Learning physics

Learning physics requires real brain work---thinking.

First, let's say first what learning physics is not. It is not the
memorization of a collection of unrelated facts. If you approach it
from that perspective, you will not do as well as you could in the
class. Further after the class, you will forget most of it very
quickly and what little knowledge you gained will be mostly lost.

This is not to say that one can get by without accumulating any facts.
Certainly it is necessary to know some factual information, but that
it just the starting point. Thus one element of learning physics is
having an information base with which to work. However, in a sense, it
is the least important because it is the easiest to fix. If you forget
the numerical value for the speed of light, it is not such a big deal.
At least you know that there is a speed of light, and you can probably
figure out how to look it up quickly and easily.

The foundation of learning physics is conceptual understanding. What
do the facts mean? Which are important? How are they related? What are
the few general principles that relate a huge body of factual
information and give an understanding of how the world works? This is
where active thinking and participation come in. There is no way to
develop this without doing the learning in your own brain. Reading,
participating in discussions, and doing problems are all ways to
stimulating your thinking, but in the end, it's what you do in your
own head that will lead to understanding. You can't memorize it, and
no one can do it for you. This understanding takes time to develop.
Continuing with the speed of light example: You learned in 9HB that
the speed of light has some unique general properties that distinguish
it from sound waves and baseballs: the measured speed of light is
independent of the relative motion of the source and observer. You
could memorize this fact, or you could think about it and realize how
strange it really is. You can then understand that this fact is the
basis for the whole Theory of Special Relativity developed by Einstein
and that all the weirdness like clocks in relative motion running at
different rates follows from the weirdness of the speed of light.

Although the acquisition of deep understanding can be very satisfying
in itself, the application of knowledge is also valuable. This is
where problem solving come in. In a physics class, problem solving has
two closely related roles. Doing problems helps to get you thinking
and and thus greatly aids the process of developing understanding. It
also provides a measure of how well your understanding has developed.
If you can solve a problem almost like one you did yesterday, well
maybe you understand it or maybe you have just memorized the steps
needed to to get to the "right" answer. If you can apply your
understanding to a problem that looks very new but is based on the
same basic concepts, then you have really understood the ideas.

When physics comes up again in your other classes and after
graduation, it is probably not going to come with the label "physics"
or say "This is a physics problem from the back of chapter 5." It is
only conceptual understand the will allow you to see into a new
situation and apply your hard-earned knowledge.