Science: Ten Thousand Billion Years to Go

To a cosmic eye this particular universe —the Milky Way—is a wispy thing, a puff of tiny particles which are billions of stars. Somewhat disk-shaped, it floats in space, spinning on its shorter axis. The sun is one of these stars, located some four-fifths of the way out from center of the universe toward the edge. At that point its spinning motion is 155 miles per second, yet it takes 200 million years to round the circuit. Ten times the earth has been around, clinging to the sun, from which, scientists believe, the earth...