Word: einstein
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Dates: during 1940-1949
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...Genesis. When Hubble finished his "velocity-distance" law, he might have sat back (but probably did not) to marvel at his accomplishment. He had formulated the very first rule, buttressed with observation, that explained the behavior of every major unit in the visible universe. Other men (including Einstein) had theorized about the universe, using their minds as telescopes. Hubble had evolved his theory by looking at the universe itself...
...announcement of the exploding universe theory threw all grades of scientists-from semi-mystic philosophers to earthy materialists-into counterattack. Some critics could not believe that the nebulae move at such breakneck speed. Einstein's Relativity (supreme law of physics) says that nothing can move faster than light (186,000 miles per second). But Hubble and Humason have clocked a nebula about 250 million light-years away that seems to be moving at 26,000 miles per second, more than one-eighth the speed of light. They have glimpsed nebulae twice as far away. If the nebulae continue...
Curved Space. Hubble also intends to count the nebulae that can be photographed up to the billion-light-year range of the 200-inch. Behind this humdrum-sounding chore lies the eerie, brain-staggering problem of the curvature of space. Mathematical physicists believe (from Einstein's ubiquitous Relativity) that space is curved back upon itself, in a four-dimensional way, by the gravitational effect of the matter it contains. The curvature is too slight to be detected on earth or even in the enormous sphere, 500 million light-years in radius, penetrated by the 100-inch telescope. But theory...
...says Robertson, add a dimension. Take a deep breath and consider spheres instead of circles. In freshman solid geometry (which deals with ordinary "flat" space), a two-inch sphere has eight times the volume of a one-inch sphere. But if space is curved (a la Einstein), the two-inch sphere (curling in upon itself in space) will have less than eight times the volume of the one-inch sphere...
...space is really curved, then the universe must be "finite," of limited (though perhaps expanding) size'. One "model of the universe" (Einstein's) gives the "circumference of space" (the path which a beam of light would cover as it circles around finite space and back to its starting place) as about 300 billion lightyears...