The Physics Game: Why I created Gravity and Levity
For those of us who immediately liked physics class in high school, physics was a game. It was like a little logic puzzle where the rules of the game were given to you (usually on a formula sheet) and you were asked to use them cleverly to come up with a solution. A friend of mine once put it succinctly: “Physics is all about finding out which variables you know and which variable you want, and then searching through your formula sheet for an equation that has all of those letters in it.” That, more or less, was the physics game. You rearrange some symbols on a paper and you come up with an answer. Instant gratification.
Those of us who went on to study physics in college almost invariably did so because we liked the game. I personally loved it, and I was good at it. But as I went further into physics, it began to be more than a game. Little by little, all the equations and “rules of the game” started coming together into a coherent perspective on the universe and how it works. A good physics class would leave me with a sense of how some great minds of the past must have looked at the world and its natural laws: Isaac Newton, James Maxwell, Albert Einstein, Erwin Schrodinger, etc. And that was fascinating. These men had some audacious and crazy-sounding ideas. The idea of gravitational attraction, for example, — that every object in the universe pulls on every other object by some mysterious “action at a distance” — is so ridiculous that it took a man with a deep interest in the occult sciences to come up with it. Over years of study my interest in physics gradually but completely shifted from “the game is fun” to “I want to know how to think about what the universe is made of and how it works.”
Unfortunately, I find that most of my fellow students are still interested in playing the game. Our discussions with each other generally center around how to manipulate one equation to produce another, and very rarely do we talk about the big, crazy ideas behind the equations. It goes without saying that this is an endlessly frustrating situation for me. I want to talk about the ideas; I want to talk philosophy. “The physics game” has become a tedious exercise that I always sit through impatiently so that, when we get to the result, I can ask “How do I think about that?”
In physics, every equation is a sentence. Mathematics is just a language: a concise way of writing precise statements that comes along with a complicated grammar. So every equation should be translatable into English to produce an idea. So every important equation in physics must have a corresponding important idea. But the translation process Math English is a difficult one. It’s easy to abandon the English version altogether and just “talk in math.” But without the translation, without the idea in words and the accompanying “picture” of what it means, physics is just a game. And it has become clear to me that I don’t want to spend my life playing a game. If physics is going to be fun for me, and I know it can be, I need to talk about the ideas, the grandiose and ludicrous ideas.
Translating math into words and pictures can be difficult for intellectual reasons, but talking about those words and pictures can be difficult for social reasons. Physics students, for the most part, are eternally insecure. Physics has sort of a cult of intelligence, where we worship the “heroic” figures of the past, pass on mythologies of their other-worldly brainpower, and glorify their acts of intellectual arrogance. It is no surprise, then, that every student is secretly afraid that s/he isn’t really smart enough to do physics as a career, and that if they talk too much they will reveal their secret. So in our conversations we stick to the math and the precise “formalism” left for us by other smart people, and it is only with great hesitancy and trepidation that we attempt to discuss the ideas behind all the math. Almost as a bluff, we act sometimes as if all the equations were self-explanatory, or that writing an equation is of itself a sufficient explanation. It isn’t.
And so I have created Gravity and Levity, a site dedicated not to precise statements of physics but to their interpretation. Upper-level physics is full of crazy and beautiful ideas, and somewhere we need to be talking about them. The anonymity of the internet seems a perfect place. I am no genius, and the things I write here are bound to be flawed on occasion or even misleading. But I will do my best to piece together the “pictures” of great physical ideas I have obtained from reading textbooks and talking to physicists and to post them here. I encourage whatever readership this blog may have to participate with questions, comments, and suggestions, however “crazy” or uncertain they may be. A concise list of what you can expect in this blog is posted under On Gravity and Levity; I hope to update weekly or better.