Age of the Universe
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Answers To An Old Question Get Better As We Keep Questioning the Answers

+ Von Del Chamberlain +

Science begins with looking around and noticing interesting things that raise questions in our minds. So science is the process of answering questions. Right? Not exactly. Most of the time what really happens is that we discover new questions that must be answered before we can answer the one we started with. Usually these new questions could not even have been asked when we started down that particular road. Each new question might seem to delay the answers we seek, but what is really happening is that we are understanding more clearly the meanings of the questions. Thus original questions get splintered into other questions that are more at the core of the quest.

Case in point. I suppose that for all of human history we have, in one way or another, been searching for the answer to the question, "How old is the universe." Of course, early man would not have phrased it that way, but somewhere in the back of his mind he wanted to know, so he looked around and invented explanations that portrayed the world as he saw it. Today we call these early answers mythology and we label them as stories involving powerful deities ranging from Zeus to Raven and Coyote.

Concerning our question about the age of the universe, it is interesting to note that early on many cultures considered the earth to have existed first leading to the rest of the universe. No, they did not ask the question, "How old is the universe?" But they did wonder about Earth and Sky, considering both to be deities themselves. There are lots and lots of stories about the origin or Earth and Sky, all of them interesting when viewed within the cultures that created them.

Eventually scientific method came along and began addressing questions in more systematic ways, seeking answers that could be verified over and over again by independent methods that would all come together in answers that we could have great confidence in. It was then that the question about the age of the universe got clearly articulated. Now that we could clearly ask the question, it was apparent that we could most easily address a host of sub-questions-bits and pieces of the bigger one:

"How old is Earth?" "How old is the Sun?" "How old are the stars?" Each of these has interesting history involving study of rocks, determination of such things as the distance of the Sun and stars and analysis of light indicating chemical compositions, temperatures and other details about the object that make up the universe.

Ever so gradually answers started coming, each one accompanied with the emergence of many new questions. We learned that Earth is a planet about 4.5 billion years old, orbiting a star about twice that age that is powered by thermonuclear reactions. We learned about the ages of stars, including how they got started and how they evolve. We thought about how planetary systems might form along with stars.

We learned enough to notice that the entire collection of stars and galaxies we call the universe is expanding indicating that everything must have been together at a common place in space and time marking the beginning-the creation. Suddenly the questions of the size and age of the universe became the same question. If we could know how big the universe is we would know how long it has been expanding, thus how old it is. Finally we were able, with credible evidences from many directions, to give an estimate of the age of the universe: something like 12 to 20 billion years.

The pace of learning accelerated, but always answers were accompanied with emerging new questions. Over recent years we have seen many revisions to the estimated age of the universe, and today it seems like every few weeks we hear a new one. Now the revisions are smaller and smaller, hovering around 12 to 13 billion years.

Still, problems rear their heads. Recently, for example, estimates of the ages of some stars came out older than the rest of the universe. This impossible situation caused questioning the answers once more. New ideas resulted. Some that would have seemed ridiculous not long ago now appeared ingenious. Perhaps the expansion of the universe is accelerating, rather than slowing down. But how can that be? What source of energy could account for such a thing on such a grand scale? Such questions are now at the cutting-edge of cosmology.

Some really big new questions came from discovery that a whole lot of invisible matter existed that effected the measurements being made. Since this matter could not be seen, it was referred to as "dark matter." What is the origin of this dark matter? How much is there? How can we study it? As more and more information was obtained it became clear that something like 90% of the universe must consist of this dark, previously undetected, matter. Just as we thought we were homing in on the answer to the age of the universe we realized that we hadn't even known about 90% of what we thought we were talking about. We still do not know much about the dark matter.

Will we ever get the definitive answer to the age of the universe? I, for one, doubt it. I think we will get closer and closer, but that will never quite satisfy scientists. Science is the quest for understanding every detail that we can; the intelligent person's sole-satisfying game of discovery. Scientists are explorers in the finest sense of exploration. The game yields knowledge with practical applications flying out for the benefit of all. Looking around we ask questions, find partial answers and new meanings to the questions. Constantly we question the answers and take branching pathways of exploration in the never ending quest for comprehension of ourselves existing in the universe.

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