Page 578 - 89 history of astronomy_opt

been geometrically expressed equally well
with the earth or any other point fixed. But
in Kepler’s case the obviously implied phys-
ical theory of the planetary motions, even
before Newton explained the simplicity of
conception involved, made astronomers quite
ready to waive the claim for a rigid proof of
the earth’s motion by measurement of an
annual parallax of stars, which they had in-
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