Space Expansion

The 1929 discovery by Edwin Hubble that the universe was expanding was one of the fascinating findings in astronomy, but also one that provided valid answers to pertinent cosmological questions (Rothstein). Naturally, people view the universe as static and the thought of it expanding might seem unreal. Looking at more clear phenomena, a house located on the equator appears static, but in reality, it travels a distance equivalent to the circumference of the earth every 24 hours. Similarly, the expansion of the universe may not be visible to people, but its stativity presents logical problems such as the sustenance of the planets in outer space without them collapsing together because of gravity. Also, the measured time taken for light emitted by a distinct star to reach the earth, which is more than the expected time, could not be explained. This paper explores the expansion of space including evaluating evidence for and against the phenomenon to establish that it is true. Actually, the space expansion occurs in a metric fashion, at a rate that is faster than the speed of light and which increases in unsteady sequences.

Background

Through history, astronomers have sought to get answers regarding the age and size of the universe. The major questions have been whether the universe has an edge or not and if it began existing at some point in history or has just been in existence. According to the early Greek experts, a finite universe was unreal because having an edge implies that there is some matter after the edge, which means continuity. On the other hand, it is difficult to imagine something without an end, therefore the size of the universe remained a mystery.

            In the early modern astronomy, the argument shifted to proving the universe’s finite state. Heinrich Olbers, a German astronomer stated that the universe must be finite because an infinite universe would result in the entire night sky being illuminated by the brightness of the stars as a result of them emitting similar brightness despite them having varying distances from the earth (Rothstein). Isaac Newton’s discovery of gravity meant that the universe could not be finite as attractive force of gravity would cause it to collapse on itself. At this time the universe presented a paradox to the astronomers that was difficult to solve. Later Einstein developed his theory of gravity, which seemed to lead to the same paradox making him suggest that the universe could either be collapsing or expanding. Nevertheless, he maintained that the universe was static and he presented a cosmological constant that he explained to cancel the effect of gravity on very large scale thus preventing the collapse of the universe. 

  The discovery of powerful telescopes that could measure the intensity of light as a spectrum of wavelength resulted in more revealing discoveries about the universe eventually leading to the conclusion that it was expanding (Yount 21).  Vesto Slipher discovered in the early 1900s that the wavelength of light from the stars and other cosmological objects shifted to longer wavelengths as the objects were further from the earth. Other astronomers established that these objects were distant galaxies. At the same time, other scientists discovered that some solutions from Einstein’s equations revealed an expanding universe (Peacock 1). Through analyzing the redshifts on some galaxies and measuring their relative brightness, Hubble established that the galaxies’ redshift were increasing in direct proportion to their distance from the earth, which suggested that there was an expansion of the universe.