TODAY:

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TODAY From The Suns Perspective
Aristarchus Occams Razor The Copernican
Theory Giordano Bruno Brahe and Kepler
Keplers 3 Laws of Planetary Motion
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THE HELIOCENTRIC SYSTEM OF ARISTARCHUS   We have
no written record of this system by Aristarchus
himself. --all his works (except the one
mentioned above) were lost when the library in
Alexandria was burned. Written accounts of this
system are found in "The Sand Reckoner" by
Archimedes (287-212 BC) and "On the Face of the
Moon Disc" by Plutarch (46-120 AD).
Features 1. Planets orbit the sun,
explaining retrograde motion 2. stellar
parallax not seen because stars are at
great distance.
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William of Occam 1200 AD OCCAMS RAZORa
simpler workable theory is a better one.
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Giordano Bruno--burned at stake in
1590 --Universe is infinite! --Stars are suns
with planets and beings on them.
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Brahes Observatory at Uraniborg, Denmark
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Keplers First Law Planets move in ellipses.
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Keplers 3rd Law P period, a avg dist. to
sun semi-major axis.
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Planetary orbit eccentricitieshow stretched is
orbit?