This argument was made at a Creationism conference that I attended several years ago: science isn’t trustworthy because every time you turn around, it’s changing its mind.

The sun goes around the earth … no, wait a minute—it’s the other way around.

Here’s the fossil of an early human … no, hold on—that one’s a hoax.

Living things hold a special energy or force—an élan vital—that animates them … nope, that’s passé.

Every wave needs a medium, so space must be filled with “ether” for light to propagate through … oops, wrong again.

An early theory of the formation of the moon said that the fast-spinning early earth flung out the moon and that the big circular Pacific Ocean basin is where it came from. The question of origin of the moon has been an active area of research, and the flung-out-moon idea is just another discarded scientific theory—this was one of the areas of research that was lampooned at this conference.

The Creationist argues that when you turn from changeable Science to Christianity’s unchanging God and Bible, you have something solid that you can trust.

How does science change?

Science does change, but let’s notice that the size of any change tends to decrease for a single theory. When the door is flung open to a new field of inquiry—say by Leeuwenhoek’s discovery of single-celled organisms or Galileo’s use of the telescope—new theories based on insufficient evidence try to organize the chaos. One theory might quickly supersede another, but as theories become better at explaining more, changes becomes smaller. Here are some examples.

Geocentrism to heliocentrism was an enormous change for the model of the solar system. Our understanding of the solar system continues to change (new theories about why Uranus is tipped on its side or the reclassification of Pluto as a dwarf planet, for example), but these are comparatively minor.

Evolution revolutionized biology, and the changes in biology today are merely refinements to this theory. Punctuated equilibrium proposes occasional rapid change instead of Darwin’s view of gradual change, but it tries to improve evolution, not overturn it.

The intuitive flat earth model was replaced by a spherical earth, and the observation that it’s actually not spherical but slightly flattened at the poles is a small change.

Quantum physics continues to change, but new discoveries are not likely to say that matter is not made up of atoms, which are themselves not made up of protons, neutrons, and electrons.

Christians eager to paint the Bible as an unchanging rock in a sea of chaos don’t seem to understand that they point to science’s strength. Science realizes that new discoveries may obsolete old theories, and every scientific statement is provisional. And, remarkably, science is self-correcting. It finds its own errors.

Science changes, and that’s its strength. The Bible never changes, and that’s its weakness.

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.

— Isaac Asimov

(This is a modified version of a post originally published 12/5/11.)