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

A process whereby → angular momentum and chemical species are transported from layer to layer within a star. The main mixing processes include: → convection, → overshooting, → rotation, and → turbulence. The extent to which the interiors of stars are mixed strongly influences their evolution, age, chemical content, and the relationship between their internal and surface → chemical abundances.

→ mixing; → process.

An process in which an excited state returns to the ground state without emitting radiation. → radiative process.

→ non-; → radiative; → process.

A process in which an → atomic nucleus changes, including → radioactive decay of naturally occurring and man-made → isotopes, → nuclear fission, and → nuclear fusion.

→ nuclear; → process.

A process involving → nucleosynthesis, such as → r-process and → r-process.

→ nucleosynthetic; → process.

A hypothetical means of extracting energy from a rotating black hole. If a particle spirals into the ergosphere of a black hole in a direction counter to the rotation of the black hole, and if the particle then breaks up into two fragments inside the ergosphere, one of the fragments can escape with energy greater than the energy of the original particle.

Named after Roger Penrose, English physicist (1931-), who devised the process; → process.

A thermodynamic process that obeys the relation: PVⁿ = C, where P is pressure, V is volume, n is any real number, called the → polytropic index, and C is a constant.
If n = 0, then P = C and it is an → isobaric process.
If n = 1, then for an → ideal gas PV = NkT = C and it is an → isothermal process.
If n = γ, → adiabatic index, then for an ideal gas it is an → adiabatic process.

→ polytropic; → process.

1) (n.) A series of actions directed toward a specific aim.
A series of natural occurrences that produce change or development.
2) (v.) To treat or prepare something in a series of steps or actions.

M.E., from O.Fr. proces, from L. processus "advance, progress," from p.p. stem of procedere "go forward," from → pro- "forward" + cedere "to go."

1) Farâravand, from farâ- "forward" → pro- + ravand, contraction of ravandé "goer, going," from raftan "to go, walk;" Mid.Pers. raftan, raw-, Proto-Iranian *rab/f- "to go; to attack."

Note: Another Pers. equivalent for process (n.), coined by the Mosâhab group on the model of the L. concept, is farâyand (فر‌آیند). This dictionary has not retained farâyand, because it is problematic and even contradictory, as first remarked by M.Sch. Adib-Soltani. The process notion denotes a forward motion, composed of two components indicating the same direction "moving forward." In contrast, farâyand implies two opposite, contrary vectors, farâ- "forward" and âyand "coming, comer," from âmadan "to come." In brief, farâyand would mean "coming in front of, before, into the presence, in advance of," while in contrast farâravand means "to go on, to proceed."

2) Âmudan, âmâyidan "to prepare, to fashion; to cause to be made;" from Proto-Iranian *ā-mā-; cf. O.Pers./Av. mā(y)- "to measure;" Mod.Pers. mâ/mun/mân "measure," as in Pers. terms âzmâ- "to test;" pirâmun "perimeter," âzmun "test, trial," peymân "measuring, agreement," peymâné "a measure; a cup, bowl;" PIE base *me- "to measure;" cf. Skt. mati "measures," matra- "measure;" Gk. metron "measure;" L. metrum.

Performing some predefined sequence of operations on an input to produce an output. → data processing; → image processing .

Noun of the verb → process.

The act of moving along or proceeding in orderly succession or in a formal and ceremonious manner, as a line of people, animals, vehicles, etc (Dictionary.com).

Verbal noun from → process.

Computers: A central processing unit.
A program that translates another program into a form acceptable by the computer being used. → data processor; → microprocessor

Agent noun of the verb → process.

A → nucleosynthesis process in which → chemical elements heavier than → zinc are created through the intense bombardment of other elements by → neutrons in rapid succession. The essential feature of the r-process is the release of great numbers of neutrons in a very short time (less than 100 seconds). The r-process is a "rapid" version of the → s-process, occurring in supernova → core collapse and possibly when a → neutron star merges with a → black hole in a → binary star.

r stands for rapid, since the process entails a succession of rapid neutron captures on iron seed nuclei; → process.

An process in which an excited state loses its absorbed energy by emission of radiation. → non-radiative process.

→ radiative; → process.

Data processing that takes place instantaneously upon data entry or receipt of a command.

→ real; → time; → processing.

Any physical process which can be performed in the reverse direction, the whole series of changes constituting the process being exactly reversed. → irreversible process.

→ reversible; → process.

A → nucleosynthesis process by which → chemical elements heavier than → copper are formed through a slow flux of → neutrons absorbed by atomic nuclei (→ neutron-capture element). The → capture of neutrons occurs on time scales that are long enough to enable unstable nuclei to decay via the emission of a → beta particle before absorbing another neutron. Prominent s-process elements include → barium, → zirconium, and → yttrium. See also: → r-process.

s stands for → slow; → process.

An equation describing how the nuclei of helium fuse together, in the interior of giant stars, to form carbon nuclei. → triple-alpha process.

Named after the Austrian-Australian-American astrophysicist Edwin Ernest Salpeter (1924-2008); → process.

Computers: A type of central processing unit in which only one operation on data is executed at a time. By contrast, in a vector processor, a single instruction operates simultaneously on multiple data items.

→ scalar; → processor.

A process that is invariant in distribution under scaling of time. Schematically, images taken of such a process at different time scales will look similar.

→ self-; → similar; → process.

Any process involving a sequence of random variables. The future evolution of a stochastic process is therefore described by probability distributions.

→ stochastic; → process.

An ordered set of → equilibrium states undergone by a → thermodynamic system. Thermodynamics processes have various types: → cyclic process, → reversible process, and → irreversible process, → isothermal process, → adiabatic process, → isentropic process.

→ thermodynamic; → process.