IN PHYSICS,
SCIENTISTS invent models, or theories, to describe and predict the data we
observe about the universe. Newton’s theory of gravity is one example;
Einstein’s theory of gravity is another. Those theories, though they describe
the same phenomenon, constitute very different versions of reality. Newton, for
example, imagined that masses affect each other by exerting a force, while in
Einstein’s theory the effects occur through a bending of space and time and
there is no concept of gravity as a force. Either theory could be employed to
describe, with great accuracy, the falling of an apple, but Newton’s would be
much easier to use. On the other hand, for the calculations necessary for the
satellite-based global positioning system (GPS) that helps you navigate while
driving, Newton’s theory would give the wrong answer, and so Einstein’s must be
used. Today we know that actually both theories are wrong, in the sense that
both are only approximations of what really happens in nature. But they are
also both correct, in that they each provide a very accurate and useful
description of nature in the realms in which they do apply.
As I said, in a
way, every human mind is a scientist, creating a model of the world around us,
the everyday world that our brains detect through our senses. Like our theories
of gravity, our model of the sensory world is only approximate and is based on
concepts invented by our minds. And like our theories of gravity, though our
mental models of our surroundings are not perfect, they usually work quite
well.
The world we
perceive is an artificially constructed environment whose character and
properties are as much a result of unconscious mental processing as they are a
product of real data. Nature helps us overcome gaps in information by supplying
a brain that smooths over the imperfections, at an unconscious level, before we
are even aware of any perception. Our brains do all of this without conscious
effort, as we sit in a high chair enjoying a jar of strained peas or, later in
life, on a couch, sipping a beer. We accept the visions concocted by our
unconscious minds without question, and without realizing that they are only an
interpretation, one constructed to maximize our overall chances of survival,
but not one that is in all cases the most accurate picture possible.
