An Etymological Dictionary of Astronomy and Astrophysics

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فرهنگ ریشه‌شناختی اخترشناسی-اخترفیزیک

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Kepler's laws
  قانون‌های ِ کپلر  
qânunhâ-ye Kepler (#)
Fr.: lois de Kepler  

  1. The planets move about the Sun in ellipses, at one focus of which the Sun is situated.

  2. The → radius vector joining each planet with the Sun describes equal areas in equal times.

  3. The ratio of the square of the planet’s period of revolution to the cube of the planet’s mean distance from the Sun is the same for all planets.

See also: → Kepler; → law.