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TIME Magazine, February 9, 1948, p. 56|
SCIENCE: Look Upward
...Palomar Mountain [Observatory] 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 for faster than the white-hot gases of detonating TNT.
Hubble's discovery threw top-level science into confused arguments which are still raging... 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 [most of what were called "nebulae" in 1948 are now known as galaxies]... Hubble's first step when he started work on Mount Wilson Observatory in 1919 was to find out definitely how far away they were...
Variable stars called Cepheids, discovered at Harvard, told him that the bright nebula called Messier 31 [the Andromeda galaxy] is 680,000 light years away. Messier 31 was therefore no mere part of the Milky Way galaxy (the star-congregation in which our sun is a fourth-rate star), but an isolated star-system far out in space and as big as our entire galaxy. Other, longer-ranged measuring sticks carried him farther on his march into space...
By a complex statistical method Hubble proved, after years of work, that these dimmest glimmers were so far away that their light, speeding at 186,000 miles per second, took 500,000,000 years to reach Mount Wilson.
His success in measuring the distance of dimmer and dimmer nebulae led to his crowning discovery-- the theory of the expanding universe.
Universe in Flight. Astronomers have a speedometer to clock the motions of skittish heavenly bodies. They take spectrographs: photographs of the body's light spread out by a prism into a band of colors. If the band is "shifted toward the red" (i.e., if it is redder than normal), it shows that the body is moving away from the earth.
Working with short, amiable spectrograph expert Milton Humason, Hubble studied the light of the distant nebulae. In every case he found a "red shift."* The farther off a nebula was, the faster it appeared to be rushing away, and the enormous speeds (thousands of miles per second) were new, strange and startling to astronomers.
While Humason's spectrographs gradually improved, Hubble theorized until he came to a momentous conclusion: that the speed of recession of the nebulae is directly proportionate to their distance. This meant that each of the large units of matter in the universe (nebulae) [now called galaxies] is moving away from every other unit...
...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.
The 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... Hubble and Humason have clocked a nebulae 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...
Hubble is glad to discuss such objections objectively. Even when an adversary uses that subtle, stylized rancor with which the more quarrelsome scientists conduct their controversies, he reacts with courtly tolerance.**
One reason for his balance, and the imagination that helps his work so much, may be that he has never been completely immersed in astronomy, which can easily become an obsession. In summer he goes on long fishing trips, as far away as the Colorado Rockies. He belongs to the American Legion, takes part in "civic activities like a good Californian." He studies Chinese philosophy. He even knows movie people. Relations between the Mount Wilson astronomers and Hollywood have never been close... but Hubble has some friends (Aldous Huxley, Michael Arlen, Anita Loos) among the movie colony's intellectual set.
...Hubble, 6 ft. 2, strikingly handsome, and built like a heavyweight boxer (just what he was in college), was born in Marshfield, Mo. in 1889, and took his bachelor's degree in 1910 at the University of Chicago. He knew by then that he wanted to be an astronomer, but he took time out for a Rhodes scholarship and two years of law at Oxford...
At Oxford, Hubble was charmed by English common law, which he still considers one of the great achievements of the human mind. He returned to the U.S. with a British accent (traces still remain), and became a member of the Kentucky bar. After one year of law practice (very dull), astronomy called with unmistakable loudness, and Hubble went to the Yerkes Observatory in Wisconsin to make friends with the sky.
He had published one scientific paper and prepared for his doctorate examinations when the U.S. entered World War I. After enlisting in the Army, Hubble sat up all night, finishing his doctoral thesis, and took his examinations next morning. His Ph.D. from the University of Chicago caught up with him at Fort Sheridan, Ill.
The tall young astronomer rose quickly from private to major. (Some of his friends still call him "Major.") After the war, astronomy called as loudly as ever, and Hubble took a long-promised job at Mount Wilson.
Weary Waiting. Mount Wilson's 100-inch telescope showed him the exploding universe, but it raised more questions than it answered. Hubble's theory needed the 200-inch to prove or disprove conclusively. The Rockefeller Foundation had agreed to finance the great new instrument as long ago as 1928, but 500-ton telescopes cannot be ordered from a catalogue. The blank glass disc for the mirror was not cast until 1934. The whole project lagged.
Meanwhile Hubble, Humason and their colleagues did the best they could with the 100-inch telescope, which had passed the peak of its effectiveness for many kinds of work. When Mount Wilson Observatory was founded in 1904, Pasadena was a quiet village, attractive to old ladies. Los Angeles was a distant, smallish city, not yet a great industrial center. But eventually, Los Angeles' suburbs sprawled over the whole mountain-surrounded plain. A strange, white, acrid haze (locally called "smog") rose from the city. Often the smog climbed over Mount Wilson, dimming the nebulae.
The Deadly Lights. The lights, of all colors, which Los Angeles uses with a showman's abandon, flowed out like glittering lava toward Mount Wilson. The sky turned from velvety black to grey, fogging the sensitive photographic plates. The most striking feature in Humason's recent spectrographs is a strong black band (mercury light from the advertising signs of Los Angeles)...
Slow Grind. As the city's lights crept toward Mount Wilson, the 200-inch telescope project also made progress. An ideal site had been found for it at Palomar Mountain, a 6,000-ft. plateau 90 miles to the south. No sea of lights would overwhelm the new observatory; the nearest sizable city, San Diego, is 50 miles away.***
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