Saturday, February 15, 2014

A Finite Universe?

When I was first exposed to the wonders of the Universe as a young third grader, I thought that it seemed so large and boundless compared to the minuscule beings who lived on Earth. It was hard to believe that there was more to existence than the environment around me. However, although the universe seemed limitless to me, I soon discovered that the Universe could possibly have finite bounds.

In the past, people believed that the Universe was either infinite in size and age, or that it was of finite size. Now, the fact that our Universe is static and unchanging but is expanding somehow triggers much conflict and debate in society. Sir Isaac Newton’s prediction was that matter is attracted to other matter by some kind of an invisible force. Going a bit further with this, he thought that the more massive cosmological bodies are, the closer they are to one another logistically. In his theory of gravity, the stars should be attracted to one another. However, other cosmologists brought up the conflict that distant stars remained in a static position and even appeared motionless. Instead of trying to refine his theory, Newton just decided that the Universe was infinite with an infinite number of stars. He argued that in an infinite Universe, every star could be regarded as lying at the center of the Universe, and thus no star would ever move.

Later, a German philosopher named Heinrich Olbers successfully presented the argument that in an infinite, yet static universe, every line of sight should shine like the surface of a star. However, though a dark night may indicate a finite age to the Universe, this does not necessarily mean it has a finite extent. Astronomers have concluded that the Universe began some 12 to 15 billion years ago which means we can only see the part of it that lies within this time frame. There may be an infinite number of stars beyond that cosmological horizon but we cannot see them because their light has not yet arrived. This contributes to the idea that the Universe is not static, but still in the process of growing.

On the other hand, other professionals claim the Universe is finite due to evidence they have found. Mathematician Jeffrey Weeks states “Just as the vibrations of a bell cannot be larger than the bell itself, any fluctuations in space cannot be larger than space itself.” Weeks and his colleagues proposed that the Universe would be like a hall of mirrors, with the wraparound effect producing multiple images of everything inside. In addition, Weeks believes that our Universe seems like an endlessly repeating set of dodecahedrons which has matched up with NASA’s Wilkinson Microwave Anisotropy Probe (WMAP) observations.

In conclusion, we still do not know if our Universe is finite or infinite. Though many theorists mostly accept the Friedmann-Lemaitre-Robertson-Walker (FLRW) model for the geometry of spacetime, other cosmologists find consistencies with other possible geometries, such as the Poincare dodecahedral space. This is due to the observation of the lack of structure in the cosmic microwave background by the WMAP spacecraft. Though many cosmologists are leaning towards the idea of a finite Universe, the topic of the limitations of our Universe is still under debate.
Clara Lee