A Better Explanation

Apr 28, 2010 11:15

In my last post I mentioned that you can avoid disproving a negative by rephrasing a problem as two opposing positives. Science doesn't determine what is "true" or "false" as much as it determines which available explanation is most favorable. If you can't prove that one explanation is wrong you can at least show how another explanation is simpler, better supported by available evidence, and more likely to be true.

In the 1500s Ptolemaic geocentrism was the best explanation for the solar system, with epicycles to explain retrograde movement. It "worked for them". Copernicus's heliocentric theory gave astronomers a rival explanation:

A: The sun, planets, and moon are embedded in 'epicycles' that rotate around the earth's epicyclic center.
B: The moon orbits the earth, and the earth and planets orbits the sun.

After Copernicus "A" remained as true as it ever was - the geocentric/epicyclic still "works" today for predicting certain kinds of planetary motion. But B is simpler, makes fewer assumptions, makes better predictions, explains more, and also explains why some people would think that A was true. B is not absolutely true either - Newton's laws of motion and general relativity are even better explanations, but B was a major step in the right direction.

Not everybody changed their minds or accepted the new wisdom. Modern geocentrists went back to the drawing board and created elaborate rationalizations to explain (on YouTube) why the earth is stationary despite all appearances to the contrary. With sufficient special pleading they've refined A to the point of unfalsifiability. Within their constraints and assumptions there's no way to prove that the sun doesn't revolve around the earth, but that still leaves us to with two rival explanations:

C: The sun and planets really do orbit the earth for arbitrary, ineffable reasons that cannot be tested. Contradicting evidence only appears so for similarly ineffable, arbitrary reasons that are also impossible to test.
D: Dishonest/self-deluded geocentrists are saying this because it is unfalsifiable, not because it is true. They are tired of their wrong theories failing tests, so they've invented a wrong theory that cannot be tested.

"C" is "as true as it ever was". It "works" to explain why the sun really does orbit the earth. But D is simpler, makes fewer assumptions, makes better predictions, explains more, and includes an explanation why A would appear to be true to some people. It's a better explanation, better supported by available evidence, and more likely to be true.

It's possible that the Emperor really is wearing invisible, undetectable clothing that happens to exactly resemble the complete absence of clothing. You'll never be able to disprove that his clothes simply haven't been detected yet. But it's far more likely that dishonest/self-deluded tailors have constructed a false theory to prevent it from being tested. Their story will always be "as true as it ever was", and some people will still believe it, but reasonable people will accept the simpler and better explanation that the emperor has no clothes.

"A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it." -Max Planck

rhetoric, skeptic

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