Science Fair Project Encyclopedia

Eccentricity

Eccentric is from the Greek for out of the centre, as opposed to concentric, in the centre.

In mathematics, eccentricity is a parameter associated with every conic section. It can be thought of as a measure of how much the conic section deviates from being circular.
In astrodynamics, the eccentricity of an orbit can be calculated from orbital state vectors as an absolute value of eccentricity vector or using other methods based on orbital energy and angular momentum.
In mechanical engineering, an eccentric is a wheel that rotates on an axle that is displaced from the focus of the circle described by the wheel —in other words, a mechanical motion that can operate either as a cam or a crank, depending upon how it is driven.
In popular usage, eccentricity refers to unusual or odd behaviour on the part of a person, as opposed to being "normal". There is a saying that "If you're rich, you're eccentric; if you're poor, you're crazy." See also List of people widely considered to be eccentric.

10-26-2009 08:16:03
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