One of the most recognized names in Twentieth Century astronomy is Edwin Hubble.Â Astronomers and astronomy students recognize the name, of course.Â Even many people from the public recognized the name.Â Now, anyone who is even a little aware of world events knows the name through the Hubble Space Telescope, which was named after Edwin Hubble.
I picked today to write about him, because Edwin Hubble was born November 20, 1889.Â As a boy in school, he made good grades, but he was most widely known by his peers and community for his athletic abilities, even setting a high jump record in high schoolÂ for the state of Illinois in 1906.
In 1910, he received his BS degree from the University of Chicago.Â He was awarded a Rhodes Scholarship, and studied for three years at Oxford, where he studied law.Â Throughout his studies, he also studied his true passion:Â astronomy.Â But, upon returning to the United States, he beganÂ practicing law.Â He soon realized that he did not have much of a taste for law, and returnedÂ to the University of Chicago to pursue a PhD in astronomy.Â He was awarded his PhD in 1917, and was immediately offered a position at Yerkes Observatory.Â However, he turned down that appointment in order to enlist in the United States Army in order toÂ serve his nation during the Great War (World War I).Â Though he enlisted as a private, within months heÂ had beenÂ made made a captain.Â He was soon promoted to major and shipped to Europe.Â He served in combat, where he was injured (he neverÂ again would be able to completely straighten his right elbow).Â Â When heÂ returned to the United States, heÂ was sentÂ to the Presidio in California, where he received his discharge papers.Â
Upon leaving the Army, Hubble reportedÂ immediately to the Mount Wilson Observatory,Â stillÂ in uniform, to work for George Ellery Hale.Â On his way there,Â he stopped at Lick Observatory, where he was a commanding presense in uniform.Â From that day forward, astronomers at Lick always refered to Hubble as “the Major.”Â In fact, he seemed to always regard himself that way, often observing in coat and tie.Â Most of his career, though,Â was spent using the 100 inch Hooker telescope at Mount Wilson.Â Â After the 200 inch HaleÂ telescope was completed at Mount Palomar, Hubble was the first to get to use it.Â The first photograph that he tookÂ with the Hale telescope was of the variable nebula NGC 2261.Â This nebula had been a focus of his PhD dissertation, the first object that he hadÂ viewed at Lick Observatory, and the first thing that he photographed from the Mount Wilson observatory.Â On September 28, 1953, Hubble wasÂ walking home from his officeÂ when his wife Grace drove by on her way home from running errands.Â She stopped and picked him up, and then drove home.Â Â SheÂ said that asÂ she pulledÂ into the driveway, he got a puzzled expression on his face, and began to breathe oddly.Â Â She parked the car and then called for the maid to help her get her husband upstairsÂ as he wasn’t feeling well.Â When she turned back to theÂ car, heÂ was slumped over, dead.Â He had died of a cerebral thrombosis.Â So ended the life of a great astronomer.
Edwin Hubble isÂ most famous for his studies of the galaxies.Â He was the first to show that the spiralÂ nebulae that astronomers were so puzzled about were in factÂ entire galaxies (or island universes, as he called them at first).Â This startling finding came through studies ofÂ M31, the Great Spiral Nebula of Andromeda (what we now call the Andromeda Galaxy).Â He showed that this body was well over two million lightyears distant, and larger than our own Milky Way.Â He then studied other “extragalactic nebulae” andÂ developed a classification scheme stillÂ in use today basedÂ upon theÂ morphology of the galaxies.Â
Even if these had been all the things that he’d done, Edwin Hubble would have earned a name for himself as a great astronomer.Â But, he did more.Â Edwin Hubble is perhaps best known for hisÂ work in 1929 showingÂ that the farther away a galaxy is from us (except for the galaxies of the Local Group), the faster it is receding.Â Hubble was not the first to discover that these “extragalactic nebulae” were receding.Â That was done by Vesto Slipher of Lowell Observatory and James Keeler of Lick Observatory.Â But, Hubble combined his results with their results and produced a linear relationship between distance and recessional velocity that we know as the Hubble Law.Â This finding of an expanding universe could best be explained by understanding that the universe is expanding.Â This result had been predicted by Alexander Friedmann in 1922 by solving Einstein’s equations of general relativity.Â Â But many cosmologists had resisted theÂ notion of an expanding universe, because it implied that the universe must have had a beginning point, and idea strongly supported byÂ Georges Lemaitre in aÂ modelÂ for the originÂ of the universe that eventually became known as theÂ Big Bang.Â Â Einstein himself, assuming that the universe must be static and unchanging forever,Â had even goneÂ so far as to put an extra term in his equationsÂ that would keep the universe from expanding.Â Hubble’s findingsÂ so shookÂ Einstein that he made the journey all the way from Germany to California just toÂ examine the data.Â It is this work that led NASA to choose to honor Edwin Hubble whenÂ it cameÂ time to name the Space Telescope.Â Â Â Â
Interestingly, Hubble may have been in line for an Nobel Prize hadÂ he not died when he did.Â Â Hubble had been part of a push for many years to get astronomy recognized internationally as a branch of physics rather than itsÂ own science.Â This makes sense, becauseÂ astronomer take all the same courses as physicists.Â In fact, an astronomy degree is generally a physics degree with an astronomy emphasis.Â MostÂ colleges and universities have physics and astronomy in the same department.Â Â But, one of Hubble’s reasons for pushing to get astronomy as a branch of physics was that asÂ a separate science,Â there was noÂ Nobel PrizeÂ for available for astronomy.Â But, in 1953, shortly after Hubble’s death, astronomy was, in fact, declared aÂ branch of physics, and severalÂ Nobel prizesÂ since that time have been awarded to astronomers and cosmologists.Â The NobelÂ Prize is not awarded posthumously, though, so Hubble was notÂ eligible.Â Â
(Images courtesy of Mount Wilson Observatory and NASA)Â Â Â