One fundamental question to ask is what is the age and size of the universe. Does it have an edge or boundary or does it go on forever. Is the universe finite or infinite? How old is it? Even in antiquity these were burning questions.
The Greeks asked, what does an infinite universe look like? But, if it is finite, what happens to you if you try to slip through or past one of it’s defining edges? As one of my daughters often asked before going to bed, “what was there when there was nothing?” It was clear that if I suggested to her that the universe was finite and that it thus had a boundary, and that it was all that we can know about, she might well ask, as the Greeks did–and as she did– “what happens to you when you try to stick your hand through to the other side? Where do you go?”
Many arguments persisted through the ages over whether the universe was finite or infinite. Newton finally gave the argument some substance because gravity is always an attractive force. Thus, if the universe were finite, it must at some point collapse on itself. However, there was no evidence that this collapse was going to happen anytime soon. To the average observational astronomer, this was a paradox. There was no basis to suspect the universe to be infinite nor any evidence to suggest that it was finite.
Even two centuries later when Einstein’s modified our views on gravitation in the context of the General Theory of Relativity, real answers were still hard to come by. Einstein suggested that the universe was static, but just as with Newton, Einstein’s equations suggested that the universe should be either collapsing or expanding. Einstein saw the inability of the theory to answer the question of the large scale (universe wide) effect of gravity to be a fundamental flaw in the theory.
In the 1920s as astronomical observation improved our ability to see distant objects and the light coming from them, increasing numbers of distant objects were shown to emit light that was shifted toward the red wavelength end of the visible light emitted from them. This indicated they were moving rapidly away from us. These so called “red-shifted” objects turned out to be mostly distant galaxies–a very large number–at all directions out away from the Earth.
As the farther distant objects were more and more “red-shifted,” showing that the size of the red shift was an approximately linearly related to the distance of the object, Hubble came to the general conclusion in 1929 that the universe must be expanding, and that an expanding universe must be finite in both space and time.
By reversing the expanded universe back in time to a single point, LeMaitre, a Belgian physicist and Roman Catholic priest, sets a start point for the expanded universe to a condition where neither time nor space exist and all that is to become the universe is trapped within this single nondescript point. This point, or singularity as it is often called, has established a major direction for theoretical physicists to think about.
What happens immediately with the start of the expansion? This start point was given a name by the physicist, Fred Hoyle, who referred to it as the “Big Bang.” Initially, all matter and energy are created and within a short period, as things start to move, the clock of the universe is set in motion. “Time” is also created. Going backwards in time suggests the starting point or the “Big Bang” was initiated about 13.6 Billion years ago. This is a hard number to think about, but it is consistent with what we now know about the other properties of the universe, including the birth, death and very long lifetimes of the stars and galaxies.
Clearly, the universe, as we now see it, is incredibly old and almost unimaginably large in ways that are nearly impossible to relate coherently to the length of a human lifetime or even to the length of time involved in the entire span of human existence on Earth.
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Richard A. Hudson is a writer, reader and blogger committed to exercise, proper nutrition and health. He’s interested in politics, economics, alternative energy, gardening and sustainability and has written brief essays on many of these topics on his bloghttp://richlynne.wordpress.com. Despite his generally positive and optimistic views about globalization, he wonders whether we will survive current destructive forces that increasingly promote warfare among political and social classes. He is also beginning to think about the declining influence of the know-it-all baby boomer generation just as the next generation born in the 60s begins to slowly stumble into a dominant position in the U.S.
He received a Ph.D. in organic chemistry from the University of Chicago (1966) and subsequently spent 42 years in academics, gradually developing all sorts of interests well beyond his basic training. He ended his academic career in 2008, having published about 100 scientific papers, reviews and commentaries. In his last several years in the academy, his role as Dean of the Graduate School afforded him many opportunities to interact with students from all over the world seeking graduate degrees.