diff options
Diffstat (limited to 'hacks/config/epicycle.xml')
| -rw-r--r-- | hacks/config/epicycle.xml | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/hacks/config/epicycle.xml b/hacks/config/epicycle.xml index 0b56922..18b23df 100644 --- a/hacks/config/epicycle.xml +++ b/hacks/config/epicycle.xml @@ -50,6 +50,17 @@ This draws the path traced out by a point on the edge of a circle. That circle rotates around a point on the rim of another circle, and so on, several times. +The geometry of epicycles was perfected by Hipparchus of Rhodes at some time +around 125 B.C., 185 years after the birth of Aristarchus of Samos, the +inventor of the heliocentric universe model. Hipparchus applied epicycles to +the Sun and the Moon. Ptolemy of Alexandria went on to apply them to what was +then the known universe, at around 150 A.D. Copernicus went on to apply them +to the heliocentric model at the beginning of the sixteenth century. Johannes +Kepler discovered that the planets actually move in elliptical orbits in about +1602. The inverse-square law of gravity was suggested by Boulliau in 1645. +Isaac Newton's Principia Mathematica was published in 1687, and proved that +Kepler's laws derived from Newtonian gravitation. + https://en.wikipedia.org/wiki/Deferent_and_epicycle Written by James Youngman; 1998. |