# Physics 5

10 Preliminaries
understanding” of some subject.
There is one more example I like to use to illustrate how important this information compression
is to memory and intelligence. I play chess, badly. That is, I know the legal moves of the game,
and have no idea at all how to use them effectively to improve my position and eventually win. Ten
moves into a typical chess game I can’t recall how I got myself into the mess I’m typically in, and
at the end of the game I probably can’t remember any of what went on except that I got trounced,
again.
A chess master, on the other hand, can play umpty games at once, blindfolded, against pitiful
fools like myself and when they’ve finished winning them all they can go back and recontruct each
one move by move, criticizing each move as they go. Often they can remember the games in their
entirety days or even years later.
This isn’t just because they are smarter – they might be completely unable to derive the Lorentz
group from first principles, and I can, and this doesn’t automatically make me smarter than them
either. It is because chess makes sense to them – they’ve achieved a deep understanding of the game,
as it were – and they’ve built a complex meta-structure memory in their brains into which they can
poke chess moves so that they can be retrieved extremely efficiently. This gives them the attendant
capability of searching vast portions of the game tree at a glance, where I have to tediously work
through each branch, one step at a time, usually omitting some really important possibility because
I don’t realize that that knight on the far side of the board can affect things on this side where we
are both moving pieces.
This sort of “deep” (synthetic) understanding of physics is very much the goal of this course (the
one in the textbook you are reading, since I use this intro in many textbooks), and to achieve it you
must not memorize things as if they are random factoids, you must work to abstract the beautiful
intertwining of patterns that compress all of those apparently random factoids into things that you
can easily remember offhand, that you can easily reconstruct from the pattern even if you forget
the details, and that you can search through at a glance. But the process I describe can be applied
to learning pretty much anything, as patterns and structure exist in abundance in all subjects of
interest. There are even sensible rules that govern or describe the anti-pattern of pure randomness!
There’s one more important thing you can learn from thinking over the digit experiment. Some
of you reading this very likely didn’t do what I asked, you didn’t play along with the game. Perhaps
it was too much of a bother – you didn’t want to waste a whole minute learning something by
actually doing it, just wanted to read the damn chapter and get it over with so you could do, well,
whatever the hell else it is you were planning to do today that’s more important to you than physics
or learning in other courses.
If you’re one of these people, you probably don’t remember any of the digit string at this point
from actually seeing it – you never even tried to memorize it. A very few of you may actually be so
terribly jaded that you don’t even remember the little mnemonic formula I gave above for the digit
string (although frankly, people that are that disengaged are probably not about to do things like
actually read a textbook in the first place, so possibly not). After all, either way the string is pretty
damn meaningless, pattern or not.
Pattern and meaning aren’t exactly the same thing. There are all sorts of patterns one can
find in random number strings, they just aren’t “real” (where we could wax poetic at this point
about information entropy and randomness and monkeys typing Shakespeare if this were a different
course). So why bother wasting brain energy on even the easy way to remember this string when
doing so is utterly unimportant to you in the grand scheme of all things?
From this we can learn the second humble and unsurprising conclusion I want you to draw from
this one elementary thought experiment. Things are easier to learn when you care about learning
them! In fact, they are damn near impossible to learn if you really don’t care about learning them.