# Physics 4

Preliminaries 9
memory or visual memory in only three seconds. There was very little time for rehearsal, and then
you went and did something else for a bit right away that was supposed to keep you from rehearsing
whatever of the string you did manage to verbalize in three seconds. Most people will get anywhere
from the first three to as many as seven or eight of the digits right, but probably not in the correct
order, unless…
…they are particularly smart or lucky and in that brief three second glance have time to notice
that the number consists of all the digits used exactly once! Folks that happened to “see” this at a
glance probably did better than average, getting all of the correct digits but maybe in not quite the
correct order.
People who are downright brilliant (and equally lucky) realized in only three seconds (without
cheating an extra second or three, you know who you are) that it consisted of the string of odd digits
in ascending order followed by the even digits in descending order. Those people probably got it all
perfectly right even without time to rehearse and “memorize” the string! Look again at the string,
see the pattern now?
The moral of this little mini-demonstration is that it is easy to overwhelm the mind’s capacity
for processing and remembering “meaningless” or “random” information. A string of ten measely
(apparently) random digits is too much to remember for one lousy minute, especially if you aren’t
given time to do rehearsal and all of the other things we have to make ourselves do to “memorize”
meaningless information.
Of course things changed radically the instant I pointed out the pattern! At this point you could
very likely go away and come back to this point in the text tomorrow or even a year from now and
have an excellent chance of remembering this particular digit string, because it makes sense of a sort,
and there are plenty of cues in the text to trigger recall of the particular pattern that “compresses
and encodes” the actual string. You don’t have to remember ten random things at all – only two
and a half – odd ascending digits followed by the opposite (of both). Patterns rock!
This example has obvious connections to lecture and class time, and is one reason retention from
lecture is so lousy. For most students, lecture in any nontrivial college-level course is a long-running
litany of stuff they don’t know yet. Since it is all new to them, it might as well be random digits
as far as their cognitive abilities are concerned, at least at first. Sure, there is pattern there, but
you have to discover the pattern, which requires time and a certain amount of meditation on all of
the information. Basically, you have to have a chance for the pattern to jump out of the stream
of information and punch the switch of the damn light bulb we all carry around inside our heads,
the one that is endlessly portrayed in cartoons. That light bulb is real – it actually exists, in more
than just a metaphorical sense – and if you study long enough and hard enough to obtain a sudden,
epiphinaic realization in any topic you are studying, however trivial or complex (like the pattern
exposed above) it is quite likely to be accompanied by a purely mental flash of “light”. You’ll know
it when it happens to you, in other words, and it feels great.
Unfortunately, the instructor doesn’t usually give students a chance to experience this in lecture.
No sooner is one seemingly random factoid laid out on the table than along comes a new, apparently
disconnected one that pushes it out of place long before we can either memorize it the hard way or
make sense out of it so we can remember it with a lot less work. This isn’t really anybody’s fault,
of course; the light bulb is quite unlikely to go off in lecture just from lecture no matter what you
or the lecturer do – it is something that happens to the prepared mind at the end of a process, not
something that just fires away every time you hear a new idea.
The humble and unsurprising conclusion I want you to draw from this silly little mini-experiment
is that things are easier to learn when they make sense! A lot easier. In fact, things that don’t make
sense to you are never “learned” – they are at best memorized. Information can almost always
be compressed when you discover the patterns that run through it, especially when the patterns
all fit together into the marvelously complex and beautiful and mysterious process we call “deep