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

A series of experiments carried out in the early 1980s by Alain Aspect and his colleagues that showed the violation of → Bell's inequality. Accordingly, quantum phenomena cannot be described by the → hidden variable theories, contrarily to the → EPR paradox interpretation.

Alain Aspect (1947-); → experiment. Aspect et al., 1982, Physical Review Letters, Vol. 49, No. 25 and references therein.

The measurement of the amount of → heat involved in various processes, such as chemical reactions, changes of state, and formation of solutions.

From L. calori- "heat," combining form of calor, → calorie, + → -metry.

Garmâsanji, from garmâ  → heat + -sanji  → -metry.

An experiment devised to produce → interference patterns from a beam of helium atoms passing through two adjacent apertures, as in → Young's experiment.

Named after O. Carnal and J. Mlynek, who first carried out this experiment in 1991 (Phys. Rev. Lett. 66, 2689); → experiment.

The measurement and definition of unknown colors in terms of standard colors.

→ color; → -metry.

That part an → impact crater that extends above the height of the local surface, usually in a circular or elliptical pattern.

→ crater; → rim.

An action or an instance of negligence that is deemed injurious to the public welfare or morals or to the interests of the state and that is legally prohibited (Dictionary.com).

M.E., from O.Fr. crimne, from L. crimen "charge, indictment, accusation; offense."

Bazah, from Mid.Pers. bazag "crime, misdeed," bazagkâr "evil-doer," Parthian bzg "evil, wicked."

1) Of the nature of or involving crime.
2) A person guilty or convicted of a crime.

L. criminalis, → crime; → -al.

The experiment carried out in 1927 that confirmed the → de Broglie hypothesis as to the → wave nature of the → electron. It showed that electrons scattering off crystals form a → diffraction pattern. The experimental setup consisted of a → nickle chloride → crystal as → target, an electron gun, and a → detector placed on a graduated circular scale. The intensity of the reflected electrons was measured as a function of angle and electron energy. The observations showed a strong intensity peak at a certain angle. The nickel crystal acted as a → diffraction grating. → Constructive interference occurred at a particular angle, where the peak intensity was observed in accord with → Bragg's law. Interestingly, the intent of the initial experiment was was not to confirm the de Broglie hypothesis. In fact, the discovery was made by accident.

Carried out by American physicists Clinton Davisson (1881-1958) and Lester Germer (1896-1971); → experiment.

To make a distinction in favor of or against a person or thing on the basis of the group, class, or category to which the person or thing belongs rather than according to actual merit (Dictionary.com).

From L. discriminatus, p.p. of discriminare "to divide, separate," from discrimen "a space between, division, separation, difference," from discernere "to separate, divide; distinguish, perceive," from → dis- "off, away" + cernere "distinguish, separate, sift;" ultimately from PIE root *krei- "to sieve," → critique.

Vâkarbidan, from prefix vâ-, → dis-, + karb-, related to stem qarb- in qarbâl, qalbur, gerbâl "sieve," probably related to PIE root *krei- "to sieve," as above.

1) An act or instance of discriminating, or of making a distinction.
2) Unfair treatment of a person, racial group, minority, etc; action based on prejudice (Dictionary.com).

Verbal noun of → discriminate.

Characterized by or showing prejudicial treatment, especially as an indication of bias related to age, color, national origin, religion, sex, etc. (Dictionary.com).

From → discriminate + adjective and noun suffix -ory.

An experiment of → diffraction and → interference of two light beams using a → double slit; → Young's experiment.

→ double; → slit; → experiment.

An act or operation for the purpose of discovering something unknown or of testing a principle, supposition. See: → Aspect experiment, → Carnal-Mlynek experiment, → Davisson-Germer experiment, → double-slit experiment, → Eratosthenes experiment, → Hafele-Keating experiment, → Hertz experiment, → Michelson-Morley experiment, → Millikan's oil-drop experiment, → Pascal's barrel experiment, → random experiment, → Stern-Gerlach experiment, → thought experiment, → toothed-wheel experiment, → Trouton-Noble experiment, → Young's experiment.

From O.Fr. experiment, from L. experimentum "a trial, test," from experiri "to test, try," from → ex- "out of" + peritus "experienced, tested."

Âzmâyeš, verbal noun of âzmudan, âzmây- "to try, experiment, test;" Mid.Pers. uzmudan, ôzmutan "to test, try, prove;" from O.Pers./Av. *uz-māy-, from uz-, → ex- + mā(y)- "to measure," Proto-Ir. *maH- "to measure;" PIE *meH- "to measure;" cf. Skt. mati "measures," matra "measure;" Gk. metra "lot, portion;" L. metri "to measure."

A → Fermat number, 2²ⁿ + 1, that is a → prime number. The only known Fermat primes are: 3, 5, 17, 257, and 65537, corresponding to n = 0, 1, 2, 3, and 4.

→ Fermat's principle; → prime.

An experiment performed in 1971 using four atomic → cesium clocks transported in jet airplanes eastward and westward around the Earth to verify the → time dilation predicted by the theory of → special relativity.

J.C. Hafele and R. E. Keating, 1972, Science 177, 166; → experiment.

A laboratory experiment carried out by Heinrich Hertz in 1888 to generate and detect → electromagnetic waves for the first time. It involved a high voltage power source, consisting of two → capacitors, each provided with a conducting rod. The rods were separated by a small → spark gap and connected to an → induction coil. When the electrodes were raised to a sufficiently high → potential difference, a spark passed across the gap, and an oscillating discharge took place. A group of waves with a wavelength of a few meters were emitted at each discharge. A wire loop provided with a detecting spark gap, held away from the oscillating sparks, produced sparks upon arrival of the oscillating electric and magnetic fields.

→ hertz (Hz); → experiment.

1a) An intervening time; interval; meantime.
1b) A temporary or provisional arrangement.
2) For, during, belonging to, or connected with an intervening period of time; temporary; provisional (Dictionary.com).

L. interim (adv.) "in the meantime, meanwhile," originally "in the midst of that," from → inter- "between" + im, an old accusative of "is, he, this, that."

Andarim, from andar-, → inter-, + im variant em "this;" Mid.Pers. im "this;" from Old.Pers./Av. ima "this;" Skt. ima; cf. Lori (Laki) im "this side." The Mid.Pers. im occurs in Mod.Pers. as em- in emruz "today," emšab "tonight," and emsâl "this year."

The first ever discovered → fast radio burst. It was done during a search of archival data from a 1.4-GHz survey of the → Magellanic Clouds using the multi-beam receiver on the 64-m Parkes Radio Telescope in Australia.

D. R. Lorimer et al., 2007, Science, 318, 777; → burst.

A → prime number of the form 2^p - 1, where p is a prime. As of February 2013, 48 Mersenne primes are known. The largest known prime number is 2^57,885,161 - 1. Each prime gives rise to an even → perfect number.

Marin Mersenne (1588-1648), French theologian, philosopher, mathematician and music theorist; → prime.

An experiment performed in 1887 to establish the presence or absence of an → ether, a medium through which light was supposed to travel. The experiment aimed to measure the speed of light coming from different directions. However no → ether drift was found. The null results obtained showed that the ether hypothesis was incorrect. Consequently, the theory of → special relativity, with its hypothesis that the speed of light is the same in all → inertial frames, reconciled the results of the Michelson-Morley experiment with the rest of physics.

→ Michelson interferometer; Michelson received the Nobel Prize in 1907 for his work, the first American to receive the Prize in science. Edward Williams Morley (1838-1923), an American chemist; → experiment.