Edwin Hubble Research Paper

One of the earliest and most influential groups we studied were the Pythagoreans. Due to the fact, that their work was so fundamental to the development of modern science and of renowned Greek philosophy Plato, I though it important to consider them here. This is despite the fact that admittedly they weren’t “astronomers” and although Pythagoras was considered the “leader,” some even question whether or not he existed, and the story is really about his followers, who were a group. The Pythagoreans, were a kind of religious cult with a deep following in Italy. Although, they had this religious aspect, the attempted to address questions of fundamental importance to cosmology, including what is the meaning of the universe, what happens after death

and how can we understand our reality? In many ways, I think this speaks to the deep interconnection between religion and science specifically during this time period the fifth century BC. One of their major contributions to modern contributions to modern cosmology was the idea that that the soul and body are separated and distinct and that the soul can live on even if the body perishes. This notion that death is not the end has been fundamental to much of philosophy and religion. Secondly, the Pythagoreans believed that numbers provide a key to understanding our reality, and form a kind basis of the physical world. The importance of this belief cannot be overstated. I think to a certain, extent it can be successful argued, that this notion that numbers have the capacity to explain the truths of our world, formed much of the basis for modern science. Although it is important to note that at the time this belief in numbers was as mystic as mathematical, as the Pythagoreans had many notions about the character of specific numbers, which dictated frankly bizarre aspects of their lives including when they could eat and how they should watch. The influence can be felt in Plato’s notion of the universe captured in timaeus, where he argues among many things, that the Earth was created by an all-knowing creator, in the image of something. Furthermore, it also influenced Plato, in his notion of the interconnection between intelligence and a soul, as well as the notion that God made the earth perfectly spherical and unique, as there are no plurality of universes. Although, some of these beliefs were eventually overturned, the influence of the Pythagoreans can be felt throughout Western science and philosophy, from Plato through astronomers like Copernicus to the present day.

Galileo was an Italian astronomer born in 1564, who is perhaps most famous for his support of the heliocentric model and his role in the Copernican revolution. During his lifetime, most people believed in a geocentric model otherwise known as the Tychonic system. Under this model, it was believed the earth was the center of the universe, and all other planets orbited the earth in perfect circles. This model was first challenged due to the retrograde of planets, but was once again accredited when due to Ptolmy’s ingenious notion of planets epicycles essentially orbiting in a circle on top of a larger orbiting circle. Although, from the modern perspective it is easy to belittle such a model, I think it is important to realize that to a certain extent it makes sense, because we are the center of our own universe, and it is natural to everything revolves around us.Although Galileo did not invent the telescope, he was the first person to use the telescope for astronomical purposes of observing celestial objects. He improved on old designs and created a newer and better telescope. Through such a telescope observed three things that finalized the heliocentric movement. Firstly, that the sun had spots. This observation was important because it indicated that the universe wasn’t perfect, which called into questioned the traditionally notion of everything revolving around the earth in perfect circles. Galileo also observed that Jupiter also had moons. He specifically discovered its four largest moons including, Lo, Ganymede, Callisto and Europa. This discovery was significant because it was perhaps the first clear example, of something that didn’t orbit around the earth. The logic surrounding this discovery was as follows: Wow, Jupitar also has moons, so not everything revolves around earth and maybe we aren’t that special. Finally, and most importantly Galileo observed that Venus has phases. This was so important because these phases could only be explained by a heliocentric model as otherwise the orbit of Venus would have to be outside the sun and sometimes the orbit of Venus would have to be inside the sun. It would make no sense for Venus and the Sun to cross paths or appear to switch orbits. It is important to note, that these phases of Venus could, no longer be explained by Ptolmy’s ingenious notion of planets epicycles essentially orbiting in a circle on top of a larger orbiting circle. From these observations Galileo help to make clear that the geocentric model was outdated. Although it would still be technical possible to explain the universe as orbiting the earth is billions of circles on top of each other it is not plausible. This discovery, that the sun not the earth was at the center of the universe, not only completely transformed our collective understanding of our place in the universe, but also helped to assure in an era of modern science. Galileo thus was instrumental in ushering in the heliocentric revolution. It is important to note that under the previous geocentric, model we believed were at the center of the universe. Galileo discoveries also fundamentally changed philosophy as it was the first time that we were able to know that the universe literally didn’t revolve around us. In many ways, this was the first of many downgrading experiences, as we would go onto discovery the vast size and time it took for our universe to form. I still am not completely sure, but I believe to a certain extent this must have been a kind of shot to humanity’s pride, as our imagined self-importance was challenged by the heliocentric model and following discoveries.

Another renowned fairly modern astronomer who fundamentally reoriented our understanding of the universe Edwin Hubble.

Edwin Hubble was born in 1889, and is usually credited with the notion that our universe began with a Big Bang. As such, Hubble’s work dealt with questions of fundamental importance to cosmology, including how old is the universe, how did the universe begin, and what will be the ultimate fate of the universe. Before getting into Hubble’s discovery it is important to realize that the possibility for an expanding universe had been an ongoing discussion in the scientific community following Einstein’s theory of gravity. Einstein himself was troubled by this concept and dismayed when he found his calculations could not produce a truly static universe. This was because the accepted model of the time was an infinite, static universe. This model of course was backed by Newton. The logic of such an argument that no other model made sense because gravitational forces of any finite number of stars would cause them all to fall together into a compact blob. Under this paradigm the universe was infinitely old and would exist forever without changes to its structure. Einstein addressed the seeming flaw in his equations by adding what he called the cosmological constant to account for a static

universe.
This conundrum continued until Edwin Hubble found a simple linear relationship between the distances to remove galaxies and the redshifts of spectral lines of these galaxies.

Hubble found this relationship while working in Pasadena. His work essentially involved measuring the redshift of a number of distant galaxies. He was also able to measure their relative distance by measuring the apparent brightness of a class of variable stars in each galaxy. This relationship now called Hubble’s law states that the greater the distance to a galaxy the greater the redshift in an equation: V=H0d. Hubble constant is believed to be around 73.2 km/s/Mpc. This finding was exciting because Hubles law is directly proportional-so an object twice as far away is receding from us twice as fast. This is just what would be expected in an expanding universe, as an expanding universe would be expanding equally on all sides. Such a thought process can easily be visualized through the “expanding chocolate chip cake analogy” whereas the cake is being baked the chocolate chips in the cake recede from one another as the cake expands. This is of course just what the galaxies do as the universe expands. This discovery was incredible and was credited with solving Olber’s paradox of the dark night sky. It is also important to understand that the term red shift with respect to light implies that the object is moving away from the observer. This is because in a Doppler shift where light waves get “redshifted”

means that the light waves become further apart. Once scientist understood that the universe was expanding, they immediately realized that it must have been smaller in the past. Thus, if it was possible to rerun time on a massive scale, there must have been a time when, they entire universe would have been a single point. This point, later became known as the “Big Bang.” This is really profound; the whole universe must have been contained in a single point. This knowledge not only tells us about our origins but since the universe at one point was incredible small, and matter cannot be created or destroyed it must have also been incredible dense and hot. We thus, have since learned a lot about the evolution of the universe. However, many fundamental questions about the universe remain including understanding the nature of dark energy and matter, which are believed to be responsible for the accelerating expansion of the universe. Hubble’s discovery of the redshifted galaxies profoundly changed our notions of how and when the universe began, and what’s its ultimate fate will be. In many ways, I would argue that this discovery goes beyond science into the realm of philosophy, and religion. However, Hubble undoubtable changed our understanding of the universe, and we are still trying to grapple with some fundamental questions raised later as a result of his discovery including, what is the nature of dark matter and energy.

Perhaps one of the most interesting things about these three scientists, and to a large extent, one of the most interesting points of this class, was the deep interconnection between science, religion, and philosophy, and the profound ramifications that the development of our model for the universe has had on all three.