elements. Such a uniform gas is gravitationally unstable." Its atoms attract one another and gradually form into clouds, rather as a film of water on glass gathers into drops. The clouds, cruising through space for billions of years eventually crowd together in enormous gaseous masses that weigh as much as billions of great stars.