Physics is Cool #2

In an effort to shun all practical thinking about how a career path is really about the people who pursue it, I continue to persist in my efforts to believe physics is cool. After all, just because Hitler was a shit painter doesn’t mean painting is a bad idea, right? Okay, the analogy does not entirely work, but it makes me happy for the moment. Speaking of Hitler, happy Passover kiddies! You may or may not have noticed that this year’s Pesach celebration began on the 65th anniversary of the beginning of the Warsaw Ghetto Uprising. As Mel Gibson (my favourite Jew-hater ever) once said in a decent movie, “You may take our lives, but you will never take our freedom!”

Can you tell that I am in the middle of Ben-Hur? I feel bad saying this since he just died, but that movie starred another fascist piece of work. But, the messaging is good, and somehow Judah Ben-Hur (Judah Son of Hur) is a slave hero even though he’s a slave owner himself …

But I digress. I was babbling about how physics might still be cool despite the coworkers who like to make Nazi jokes. Ha … h ….

In physics there is physics and then there is technique. The difference between technique and mathematics may simply be personality and personal taste — one man’s technique is another man’s physical wonderland (just ask the string theorists if you don’t believe me). Quantum field theory is an example of something I think of as technique, but it would never be taught in a maths department. In the maths department it would be called group theory for physics, or group theoretical applications to physics for mathematicians. Bla bla bla.

What is quantum field theory? It is a way of making the possibly unholy marriage of special relativity with quantum mechanics possible. In some sense this is a very basic idea — we want quantum mechanics to be accountable for the fact (so far) that the speed of light is finite. In other words, information takes time to arrive somewhere and cannot instaneously jump from point A to point B.

In order to make quantum mechanics amenable to our purpose, however, we must do some fancy tap dancing. Dance puppets dance, the universe yells! The modifications are somewhat complex, but I think it can be put simply to this sort of strange idea: we have to build a quantum mechanics at each point in spacetime, and this collection of quantum mechanics’ is known as a quantum field.

Tada!

To the hoosier who is saying, “but who gives a fuck?” I offer the following. Isn’t it kind of radical that such a simple idea requires a complete rethinking of how we apply what we already know? Even as we build on what we already know, in the process we reshape what we thought we knew. The development of quantum field theory is a case in point. Additionally, it turns out to be an incredibly rich way of looking at the quantum world: every tiny particle that we have observed so far has been predicted in the rich accounting of quantum field theories, which we call the Standard Model.