 |
USA Edition | Today Is Monday, March 22, 2010 |
|---|
|
USA Edition | Today Is Monday, March 22, 2010 |
|---|
| Who Shall Run America? | « Scan Content In The Order It Was Published » | Goodman’s Secret | |
| « Scan Only The Science Section » | Next In Section | ||
Edwin Powell Hubble - American Astronomer
Equipped with his five senses, man explores the universe around him and calls the adventure Science.
Edwin Hubble
Harley Blank
The author embarked on an avocation in astronomy in 1979. He began with an 8-inch Celestron Super C-8 SCT with all of the bells and whistles, including a hand guider and electric focus, both of which were new at that time. Later Blank added a Meade 2045 4-inch scope that is portable and far quicker to set up. He uses the Meade for 35mm astrophotography as well as through-the-lens digital photography.
His travel companion is a pair of Pentax 9-power binoculars with 63mm objectives. With an ordinary photographic tripod and mount, the Pentax binoculars make it possible to observe anywhere there is a dark sky.
Chances are the name Hubble is familiar to you wherever in the world you may read Newsroom Magazine. And for good reason, for orbiting only 250 miles above Earth, the Hubble Space Telescope has become the best-known scientific instrument in human history. The HST, as it is called, was launched from the Kennedy Space Center in Florida 19 years ago. I remember, for I was there. I’ll never forget the breathtaking liftoff, the rumbling ground beneath my feet when the boosters ignited, and the beautiful bright light climbing skyward reaching for the stars.
My name is Harley Blank and I’m an amateur astronomer. In this inaugural Newsroom Magazine science essay series, Hubble: Man To Legend, I’ll tell you about Edwin Hubble and what he has contributed to our knowledge about the universe in which we live. I’ll share what we know about the impact the Hubble telescope has had, and will continue to have, on all of us who share this planet. I’ll even reveal why HST will end its useful life in 2014-15 and that by the time it’s retired, HST will have cost 6 billion dollars to design, build, launch and maintain for its 30 year life cycle. Did we get our money’s worth? When I am finished I hope you will agree with me — yes, we surely have.
Best we begin at the beginning. What we know about the vast universe that surrounds us has been accumulated on the shoulders of giants — Nicholas Copernicus, Tycho Brahe, Galileo Galilei, Johan Kepler, Christian Huygens, Giovanni Cassini, Isaac Newton, and our man Edwin P. Hubble to name but a few.
To know about Hubble, is to know about modern astronomy – for it is the world of Edwin Hubble and the HST that have filled the imaginations of everyone in astronomical science and defined the universe in ways astronomers could not have imagined only a quarter century ago.
Edwin Hubble was born November 20, 1889 in Marshfield, Missouri. His parents moved to Wheaton, Illinois outside of Chicago before his first birthday. Young Hubble had been fascinated by science and mysterious new worlds from an early age. He spent his childhood reading the works of Jules Verne ( 20,000 Leagues Under the Sea, From the Earth to the Moon ), and Henry Rider Haggard ( King Solomon’s Mines ). Edwin Hubble was a fine student and an even better athlete, having broken the Illinois State High School high-jump record.
Hubble graduated from the University of Chicago with a degree in mathematics and astronomy in 1910. Although an accomplished boxer, he rejected a professional boxing career to accept a Rhodes scholarship to Oxford where he studied law. After a year of law practice in Louisville, Kentucky, young Hubble became bored and returned to the University of Chicago and its Yerkes Observatory ( home of the largest refractor telescope in the world ) to earn a PhD in astronomy in 1917. He then served in the US Army during WW II, rising to the rank of major.
Yerkes Telescope - University of Chicago
In 1919 Hubble was lucky enough to start his career at California’s Mount Wilson Observatory, where the Hooker Telescope, the largest and most technologically advanced telescope in the world had just been built. The astronomical debate over whether the Milky Way was the entire universe was in full bloom at this time. Most astronomers of Hubble’s day thought that all of the universe — the planets, the stars whether seen with the naked eye or with powerful telescopes, and fuzzy objects called nebulae — was contained within the Milky Way galaxy. It was believed that our galaxy was synonymous with the universe.
“We find them smaller and fainter, in constantly increasing numbers, and we know that we are reaching into space, farther and farther, until, with the faintest nebulae that can be detected with the greatest telescopes, we arrive at the frontier of the known universe.”
Edwin Hubble
In what so often is a mysterious combination of luck and brilliance, Hubble set the sights of his telescope on the nebulae. In one such nebula ( Andromeda ) he discovered a Cepheid ( pronounced CEE-feed ) variable star. Leapfrogging on Henrietta Leavitt’s work of determining cosmic distance using the luminosity of Cepheid stars ,Hubble realized, in fact, that Andromeda wasn’t a nebula at all, but a galaxy made up of billions of stars, just like our own.
This discovery in 1923 proved that our Milky Way is just one of many galaxies, settling the controversy once and for all. This one discovery forever changed the way we view our place in the universe.
“At the last dim horizon, we search among ghostly errors of observations for landmarks that are scarcely more substantial. The search will continue. The urge is older than history. It is not satisfied and it will not be oppressed.”
The history of scientific discovery is a history of the unexpected, and what Hubble would soon reveal was no exception. In observatories, astronomers had taken some giant leaps forward. They could not only determine how far away a galaxy was ( using Cepheids ), but had also figured out a way to use the light from a galaxy to determine how fast it was moving. From our point of view, the spectra of light emitted by celestial bodies shifts depending upon whether they’re moving toward or away from earth.
This is called a Doppler Shift. Galaxies moving toward earth shift toward the blue end of the spectrum; those moving away shift toward the red. By plotting the distance of 18 galaxies against their red shifts, Hubble discovered a direct relationship: Galaxies were moving away from earth at a rate proportional to their distance from us.
Edwin Hubble And Milton Humason at Mt. Wilson
Hubble and his colleague at Mt. Wilson, Milton Humason ( who started as a mule driver during the construction of the observatory, then janitor, then night telescope assistant ), estimated the expansion rate of the universe to be 500 kilometers per second per megaparsec. ( A megaparsec, or a million parsecs, is a distance equal to about 3.26 million light-years; so a galaxy two megaparsecs away is receding from us twice as fast as a galaxy only one megaparsec away. ) This phenomenon, known as the Hubble Constant, meant that the universe was expanding.
From this realization, Hubble went one step further. If galaxies that were twice as far away were moving away from each other at twice the speed, he reasoned, they must have begun their cosmic expansion from the same space at the same time. Using his distance/speed ratio, Hubble fixed that time at about two billion years ago. He was off by 11.7 billion years by today’s estimates, but he laid the foundation for the Big Bang theory, providing evidence that the universe exploded into existence with a furious burst of energy, and has been expanding ever since. It was a shattering blow to the centuries-old notion of a static universe.
The universe is unfolding as it should.
Edwin Hubble
Hubble’s name is attached to many things of everyday astronomical life. There is Hubble’s zone of avoidance, the Hubble galaxy type, the Hubble sequence, the Hubble luminosity law for reflection nebulae, the Hubble luminosity profile for E galaxies, the Hubble constant, the Hubble time, the Hubble diagram, the Hubble red shift-distance relation, the Hubble radius for the universe, and now the Hubble Space Telescope.
In the 12 years from 1924 to 1936 Hubble had set down the foundations upon which observational cosmology rests. From his central role in the solution of so grand a problem, Hubble has become a legend. It is interesting to note that in 1917, Albert Einstein had already introduced his general theory of relativity, and produced a model of space based on that theory.
Einstein claimed that space was curved by gravity, therefore that it must be able to expand or contract; but he found this assumption so far fetched, that he revised his theory, stating that the universe was static and immobile. Following Hubble’s discoveries, he is quoted as having said that second-guessing his original findings was the biggest blunder of his life, and he even visited Hubble to thank him in 1931.
Edwin Hubble left Mount Wilson in 1942, determined to help fight the Nazis in World War II. At first he wanted to join the armed forces as he had done during the First World War but soon realized he could do more for his country by offering his services as a scientist. In 1946, he was awarded the Medal of Merit, for exceptional conduct in providing outstanding services to citizens.
Mt. Palomar Observatory
As the preeminent astronomer of his generation Edwin Hubble was chosen to be the first to use the preeminent the 200-inch Hale Telescope on Mt. Palomar in 1948. When asked what he hoped to find with the new telescope by the BBC, Hubble replied “We hope to find something we hadn’t expected.”
Edwin Hubble continued his work at both the Mount Wilson and Mount Palomar observatories until his death from a cerebral thrombosis, on September 28, 1953. And look at the wonders he left behind.
Although Hubble’s name is attached to many things of note in astronomical study I have focused on the two most important. In addition to these, there are Hubble’s zone of avoidance, the Hubble galaxy type, the Hubble sequence, the Hubble luminosity law for reflection nebulae, the Hubble luminosity profile for E galaxies, the Hubble constant, the Hubble time, the Hubble diagram, the Hubble red shift-distance relation, the Hubble radius for the universe, and now the Hubble Space Telescope. We will be revisiting some of these discoveries in the third installment as we discuss the vistas that HST has opened for us.
Whether it was track and field, boxing, studying law as a Rhodes Scholar, volunteering for the Army in WW I, astronomy, or being a patriotic American in WW II, Edwin Hubble’s life can be summed up in one statement — Professional Excellence.
It was Edwin Hubble’s lifetime contributions to astronomy that led to the most complex scientific instrument ever devised being named in his honor.
