Hubble's discovery meant a major change in our idea of the universe.

The universe had not been quiet and unchanging since the beginning of time, as many people had thought. It was expanding. And that, Hubble said, meant it probably began with an explosion of unimaginable force. The explosion often is called "the big bang."

Hubble's work did not end with this discovery. He continued to examine galaxies. He continued to gain new knowledge about them. Astronomers from all over the world went to study with him.

Edwin Hubble looks through a guidescope of the 1.2 meter telescope at the Palomar Observatory in California.

Hubble left the Mount Wilson Observatory during World War Two. He did research for the United States War Department. He returned after the war. Then, he spent much of his time planning a new, much larger telescope in Southern California. The telescope was completed in nineteen forty-nine. It had a mirror five hundred centimeters across. It was named after astronomer George Ellery Hale.

Edwin Hubble was the first person to use the Hale Telescope. He died in nineteen fifty-three while preparing to spend four nights looking through the telescope at the sky.

Hubble's work led to new research on the birth of the universe. One astronomer said scientists have been filling in the details ever since. And, he said, there is a long way to go.

This Special English program was written by Marilyn Rice Christiano. Your narrators were Richard Rael and Tony Riggs. Listen again next week for another EXPLORATIONS program on the Voice of America.