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

The property of a dynamical system such that in an interval of sufficient duration, it will return to states that are closely similar to previous ones.

From → erg + Gk. (h)od(os) "way, road" + → ic.

A → redshift space distortion which causes the dense central regions of → galaxy clusters to appear elongated along the → line of sight. This effect is attributed to random velocities in clusters of galaxies deviating from pure → Hubble flow. For an observer galaxies with peculiar velocity perpendicular to the line of sight do not change the redshift, which is given just by the normal Hubble expansion. On the contrary, galaxies with peculiar velocity along the line of sight appear with a different redshift, resulting from the Hubble expansion velocity plus the peculiar velocity. Since this affects only redshift and not position on the sky, the stretching occurs only radially, toward the observer. See also → Kaiser effect, → peculiar velocity.

→ finger; → God.

1) The Being perfect in power, wisdom, and goodness who is worshipped as creator and ruler of the Universe.
2) (lowercase) A being or object believed to have more than natural attributes and powers and to require human worship (Merriam-Webster.com). See also: → fingers of God

M.E. from O.E. akin to O.H.G. got, Ger. Gott, O.N. guð, Goth. guþ, from PIE *g^heuH- "to call upon;" cf. Av. zu- "to call, invoke;" O.Pers. (upa)zu- "to proclaim;" Skt. hu-, variant hve- "to call upon, invoke," huta- "invoked," an epithet of Indra, from root *gheu(e)- "to call, invoke."

Xodâ, xodây "god, lord, master;" Mid.Pers. xwadây "king, master;" Av. xvadāta- "autonomous" (darego.xvadāta- "highly autonomous"), from xva-, → self- + dā- "to give, grant, yield" (Pers. dâdan, → datum); cf. Skt. svadhā- "inherent power, habitual power, self-placed," from sva- "self," + dhā- "to place, fix, maintain"

In numerical analysis and fluid dynamics, a conservative scheme for solving → partial differential equations based on utilizing the solution of the local → Riemann problem at each time step.

Suggested by Sergei K. Godunov (1929-) in 1959, Math. Sbornik, 47, 271, translated 1969, US Joint Publ. Res. Service, JPRS 7226; → method.