• Choose a category
• All
• Classic-Fiction

By Root 412 0

the galaxies were truly moving outward in a uniform way and Lemaître's model, circulated more prominently in the Monthly Notices in 1931, could at last explain it as the fabric of space-time stretching outward, carrying the galaxies ever farther apart. Now it was no longer Einstein's universe or de Sitter's universe, but the expanding universe, and Lemaître became the toast of the cosmological town for being one of its primary creators. Hubble did not really discover the expanding universe in 1929, as written up in textbooks and commonly presumed these days. That realization did not actually occur until Hubble's data could be viewed with Lemaître's model firmly in mind. Lemaître, far more than Friedmann, had linked his model with ongoing astronomical ob servations. His solution was described as a “brilliant discovery.” Top mathematical theorists began to flock to the new field of relativistic cosmology, both to extend the model and to produce variations on Lemaître's original theme of a universe in bloom. In preparing a review paper for a physics journal in the early 1930s, Princeton theorist Howard P. Robertson, himself a leading expert in this new endeavor, noted, “Imagine my surprise on being able to rustle together more than 150 references on relativistic cosmology! It seems to me that some of our highlights…are going off the deep end.”

Astronomers and theorists alike were thunderstruck by this radically new picture of the universe, which was reported as breathtaking in its grandeur and terrifying in its implications. “The theory of the expanding universe is in some respects so preposterous,” said Eddington, “that we naturally hesitate before committing ourselves to it. It contains elements apparently so incredible that I feel almost an indignation that anyone should believe in it—except myself.” That's because by then he knew that it was rooted in the most powerful idea to be introduced in the world of physics since Isaac Newton—Einstein's general theory of relativity—and test after test was proving it true.

James Jeans, a prolific writer as well as theorist, employed the iconic description of the cosmic expansion used to this day. “On the face of it,” he said, “this looks as though the whole universe were uniformly expanding, like the surface of a balloon while it is being inflated, with a speed that doubles its size every 1,400 million years… If Einstein's relativity cosmology is sound, the nebulae have no alternative—the properties of the space in which they exist compel them to scatter.” Eddington first devised this picture when he introduced his colleagues to Lemaître's solution in a 1930 paper to the Monthly Notices of the Royal Astronomical Society. Paint dots on that balloon and, as it expands, every dot will move farther from every other dot in a regular fashion. Similarly, wrote Eddington, in the expanding universe the galaxies appear to be “embedded in the surface of a balloon which is steadily inflating.” Every galaxy in the cosmos thus sees its neighbors receding into distant space.

Though Hubble left such interpretations of the velocity-distance relationship to others, he did participate in the discussions, hoping to glean what data needed to be gathered to select between competing theories. Astronomers and theorists previously resided in separate domains, but now he got them talking. Grace Hubble recalled the commotion it created in her household, shortly after Lemaître's model got wide circulation: “About every two weeks some of the men from Mount Wilson and Cal Tech came to the house in the evening…astronomers, physicists, mathematicians. They brought a blackboard from Cal Tech and put it up on the living-room wall. In the dining-room were sandwiches, beer, whiskey and sodawater; they strolled in and helped themselves. Sitting around the fire, smoking pipes, they talked over various approaches to problems, questioned, compared and contrasted their points of view. Someone would write equations on the blackboard and talk for a bit, and a discussion would follow.”

There was much to argue about. Those