Information Technology Reference
In-Depth Information
1
Thinking and Computation
Consider the following scenario:
A professor enters a classroom where a group of undergraduates is sitting, and
announces “There is free pizza in the hall!” Suddenly, the students stand up and
stampede toward the classroom door.
The events described here seem so ordinary that it is easy to miss how truly remark-
able they are. But step back from them for a moment and imagine that you are
studying these students as a curious scientist from another world. You observe that a
certain sound emanates from the professor and that this causes a flurry of activity in
the students. Now, as a scientist, ask yourself this: What sort of
physics
would explain
how acoustic energy can be transformed into kinetic energy in this way? In particu-
lar, note that a very small change in the acoustic energy (like the professor's saying
“There is free pizza in Nepal.”) can result in
no
kinetic energy being produced at all,
except maybe for some puzzled head shaking.
This is the wonder of
intelligent behavior
, perhaps the single most complex natural
phenomenon that we are aware of. As a sheer mystery, it easily overshadows topics
like dark matter, the source of gravity, and the mechanics of cancer.
One striking aspect of intelligent behavior of this sort is that it is clearly conditioned
by
knowledge
: for a very wide range of activities, people make decisions about what
to do based on what they know (or believe) about the world, effortlessly and often
unconsciously. It's certainly not the
sounds
themselves that cause the students to stand
up like animals that have been trained to respond to a bell. This is easy enough
to confirm. The professor could have brought in a
sign
with a pizza message on it
written in big letters, and the effect would have been just the same. In fact, one can
imagine a situation where the following is written on the whiteboard at the front of
the classroom:
As part of a psychology experiment, the professor will soon enter and tell you
that free food is available. This is just a test. Please remain seated.
In this case, neither the sounds nor the sign would have any effect at all. One can
try other small variations, and it will become clear that what makes the difference is
whether the students come to
believe
there is free pizza to be had nearby.
