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From the dusty lowlands of San Diego County, the road leads up Palomar Mountain in sharp, steep curves. Near the top the air turns cold; the dry, thorny brush of southern California yields to evergreen forests. Deer bounce across the roadway; squirrels peek from the incense cedars; through the primitive underbrush pads an occasional mountain lion. But the summit of Palomar Mountain is one of the high points of the 20th Century. For there stands the dazzling new 200-inch telescope that will peer a billion lightyears* into space—man's deepest look at the unknown universe he lives in.
Palomar Mountain became a scientific necessity 18 years ago. With the 100-inch telescope on Mount Wilson, near Pasadena, Astronomer Edwin Powell Hubble had made one of the most flabbergasting discoveries science has ever made. The whole visible universe, Hubble's data told him, is apparently exploding. The matter in space appears to be flying apart far faster than the white-hot gases of detonating TNT.
Hubble's discovery threw top-level science into confused arguments which are still raging. For various reasons (besides "common sense"), the idea of an exploding universe gave sober scientists goose-pimples. But every attempt to reason the theory away raised even more serious problems. Since Hubble had seen so much with the 100-inch telescope (whose range is 500 million light-years), the astronomers simply had to see still farther.
This week the greatest telescope is almost ready. It is housed in a softly revolving dome 137 feet in diameter. The telescope weighs 500 tons, but is so exquisitely mounted that an electric motor not much bigger than an orange turns it on its bearings. Its 200-inch parabolic mirror gathers four times as much nebula light as Mount Wilson's 100-inch mirror. Palomar will see twice as far, and it may tell Hubble whether the universe is really exploding—or whether even stranger things are happening.
Out Into Space. Even as an apprentice astronomer, Hubble concentrated on the nebulae—the faint patches of light scattered among the stars. Some had been proved mere wraiths, irregular clouds of dust shining by reflected starlight. Others, more interesting, were globes, ellipses, open spirals like patterns of fire from great spinning pin wheels. When the brightest of these were photographed with powerful telescopes, they dissolved into vast congregations of faint stars, whose dimness suggested that they might be very far away. But astronomers, lacking a proper measuring stick, were not agreed. Some thought that the nebulae were comparatively near and small. Hubble's first step when he started work at Mount Wilson Observatory in 1919 was to find out definitely how far away they were.