eccentric circle
Quick Summary
An eccentric circle is a circle that is not centered at the same point as another circle. In geometry, the term "eccentric" originally referred to celestial bodies not having the Earth at their center.1
The eccentricity of an ellipse measures how flattened it is compared to a circle. For a perfect circle, the eccentricity is zero. For example, Earth's orbit has an eccentricity of 0.0167, making it very close to a perfect circle.2
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astronomyThe motion of the planets…models were developed, based on eccentric circles and epicycles. (An eccentric circle is a circle that is slightly off-centre from Earth, and an epicycle is a circle that is carried and rides around on another circle.) This innovation is usually attributed to Apollonius of Perga (c. 220 bce), but it…
Read More…models were developed, based on eccentric circles and epicycles. (An eccentric circle is a circle that is slightly off-centre from Earth, and an epicycle is a circle that is carried and rides around on another circle.) This innovation is usually attributed to Apollonius of Perga (c. 220 bce), but it…
Read More- astronomyThe motion of the planets
…of the planets involved an eccentric circle, which carried an epicycle. Imagine looking down on the plane of the solar system from above its north pole. The planet moves counterclockwise on its epicycle. Meanwhile, the centre of the epicycle moves counterclockwise around the eccentric circle, which is centred near (but…
Read More…of the planets involved an eccentric circle, which carried an epicycle. Imagine looking down on the plane of the solar system from above its north pole. The planet moves counterclockwise on its epicycle. Meanwhile, the centre of the epicycle moves counterclockwise around the eccentric circle, which is centred near (but…
Read More