Biography - HE - Edwin Hubble Changed Our Ideas About the Universe -

10/31/2012
Edwin Hubble Changed Our Ideas About the Universe and Its Birth
EXPLORATIONS -- a program in Special English by the Voice of America.

Today, Richard Rael and Tony Riggs tell the story of American astronomer Edwin Hubble. He changed our ideas about the universe and how it developed. Edwin Hubble made his most important discoveries in the nineteen twenties. Today, other astronomers continue the work he began. Many of them are using the Hubble Space Telescope that is named after him.

Edwin Powell Hubble was born in eighteen eighty-nine in Marshfield, Missouri. He spent his early years in the state of Kentucky. Then he moved with his family to Chicago, Illinois. He attended the University of Chicago. He studied mathematics and astronomy.

Hubble was a good student. He was a good athlete, too. He was a member of the University of Chicago championship basketball team in nineteen-oh-nine. He also was an excellent boxer. Several people urged him to train for the world heavyweight boxing championship after college. Instead, he decided to continue his studies. He went to Queen's College at Oxford, England.

At Oxford, Hubble studied law. He was interested in British Common Law, because his family had come to America from England many years before. He spent three years at Oxford.

In nineteen thirteen, Hubble returned to the United States. He opened a law office in Louisville, Kentucky. After a short time, however, he decided he did not want to be a lawyer. He returned to the University of Chicago. There, once again, he studied astronomy.

Hubble watched the night sky with instruments at the university's Yerkes Observatory. His research involved a major question astronomers could not answer: What are nebulae?

The astronomical term "nebulae," Hubble explained, had come down through the centuries. It was the name given to permanent, cloudy areas in the sky outside our solar system. Some astronomers thought nebulae were part of our Milky Way galaxy. Others thought they were island universes farther away in space. In his research paper, Hubble said the issue could be decided only by more powerful instruments. And those instruments had not yet been developed.

In nineteen seventeen, the United States was fighting in World War One in Europe. Edwin Hubble joined the American army and served in France.

Earlier, astronomer George Ellery Hale had offered Hubble a position at the Mount Wilson Observatory in Southern California. When Hubble returned to the United States after World War One, he accepted Hale's offer. Hubble was thirty years old. He was just beginning the work that would make him famous.

In his first observations from Mount Wilson, Hubble used a telescope with a mirror one hundred fifty-two centimeters across. He studied objects within our own galaxy. And he made an important discovery about nebulae.

Hubble said the light that appeared to come from nebulae really came from stars near the nebulae. The nebulae, he said, were clouds of atoms and dust. They were not hot enough -- like stars -- to give off light.

Soon after, Hubble began working with a larger and more powerful telescope at Mount Wilson. Its mirror was two hundred fifty centimeters across. It was the most powerful telescope in the world for twenty-five years. It had the power Hubble needed to make his major discoveries.

From nineteen twenty-two on, Edwin Hubble began examining more and more distant objects. His first great discovery was made when he recognized a Cepheid variable star. It was in the outer area of the great nebula called Andromeda. Cepheid variable stars are stars whose brightness changes at regular periods.

An astronomer at Harvard College, Henrietta Leavitt, had discovered that these periods of brightness could be used to measure the star's distance from Earth. Hubble made the measurements. They showed that the Andromeda nebula lay far outside our Milky Way Galaxy.

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