Page 21 - GALIET PHYSICS BLOSSOMS I+
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Ptolemy’s Eccentric Model
As a result, and as seen below, in order for Ptolemy to account for changes in velocity of the apparent planetary motions, he displaces the earth-centered deferent from:
“C” to “Q”
Point “Q”
is placed symmetrically on the opposite side of C on the deferent’s apogee-perigee line.
“Q” becomes the equant point or punctum aequans.
These Figures were taken from Dr. Stamp’s slides on Greek Astronomy.
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