Studying to become a physicist

Hello:

I get an email from time to time about what to study to learn a unified field theory for physics. The answer is here, written by a Nobel prize winner:

http://www.phys.uu.nl/~thooft/theorist.html

He sounds spot on to me. He has more detail than I can provide, so read it carefully. Here are my most general educational observations, then get into specifics.

For any topic, get the books from the most famous dead teacher of the subject. The reason is that your brain like mine is not that big - clarity matters more than anything. So for classical physics, that would be the Feynman lectures. If you take quantum mechanics, one would want Dirac's Introduction on Quantum Mechanics.

Such books often are not assigned, but buy them anyway. It is like admiring a sculpture, you need to walk around a subject. Different authors have slightly different angles on exactly the same subject. Reading the same thing from three or four authors can be effective because one of the authors happens to make sense.

In this age of the internet, I also would look through the offerings from MIT and Stanford. I particularly think it is of value to find lectures on nearly the same darn thing. If you can spot small differences in how things are taught, that demonstrates you were remembering the subject in the first place :-)

OK, that applies to _any_ subject, but it is my general methodology.

> unification of the gravitational force and the electromagnetic force.

You do know that is dangerous? This is kind of a half joke. The serious side is that you cannot get a job studying unification. If Einstein spent 30+ years trying to do exactly that and failed, then it will not be funded. Stop. No discussion.

What does get funded the most these days is work on strings. As you also probably know, there are people who think it is a beautiful area of study which may ultimately lead to unification, and there are people who argue against its value. For full disclosure, I am in the second group, which is why I was careful to call it "work on strings" since I reserve the word "theory" for the finest, most robust results of the 400+ years of the scientific process. Evolution and special relativity are theories, while people study strings.

At this point of your career, you will need to make a strategic decision based on incomplete information. If you think that string theory holds a profound truth, you will need to ask someone else for advice, although I might start with an undergrad class taught on strings which might be on the web.

> What kind of theoretical research do you think a student such as myself could embark on at the university level?

I can give you one concrete job: derive the Maxwell equations from the action. I wrote this up on a blackboard once. The process took an hour and fifteen minutes, and looked amazing, so many darn partial differential equations. Often that task will be assigned early on in a graduate level EM class as an assignment. If you know the derivatives of x^2 and xy with respect to x, that is enough. The problem is kind of like a sudoku puzzle: a few simple rules, lots of details, and things work out beautifully.

If you figure out how to apply the Euler-Lagrange equation to the Maxwell action and result in Maxwell field equations, that should almost fit on one page of paper. If you leave that around your room, people will presume you are smart as hell :-)

No one teaches undergrads about actions and Lagrangians. Too bad, because it is a simple idea: they represent all the ways energy can be exchanged in a given volume. Integrate that over space and time, and your get energy times time. Integrate over an arbitrary amount of time, and you get an arbitrary result. So why care? Because of the calculus of variations. Look for something that you can change without changing the arbitrary integral. That is a symmetry of the action. Where there is a symmetry, there is a conserved quantity.

As you also may have picked up, I have LOTS of youtube videos out there, some of which I do these exact calculations. If you decide to watch a few, in order to learn it you would need to write out the math blinking by and prove to yourself it is not bs.

For specific classes, I would probably do 3/2 math/physics. It is the math wonks that are stars in physics. I would be surprised if a college has a class that featured the calculus of variations, but that should be taken since it is the key do working with actions.

But what about non-physics stuff that could give you an advantage in thinking? I would stress three things: visual studies, music and working on creativity. More of our brains are devoted to visual analysis than anything else. That is the layout of the hardware you have. Yet we do not stress developing basic visual skills on the long road to a Ph.D.. If you have _no_ training, a good place to start is "Drawing on the Right Side of the Brain" by Betty Edwards. She is able to apply things learned from brain studies to practical lessons. Take drawing classes, and take them seriously. Drawing is not a physical thing, it is a mental skill. As with all skills, it can be learned with enough time and effort. You do not need to become a great draftsman, but you do need to have confidence in the visual part of the brain.

Music is important because it is about rhythm. Much of what the brain stores may be by timing alone, so the better your own timing, the better your thinking. College can be insanely busy, and you may decide to drop playing an instrument or signing. Well, you can pick it back up. Make noise for yourself. I stopped playing piano for 6 or 8 years, but got back into in, a major gain.

Here is my definition of creativity: Creativity is imagination bound by logic. All the classes will teach you about logic. The art and music will be about imagination. Great theoretical physics involves finding something new to do in a logically rigid subject. Challenging your own ideas about what is right is the biggest barrier. You need to get used to taking away the pillars of the chair you sit on. I do that in art, in improvising on the piano, in cooking dinner (Mexican spaghetti is one of my concoctions).

Might as well say it: you should also be creative in your private life, challenging assumptions you have there too. I have taken a dozen adult adult ed classes. One does not have to do these wacky things, but making sense of the diversity of human sexuality is a valuable thing.

Famous physicists had variations on these traits. Einstein improvised on the violin, and had a room his wife was not suppose to visit but other women were welcome. Feyman like to draw while hanging out in strip clubs, and knew how to do polyrhythms on the bongos. I don't know about Leonard the lover, but he was good on the lute, knew how to throw a party, and could out draw anyone. Take the art stuff seriously.

Doug