Kepler's laws of planetary motion

Scientific  

/ kĕp′lərz /

1. Three laws devised by Johannes Kepler to define the mechanics of planetary motion. The first law states that planets move in an elliptical orbit, with the Sun being one focus of the ellipse. This law identifies that the distance between the Sun and Earth is constantly changing as the Earth goes around its orbit. The second law states that the radius of the vector joining the planet to the Sun sweeps out equal areas in equal times as the planet travels around the ellipse. As such, the planet moves quickest when the vector radius is shortest (closest to the Sun), and moves more slowly when the radius vector is long (furthest from the Sun). The third law states that the ratio of the squares of the orbital period for two planets is equal to the ratio of the cubes of their mean orbit radius. This indicates that the length of time for a planet to orbit the Sun increases rapidly with the increase of the radius of the planet's orbit.

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Example Sentences

Buffon could, if he wished, look back to the seventeenth century and identify a whole series of laws that had been discovered during the Scientific Revolution: Stevin’s law of hydrostatics, Galileo’s law of fall, Kepler’s laws of planetary motion, Snell’s law of refraction, Boyle’s law of gases, Hooke’s law of elasticity, Huygens’ law of the pendulum, Torricelli’s law of flow, Pascal’s law of fluid dynamics, Newton’s laws of motion and law of gravity.

From Literature

This is obviously false, because one test of measurements of the speed of light is whether, when used in conjunction with Kepler’s laws of planetary motion, they enable you to predict the apparent position of planets in the sky.

From Literature

Ptolemy gave the astrologers the information they needed, and Newton explained Kepler’s laws of planetary motion.

From Literature

You may think that this is simply because Galileo’s law is incomplete: Newton’s theory of gravity provides an explanation both of Galileo’s law of fall and of Kepler’s laws of planetary motion.

From Literature

HR 5183 b spends most of its time loitering in the outer part of its star’s planetary system, then it accelerates and slingshots around its star, consistent with Kepler's laws of planetary motion.

From Salon