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

→ relative atomic mass.

→ atomic; → weight.

A weight that balances another weight.

→ counter-; → weight.

Pârsang "a make-weight," from pâr-, a variant of pâd-, → counter-, + sang a variant of sanj, sanjidan "to measure; compare, put in balance," → object; alternatively, pârsang "a piece of stone," from pâr, short for pâré "piece, part," + sang, → stone, meaning "weight."

A → cardinal number between → seven and → nine.

M.E. eighte, from O.E. eahta, æhta, related to O.Norse atta, Swed. åtta, Du. acht, O.H.G. Ahto, Ger. acht; Pars. hašt, as below, from PIE *okto(u) "eight."

Hašt, from Mid.Pers. hašt; Av. ašta; cognate with Skt. asta; Gk. okto; L. octo (from which It. otto, Sp. ocho, Fr. huit).

Distance upward from a given level to a fixed point.

M.E., from O.E. hiehthu; → high + -th a suffix forming nouns of action (e.g., birth) or abstract nouns denoting quality or condition (depth; length; warmth).

Bolandi, bolandâ "height," noun forms from boland "high," variants bâlâ "up, above, high, elevated, height," borz "height, magnitude" (it occurs also in the name of the mountain chain Alborz), Lori dialect berg "hill, mountain;" Mid.Pers. buland "high;" O.Pers. baršan- "height;" Av. barəz- "high, mount," barezan- "height;" cf. Skt. bhrant- "high;" L. fortis "strong" (Fr. & E. force); O.E. burg, burh "castle, fortified place," from P.Gmc. *burgs "fortress;" Ger. Burg "castle," Goth. baurgs "city," E. burg, borough, Fr. bourgeois, bourgeoisie, faubourg); PIE base *bhergh- "high."
Farâzâ, noun of farâz "above, up, upon, on the top, aloft," from Mid.Pers. farâz, farâc "forward, prominent, distinguished;" Av. frānk- (adj.) "turned toward the front," fraca (adv.) "forward, forth," fraš (adv.) "forward, forth; before;" Proto-Iranian *frānk-.

Something put in a scale to complete a required weight.

→ make; → weight.

Pârsang, → counterweight.

The total atomic or molecular weight divided by the total number of particles. For instance, the mean molecular weight of a plasma of pure ionized ⁴He would be 4 (the atomic mass number) divided by 3, the total number of particles (1 nucleus plus 2 electrons), i.e. 4/3.

→ mean; → molecular; → weight.

The sum of the atomic weights of all the atoms in a molecule.

→ molecular; → weight.

A basic ingredient of the → mixing length theory that scales with the → mixing length. It is defined by the relation: H_P = -dr/dln P = -Pdr/dP , where r is the height and P the pressure. See also → scale height.

→ pressure; → scale; → height.

The height within which some parameter, such as pressure or density, decreases by a factor of e. For example, an atmospheric scale height of 100 km means that the value at 100 km is 1/e the value at the surface.

→ scale; → height.

1) Statistics: A number assigned to each value or range of values of a given quantity, giving the number of times this value or range of values is found to be observed.
2) Statistical mechanics: A multiplicative factor in the expression for the probability of finding a system in a given quantum state. Usually the number of degenerate substates contained in the state.

→ statistical; → weight.

1) The force of attraction of the Earth on a given mass. → molecular weight; → weightlessness.
2) Statistics: A measure of the relative importance of an item in a statistical population. → weighted mean.
See also: → atomic weight, → counterweight, → mean molecular weight, → molecular weight, → statistical weight, → weight concentration, → weight fraction, → weight of a tensor density, → weight-fraction concentration, → weightlessness.

M.E., from O.E. gewiht, cf. O.N. vætt, O.Fris. wicht, M.Du. gewicht, Ger. Gewicht.

Vazn, loan from Ar. wazn.

of a gas included in the composition of a → gas mixture, the ratio of mass of this gas to the mass of the whole mixture. Same as → weight fraction and → weight-fraction concentration.

→ weight; → concentration.

Same as → weight concentration.

→ weight; → fraction.

A constant the value of which is characteristic for any given → tensor density.

→ weight; → tensor; → density.

Same as → weight concentration.

→ weight; → fraction; → concentration.

An mean which is obtained by combining different numbers according to the relative importance of each.

→ weight; → mean.

The phenomenon experienced by a body when there is no force of reaction on it. This happens when the body is in → free fall in a → gravitational field or when the net force on it is zero.

From → weight + -less suffix meaning "without" + -ness a suffix of quality or state.

Bivazni, from bi- "without," → a-, + vazn, → weight, + -i.