Geocentric? Heliocentric? The Janus-faced “Aberration” Can’t Tell

The present paper is intended to reconsider the reason why George Biddell Airy (1802-1892) is presumed to have failed to resolve the quandary whether astronomical aberration shows a starry dome very slowly orbiting the Sun, and with this Sun orbiting the Earth, or whether contrariwise we orbit a Sun, which for that purpose is taken to be at rest in said dome. It will only deal with the kinematical aspects of the affair and will discuss the subject matter from a modest pedestrian position. That is from the celestial body on which mankind finds itself, taking nothing a priori for granted about that body’s status in the cosmos observable around it. And in doing that it will be earning – until further notice! – the “New Scientist’s” accolade for not betraying the very standards on which the scientific community has been built.

To begin with: non-astronomically informed people still cherish the tough untruth that Galileo, risking martyrdom for the sake of the true truth, irrefutably proved that the Earth “goes around the Sun”. Those who are to some degree familiar with the history of astronomy know better: the man had no unequivocal evidence at all for his heliocentric model. Granted: at first sight and overlooking the square and higher powers of the eccentricities of the planetary orbits, it seems simpler than the Ptolemaic one, and Occam’s razor hence advocates the acceptance of the hypothesis. Yet, simplicity is decidedly not the hallmark of the Great Chain of Created Being. Galileo’s observations showed him that it was possible and attractive to look at the

heavens heliocentrically, not that such was on any account necessary. And today this is still, or better, again the situation. “We can’t feel our motion through space; nor has any experiment ever proved that the earth actually is in motion”, says the author of a book that Einstein declared to be “a valuable contribution to popular scientific writing”.(12) Furthermore: everyone who has investigated the matter and its ramifications knows that from the lifetime of James Bradley (1692-1762) until our days, (with their rising number of anti-relativists!) scores of experts have applied themselves to the task of either demonstrating the Earth’s motions, or conversely, to devising theories that acceptably try to explain why these motions cannot be demonstrated. The latter surely being quite an undertaking, because it first of all requires incontestable evidence that Mother Gea is not only relatively, but really in motion, and subsequently a proof that proving that motion is impossible. For after all: to declare an Earth at rest to be unacceptable is not the same as authenticating it to be on the move!