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

A method of making decision between rejecting or not rejecting a → null hypothesis on the basis of a set of observations.

→ statistical; → hypothesis; → test.

The process of inferring certain facts about a → statistical population from results found in a → sample.

→ statistical; → inference.

A law that governs the behavior of a system consisting of a large number of particles and which differs from the laws obeyed by each of the particles making up the macroscopic system. See also → dynamical law.

→ statistical; → law.

→ statistical physics.

→ statistical; → mechanics.

The mean parallax of a group of stars that are all at approximately the same distance, as determined from their radial velocities and proper motions.

→ statistical; → parallax.

The branch of physics that applies methods of → probability theory and → statistics to the behavior of large numbers of microscopic particles (such as molecules, atoms, or subatomic particles) in order to explain and predict the overall properties of the system composed of such particles.

→ statistical; → physics.

Any collection of individuals or items from which → samples are drawn. See also → finite population, → infinite population.

→ statistical; → population.

Same as → statistical mechanics.

→ statistical; → thermodynamics.

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.

A branch of applied mathematics that deals with the collection and interpretation of quantitative data and the use of probability theory to estimate population parameters.

From Ger. Statistik "political science," from Mod.L. statisticus (collegium) "state affairs," from It. statista "person skilled in statecraft," from stato "state," ultimately from L. status "position, form of government;" cognate with Pers. ist-, istâdan "to stand" (Mid.Pers. êstâtan; O.Pers./Av. sta- "to stand, stand still; set;" Av. hištaiti; cf. Skt. sthâ- "to stand;" Gk. histemi "put, place, weigh," stasis "a standing still;" L. stare "to stand;" Lith. statau "place;" Goth. standan; PIE base *sta- "to stand").

Âmâr "computation, arithmetic; statistics," from âmârdan "to reckon, to calculate," related to ošmârdan, šomârdan, šomordan "to count, to calculate," mar, mâr- "count, reckon, measure," bimar "countless," nahmâr "great, large, big;" Mid.Pers. âmâr "calculating, reckoning;" Av. base mar- "to have in mind, remember, recall," hišmar-; cf. Skt. smr-, smarati "to remember, he remembers," L. memor, memoria, Gk. mermera "care," martyr "witness."

1) The natural height of a human or animal in an upright position.
2) An achieved level; status (The FreeDictionary.com).

M.E., from from O.Fr. stature, estature "build, structure," from L. statura "height, size of body, size," from PIE root *sta- "to stand, make or be firm," cf. Pers. ist-, istâdan "to stand," → opposition.

Bašn "stature, height; the body;" Mid.Pers. bašn "the top;" O.Pers. baršan- "height," variant borz "height, magnitude" (it occurs also in the name of the mountain chain Alborz), related to boland "high," bâlâ "up, above, high, elevated, height," berg "mountain, hill;" Mid.Pers. buland "high;" Av. barəz- "high, mount," barezan- "height;" cf. Skt. bhrant- "high;" L. fortis "strong" (Fr. & E. force); O.E. burg, burh "castle, fortified place;" Ger. Burg "castle," Goth. baurgs "city," E. burg, borough, Fr. bourgeois, bourgeoisie, faubourg); PIE base *bhergh- "high."

1) The position of an individual in relation to another or others, especially in regard to social or professional standing.
2) State or condition of affairs (Dictionary.com).

From L. status "condition, position, state, attitude" from p.p. stem of stare "to stand," from PIE *ste-tu-, from root *sta- "to stand," → state., + -tus suffix of action.

Estâté, from estat, → state, + nuance suffix -é.

A flow in which the characterizing conditions, such as → streamlines or velocity at any given point, do not change with time.

→ steady; → flow.

Tacân, → flow; pâyâ "steady, constant," from pâyidan "to stand firm, to be constant, steady," from Mid.Pers. pattây-, pattutan "to last, endure, stay."

A → cosmological model according to which the → Universe has no beginning and no end and maintains the same mean density, in spite of its observed expansion, by the continual creation of matter throughout all space. The theory was first put forward by Sir James Jeans in about 1920 and again in revised form in 1948 by Hermann Bondi and Thomas Gold. It was further developed by Sir Fred Hoyle to deal with problems that had arisen in connection with the alternative → Big Bang model. Observations since the 1950s have produced much evidence contradictory to the steady state theory and supportive of the Big Bang model. More specifically, the steady state theory attributed the → cosmic microwave background to → thermal radiation from → dust clouds, but this cannot account for a single → blackbody spectrum. Moreover, the steady state theory lacked a plausible mechanism for the creation of matter in space. See also → perfect cosmological principle.

→ steady; → state; → theory.

The vapor into which water is changed when boiled.

From M.E. steme, O.E. steam; cognate with Du. stoom, of unknown origin.

Boxâr, → vapor.

An engine in which the energy of hot → steam is converted into → mechanical power, especially an engine in which the force of expanding steam is used to drive one or more → pistons. The source of the steam is typically external to the part of the machine that converts the steam energy into → mechanical energy (Dictionary.com).

→ steam; → engine.

A strong → alloy of → iron containing up to 1.5 percent → carbon along with small amounts of other → chemical elements such as → manganese, → chromium, → nickel, and so forth.

O.E. style; cf. O.S. stehli, O.N., M.L.G. stal, Dan. staal, Swed. stål, M.Du. stael, Du. staal, O.H.G. stahal, Ger. Stahl.

Pulâd, variant fulâd, from Mid.Pers. pôlâwad, pôlâvat, loaned in Arm. polopat, polovat, maybe related to Skt. pavīra- "a weapon with metallic point, a spear, a lance."

A balance used for weighing loads that has a two beams of different lengths. The shorter beam has a hook or the like for holding the object to be weighed and the longer one supports a movable counterpoise that slides to attain a balance.

→ steel; yard, from M.E. yard(e), O.E. gerd "straight twig;" cognate with Du. gard, Ger. Gerte "rod."

Qapân, from kapân "a large balance with one scale, being kept in equilibrium by a weight on the other end of the beam, a lever balance" (Steingass).

The constant of proportionality present in the → Stefan-Boltzmann law. It is equal to σ = 5.670 × 10^-8 W m^-2 K^-4 or 5.670 × 10^-5 erg cm^-2 s^-1 K^-4.

→ Stefan-Boltzmann law; → constant.

The flux of radiation from a blackbody is proportional to the fourth power of its absolute temperature: L = 4πR²σT⁴. Also known as Stefan's law.

Ludwig Eduard Boltzmann (1844-1906), an Austrian physicist, who made important contributions in the fields of statistical mechanics and statistical thermodynamics and Josef Stefan (1835-1893), an Austrian physicist; → law.