Relativity shows geocentrism is true
We know that the difference between a heliocentric theory and a geocentric theory is one of relative motion only, and that such a difference has no physical significance. [Hoyle, 1975, cited in Willis, below]
- Willis, Tom, 2000 (Mar/Apr). The Laws of Cause and Effect, and the 1st and 2nd Laws of Thermodynamics have been invalidated by modern science, Part 2. CSA News 17(2): 1-2.
- Although motion is relative, it is usually assumed to be relative to an object's environment unless explicitly stated. If you throw a paper airplane while traveling in an airliner, it will move at something like 500 mph relative to the air outside the airliner -- and only a few mph relative to the air it travels through, the airliner's cabin air. But that paper airplane directly interacts with the cabin air, not with the outside air, so it would be cheating to maintain that you can throw a paper airplane at 500 mph. And when the environment is not clear from context, one does have to explicitly state what a speed is relative to; that airliner's pilot must distinguish between the airliner's airspeed (relative to the air) and groundspeed (relative to the ground). Applying this environment-relativity criterion to the Solar System, one finds that the Earth is indeed moving around the Sun.
- Strictly speaking, both the Earth and the Sun move around the Solar System's barycenter (center of mass, center of gravity, centroid), but the Earth moves in a much larger orbit around it than the Sun does. This point is readily defined in Newtonian mechanics, but in general relativity, defining that point gets more difficult on account of the curvature of space-time. However, that curvature is very small in the Solar System (about 10-5 at the Sun's surface and 10-8 at the Earth's orbit), and its only readily-apparent effect is the Newtonian gravitational potential. Thus, general relativity still indicates that the Earth moves around the Sun.
- Neither Earth, nor the sun are an inertial reference frame. They both constantly experience acceleration, which is not relative (that is, it can be measured by internal experiments within an accelerated reference frame). Because of the sun's larger mass, Earth is accelerated much more than the sun. The center of gravity around which both objects actually orbit is approximately at the location of the sun.
- Since relativity maintains that there is no favored frame of reference, the entire question of geocentrism vs. heliocentrism is rendered irrelevant. Creationists who cite this as an argument against heliocentricity are proving nothing, and creationists who cite this as an argument in favor of geocentrism either do not understand the logic involved, or are being deliberately disingenuous.
- A rotating frame of reference is indestinguishable from one which is not rotating. - This is easily disproved with a foucault pendulum. Read the "See for yourself" section of "Bible says the sun goes around the earth".
- The statement that all inertial frames are equally valid is the Special Relativity statement. The airplane discussion of point 1 is readily misinterpreted as being inconsistent with Special Relativity. In Special Relativity, it is exactly equally valid to say that the earth is still and the airplane is moving, and to say that the airplane is still and the earth is moving (the other way). In particular, if I throw a paper airplane down the walkway of a flying airliner (do not try this; safety issues) ground based observers will agree it is travelling at, say, 500 mph.
- The geocentric frame is an accelerating reference frames. The statement that all reference frames, including accelerating ones, are equally valid is the correct General Relativity statement. However, if you use an earth-centered reference frame, you need extremely large "fictitious" forces to tug the stars and the distant galaxies in a circle around you every day. Therefore, the original statement "a geocentric frame is as good as a heliocentric one" is false.
- By this logic you can also argue an x-centered solar system for any body in the entire solar system. Why only include the earth or the sun? Why not a Venus centered or Jupiter centered Solar System?
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Fallacies contained in this claim
- Gardner, Martin, 1957. Fads and Fallacies in the Name of Science, Dover.
- Hoyle, F., 1975. Astronomy and Cosmology - A Modern Course, San Francisco: W.H. Freeman & Co., p. 416.