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

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 428
feedforward
  پیش‌خورد   
pišxord

Fr.:   

In a self-regulatory system, monitoring a disturbance before it enters the → system to apply corrections before the disturbance has influenced the system. See also → feedback.

feed; → forward.

feedhorn
  کرنا، کرنای ِ خوراند   
karnâ, karnâ-ye xorând

Fr.: cornet d'alimentation   

In a → radio telescope, a device located at the → focal point of the → antenna. It receives the → radio waves which the antenna collects and guides them to the → detector.

feed; → horn.

feel
  سهیدن   
sohidan (#)

Fr.: sentir   

1) To perceive or examine by touch.
2) To have a sensation of (something), other than by sight, hearing, taste, or smell (Dictionary.com).

M.E. felen, from O.E. felan "to touch;" cf. O.S. gifolian, O.Fr.fela, Du. voelen, O.H.G. vuolen, Ger. fühlen "to feel;" from PIE root *pal- "to touch, feel, shake, strike softly" (cognates: Gk. psallein "to pluck (the harp)," L. palpare "to touch softly, stroke").

Sohidan, from Mid.Pers. sôhistan "to feel, to touch," sôhešn "feeling, sense," of unknown origin. Note Pers. sahestan "to fear," from Proto-Ir. *θrah- "to shake; to fear;" Pers. tars, harâs, sham "fear;" may be they are of different roots.

feeling
  سهش   
soheš (#)

Fr.: sensation   

1) The function or the power of perceiving by touch.
2) Physical sensation not connected with sight, hearing, taste, or smell.
3) A particular sensation of this kind (Dictionary.com).

Verbal noun of "to → feel."

feminine
  مادین   
mâdin (#)

Fr.: féminin   

1) Characteristic of or appropriate or unique to women.
2) Of, relating to, or constituting the gender that ordinarily includes most words or grammatical forms referring to females (merriam-webster.com).

M.E. feminin, from O.Fr. femenin "feminine, female; with feminine qualities," from L. femininus "feminine," from femina "woman, female," literally "she who suckles," from root of felare "to suck, suckle;" cf. Gk. thele "mother's breast, nipple," thelys "female, fruitful;" Pers. dâyé, dâyah "(wet-nurse);" PIE root *dhe(i)- "to suck, suckle."

Mâdin, from mâdé "female," from Mid.Pers. mâdag, "female," from mâd, → mother.

feminism
  زاد-زن-باوری، زادزن‌باوری   
zâd-zan-bâvari (#)

Fr.: féminisme   

1) Belief in the social, political, and economic freedom of women and equality of the sexes. Feminism is closely tied to democracy and → secularism.
2) The movement organized around this belief.

From Fr. féminisme, from féminin "feminine, female," from L. femininus "feminine" (originally in the grammatical sense), from femina "woman, female," literally "she who suckles," cognates fecund "fruitful, fertile," felix "happy," fetus "offspring, pregnancy;" PIE base *dheh(i)- "to suck, suckle;" cf. Gk. thele "mother's breast;" Pers. dâyé "wet nurse."

Zâd-zan-bâvari, from zâdzan "free woman" (on the model of zâdmard "free man, valiant man, generous man," zâdsarv "tall and upright cypress tree"), from zâd, contraction of âzâd, → free, + zan, → woman, + bâvari, → -ism.

femto-
  فمتو-   
femto- (#)

Fr.: femto-   

In the International System of Units, a prefix meaning 10-15.

From Danish and Norwegian femten "fifteen," from O.N. fimmtān (Sw. femton, Du. vüftien, Ger. fünfzehn, E. fifteen, Pers. pânzdah), ultimately from PIE base *penkwe "five" (cf. Mod.Pers. panj, Av. panca, Skt. pánca, Gk. pente, L. quinque) + PIE *dekm "ten" (cf. Mod.Pers. dah, Av. dasa, Skt. dáśa, Arm. tasn, Gk. deka, L. decem, Ger. zehn, E. ten, Fr. dix).

Fermat number
  عدد ِ فرما   
adad-e Fermat

Fr.: nombre de Fermat   

Any number of the form 22n + 1, where n is a connective → integer. If Fermat number is → prime, it is called a → Fermat prime.

Fermat's principle; → number.

Fermat prime
  نخست ِ فرما   
naxost-e Fermat

Fr.: nombre de Fermat premier   

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.

Fermat's last theorem
  واپسین فربین ِ فرما   
vâpasin farbin-e Fermat

Fr.: dernier théorème de Fermat   

In → number theory, the statement that for all → integers, the equation xn + yn = zn has no solution in → positive integer. After 358 years of effort by mathematicians to prove the theorem, a complete proof was found by Andrew Wiles in 1995.

Fermat's principle; → last; → theorem.

Fermat's principle
  پروز ِ فرما   
parvaz-e Fermat

Fr.: principe de Fermat   

The path taken by a ray of light going from one point to another through any set of media is such that the time taken is a minimum. This principle governs the light propagation and determines the geodesics of optical paths.

Put forward by Pierre de Fermat (1601-1665), French mathematician, born at Beaumont-de-Lomagne; → principle

fermi
  فرمی   
fermi (#)

Fr.: fermi   

A unit of length equal to 10-13 cm.

After Enrico Fermi (1901-1954), the Italian-born American physicist who was a key figure in the development of nuclear physics. He was awarded the 1938 Nobel Prize for Physics.

Fermi constant
  پایای ِ فرمی   
pâyâ-ye Fermi

Fr.: constante de Fermi   

The → coupling constant associated with the → weak interaction, which gives rise to → beta decay. CF = 1.167 x 10-5 GeV-2.

Fermi; → constant.

Fermi energy
  کاروژ ِ فرمی   
kâruž-e Fermi

Fr.: énergie de Fermi   

The energy of the highest occupied quantum state in a system of fermions at absolute zero temperature. See also → Fermi sea.

fermi; → energy.

Fermi Gamma-ray Space Telescope
  دوربین ِ فضایی ِ پرتوهای ِ گاما فرمی   
Durbin-e fazâyi-ye partowhâ-ye gâmâ Fermi

Fr.: Télescope spatial à rayons gamma Fermi   

A space observatory, formerly named GLAST, devoted to the study of → gamma rays emitted from astrophysical objects. Developed by NASA in collaboration with the U.S. Department of Energy, along with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden, and the United States, Fermi was launched on June 11, 2008. The main instrument, the Large Area Telescope (LAT), is an imaging → camera covering the energy range from about 20 → MeV to more than 300 → GeV. Such gamma rays are emitted only in the most extreme conditions, by particles moving very nearly at the → speed of light. The LAT's → field of view covers about 20% of the sky at any time, and it scans continuously, covering the whole sky every three hours. Another instrument, the Gamma-ray Burst Monitor (GBM) has a field of view several times larger than the LAT and provides → spectral coverage of → gamma-ray burst that extends from the lower limit of the LAT down to 10 → keV.

Fermi; → gamma ray; → space; → telescope.

Fermi interaction
  اندرژیرش ِ فرمی   
andaržirš-e Fermi

Fr.: interaction de Fermi   

An old explanation, proposed by Enrico Fermi, of the → weak interaction.

fermi; → interaction.

Fermi level
  تراز ِ فرمی   
tarâz-e Fermi

Fr.: niveau de Fermi   

A measure of the → energy of the least tightly held → electrons within a → solid at a → non-zero → temperature. The value of the Fermi level at → absolute zero (-273.15 °C) is called the → Fermi energy and is a constant for each solid. In other words, the Fermi level is any → energy level having the probability that it is exactly half filled with electrons in the → Fermi-Dirac statistics. Levels of lower energy than the Fermi level tend to be entirely filled with electrons, whereas energy levels higher than the Fermi tend to be empty.

Fermi; → level.

Fermi paradox
  پارادخش ِ فرمی   
pârâdaxš-e Fermi

Fr.: paradoxe de Fermi   

The apparent contradiction between the high probability of the existence of extraterrestrial civilizations and the lack of evidence of contact with such civilizations.

fermi; → paradox.

Fermi pressure
  فشار ِ فرمی   
fešâr-e Fermi

Fr.: pression de Fermi   

Same as → degeneracy pressure.

fermi; → pressure.

Fermi sea
  دریای ِ فرمی   
daryâ-ye Fermi

Fr.: mer de Fermi   

A large aggregate of single-state → fermions of lowest energy. When the temperature is lowered to absolute zero, all electrons in solids attempt to get into the lowest available energy level. However, electrons cannot all occupy the lowest energy, or ground state, in virtue of the → Pauli exclusion principle. They stack up in the lowest energy states, with two fermions in each state, one spin up and one spin down. Such assemblage of filled states is called the Fermi "sea," and this state of matter is called → degenerate. All states with energy less than the Fermi energy are filled, and all states above the Fermi energy are empty.

fermi; → sea.

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