Hubble Expands the Universe

s a young boy, American astronomer Edwin Powell Hubble read tales of traveling to undersea cities, journeying to the center of the Earth, and trekking to the remote mountains of South Africa. These stories by adventure novelists Jules Verne and H. Rider Haggard stoked young Hubble’s imagination of faraway places. He fulfilled those childhood dreams as an astronomer, exploring distant galaxies with a telescope and developing celestial theories that revolutionized astronomy.

But Hubble (1889-1953) didn’t settle immediately on the astronomy profession. He studied law as a Rhodes Scholar at Queens College in Oxford, England. A year after passing the bar exam, Hubble realized that his love of exploring the stars was greater than his attraction to law. So he abandoned law for astronomy. I "chucked the law for astronomy and I knew that, even if I were second rate or third rate, it was astronomy that mattered," Hubble said.

He studied astronomy at the University of Chicago and completed his doctoral thesis in 1917. After serving in World War I, he began working at the Mount Wilson Observatory in Pasadena, Calif., studying the faint patches of luminous "fog" or nebulae - the Greek word for cloud - in the night sky.

Using the 100-inch reflecting Hooker Telescope - the largest telescope of its day - Hubble peered farther into space to study the Andromeda nebula. With this powerful telescope, he discovered stars on the outskirts of Andromeda, proving that galaxies - a collection of stars and planets - existed beyond our Milky Way.

Hubble also devised the classification system for galaxies, grouping them by sizes and shapes, that astronomers still use today. He also obtained extensive evidence that the laws of physics outside our galaxy are the same as on Earth, "verifying the principle of the uniformity of nature," he said.

As Hubble continued his study, he made another startling discovery: The universe is expanding. In 1929 he determined that the more distant the galaxy from Earth, the faster it appears to move away. Known as Hubble’s Law, this discovery is the foundation of the Big Bang theory. The theory says that the universe began after a huge cosmic explosion and has been expanding ever since. Hubble’s discovery is considered one of the greatest triumphs of 20th century astronomy.

Albert Einstein could have foretold Hubble’s discovery in 1917 when he applied his newly developed General Theory of Relativity to the universe. His theory - that space is curved by gravity - predicted that the universe could not be static but had to expand or contract. Einstein found this prediction so unbelievable that he modified his original theory to avoid the problem. Upon learning of Hubble’s discoveries, Einstein said that changing the theory was "the biggest blunder of my life."

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