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

A mechanism, made possible by certain chance coincidences between → spectral lines of He II, O III and N III in some → planetary nebulae , that explains the presence with a high intensity of a selected group of O III and N III lines while all other lines of these elements are missing.

After I. S. Bowen who first discovered this mechanism in 1935; → fluorescence; → mechanism.

The doctrine that certain vast geological changes in the Earth's history were caused by sudden, short-lived, violent events rather than gradual evolutionary processes. Catastrophism explains the differences in → fossil forms encountered in successive → stratigraphic levels. This doctrine is associated with the French naturalist Baron Georges Cuvier (1769-1832). Catastrohism is contrasted to the → uniformitarianism.

→ catastrophe; → -ism.

A standard → syllogism that consists of three → categorical propositions in which there are three terms, and each term appears exactly twice. The three terms in a standard categorical syllogism are the → major term, → mino term, and → middle term.

→ categorical; → syllogism.

1) The principle of ownership of the means of production, by the state or the people.
2) A social system based on this principle (Dictionary.com).

→ collective; → -ism.

A theory or system of social organization based on the holding of all property in common, actual ownership being ascribed to the community as a whole or to the state (Dictionary.com).

→ commune; → -ism.

A doctrine or system of social organization that upholds the importance of communities. It tends to lessen the focus on individual rights and increase the focus on communal responsibilities.

→ communitarian; → -ism.

Any of several doctrines existing as a compromise between realism and nominalism and regarding universals as concepts (Dictionary.com).

→ conceptual; → -ism.

The disposition, or political philosophy, to preserve the existing or traditional order and oppose radical change.

→ conservative; → -ism.

A combination of two 30° prisms, one of left-handed quartz and the other of right-handed quartz. The prisms are cemented together in order to get a 60° prism. The device will correct for light rotation and will transmit the beam in a straight direction. The Cornu prism has good ultraviolet transmitting qualities and no → double refraction.

→ Cornu's spiral; → prism.

The religious belief that considers the account of creation given in Genesis to be a scientific description and rejects the Big Bang theory and the theory of evolution. Creationism is a → pseudoscience. Same as "creation science" and "scientific creationism."

→ creation; → -ism.

1) The act of passing judgment as to the merits of anything.
2) The act or art of analyzing and evaluating or judging the quality of a literary or artistic work, musical performance, art exhibit, dramatic production, etc.
3) A critical comment, article, or essay; → critique (Dictionary.com).

→ critic; → -ism.

1) Belief in the existence of a → God on the evidence of → reason and → nature only, with rejection of supernatural revelation (distinguished from → theism).
2) Belief in a God who created the world but has since remained indifferent to it (Dictionary.com).

From Fr. déisme, from L. de(us) "god," → deity, + → -ism.

Dâdâr-bâvari, from dâdâr "creator," → author, + bâvari, → ism; izad-bâvari, from izad "god," → deity.

The belief that every event is necessitated by antecedent events and conditions together with the laws of nature. → deterministic physics.

From → determine + → -ism.

Âtarmbâvari, from âtarm, → determine, + bâvari, noun of bâvar "beleif;" Mid.Pers. wâbar "beleif;" Proto-Iranian *uar- "to choose; to convince; to believe;" cf. Av. var- "to choose; to convince" varəna-, varana- "conviction, faith;" O.Pers. v(a)r- "to choose; to convince;" Skt. vr- "to choose," vara- "choosing."

The property of a substance, like bismuth, that creates a weak magnetic field in opposition of an externally applied magnetic field, thus causing a repulsive effect. In diamagnetic materials the → magnetic moments of individual atoms are not permanent. Within each atom the electron spins and orbital motions all exactly balance out, so any particular atom has no net magnetic moment. The external magnetic field generates little currents by induction. According to → Lenz's law, the induced magnetic moments of the atoms are directed opposite to the magnetic field.

Diamagnetic, from Gk. dia- a prefix used with several meanings "passing through; thoroughly; completely; going apart," and in the present case "opposed;" → magnetic. magnetic.

Pâdmeqnât, from pâd- "against, contrary," → anti-, + megnât→ magnetism.

Property of some crystals in which radiation polarized in one plane relative to the crystalline axes is freely transmitted, but radiation polarized perpendicular to this is absorbed. Tourmaline is a natural mineral with this property; Polaroid is a synthetic dichroic substance.

From Gk. dichro(os), from di- "two," → di-, + chroma "color" + -ism.

Dofâmi, from do "two," → bi- + fâm "color," + -i noun suffix.

The tendency to lay down principles as undeniably true, without consideration of evidence or the opinions of others (OxfordDictionaries.com).

→ dogmatic;→ -ism.

1) Philo.: The doctrine, as opposed to idealism and materialism, that reality consists of two basic types of substance usually taken to be mind and matter or two basic types of entity, mental and physical.
2) The state of being twofold or double. → dualism, → pluralism (Dictionary.com).

→ dual; → -ism.

1) The science dealing with the physical relations between → electricity and → magnetism. Same as → electromagnetic theory.
2) One of the four fundamental forces of nature, governing the electric and magnetic interaction between particles.

→ electro-; → magnetism.

A → chemical reaction on solid surfaces in which one atom or molecule is → adsorbed on the catalyst surface, and another reacts directly from the gas phase. This type of mechanism may occur preferentially on very small → dust grains, where transient heating events prevent weakly bound species from remaining and in larger grains at high temperatures. Compare with the → Langmuir-Hinshelwood mechanism.

Proposed in 1938 by D. D. Eley (1914-2015), a British chemist and Professor of Physical Chemistry and E. K. Rideal (1890-1974), an English physical chemist.

1) In several → lunisolar calendars, an → intercalary month employed to preserve a seasonal relationship between the Lunar and Solar cycles. For example, in the → Hebrew calendar the extra month, called Adar Alef, was inserted after Shvat so that the month of Nissan (month of spring) does not begin in winter.
2) In ancient Iranian → solar calendar the additional whole month of 30 days employed every 120 years to compensate for the left-over quarters of days in a calendar year of 365 days (120 years × 0.25 days = 30 days).

M.E. embolisme, from M.L. embolismus "intercalation," from Gk. emballein "to throw into, to insert," from em- "in" + ballein "to throw" (source of the medical term embolism "the obstruction (of an artery, etc.) by a clot of blood, bubble of air, etc."); → month.

Behizak, from Mid.Pers. vihezagig or vihezakik "movable," from vihezag "movement, progression," from vihez- "to move, progress;" mâh, → month.