Why biblical geocentrism is wrong
Why biblical geocentrism is wrong
Bad Astronomy
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Feb. 15 2007 11:46 AM

Why biblical geocentrism is wrong

Every now and again I get email about Geocentrism; literally, the belief that the Earth is the center of the Universe. PZ mentioned it the other day (as did SciGuy) and I'm getting email again, so now's as good a time as ever to debunk this garbage.

Now let me be clear: don't confuse this with lower-case-"g" geocentrism, which is just using a coordinate system with the non-rotating Earth at the center. We use this every day whenever we say "The Sun rose today." It's a perfectly reasonable coordinate system, and astronomers use it all the time to guide their telescopes.

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  


No, what I'm talking about here is capital-"G" Geocentrism, where the advocator is doing the literal interpretation of the bible thing. You can guess how I feel about that.

It's wrong. What's funny is that it's provably wrong using simple logic. Most people miss this point, but it's valid, and to my knowledge it has never been refuted. I wind up posting this every now and again to the bulletin board, but here it is for the general public, slightly paraphrased:

Geocentrism, as advocated by creationists or other religiously fundamental people, is certainly wrong.

How, you may ask? What is going on is that you can do a change of reference frame to a geocentric one, and by Einstein's mathematics of relativity the math must still work out. I readily admit that. This means that, physically, geocentrism is just as valid as, say, heliocentrism.

But note the words "just as valid". Also, by relativity, it cannot be any more valid; geocentrism is just another change of frame (although to a non-inertial one).

What Geocentrists are saying is that geocentrism is the one, true frame. They must say that because that is what is says in the bible. Now pay attention here, because this is the important bit: to say Geocentrism isn't wrong, you have to accept the premise that any frame of reference is just as valid as any other. But to claim that Geocentrism is correct, you have to ignore that very same premise.

Geocentrism as the One True Way is therefore self-contradictory. It doesn't work.


Creationists, fundamentalists, flat-earthers, anti-scientists of all stripes: I'm listening. If this is wrong, tell me how. Why, I'll even invite rational people to tackle it. If I'm wrong, I wanna know why, and see if there is some way to fix it.

Oh, and I suppose I should mention the final irony of all this: creationists and other literal biblical fundamentalists think the world revolves around them. Talk about self-defeating beliefs!