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."

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.

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.