2 EDWIN HUBBLE BIOGRAPHY 720L
EDWIN HUBBLE EVIDENCE FOR AN EXPANDING UNIVERSE Born November 20, 1889 Marshfield, Missouri Died September 28, 1953 San Marino, California By Cynthia Stokes Brown, adapted by Newsela
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. 2 3
Early life and education Edwin 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 Observatory Hubble 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. 4 5
Major discoveries at Mount Wilson Observatory Hubble 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. Hubble used the Hooker Telescope at Mount Wilson Observatory for some of his most important discoveries It also supported the new Big Bang theory. After all, an expanding Universe must once have been smaller. 6 7
Timeline of Hubble s life 1917 1919 Enlists in the U.S. Army, serves in World War I 1902 1906 Attends Wheaton High School in Illinois 1889 Born in Marshfield, Missouri on November 20 1906 1910 Attends University of Chicago 1914 1917 Studies astronomy at the Yerkes Observatory; earns a doctorate from the University of Chicago 1919 Joins the staff of the Mount Wilson Observatory 1924 Demonstrates that there are galaxies beyond the Milky Way 1929 Using the work of Vesto Slipher, Hubble and Milton Humason identify Hubble s Law, proving that the Universe is expanding 1935 Discovers asteroid 1373 Cincinnati 1941 1948 Helps design the Hale Telescope on Mount Palomar in California 1890 1900 1910 1920 1930 1940 1901 The Nobel Prize is founded by Swedish inventor Alfred Nobel 1903 Marie Curie shares the Nobel Prize in physics with Pierre Curie and Henri Becquerel 1914 World War I begins 1907 Dmitri Mendeleev dies in St. Petersburg, Russia 1921 Albert Einstein receives the Nobel Prize in physics 1928 Biologist Alexander Fleming discovers penicillin 1939 Nazi invasion of Poland triggers the start of World War II During the time of Hubble
His later life Hubble became a scientific superstar for his discoveries. He is still remembered 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. 1953 Dies of a heart attack on September 28 in San Marino, California 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. 1940 1950 1960 1953 Watson, Crick, and Franklin discover the structure of DNA 1945 The United States deploys the atomic bomb; World War II ends 1952 Jonas Salk develops the first effective polio vaccine
Sources Bryson, 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 credits Edwin 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. Articles leveled by Newsela have been adjusted along several dimensions of text complexity including sentence structure, vocabulary and organization. The number followed by L indicates the Lexile measure of the article. For more information on Lexile measures and how they correspond to grade levels: http://www.lexile.com/about-lexile/lexile-overview/ To learn more about Newsela, visit www.newsela.com/about. The Lexile Framework for Reading The Lexile Framework for Reading evaluates reading ability and text complexity on the same developmental scale. Unlike other measurement systems, the Lexile Framework determines reading ability based on actual assessments, rather than generalized age or grade levels. Recognized as the standard for matching readers with texts, tens of millions of students worldwide receive a Lexile measure that helps them find targeted readings from the more than 100 million articles, books and websites that have been measured. Lexile measures connect learners of all ages with resources at the right level of challenge and monitors their progress toward state and national proficiency standards. More information about the Lexile Framework can be found at www.lexile.com. 12 13