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

A → cyclic process comprising a sequence of → isothermal and → adiabatic expansions and compressions that bring a system back to its initial state.

Nicolas Léonard Sadi Carnot (1796-1832), a French physicist and military engineer who, in his 1824 Reflections on the Motive Power of Fire, gave the first successful theoretical account of heat engines; → cycle.

A notation convention in → tensor analysis whereby whenever there is an expression with a repeated → index, the summation is done over that index from 1 to 3 (or from 1 to n, where n is the space dimension). For example, the dot product of vectors a and b is usually written as: a.b = Σ (i = 1 to 3) a_i.b_i. In the Einstein notation this is simply written as a.b = a_i.b_i. This notation makes operations much easier. Same as Einstein summation convention.

→ Einstein; → notation.

The belief or doctrine that there is only one → God.

→ mono-; → theism.

Of a mathematical function, either continuously increasing or decreasing.

From Fr. monotone, from Gk. monotonos "monotonous, of one tone," from monos, → mono- "single, alone" + tonos "tone" + → -ic.

Yeknavâxt "monotonous," from yek "one, single," + navâxt"rhythm," from navâxtan, navâzidan "to play an instrument; to gratify," navâ "music, song, melody;" Mid.Pers. nw'c "to treat kindly, honour," niwag "music, melody;" Proto-Iranian *ni-uac-, from *ni- (→ ni-) + *uac- "to speak, treat kindly," → word.

The science and technology of producing and exploiting structures and systems at dimensions of roughly 1 to 100 → nanometers, that is those of single atoms and molecules. Materials with such minute structures possess mechanical, optical, chemical, magnetic or electronic properties not found in ordinary materials.

→ nano-; → technology.

A → particle used to express → negation, → denial, refusal, or prohibition.

Not, variant of noht, naht "in no way," from O.E. nawiht "nothing" (from na "no, never" + whit "whit"), akin to Pers. na, nâ, as below.

Na "no, not," variants nâ, ni, ma- (prohibitive) "not;" from Mid.Pers. nê, ma "no, not;" O.Pers. naiy, nai "not;" Av. nôit, naē "not;" cf. Skt. ná "not;" cf. L. ne-, in-, un-; Gk. ni; Lith. nè; O.C.S. ne "not;" E. not, as above; PIE *ne-.

Representation of numbers, quantities, or other entities by symbols; a system of symbols for such a purpose.

From L. notationem (nom. notatio) "a marking, explanation," from notatus, p.p. of notare "to note."

Namâdgân, from namâd, → symbol, + -gân suffix denoting order, organization, multiplicity.

Musical sound of specified frequency (pitch) produced by a musical instrument, voice, etc.

From M.E., from O.F., from M.L. nota "sign for musical tone; mark, sign, lettering."

Not, loanword from Fr.

1) No thing; not anything; naught.
2) Nonexistence; nothingness.

M.E., from O.E. nathing, nathinc, from nan "not one," → non-, + → thing.

Mid.Pers. hêc, hêc(i), hâca "any."

A general understanding; vague or imperfect conception or idea of something.

From L. notio "concept, conception, idea," from noscere "to know," → knowledge.

Pendâré, noun from pendâštan "to imagine, consider, think," → imaginary number.

A mathematical notation system in which the → numerals get different values depending on their position relative to the other numerals. Same as → positional notation and → positional number system.

→ place; → value; → notation.

A system of representing → numbers in which the → position of a → digit in a string of digits affects its value. The decimal system is a positional notation for expressing numbers. Same as → place-value notation and → positional number system.

→ positional; → notation.

A compact format for writing very large or very small numbers. Numbers are made up of three parts: the coefficient, the base and the exponent. For example 3.58 x 10⁴ is the scientific notation for 35,800.

→ scientific; → notation.