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

1) Biology: A living individual composed of mutually interdependent parts that maintain various vital processes.
2) Any organized body or system conceived of as analogous to a living being. → microorganism

From → organ + -ism a suffix appearing in loanwords from Gk. denoting several senses, among which state or condition, principles, doctrines.

Sâzvâré, from sâz present stem of sâxtan, sâzidan "to build, make, fashion; to adapt, adjust, be fit" (from Mid.Pers. sâxtan, sâz-, Manichean Parthian s'c'dn "to prepare, to form;" Av. sak- "to understand, to mark," sâcaya- (causative) "to teach") + -vâré, from -vâr a suffix meaning "resembling, like" (from Mid.Pers. -wâr; Av. -vara, -var; cf. Skt. -vara).

The study of natural remanent magnetization in order to determine the intensity and direction of the Earth's magnetic field in the geologic past.

→ paleo-; → magnetism.

1) The doctrine that God is the transcendent reality of which the material universe and human beings are only manifestations: it involves a denial of God's personality and expresses a tendency to identify God and nature.
2) Any religious belief or philosophical doctrine that identifies God with the universe (Dictionary.com).

→ pan-; → theism.

The property of a substance that possesses a → magnetic permeability greater than that of a vacuum but significantly less than that exhibited by → ferromagnetism. In the absence of an external magnetic field the atomic → magnetic moments of the substance are randomly oriented and thus cancel each other out with no net total magnetic moment. Moreover the coupling between neighboring moments is weak. However, when a magnetic field is applied magnetic moments align with the direction of the field and so the magnetic moments add together. Therefore paramagnetic substances affect external fields in a positive way, by attraction to the field resulting in a local increase in the magnetic field. The → magnetization vanishes when the field is removed.

→ para- + → magnetism

1) Any of various doctrines holding that religious, moral, social, or political perfection is attainable.
2) A personal standard, attitude, or philosophy that demands perfection and rejects anything less (Dictionary.com).

→ perfection; → -ism.

The property of certain crystals of exhibiting different colors when viewed from different directions under transmitted light. This is because the degree with which certain birefringent crystals transmit polarized light is different, depending on whether the ray is ordinary or extraordinary. Pleochroism is the general term for both dichroism, which is found in uniaxial crystals (crystals with a single optic axis), and trichroism, found in biaxial crystals (two optic axes).

From pleochro(ic), from pleo- prefix meaning "more," from Gk. pleion "more," cognate with Pers. por, → full, + chroic, from chroos "skin, color" + -ism.

Candfâmi, from cand "so many, much; how many, how much" (O.Pers. yāvā "as long as;" Av. yauuant- [adj.] "how great?, how much?, how many?," yauuat [adv.] "as much as, as far as;" cf. Skt. yāvant- "how big, how much;" Gk. heos "as long as, until") + fâm "color," + -i noun suffix.

1) A state of society in which various religious, ethnic, racial, and political groups are allowed to thrive in a single society.
2) Philo.: A belief that there are more than two kinds of principles, as contrasted to the → dualism and → monism.

→ plural; → -ism.

A prism that is used to produce or analyze plane-polarized light.

Polarizing, adj. of → polarize; → prism.

A kind of → deism according to which multiple deities created the Universe, but do not interact with the physical world. → polytheism.

→ poly-; → deism.

The doctrine of or belief in more than one god or in many gods (Dictionary.com). → polydeism.

→ poly-; → theism.

Any doctrine that excludes a priori affirmations and admits only positive truth, i.e. factual knowledge gained through observation.

From Fr. positivisme, from positif, → positive, in its philosophical sense of "imposed on the mind by experience;" → -ism.

An approximate version of → general relativity that applies when the → gravitational field is → weak, and the matter → velocity is → small. Post-Newtonian formalism successfully describes the gravitational field of the solar system. It can also be applied to situations involving compact bodies with strong internal gravity, provided that the mutual gravity between bodies is weak. It also provides a foundation to calculate the → gravitational waves emitted by → compact binary star systems, as well as their orbital evolution under radiative losses. The formalism proceeds from the Newtonian description and then, step by step, adds correction terms that take into account the effects of general relativity. The correction terms are ordered in a systematic way (from the largest effects to the smallest ones), and the progression of ever smaller corrections is called the → post-Newtonian expansion.

→ post-; → Newtonian; → formalism.

Any of a number of trends or styles in architecture, philosophy, literature, and art developed in the latter part of the 20th century often in reaction to → modernism. In philosophy, postmodernists claim that value systems are concoctions of human partial knowledge rather than systems reflecting universal objective truth. The most influential early postmodern philosophers include Jean Baudrillard, Jean-François Lyotard, and Jacques Derrida.

The term postmodernism was first coined by architects to designate an architectural response against the earlier Bauhaus style, which was characterized by box-like apartment buildings, the absence of ornamentation and harmony between the function of a building and its design; → post- + → modernism.

Philo.: The doctrine that the truth or value of a concept or assertion is determined by its practical effects upon human interests.

→ pragmatic; → -ism.

A mathematical analysis, based on → self-similarity, used to predict the → mass function of spherically collapsing → dark matter halos. The formalism assumes that the fraction of mass in halos more massive than M is related to the fraction of the volume in which the smoothed initial density field is above some threshold δ_cρ, where ρ is the average density of the Universe, with the volume encompassing a mass larger than M. A variety of smoothing → window functions and thresholds have been argued, but the most common is a top-hat window in real space and δ_c≅ 1.69. The Press-Schechter formalism provides a relatively good fit to the results of numerical simulations in cold dark matter theories.

First described by William H. Press and Paul Schechter's paper (1974, ApJ 187, 425); → formalism.

Optics: A transparent solid body, having at least two polished plane faces inclined relative to each other, from which light is reflected or through which light is refracted.
Geometry: A solid having two faces lying in parallel planes and with the other faces parallelograms.

L.L. prisma, from Gk. prisma, literally "something sawed," from prizein "to saw."

Manšur, etymology not clear, may be related to Ar. mawšur "prism," of unknown origin.

The angle between the faces on which light is incident and from which it emerges.

→ prism; → angle.

An optical device consisting of a pair of small telescopes mounted side by side, each telescope having two prisms between the eyepiece and objective for erecting the image.

→ prism; → binoculars.

An ocular equipped with a prism that forms an upright image in an astronomical telescope.

→ prism; → ocular.

An instrument used to determine the precise timing of a star's passage across a vertical circle. It is used for making precise determinations of the positions of stars and planets, and can be used inversely to determine the latitude and longitude of the observer, assuming the star positions are accurately known. It consists of an accurate prism, a small pool of mercury to serve as an artificial horizon. The most notable example of this type of instrument is that of → Danjon astrolabe.

Adj. of → prism + → astrolabe.