An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 3 Search : ellipsoid
ellipsoid
  بیضی‌وار   
beyzivâr (#)

Fr.: ellipsoïde   

A three-dimensional geometric figure resembling a flattened sphere. It is generated by rotating an ellipse around one of its axes.

From → ellipse + → -oid.

inertia ellipsoid
  بیضی‌وار ِ لختی   
beyzivâr-e laxti

Fr.: ellipsoïde d'inertie   

An ellipsoid used in describing the motion of a rotating rigid body. It is stationary with respect to the rotating body, and is determined by the body's moments of inertia.

ellipsoid; → inertia.

reference ellipsoid
  بیضی‌وار ِ بازبرد   
beyzivâr-e bâzbord

Fr.: ellipsoïde de référence   

A mathematically defined surface that approximates the Earth's shape, which is basically a sphere "flattened" at its poles. The length of one of the axes at the Equator is chosen so that the ellipsoid coincides at this latitude with the mean sea level. It is the first-order definition of the non-spherical shape of the Earth as an ellipsoid of revolution. To first order, it accounts for over 90% of the → geoid.

reference; → ellipsoid.