| |
| | Kepler's laws of planetary motion |
 | | Kepler's Third Law (1618): The square of the sidereal period, of an orbiting planet, is directly proportional[?] to the cube of the orbit's semimajor axis. |
 | | This law was developed, in part, from the observations of Brahe; which, indicated that the velocity, of planets, was not constant. |
 | | Kepler did not understand why his laws were correct, it was Isaac Newton who discovered the answer to this. |
| www.ebroadcast.com.au /lookup/encyclopedia/ke/Keplers_laws.html (513 words) |
|