Tycho Brahe and Johannes Kepler

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Tycho Brahe and Johannes Kepler
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Keplers Three Laws of Planetary Motion

• Law 1. All planets move in elliptical orbits
  with the sun at one focus.
• http//www.physics.nwu.edu/ugrad/vpl/mechanics/pla
  nets.html
• Law 2. A line joining any planet to the sun
  sweeps out equal areas in equal times.
• http//www.physics.nwu.edu/ugrad/vpl/mechanics/pla
  nets.html
• Law 3. The square of the period of any planet is
  proportional to the cube of the semimajor axis of
  its orbit.
• http//www.physics.sjsu.edu/tomley/Kepler3.html

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British One Pound Note featuring
Sir Isaac Newton
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From the British One Pound Note
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Newtons Ideas
Path of object depends on
FORCES andINITIAL CONDITIONS.
http//www.phy.ntnu.edu.tw/java/projectileOrbit/pr
ojectileOrbit.html