Do these statements sound familiar to you?
·
“An atom is like a little solar
system, where the nucleus is the sun, and the electrons are the planets.”
·
“The kingdom of heaven is like
treasure hidden in a field.”
·
“Working memory is a conveyor
belt.”
During the last few years, as I spent time listening to
Great Courses, learning about disparate disciplines like writing, philosophy,
physics, history and theology, I have been struck with one recurring method
used by the many teachers I’ve heard, and it occurred to me that every teacher
I could remember used that same method.
What is the method? Comparison as
explanation. Simile, metaphor, models:
all of these are ways to explain one concept in terms of another, and they all
depend on the ability to compare something you already know to something you
want to learn more about.
When you’re learning something new, you’re standing on what
you can think of as an island of existing knowledge, and you want to cross over
to some new island of knowledge. To get
from one island to another you can walk over a bridge of metaphor. That is, you can base your understanding of
the new, by comparing it to something you already know.
This is not simply an effective teaching technique, it’s
also both something our minds seem programmed to do and a method we apply to
our own lives without even thinking about it.
Often, when we learn about something for the first time, especially if
the new topic is complex, we can get a basic understanding by comparing one
thing to another. For example, the first
statement above compares atoms to planets.
By the time we start learning about atoms in school, we have typically
been exposed to the solar system in previous science classes. The comparison, then, makes sense. It gives us a mental picture on which we can
scribble mental notes. This is very,
very helpful.
But as we drive over the bridge of simile, we need to be
careful that it does not collapse and drop us to our doom. Why would that happen? Well, the comparison can only be as good as
the underlying structure of the known thing is similar to the underlying
structure of the new thing. If the two
things are not extremely similar, we might make a generalizing assumption which
gets us in trouble. For example, two
primates are very similar, whereas a primate and a jellyfish are not. So, while you might deduce some similarities
between a jellyfish and an ape, based on them both turning food into energy,
for example, you probably don’t want to generalize a similarity when it comes
to how they will react to a mirror introduced into their environment.
And, in the case of the atomic structure being like a solar
system, you might picture electrons being solid objects, similar to
planets. This would be carrying the
analogy, perhaps, too far – depending on the degree of detail you need. Electrons, as explained by current quantum
theory anyway, don’t “really” travel in circles (or some other relatively
“flat” closed-loop paths) but sometimes it helps to think of them that way,
especially when first learning about them.
Once you get to a point, as an engineer or physicist, to require a
deeper understanding of subatomic structure, however, you need to know quantum
theory, and that is not much like a solar system at all.
The trouble with using these comparisons, you see, is
noticing when you have fallen off the bridge.
If the bridge were a real thing, instead of a metaphor, it would be
obvious. You’d be falling, or submerged
in water, or smashed to a pulp. But, as
this bridge is metaphorical, it can be more like a wrong turn, which seems to
be making progress towards your goal, but which is really taking you somewhere
you didn’t intend to go.
Many years ago, for example, scientists thought that light
was a wave. This caused them to posit a
material through which the wave traveled.
They called it “ether.” Why did
they think ether existed? Well, the waves
they knew about all had some substance through which the wave transmitted
itself. Waves in the ocean have, at their
basis, water. Without the water, there
is no wave, so clearly light – because it was a wave – must have some “stuff”
in which to carry itself.
Of course, ultimately, scientists proved this was nottrue. They had been using the metaphor
of a fluid wave, and it had led them down an incorrect path. Light might have some properties of
“physical” waves, but not the requirement to have a transmitting material.
None of the above is meant to discourage anyone from using
comparisons! Far from it! As I said before, our minds seem to look for
similarities, and those similarities help us learn. My point today is about being aware of the
metaphors you are using, so that if you need a more thorough understanding of something,
you can use more than the model.
Of course, even when you do, you’re probably going to just
encounter another model – those scientists who care about electrons need to
understand mathematical probability – because true understanding of many topics
might just be beyond what you need, or what we can accomplish. But if an additional metaphor helps you
comprehend the thing more completely, then, by all means, use it! Just be aware, it’s still just a model.
==========================================
[I have been wanting to write about this topic for well over
a year, but I’ve been avoiding it because I feel it’s very expansive, which
makes it hard to cover properly in a blog, which I feel is a medium typically
more conducive to taking a concise approach.
So, what changed my mind? Well, I
recently bought another Great Course, and as I looked at the list of lectures,
it appears I will be hearing 30 minutes on this very topic. I decided that I want to get my thoughts
captured before being exposed to those of the professor. I will be happy to revisit the whole idea
later. Meanwhile, I remain abashed proud
of the silly pun in the title. So I like
Star Wars; so sue me. ]
2 comments:
Oh go take a long walk on a short Bridge!!
Wittgenstein has some interesting thoughts on language and shared experience. When you and I have a common framework, a simple phrase like "MacArthur on the beach" conveys many things despite the spare word count. Promises kept, vows fulfilled, inevitable victory, we make our own fate...
Without a shared framework, something that says a LOT to me may be quite incomprehensible to you, despite common English words: "The new East Coast distance record for 78GHz is over 125km!" The words seem clear enough, but where's the emotional content? Meh, am, I right?
Metaphor helps to establish a shared context between speaker and listener, writer and reader. No communication is perfect, but having a common framework helps.
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