Skip to main content
Kepler's law

Kepler's law

1 7.4
A rule that describes how planets move around the Sun
  • noun
  • /ˈkɛplərz lɔ/
  • Specialized
translation icon : ley de Kepler
  • Newton took into account not only Kepler's laws and Galileo's astronomical observations, but also Galileo's work on projectiles and falling bodies.
  • Kepler's laws of planetary motion
  • Kepler's laws of planetary

Examples

  • From Kepler's laws of planetary motion, the farther a planet is from its host star, the longer the planet's orbital period.

    Academic text (2000)
  • Kepler's laws require that speed decreases with increasing orbital distance.

    Academic text (2000)
  • The disc around the star, young or old, rotates approximately according to Kepler's laws.

    Academic text (1995)
  • These orbits and a simple application of Kepler's laws provide the best evidence yet for a supermassive black hole, which has a mass 4 million times that of our Sun.

    Academic text (2004)
  • As energy is drained away, the orbit slowly shrinks, reducing the orbital period according to Kepler's law (with some relativistic corrections).

    Academic text (2001)
  • Kepler's laws explain how planets move in elliptical orbits around the sun.

  • According to Kepler's laws, a planet's speed varies based on its distance from the sun.

  • Kepler's laws of planetary motion show that planets further from the sun take longer to complete their orbits.

Synonyms

Kepler's law of planetary motion
vsKepler's law
  • Specialized
7.3

A rule that describes how planets move around the Sun in oval paths

is the shorter, general name for the same three empirical rules

Surface Forms

Kepler's law singular

Morphology

Kepler's + law

The noun 'law' is transparent (a scientific/general rule) and the possessive 'Kepler's' signals the law is named after a person, so a learner would infer it is a scientific law associated with Kepler. However, the specific content (the three laws of planetary motion and their details) cannot be derived from the constituents alone, so the meaning is only partially predictable from the parts.

Etymology

Kepler's law comes from the scientist Johannes Kepler, who studied the sky and used careful observations to find simple rules for the planets' paths. He saw that planets move in oval paths and at different speeds, so today Kepler's law means 'the rules that describe how planets move around the Sun'.