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law of equal areas

law of equal areas

9.5
A rule that a line from a planet to the sun covers equal areas in equal times
  • noun
  • Specialized
translation icon : ley de áreas iguales
  • According to the law of equal areas, planets move faster when they are closer to the sun.

Examples

  • Astronomers use the law of equal areas to predict a planet's changing speed along its orbit.

  • The law of equal areas states that planets sweep out equal areas.

  • Kepler's law of equal areas was a breakthrough in understanding planetary motion.

  • According to the law of equal areas, planets move faster when they are closer to the sun.

  • According to Kepler's law of equal areas, a planet's speed increases as it approaches the sun.

  • Astronomers apply the law of equal areas to calculate the positions of planets in their orbits.

  • Kepler established the law of equal areas to describe how planets move in elliptical orbits.

Synonyms

Kepler's second law
vslaw of equal areas
  • Specialized
7.9

A planet's line to the sun covers equal areas in equal times

is the same principle but focuses on areas rather than emphasizing speed
law of areas
vslaw of equal areas
  • Specialized
8.4

A rule that a planet moves faster when closer to the sun and slower when farther away

is the same principle but presented more generally without explicit speed wording

Surface Forms

Morphology

law + of + equal + area

The phrase is fully compositional: 'law' + 'of' + 'equal areas' straightforwardly denotes a scientific rule about areas that are equal. A B1 learner who knows the constituent words can infer that this is a law concerning equal areas (even if they lack the specific astronomical detail about planets and time intervals), and the construction is cross-linguistically transparent.

Etymology

Law of equal areas comes from a simple picture: imagine the sun and a moving planet joined by a line that sweeps out a slice like a piece of pie. Kepler found each of these 'slices' is the same size in the same time, so a planet must go faster when it is closer to the sun and slower when it is farther away.