 | Joseph Ames - 1904 - 782 páginas
...proportional to the time ; ie equal areas are described in equal intervals of time. (2) The orbit of a planet is an ellipse, having the sun at one of its foci. (3) The squares of the periods of different planets are proportional to the cubes of the major axes... | |
 | United States. War Department - 1944 - 314 páginas
...accordance with the following laws known as Kepler's Laws: (1) The orbit of the earth (and other planets) is an ellipse, having the sun at one of its foci. (2) The radius vector of a planet sweeps over equal areas in equal times. (3) The square of the times of... | |
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... for practical purposes, the sun may be considered as being at rest with regard to the other members of the solar system. The planets move about the sun in accordance with the following laws, known as Kepler's Laws: 1. The orbit of every planet is... 