In a roundabout way, it is Edwin Hubble we have to thank for the Star Wars franchise. Without his work, we would not have the concept of a galaxy far, far away. If you were alive before the 1920s, when you gazed into the night sky, you believed everything in the heavens was a member of the Milky Way. What we now know to be galaxies were thought to be nebula.
Hubble was born 1889 and received a degree in mathematics and astronomy in 1910. The stars were a lifelong passion for Hubble, but the path to his ideal career was not a straightforward one.
Hubble’s father didn’t approve of a profession in astronomy, so Hubble earned a law degree. He only practiced law for one year before going into teaching. At New Albany High School in Indiana, he taught Spanish, physics and mathematics.
“To our beloved teacher of Spanish and Physics,” the school yearbook said, “who has been a loyal friend to us in our senior year, ever willing to cheer and help us both in school and on the field, we, the class of 1914, lovingly dedicate this book.”
Again, Hubble only stayed in his position for one year. His passion was calling, and he returned to school for his PhD.
Service in the Great War
When the United States joined World War I in April 1917, Hubble turned down a position at Mount Wilson Observatory to serve in the army. He would spend the next two years in France – although his unit did not see combat – and reached the rank of major.
After being discharged, Hubble hurried to Mount Wilson, still dressed in his uniform, to accept the position that had been held open for him. He completed his dissertation, “Photographic Investigations of Faint Nebulae,” shortly before his enlistment.
Working at Mount Wilson was an exciting opportunity. The observatory was home the world’s most powerful telescope at the time.
Edwin Hubble’s Momentous Discovery
Hubble had a rival named Harlow Shapley who had concluded that the Milky Way was 300,000 light-years across. As was the accepted view at the time, Shapley believed everything in existence was contained within the Milky Way.
Hubble wasn’t convinced, but it wasn’t until October 1923 that he could prove his theory. One night, he witnessed a nova in a nebula called M31. Comparing photographic plates and using an astronomic method of measurement, Hubble concluded the nova was a million light-years away. This placed M31 outside of the Milky Way.
Today, M31 still holds that scientific designation. It is better known to the public as the Andromeda Galaxy, the largest member of the Local Group, our galactic neighborhood.
Hubble was able to repeat this test with other nebula, all of which turned out to be galaxies.
By the end of the decade, Hubble also had discovered that the universe was expanding. While most galaxies are moving away from the Milky Way, Andromeda is moving toward us and millions of years in the future will merge with us to form one mega galaxy. This may sound violent, but space is so vast that the galaxies will probably merge without any star systems colliding.
The Hubble Space Telescope
In April 1990, NASA launched the Hubble Space Telescope, the first major space telescope. Its mission is to detect the outer reaches of the known universe. So far, it has detected the faint light of galaxies more than 13.4 billion light-years away. That means the light from those galaxies left 13.4 billion years ago, about 9 billion years before Earth came into existence.
According to NASA, “the telescope is able to lock onto a target without deviating more than 7/1000th of an arcsecond, or about the width of a human hair seen at a distance of 1 mile.”
In addition to photographing the early days of the universe, the telescope has made some fantastic discoveries, including an exoplanet [a planet outside our solar system] that is “evaporating.”
Updated: 27 October 2020