How to learn physics

Intro

The question is asked: "How do I learn physics?"

The answer follows.

The Short Answer

Get a good math background, all the way up to Calculus. It's important to be very, very good at math, so don't skip anything and don't ever cheat.

Play with everything you can get your hands on like a child. Take things apart. Smash things. Build things.

Now go to a good college with a decent physics program and get admitted to the program and study your butt off. Don't forget math + play.

Pay attention when physicists do the labs, and be sure to "play" according to the strange rules they teach you. Note carefully about the thing they call "measurement."

If you approach this with the right attitude, you should easily get a BS in physics, and you should understand most of what physics is all about: math and playing with reality.

The Long Answer

Physics is equal parts math and experiment. Experiment is a fancy word for "playing with reality".

Learn Math

The math bits you learn are tools in your tool chest. You will abuse math the same way a mortician abuses a dead body. You will hide all the icky bits and make the nifty bits seem niftier than they really are. This attitude towards math means you will never be a good mathematician. That's ok, mathematicians make terrible physicists.

Your math education starts with basic arithmetic and moves quickly into algebra, geometry, trigonometry and finally calculus. It is not until calculus that physics will start to make sense. Remember the inventor of calculus is also one of the most renowned physicists (Isaac Newton). But your math education must proceed beyond algebra and encompass as much math as you can get your hands on. Since you are not a mathematician, you will treat math the same way engineers treat science. Look for the shiny, interesting bits, memorize them, and learn how they can be used and abused.

Among the concepts of mathematics you should eventually learn predicate logic. You should also learn how to program. If you find writing theorems in geometry easy, then you are a good fit for physics.

If you are having a tough time with math, then you are doing it wrong or you are trying too hard. Read about the next topic (experiment) and come back to math with the same attitude.

Learn to Experiment

Next, you need to learn how to play with reality. Physicists call this "experimentation".

At the most basic level, you need to understand how things work and start building up your idea of how everything works. Then you need to challenge your own understanding of the world by trying to find violations of your ideas.

Say, for instance, that you notice that metal objects in a room feel colder than everything else. Well, start looking for something besides metal that feels cold as well. See whether painted metal or metal covered with plastic feels cold to. Arrange all the objects you can identify into a spectrum of how cold they are, and try to see any patterns. Once you identify a pattern, try to find a violation of the pattern, which should force you to think of a better pattern. If you can't find violations, then think of different patterns that give the same or similar results, and try to think about which pattern seems simpler to remember.

Over time, your experiments will grow more complicated and you'll want to start quantifying (assign numbers) to things. This involves the science of measurement, one of the most fundamental things physicists do. This is where you start playing with rulers and scales and thermometers and stop watches. It also helps to start keeping records in a notebook---your first lab book. As you play with measurements, try measuring something with two different scales or measuring sticks. Which one is right? Are they both wrong? What's the real measurement? These are questions physicists struggle with all the time.

Learn to Apply Math to Experiments

If you start quantifying your observations, and you start progressing in math, you'll start to use math to describe the patterns you discover. Congratulations, you're doing physics!

Get educated

Go to a good university and get a BS in physics. It's important that you get up to speed with the latest in physics and spend a lot of quality time working with real physicists. Spend as much time as you can in the labs, even trying to find a job working on a physics research project.

Experimental or Theoretical?

You'll come to the realization that there are two types of physics out there: experimental and theoretical. Experimental physics is physics you do with your hands and a tape measure. It doesn't require a lot of math, but it does require patience and consistence. Theoretical physics is what you do in your head. It doesn't require tools except pencil and paper.

Both are important, so don't allow yourself to get caught in one area or the other. Try to be both. You'll appreciate it more.

Engineering

If you find yourself trying to solve specific problems with the knowledge you've obtained, you're doing engineering. Engineering is fun and it pays good money, but it is not physics. As you do engineering, take careful notes on the questions you come up with so you can do some experimentation, which is physics. If you're spending about 20% of your time doing physics and 80% of your time doing engineering, you'll be far better than any other engineer in your field.

"Lesser" Sciences

All sciences branch from physics, even math. (The math people tried to rebel a long time ago and form their own independent country called Logicistan, but it turned out to be an utter mess.)

The next most important form of physics is chemistry, which is interesting, but very limited. After all, when your entire universe only consists of 3 interesting particles, life gets boring pretty quickly and you have to make things up to make it interesting. Nuclear physics is moderately more interesting than chemistry, but only because interesting things happen at random.

Below that is engineering, which is valuable. However, hang around engineers too long and you'll soon find that they are boring and uninterested in reality. They'd rather live in their model of the world than let someone challenge their assumptions and wrong-headed ideas. Physicists often find themselves cast out of engineering circles because we tend to really screw things up for them.

After that is medicine, which compared to engineering is almost witch doctory. Doctors try to engineer the body, but in the end all they are doing is making really good guesses and crossing their fingers.

Below that are the fields we can barely even label a science, things like psychology.