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BIOGRAPHY

EDWIN HUBBLE

720L

EVIDENCE FOR AN EXPANDING UNIVERSE

EDWIN HUBBLE

BornNovember 20, 1889Marshfield, Missouri

DiedSeptember 28, 1953San Marino, California By Cynthia Stokes Brown, adapted by Newsela

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Edwin Hubble was an American astronomer who made two major discoveries. Hubble showed that the Universe is much larger than anyone thought. He also proved that the Universe is expanding. Both changed the way we understand the Universe. His discoveries helped to support the Big Bang theory.

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Early life and educationEdwin Hubble was born on November 20, 1889, and grew up outside Chicago. When he was young, he was a better athlete than a student. He did earn good grades in every subject, except spelling.

At the University of Chicago, Hubble studied mathematics, astronomy, and philosophy. He also played for the school’s basketball team.

After he graduated, he went to England to get his master’s degree. He studied law and Spanish there, but he never lost his love of astronomy.

At Yerkes ObservatoryHubble moved back to the United States and enrolled at the University of Chicago. He studied the stars at the Yerkes Observatory in Wisconsin.

It was here that Hubble began to study nebulae. A nebula is a cloud of dust and gasses in outer space. The plural of nebula is nebulae. Far-away nebulae were the key to his greatest discoveries.

Hubble got his Ph.D. in astronomy from the University of Chicago in 1917. He then joined the staff at the famous Mount Wilson Observatory in California.

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Major discoveries at Mount Wilson ObservatoryHubble arrived at Mount Wilson in 1919. At that time, astronomers were trying to measure the huge distances in space.

Scientists measured these massive distances using Cepheid variable stars. Cepheid stars brighten and dim in a pattern. If we measure how bright they are, we can figure out how far away they are.

The Mount Wilson Observatory was using a new telescope when Hubble started work. The 2.56-meter Hooker Telescope was the most powerful on Earth. Hubble used it to see the sky in greater detail than anyone had before.

Hubble made an extraordinary discovery in 1923. He used Cepheid stars to show that one nebula was one million light years away.

He also proved that other galaxies exist outside our own. He became the most famous astronomer in the world.

People now had to accept that the Universe was much larger than anyone had imagined.

In 1926, Hubble discovered an odd fact. Almost every galaxy he observed appeared to be moving away from the Earth. The light coming from these galaxies showed “redshift.” As light travels to Earth from distant galaxies, it gets stretched by the expansion of the Universe. This makes it appear red.

After studying 46 galaxies, Hubble and his assistant wrote Hubble’s Law. It states that the farther a galaxy is from us, the faster it moves away from us. It was proof that the Universe is expanding.

It also supported the new Big Bang theory. After all, an expanding Universe must once have been smaller.Hubble used the Hooker Telescope at Mount Wilson Observatory for some of his most

important discoveries

1928Biologist Alexander Fleming discovers penicillin 1939

Nazi invasion of Poland triggers the start of World War II

1921Albert Einstein receives the Nobel Prize in physics

1914World War I begins

1907Dmitri Mendeleev dies in St. Petersburg, Russia

1903Marie Curie shares the Nobel

Prize in physics with Pierre Curie and Henri Becquerel

1901The Nobel Prize is founded

by Swedish inventor Alfred Nobel

During the time of Hubble

1935Discovers asteroid 1373 Cincinnati

1941–1948Helps design the Hale Telescope on Mount Palomar in California

1929Using the work of Vesto Slipher, Hubble and Milton Humason identify Hubble’s Law, proving that the Universe is expanding

1917–1919Enlists in the U.S. Army, serves in World War I

1919Joins the staff of the Mount Wilson Observatory

1924Demonstrates that there are galaxies beyond the Milky Way

1914–1917Studies astronomy

at the Yerkes Observatory; earns

a doctorate from the University of

Chicago

1906–1910Attends University of Chicago

1902–1906Attends Wheaton High

School in Illinois

1889Born in Marshfield, Missouri on November 20

Timeline of Hubble’s life

1890 1900 1910 1920 1930 1940

1952 Jonas Salk develops the first effective polio vaccine

1953Watson, Crick, and Franklin discover the structure of DNA

1945The United States deploys the atomic bomb; World War II ends

1940 1950 1960

1953Dies of a heart attack on September 28 in San Marino, California

His later lifeHubble became a scientific superstar for his discoveries. He is still remem-bered as a brilliant astronomer.

He ran the Mount Wilson Observatory for the rest of his life. His books and lectures helped make astronomy more popular among the public. He also worked to make astronomers able to win the Nobel Prize.

Hubble helped design the Hale Telescope in California. It was the most advanced telescope on Earth for some time.

After its completion in 1948, Hubble was allowed to use it first. When asked by a reporter what he expected to find, Hubble answered: “We hope to find something we hadn’t expected.” He died in 1953 in San Marino, California.

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SourcesBryson, Bill. A Short History of Nearly Everything. New York: Broadway Books, 2003.

Christianson, Gale E. Edwin Hubble: Mariner of the Nebulae. Chicago: University of Chicago Press, 1995.

Image creditsEdwin Hubble © SPL / Photo Researchers, Inc.

Edwin Hubble © Science Source

Hubble using the Hooker Telescope at Mount Wilson Observatory © Emilio Segrè Visual Archives / American Institute of Physics / Photo Researchers, Inc.

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