Wednesday, January 13, 2010

A Unified Theory of Everything

I don't know if you have been paying much attention to what's been happening in the sciences since we went to school (am talking to old codgers like me for the moment) but a lot has changed since our high school chemistry class in the Sixties. I'm referring generally to the attempts by physicists and scientists to explain how everything in the universe is connected, and the research being done to prove these theories about what holds the universe together, why it is what it is, etc.

What got me stimulated here is the book I started reading yesterday, The Complete Idiot's Guide to String Theory. The book's description begins with the statement "Everything is connected."

We’re living in the midst of a scientific revolution that’s captured the general public’s attention and imagination. The aim of this new revolution is to develop a “theory of everything”—a set of laws of physics that will explain all that can be explained, ranging from the tiniest subatomic particle to the universe as a whole. Here, readers will learn the ideas behind the theories, and their effects upon our world, our civilization, and ourselves.

One way to look at the problem goes like this. What are objects made of? Molecules. And what are molecules made of? Atoms. Now that is as far as we got in chemistry class when I was in school, trying to understand the behavior of electrons, protons, and neutrons. But many of us did have a nagging question. What are electrons, protons and neutrons made of? Science is getting into the theoretical here, but their answer is quarks. Then the question is, what are quarks made of? At this point, string theory enters the picture.

According to Wikipedia, "String theory is a developing branch of quantum mechanics and general relativity with the aim of merging and reconciling the two areas of physics into a quantum theory of gravity. The strings of string theory are one-dimensional oscillating lines, but they are no longer considered fundamental to the theory, which can be formulated in terms of points or surfaces too."

We're talking about super tiny stuff that can't even be measured or seen, but which physicists are striving to measure and make sense out of. The website is a good place for getting a handle on the current research, with answers and explanations to questions presented in both layman's and scientific terms. "Think of a guitar string that has been tuned by stretching the string under tension across the guitar. Depending on how the string is plucked and how much tension is in the string, different musical notes will be created by the string. These musical notes could be said to be excitation modes of that guitar string under tension." (So, the universe is a miniature Rolling Stones tour?)

"In a similar manner, in string theory, the elementary particles we observe in particle accelerators could be thought of as the 'musical notes' or excitation modes of elementary strings.

"In string theory, as in guitar playing, the string must be stretched under tension in order to become excited. However, the strings in string theory are floating in spacetime, they aren't tied down to a guitar. Nonetheless, they have tension. The string tension in string theory is denoted by the quantity 1/(2 p a'), where a' is pronounced "alpha prime"and is equal to the square of the string length scale.

The reason scientists are so excited about all this is that they have a conviction that a properly conceived understanding of string theory will help explain the way the universe works, including black holes, quantum mechanics, space and time. The need for a suitable unifying theory is that current theories have contradictory aspects which do not satisfy all the questions they raise.

A lot of it has to do with relationships. For example, on first blush there does not appear to be any relationship between the full moon rising on the horizon and an apple falling from a tree. But we know now, thanks to Newton, that the theory of gravity has a bearing upon the behavior of both.

35 years ago or more I used to ponder the relationship between these four things... a tree, the sun, a butterfly and laughter. Think about that for any length of time and it really blows your mind. How different these things are. Two are different forms of life. Both of these are dependent on the sun. Think of the size differentials and how different the various substances. Then add laughter. Laughter is totally different, yet it is something that exists. Where did laughter come from?

I think it is interesting that in the Old Testament story of Abraham, God told Abraham to name his son Isaac, which meant laughter. The child was product of a miracle since Sarah was beyond child bearing years by decades. The name reveals something about the character of God, who created this universe of suns and butterflies and trees.

My own first foray in developing a unified theory of everything concluded then with the conviction that the common denominator in everything was God, who created it all.

As for string theory, it looks like The Complete Idiot's Guide is going to be a good read. It's like I'm playing "catch up" on four decades of research since my high school daze. What an amazing universe... and time to be part of it!

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