I recently watched the video entitled Evolution and Faith by DonExodus, and it reminded me
of an essay by Isaac Asimov. I'll link to his full text in the sidebar.
Asimov, as many of you know, was a great writer of fiction and non-fiction, science and science
fiction. He was a pioneer of the imagination, and the spark that started roaring fires in
the imaginations of a lot of current scientists. He was one of my great inspirations, and a
great champion of reason, logic, and skepticism.
His argument concerns the response he received from a comment he made in one of his articles
on the advancing knowledge of science, how much we know about the universe that ancient
humans did not. He received a letter from a non-scientist, an English Lit major, who
wanted to correct his attitude about science.
I'll quote him: The young specialist in English Lit, having
quoted me, went on to lecture me severely on the fact that in every century people have
thought they understood the universe at last, and in every century they were proved to be
wrong. It follows that the one thing we can say about our modern "knowledge" is that it
is wrong....
My answer to him was, "John, when people thought the earth was flat, they were wrong. When
people thought the earth was spherical, they were wrong. But if you think that thinking
the earth is spherical is just as wrong as thinking the earth is flat, then your view
is wronger than both of them put together."
The basic trouble, you see, is that people think that "right" and "wrong" are absolute;
that everything that isn't perfectly and completely right is totally and equally wrong.
However, I don't think that's so. It seems to me that right and wrong are fuzzy concepts,
and I will devote this essay to an explanation of why I think so."
For the sake of space, I'm going to condense most of his beautifully worded argument and
paraphrase.
Once, people believed the Earth was flat, and they were wrong. But they were also very
nearly right. The curvature of a flat surface is 0, and the curvature of the Earth's surface
is very nearly 0, to a certain level of approximation, the kind of measurements the ancients were
capable of.
After some rather brilliant observation by great scientists such as Aristotle, the basic
idea of a spherical Earth was advanced, and measured a century later by the Greek philosopher
Eratosthenes by noting the differences in shadow lengths at different latitudes. We
thought then that the Earth was a sphere and that the actual curvature of the earth must
be 0.000 126 per mile, a quantity very close to, but not quite equal to zero. This difference
was important to our ability to make accurate maps and sail great distances without missing
our destination.
So, then we thought the Earth was a sphere, but that was also wrong. Based on observations
of the other planets Newton showed that rotating masses are very slightly flattened at the
poles. Scientists, measuring the Earth very precisely using newer instruments were able
to determine the degree of oblateness, the measure of departure from a true sphere. If
the Earth were a true sphere, it would have a curvature of 8 inches to the mile, but the
actual curvature varied from 7.973 inches to the mile to 8.027 inches to the mile.
The correction in going from spherical to oblate spheroidal is much smaller than going
from flat to spherical. Therefore, although the notion of the earth as a sphere is wrong,
strictly speaking, it is not as wrong as the notion that the earth is flat.
Even the oblate-spheroidal notion of the earth is wrong, strictly speaking. In 1958, when
the satellite Vanguard I was put into orbit about the earth, it was able to measure the
local gravitational pull of the earth--and therefore its shape--with unprecedented precision.
It turned out that the equatorial bulge south of the equator was slightly bulgier than the
bulge north of the equator...
There seemed no other way of describing this than by saying the earth was pear-shaped,
and at once many people decided that the earth was nothing like a sphere but was shaped like
a Bartlett pear dangling in space. Actually, the pearlike deviation from oblate-spheroid
perfect was a matter of yards rather than miles, and the adjustment of curvature was
in the millionths of an inch per mile.
In short, my English Lit friend, living in a mental world of absolute rights and wrongs,
may be imagining that because all theories are wrong, the earth may be thought spherical
now, but cubical next century, and a hollow icosahedron the next, and a doughnut shape
the one after.
What actually happens is that once scientists get hold of a good concept they gradually
refine and extend it with greater and greater subtlety as their instruments of measurement
improve. Theories are not so much wrong as incomplete.
This can be pointed out in many cases other than just the shape of the earth. Even when
a new theory seems to represent a revolution, it usually arises out of small refinements.
If something more than a small refinement were needed, then the old theory would never
have endured.
Copernicus switched from an earth-centered planetary system to a sun-centered one. In
doing so, he switched from something that was obvious to something that was apparently
ridiculous. However, it was a matter of finding better ways of calculating the motion of the
planets in the sky, and eventually the geocentric theory was just left behind. It was precisely
because the old theory gave results that were fairly good by the measurement standards of
the time that kept it in being so long.
Again, it is because the geological formations of the earth change so slowly and the living
things upon it evolve so slowly that it seemed reasonable at first to suppose that there
was no change and that the earth and life always existed as they do today. If that were
so, it would make no difference whether the earth and life were billions of years old
or thousands. Thousands were easier to grasp.
But when careful observation showed that the earth and life were changing at a rate that
was very tiny but not zero, then it became clear that the earth and life had to be very
old. Modern geology came into being, and so did the notion of biological evolution.
If the rate of change were more rapid, geology and evolution would have reached their modern
state in ancient times. It is only because the difference between the rate of change
in a static universe and the rate of change in an evolutionary one is that between zero
and very nearly zero that the creationists can continue propagating their folly.
Since the refinements in theory grow smaller and smaller, even quite ancient theories must
have been sufficiently right to allow advances to be made; advances that were not wiped out
by subsequent refinements.
Naturally, the theories we now have might be considered wrong in the simplistic sense
of my English Lit correspondent, but in a much truer and subtler sense, they need only
be considered incomplete.