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

In general relativity, the time as measured on a clock that travels with the observer in the same system. An accelerated clock will measure shorter time intervals between events than a non-accelerated clock between the same events. → twin paradox.

→ proper; → time.

1) General: An essential or distinctive attribute or quality of a thing.
2) Physics: A quantity, such as length, mass, pressure, temperature, or volume, that relates to the state of a system and can be expressed in numbers obtained from well-defined measurement operations.

From M.E. propriete "ownership, something owned, one's own nature," from M.Fr. propriété, from L. proprietas "ownership, property, propriety," literally "special character," noun of quality from proprius "one's own, special."

Dârâk "thing owned," from dâr present stem of dâštan "to have, to possess" + -âk (on the model of xorâk, pušâk, kâvâk). The first element dâštan, from Mid.Pers. dâštan, O.Pers./Av. root dar- "to hold, keep back, maintain, keep in mind;" Skt. dhr- "to to hold, keep, preserve," dharma- "law;" Gk. thronos "elevated seat, throne;" L. firmus "firm, stable;" Lith. daryti "to make;" PIE *d^her- "to hold, support."

A circumstellar disk of dense gas and dust surrounding a young newly formed star, a T Tauri star or Herbig star. In particular, an externally ionized protoplanetary disk seen in emission in the Orion Nebula. → silhouette disk.

Contraction of protoplanetarydisk.

Comparative relation between things, sizes, quantities, numbers, parts, etc.
Math.: A statement of the equality of two ratios.

M.E. proporcio(u)n, from O.Fr. proportion, from L. proportio "comparative relation, analogy," from the phrase pro portione "according to the relation" (of parts to each other), from pro "for" + portio "part, shar."

Barpâreš, from bar- "on; up; upon; in; into; at; forth; with; near; before; according to" (Mid.Pers. abar; O.Pers. upariy "above; over, upon, according to;" Av. upairi "above, over," upairi.zəma- "located above the earth;" cf. Gk. hyper- "over, above;" L. super-; O.H.G. ubir "over;" PIE base *uper "over") + pâr "part, portion, piece" (variants pâréparré "portion, segment (of an orange)," pargâlé, "piece, portion; patch;" (dialects Kermâni pariké "portion, half;" Tabari perik "minute quantity, particle;" Lârestâni pakva "patch;" Borujerdi parru "patch"); Mid.Pers. pârag "piece, part, portion; gift, offering, bribe;" Av. pāra- "debt," from par- "to remunerate, equalize; to condemn;" PIE *per- "to sell, hand over, distribute; to assigne;" Gk. peprotai "it has been granted;" L. pars, as above; Skt. purti- "reward;" Hitt. pars-, parsiya- "to break, crumble") + -eš suffix.

Being in or characterized by proportion.
Math.: Of two quantities, having the same or a constant ratio or relation.

→ proportion + → -al.

A device in which an electronic detection system receives pulses that are proportional to the number of ions formed in a gas-filled tube by ionizing radiation.

→ proportional; → counter.

Math.: A relationship bewteen two quantities such that if one quantity changes the other changes in the same proportion; denoted as y ∝ x.

→ proportional + → -ity.

Math.: A → constant that converts a proportionality into an → equation. Thus the proportionality constant k converts the proportionality y ∝ x into the equation y = kx.

→ proportionality + → constant.

To offer or suggest (a matter, subject, case, etc.) for consideration, acceptance, or action (Dictionary.com).

M.E., from M.Fr. poposer, from → pro- "forth," + poser "put, place," → position.

Farâhelidan, from farâ-, → pro-, + helidan, heštan "to place, put" from Mid.Pers. hištan, hilidan "to let, set, leave, abandon," Parthian Mid.Pers. hyrz; O.Pers. hard- "to send forth," ava.hard- "to abandon;" Av. harəz- "to discharge, send out; to filter;" hərəzaiti "releases, shoots;" cf. Skt. srj- "to let go or fly, throw, cast, emit, put forth;" Pali sajati "to let loose, send forth."

1) The act of offering or suggesting something to be considered, accepted, adopted, or done.
2) A plan or scheme proposed.
3) Logic: A statement in which something is affirmed or denied, so that it can therefore be significantly characterized as either true or false.
4) Math.: A formal statement of either a truth to be demonstrated or an operation to be performed; a theorem or a problem (Dictionary.com).

Verbal noun of → propose.

Logic: Of, relating to, or in the form of a → proposition.

→ proposition; → -al.

Logic: A → propositional symbol that represents a → specific → proposition.

→ propositional; → constant.

A branch of logic that deals with the → truth values of logical statements (→ sentences, → propositions) and uses → logical connectives to build more complex → expressions. The distinctive feature of propositional logic is that it does not deal with logical relationships and properties that involve the parts of a statement smaller than the simple statements making it up. The propositions are evaluated as → true or → false. A more expressive system is provided by the → first-order logic.

→ proposition; → -al; → logic.

An upper case letter, e.g. "A," "B," "C," etc. representing a → proposition. Propositional symbols are divisible into two sorts: → propositional constants and → propositional variables.

→ propositional; → symbol.

Logic: A → propositional symbol that represents any → proposition whatsoever.

→ propositional; → variable.

The act or process of propelling. The state of being propelled.

Verbal noun from → propel.

A colorless, flammable gaseous → hydrocarbon C₃H₆, also known as propene. It is found in coal gas and can be synthesized by cracking petroleum or by the dehydrogenation of propane.

From propyl (prop(ionic acid) + -yl) + -ene.

A person who institutes or conducts legal proceedings, especially in a criminal court.

M.L. prosecutor, agent noun from prosequi "follow after, accompany; chase, pursue;" from → pro- "forward" + sequi "to follow," → sequence.

Dâsetân, literally "justice obtainer," from dâd, → justice, + setân agent noun of setândan "to obtain, to take," from Mid.Pers. statan "to take, seize;" Av. (+ *fra-) frastan- "to take, convey forward;" Proto-Ir. *staHn- "to take;" cf. L. prae-stināre "to buy, fix a price" (Cheung 2007).

1) The outlook for the future.
2) To explore a region for mineral deposits.

M.E. prospecte, from L. prospectus "view, outlook," from prospicere "look out on, look forward," from → pro- "forward" + specere "look at," → speculate.

Farâgâs, from farâ-, → pro-, + gâs "to look," → speculate.

1) Of or in the future.
2) Likely to be or become or come about.

From Fr. prospectif, from M.L. prospectivus, from L. prospect-, from prospicere, → prospect.

Adj. from farâgâs, → prospect.