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| author | Simon Rettberg | 2021-04-06 14:43:39 +0200 |
|---|---|---|
| committer | Simon Rettberg | 2021-04-07 13:38:37 +0200 |
| commit | 38886de0c3e9ea5729ef23e4c653fa2822f52e8f (patch) | |
| tree | 9b799c8c968a92cc77746a95e0e8bdd90b6b13c3 /hacks/config/epicycle.xml | |
| parent | Maybe not remove, but ... (diff) | |
| download | xscreensaver-openslx.tar.gz xscreensaver-openslx.tar.xz xscreensaver-openslx.zip | |
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. |