# I guess I should have expected this: Bible-based geocentrism proponents

Yes, and a couple of posts have alluded to that.

However, by far the simplest model of motion has us going around the sun, which goes around the galaxy.

Tripped across geocentrism.com a few years ago. I think it’s wonderful what people can talk themselves into. What’s particularly wonderful is that the main proponent of the theory, Gerardus Bouw, has a Ph.D. in astronomy. See bio here.

BTW, Mangetout, the c problem has been raised before. Bouw’s answer.

in a two point system, that might be the case. But as soon as you have three points, you have to account for the motions of all three, which becomes more complex. Four points, more complex still, and so on. Some explanations are better descriptors of a multi-point system than others. Helio-centrism explains the motions of the Solar System better than geo-centrism.

No no no, sorry, I should have been more clear. Here we go:

Geocentrism also postulates two different motions to account for what we now call the earth’s rotation and revolution. The first of these is the rotation of the outermost sphere of the fixed stars about the earth once a day (instead of the daily rotation of the earth). This rotation of the entire sky carries all the interior spheres of the sun, moon, planets etc. along with it, even though those bodies are also moving individually with respect to the fixed stars. So everything in the sky rises and sets just as we’re used to.

The second motion is the annual revolution of the sun, in a tilted orbit in its own sphere, around the earth, which is just a mirror image of what we now consider the annual revolution of the earth around the sun. So the changing of the seasons and all other annual phenomena are accounted for in exactly the same way as we now do, in terms of the relative motion and positions of the earth and sun.

The daily rotation of the sky can be replaced by the rotation of the earth in a geocentric system, so that the earth is still at the center of the universe but is no longer entirely stationary. In practice, though, very few pre-modern geocentric astronomers accepted the earth’s rotation (the fifth-century Indian astronomer Aryabhata was one of them, which I throw in just because I so seldom get to mention medieval Indian astronomers outside of working hours :)). It just didn’t seem physically logical to most scientists to assume that the earth would be whirling around without our feeling the wind of it.

Better?

There have been lots of good answers to these questions so far, but let me tell you the answers that really matter.

Changing seasons? God does it.
Geosynchronous satellites? God does it.
Retrograde motion of Venus? God does it.
Tides? God does it.
Other basic experiments? God is messing with you.

It’s a bit hard to score debating points when, as the article states, that the Foucault pendulum doesn’t prove earth’s rotation because the pendulum could just as easily be moving as a result of “some other force, like the stars.”

I don’t think so; relativity works really well for vectors, but for things that are rotating, I don’t see how it can.

Imagine you’re floating in space, inside a large cavernous spaceship; a force is applied to you that causes your body to begin spinning around at, say, 100RPM. - You’re going to experience some effects of that rotation; centrifugal force (or whatever it’s proper to call it) will cause your extremities to tend to spread out from your body and if you relax, you might adopt something like a star-jump type of posture.
If instead, the spaceship within which you are floating suddenly begins to rotate at 100RPM, it might look the same to you, but it won’t feel the same - you will not experience the centrifugal forces; the spaceship will experience them instead.

I don’t think so; relativity works really well for vectors, but for things that are rotating, I don’t see how it can.

Imagine you’re floating in space, inside a large cavernous spaceship; a force is applied to you that causes your body to begin spinning around at, say, 100RPM. - You’re going to experience some effects of that rotation; centrifugal force (or whatever it’s proper to call it) will cause your extremities to tend to spread out from your body and if you relax, you might adopt something like a star-jump type of posture.
If instead, the spaceship within which you are floating suddenly begins to rotate at 100RPM, it might look the same to you, but it won’t feel the same - you will not experience the centrifugal forces; the spaceship will experience them instead.

Or to put it another way; take Alpha Centauri as a comparatively tame example; orbiting the earth at a radius of about 4 light years, but with an orbital period of 24 hours; what force would be required to constrain it to this orbit and where is the evidence for the existence of that force?

Centrifugal is indeed the outward-bound force. (Not actually a force, FWIW, but not an important distinction for present purposes.) What you’re pointing out is that Bouw’s thesis needs a centripetal force and suggests no plausible one. Good point.

And as I said, that’s just a really tame example; imagine the forces that would be required to constrain some of the more distant and massive objects, such as the Abell 2218 galaxy cluster; orbiting the fixed, immovable earth at a radius of three billion light years, but still having an orbital period of 24 hours.

Seriously, if anyone is that determined to deny the prevailing model of astrophysics, they might just as well claim that the stars are merely painted on the dome of the sky; it’s every bit as plausible and supportable as geocentrism, that is to say, not at all supportable.

Re: modern geocentrism

Intelligence has its limits, the same cannot be said for stupidity.

Geocentrists would claim that the stars are just small points of light relatively close-by and are not actually huge stars/galaxies that are very far away.

As indeed I said; they might just as well claim that the stars are painted on the skydome or that they are the moon fairy’s dandruff or that they are simply a collective delusion that the human race happens to suffer from; it doesn’t take very much more denial of factual evidence for any of these than it does to insist on geocentrism.

So when do we get an article on the medical wonder cure of blood letting. My humours have been out of balance for quite some time now. Too much bile I suppose.

I was going to say you looked a little bilious.

On the upside, it will be nice for my kids to get to memorize a Periodic Table of the Elements consisting only of Earth, Air, Fire and Water. Hell, my six year old son has those four down already just from playing Yu-Gi-Oh.

Nah, since in that case the outer planets would come between us and the Sun, which they don’t.

No they wouldn’t. As long as an outer planet’s (say, Mars’) approximately-circular orbit around the Sun is bigger than the “Sun’s orbit” around the earth, Mars will never get between the Earth and the Sun. Draw the circles on a piece of paper and you’ll see.

Honest, there’s no difference in the kinematics (i.e., geometrical configuration of motions and positions) between the heliocentric system and the so-called “Tychonic” one, i.e., a geocentric system where all the non-earth planets orbit the sun and the sun orbits the earth. (Named after Tycho Brahe, who figured it was a successful compromise in the geocentric/heliocentric debate of his day.)

The geometry works out just fine in a geocentric system. It’s the physics that gets irretrievably fucked up.

Well in that case the outer planets could be said to be orbiting the Sun-Earth group. If you say they are orbiting the Sun, you could with equal validity say that they are orbiting the Earth in the real solar system. Sure, the distances don’t work out, but did Tycho have that information? I assume the ancients thought the sun smaller than the earth, right? A larger object orbiting a smaller one would seem to offend the sense of symmetry in these models.

Noper, since at least the ancient Greeks it was known that the sun is much bigger than the earth. And yes, Tycho had reasonable values for planetary distances.

Like I say, what killed the Tychonic system was not the geometry but the physics. There just wasn’t any way to make sense of Newtonian mechanics other than the full heliocentric hypothesis, with the earth orbiting the sun just like all the other planets.

The Sun is only the size of a US quarter. Hold up the quarter at about arm’s length. Note its size. Now, look DIRECTLY at the Sun.* Same size.

• Disclaimer for idiots: Of course, this is a very mean experiment to get people to do, what with the damaging one’s eyes and stuff. Meant as joke only. Don’t look directly at the Sun. It’s bad. It’s bad.