Gravity of Earth or (). Gravitational acceleration contributes to the total gravity acceleration, but other factors, such as the rotation of Earth, also contribute, and, therefore, affect the weight of the object. Gravity does not normally include the gravitational pull of the Moon and Sun, which are accounted for in terms of tidal effects. It is a vector (physics) quantity, whose direction coincides with a plumb bob. A non-rotating perfect sphere of uniform mass density, or whose density varies solely with distance from the centre (spherical symmetry), would produce a gravitational field of uniform magnitude at all points on its surface. The Earth
Union of the Sun and Moon be assured a rebirth in a natural nirmanakaya realm during the bardo of becoming and there reveal buddhahood without further rebirths." Namkha'i and Shane (1986, 1999: p. 91) open the discourse of the 'Song of the Vajra' (Wylie: rdo rje'i glu zhig) an excerpt of the "Union of the Sun and Moon" into the English language and render it thus: <poem> Union of the Sun and Moon The Union of the Sun and Moon () is one of the Seventeen tantras of the esoteric instruction cycle () which are a suite of tantras known variously as: Nyingtik, Upadesha or Menngagde