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Why I Went Into Physics (finished version)

Thank you to all those on my friends list who contributed suggestions for fixing up the last draft of my essay. I just submitted the "final copy" and it's now in the lobby of our physics office for all to enjoy. Here is the essay in its final form:

Why I Went Into Physics
by Jeff L Jones

In the 1st century BC, Hippocrates said "There are in fact two things, science and opinion; the former begets knowledge, the latter ignorance." More recently, after science had split into separate fields, Ernest Rutherford added "All science is either physics or stamp collecting." While both of these are no doubt absurd exaggerations, I agree emotionally with the sentiment behind both and they are the best starting point I can think of for an explanation of why I went into physics.

When people ask me that question I usually give them a confused look for a moment until I realize what they're asking. It's the same look I'd give someone if they were to ask me "what do you like about sex?" Liking it as much as I do, it's very difficult for me to imagine someone not liking it or not understanding what there is to like about it; nevertheless, I will make my best attempt here to explain its appeal to me.

When I was young I was one of those kids who could never stop asking "why?" Every time I got an explanation from my mother or father for why things were the way they were, or how things worked, it would just lead me to ask another question. Eventually, my parents ran out of answers and started directing me to the encyclopedia. That sated my curiosity for quite a while, but the problem with the encyclopedia is that it's mostly just a collection of facts. What I wanted was an organizing principle for these facts. I sensed even then that there had to be some very simple and quite general rules which gave rise to all the order I saw. And I imagine this is what Rutherford meant by his stamp collecting comment. Science is crucial for understanding the world, however most of science is dedicated to collecting facts. While fact collecting is certainly important, I myself do not find it interesting. Physics explains those facts by compressing a huge amount of observed information down into a very tiny set of organizing principles called a theory. These principles, whether or not they are really the fundamental ones or if there is a deeper layer of structure we have yet to uncover, are often called "the laws of physics" (although theory and principle are both better terms for this because of some unfortunate connotations the word “law” has). This process of the compression of knowledge, and the insight that very complex systems can emerge from incredibly simple and elegant mathematical rules, is known as reductionism. Others may have different--but mostly equivalent--definitions for this word; this is the one which makes the most sense to me.

Reductionism is, in my opinion, the most powerful and beautiful tool humankind has ever wielded. It gives us the ability to abstract away the circumstances of a particular set of observations (for instance, a scientific experiment) and generalize them to gain an understanding of the world at large. I say reductionism is powerful because it has led to countless breakthroughs in technology--giving people control over their lives where they previously had none—as well as vastly increased our knowledge and understanding about this strange place where we live. I say reductionism is beautiful because it reveals the surprisingly ordered and symmetric patterns of structure behind the apparent chaos we experience in our lives. The personal sense of beauty and perfection I derive from working in the enormously successful reductionist paradigm to understand nature's elusive mysteries is what attracts me most to physics.

One of the first and greatest principles of physics was discovered by the great grandfather of modern physics--and one of my personal heroes--Galileo Galilei. This is the Principle of Relativity, a beautiful symmetry of space which Galileo discovered and Einstein later generalized from 3 dimensions to 4 (to include time as well as space). This is one of the best examples I can think of where the introduction of a simple organizing principle was able to compress a seemingly huge amount of information about the world down into a very tiny and easily manageable package, illustrating the awesome power of reductionism. Nowadays, more and more of the important principles of physics are expressible in terms of symmetries. In addition to being an avid lover of reductionism, I have always had an intense fascination with symmetry (of all kinds) and I believe there is a deep connection between the two. (And I see duality--something I'm also fascinated by which shows up in physics quite a bit--as a special case of symmetry). They have both become cornerstones of physics, and I think that they may both represent the same key component of conception itself--the method through which our minds make sense of the world.

In addition to discovering relativity, Galileo's life taught us an important lesson in epistemology. Namely, that empiricism--gaining knowledge through experience, whether personal or shared--should be trusted far more than intuition in judging the relative merits of theories about the world. He had the choice of believing in the folk knowledge of the day (ancient texts and the collective intuitions of the people about how things should work) or believing in Copernicus's controversial and blasphemous theory that the earth revolves around the sun. Copernicus's theory was supported by the observational evidence in his telescope but bitterly rejected by the people's intuitions and anthropocentric religious dogma. They believed, a priori, that any theory which doesn't place man at the center of the universe was too disconcerting and upsetting to be true, regardless of any a posteriori evidence to the contrary. Galileo decided to trust what he saw in his telescope, and was severely persecuted by the church for that decision. Even though it took 350 years for him to be publicly pardoned for his "heresy", it became plainly obvious long before then that Galileo had indeed been correct and the people's intuitions were misplaced. Since then, physics has become ever more counter-intuitive and less anthropocentric, and there is still much difficulty in reconciling it with popular intuition which often lags behind. Empiricism, while unfortunately not appreciated much in society as a whole, has become the foundation for all of science including physics. And like reductionism, it has been a major reason for the success of science in rapidly accelerating the growth of knowledge and technology held by society. I believe these are rough indicators of societal freedom and total happiness, in a utilitarian sense; although I would warn against attempts at constructing any sort of tighter moral calculus.

It was reading about the astounding discoveries and insights into the foundations of reality made by Galileo, Newton, Maxwell, Einstein, Dirac, Feynman, and others which inspired me to go into physics. How could they have explained so much with such lean assumptions? I see no comparison to the magic and beauty of physics, and no match for the epistemic power of reductionism and empiricism in concert. Physics is a source of enlightenment which for me goes far beyond anything art or religion can offer. There are many layers of structure in the world, and physics is an attempt to probe the deepest of them. Will reductionism continue to live up to its unparalleled track record? Or will we eventually reach a limit beyond which we cannot further reduce the number of degrees of freedom we use to describe reality? And if there are limits to reductionism, will we be able to find a new means of conception or description which can take us beyond these boundaries and complete our picture of the world? I do not know the answers to these questions, but I hope to spend the majority of my life helping to find out.


( 4 comments — Leave a comment )
Jan. 17th, 2006 09:20 pm (UTC)
Nice, very nice. Well done and an interesting read - even for someone not in the field. :)
Jan. 18th, 2006 05:37 am (UTC)
still good.
Jan. 18th, 2006 05:54 am (UTC)
Your responses to this and my last entry remind me of when you wrote your delightful Add-vice entry and I replied "good advice!" I wonder if the similarity was intentional.

I think the problem is, we agree too much so there's just not much else to say other than yes :)
Jan. 18th, 2006 07:59 am (UTC)
( 4 comments — Leave a comment )


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