Edwin Hubble - Discovering Galaxies - Research Paper Example

Edwin Hubble: Understanding the Galaxies Introduction - Brief Biography Edwin Hubble was born on November 20, 1889 in Missouri, though a lot of his childhood was spent in Illinois. Although he was a good student, Hubble was known more for his athletic abilities than his intelligence. He got good grades while he was in school, though he focused more on his athletic skills, such as track and field and amateur boxing. However, while he attended college at the University of Chicago, he focused on mathematics and astronomy, eventually getting a bachelor of science. He later changed his major to Spanish; he used both his Spanish and science majors to teach at a high school in Indiana. It was in 1917 when Hubble had received his Ph.D. in astronomy, having finally decided on what he wanted to do as a career. From then on, Hubble dedicated all of his time to the enhancement of astronomical knowledge, allowing us to better understand our galaxy, as well as others. Hubble remained in the astronomy field until his death on September 28, 1953 from a blood clot in his brain. “Island Universe” Theory Out of the many observations and discoveries that were made involving our universe, whether they were done by other astronomers or by Hubble himself, the most amazing one was the discovery of even more galaxies within our own solar system. In the early twentieth century, back when it was widely believed that our Milky Way galaxy was the only galaxy in existence, there were many disputes about the astronomy field in regard to clusters of stars known as nebulae. The arguments were about whether or not these nebulae were part of our Milky Way galaxy or star formations beyond the galaxy. It must be understood that in these times, there was no concept of the possibility of other galaxies besides our own; thus, the disputes over the nebulae. Although Hubble had yet to fully engage himself into the astronomy field, he was the one to figure out that since the nebulae were moving away from Earth that they were other galaxies. Hubble concluded that “these star systems are each ‘island universes,’ not part of our own galaxy (Haley, 1996).” This was such an important discovery during the twentieth century. Not only did it show that our galaxy is not the only galaxy in existence, opening up a whole new concept to be researched, but it also provided the foundation for the theory that the universe is still expanding, which is another theory that Hubble spent the majority of his time on researching and studying. Not only did Hubble give us something to think about in regard to our own galaxy, but he gave us something to think about in regard to other galaxies. The Expanding Universe After Hubble brought to light the thought that the universe was still expanding and that there were other galaxies besides our own, he continued to research and really study these other galaxies, paying close attention to the direction in which they were moving. While Hubble made it clear that these galaxies were moving away from Earth, he wanted to figure out in which directions they were actually moving. As he observed the galaxies as they passed Earth, Hubble noted that those with longer, reddish wavelengths are moving away from us, which is known as redshifting; galaxies with shorter, bluish wavelengths are moving toward, which is called blueshifting (Christianson, 1996). While studying the directions of the galaxies moving away and towards the Earth, Hubble discovered that the further away a galaxy is, the quicker it moves, while the closer they are, the slower they move. This helped aid Hubble in expanding upon the idea that the universe is still expanding, improving upon the Big Bang theory, essentially making it what others call Hubble’s own theory. Indeed, even Albert Einstein adjusted his relativity equations to consider the concept that the universe was continuing to expand. The Big Bang Theory The Big Bang Theory, the idea that the universe expanded from an ancient hot and dense initial condition and still continues to expand today, was originally birthed by Georges Lamaitre, a Roman Catholic priest. At this time it was not known as the Big Bang Theory, nor was it a concept that was actually connected to our galaxy. Lamaitre had used it to describe the expanding of an atom. All the same, as science and technology began to grow, astronomers and scientists began to contribute the theory to the concept that the universe might still be increasing in size. Hubble was one of these contributors, having made the biggest discovery of the other galaxies that were moving away from Earth as well as towards it. Not only did Hubble discovery the existence of other galaxies and their movements in regard to where Earth stands in our solar system, but he was able to use this knowledge, as well as the basic concept of the original Big Bang Theory, to fully expand on the expansion of the universe. Hubble determined that if the universe were expanding outward, based on the movements of the passing galaxies, then it must have come from a primary point. If this were to be true, then something must have caused that primary expansion to begin with (Sharov & Novikov, 2005). It is because of Hubble’s connections between the moving of the galaxies and the initial idea of something great expanding from a primary point that the Big Bang Theory was truly founded. Hubble’s Law Hubble further elaborated on the Big Bang Theory and the continuous movements of the many galaxies while, at the same time, trying to decide how old our own universe really was. By closely monitoring the other passing galaxies and making notes on what direction they were going and at what rate of speed, Hubble came up with Hubble’s Law, which would help to give an estimate of the age of our universe. The equation of Hubble’s Law is as follows: v = H0D. V is the velocity, H0 is the constant of proportionality between the distance, which is D (Greene, 2003). While formulating his Law, Hubble paid close attention the the individual galaxies. When he noticed that the first ones he had seen were not making more appearances and that new ones were coming into view, he began to realize how large the universe really must be. From this, Hubble fully started to realize just how big the universe is, sparking the question as to how old something of this size must be. He started taking note of the distances between the various galaxies that would pass by Earth, as well as their speed and size. As Hubble studied the various passing galaxies over more than a decade, he saw dozens of new ones, yet never the same ones as before. Based on the results from his calculations on these galaxies, it was decided that our universe is roughly fourteen billion years old. Though there is no equation that can give us a definite answer, Hubble made it possible to give us a pretty accurate estimate. Classification of Galaxies Though it is not considered to be his greatest work, nor his biggest discovery, Hubble’s classification of the various galaxies has helped astronomers, students, and enthusiasts alike. The classification system sorts galaxies based on content, distance, shape, and brightness. Hubble listed four distinguishable galaxy shapes: elliptical, spiral, lenticular, and irregular. Elliptical galaxies have smooth light distributions and look like ellipses when being viewed in imaged. In the classification, they are indicated by the letter E, followed by a number that describes their degree of ellipticity. Spiral galaxies looked like flattened disks that contain two spiraled arms made of stars, with a large amount of stars forming the center of the spiral. In Hubble’s classification, spiral galaxies are indicated by the letter S. Spiral galaxies have a subcategory known as barred spirals, where the spirals appear to be bar-like. These galaxies are indicated by SB. Lenticular galaxies look circular in appearance, having a disk at its center, but no spirals and no actively-forming stars. These galaxies are classified by S0. Irregular galaxies have no regular structure and do not have a general classification letter-number combo (Datnow, 2007). As aforementioned, the classification system might not have been Hubble’s greatest discovery, but it has aided astronomers in better understanding not only the many galaxies that pass us by, but our own galaxy. Through Hubble’s classification system, we know that the Milky Way Galaxy is a Spiral Barred (SB). We can also understand the types of star systems, if any, reside in any given galaxy. Telescopes As an astronomer, Hubble was in dire need for the perfect telescope, one that would be better than those already available to him. In astronomy, there is no such thing as the best telescope; each new telescope created may allow us to see a little more of the universe, but in a place so vast, the desired telescope has yet to exist. This did not stop Hubble, however, who took it upon himself to help design his own telescope, one that would be shared amongst the astronomy community. The 200-inch Hale telescope allowed Hubble and other astronomers to see more defined views of the newfound galaxies (Kanipe, 2007). Due to Hubble’s contribution to this telescope, as well as his general contribution in astronomy, the Hubble Space Telescope, launched in 1990, was named after him. Conclusion Edwin Hubble may not have been the father of astronomy, but he made so many contributions to the astronomy field that he could be rightfully considered a close relative. It is because of Hubble that we know what we do about galaxies. While astronomers, ancient and otherwise, have been viewing these other galaxies for centuries, it was Hubble who made them known for what they really are -- other galaxies, as opposed to simple nebulae. As if this were not an amazing discovery by itself, Hubble took his research and studying many steps further, learning all that he could about the galaxies that passed our earth, and his tireless observations were not done in vain. Not only do we know that our universe consists of hundreds of galaxies, but we also know about these galaxies, again, all thanks to Edwin Hubble. Red- and blueshifting exist because of his observations, noticing that the galaxies with long, red wavelengths were moving away from us, and galaxies with short, blue wavelengths were moving towards us. Instead of accepting this knowledge for what it was, he continued his research further. Hubble came to the conclusion that, based on the movements of the galaxies, the universe must still be expanding. In his attempts to understand the growth of our universe, he studied the passing galaxies, classifying them based on content, distance, shape, and brightness. He also labeled them as such: elliptical, spiral, lenticular, and irregular. He used his classification system to help him keep track of the galaxies coming and going. As he noticed that he saw more new galaxies and did not see the old ones again, he contemplated on the vast size of the universe. By creating Hubble’s Law, which measured the distance of and between galaxies, Hubble was able to get an estimate of how large our universe is. Edwin Hubble had started off as an athlete, someone who kept average grades throughout school. In college, he focused on astronomy, yet he also dabbled in Spanish, eventually choosing to teach Spanish at a high school after graduating college. In a turn of events, this Spanish-teaching athlete turned his sights towards the sky, studying, researching, and contributing his time and intelligence so that we may understand our galaxy and others better than ever, and opening the doors for more wondrous discoveries. Works Cited Christianson, Gale. Edwin Hubble: Mariner of the Nebulae. Chicago: University of Chicago Press, 1996. Print. Datnow, Claire. Edwin Hubble: Discoverer of Galaxies. Berkeley Heights, NJ: Enslow Publishers, Incorporated, 2007. Greene, Shane. “Edwin Powell Hubble.” EdwinHubble.com. Edwin Hubble, 03 May 2003. Web. 27 April 2010. Haley, Riki. “The Life of Edwin Hubble.” Library.thinkquest.org. The Online Planetarium Show, 10 November 1996. Web. 25 April 2010. Kanipe, Jeff. Chasing Hubble’s Shadows: The Search for Galaxies at the Edge of Time. New York: Farrar, Straus and Giroux, 2007. Print. Sharov, Alexandr and Igor Novikov. Edwin Hubble, the Discoverer of the Big Bang Universe. Cambridge, UK: Cambridge University Press, 2005. Print. Read More