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: 9 Search : prime
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.

Mersenne prime
  نخست ِ مرسن   
naxost-e Mersenne

Fr.: nombre de Mersenne premier   

A → prime number of the form 2p - 1, where p is a prime. As of February 2013, 48 Mersenne primes are known. The largest known prime number is 257,885,161 - 1. Each prime gives rise to an even → perfect number.

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

Moon's prime meridian
  نیمروزان ِ نخستی ِ مانگ   
nimruzân-e naxosti-ye Mâng

Fr.: méridien origine de la lune   

The line connecting the Moon's north pole with its south pole, and passing through the center of the lunar disk. The longitude of the Moon's prime meridian is zero degrees.

Moon; → prime meridian.

prime
  نخست، نخستین، نخستی   
naxost, naxostin, naxosti

Fr.: premier   

1) Of the first importance; of the highest rank.
2) Same as → prime number.

M.E., from L. primarius "of the first rank, principal," from primus "first."

Naxost, naxostin, naxosti, from Mid.Pers. naxust "the first," Parthian Mid.Pers. nxwšt, from naxu, Manichean Parthian nwx "beginning" + -ist superlative suffix, Av. -išta-, cf. Skt. -istha-, Gk. -istos, O.H.G. -isto, -osto, O.E. -st, -est, -ost.

prime focus
  کانون ِ نخستی   
kânun-e naxosti

Fr.: foyer primaire   

The focal point of a large primary reflecting mirror. This focus actually falls at a point just within the upper structure of the telescope and provides a large field of view.

primary; → focus.

prime meridian
  نیمروزان ِ نخستی   
nimruzân-e noxosti

Fr.: méridien origine   

The meridian at which longitude is defined to be 0°. The meridian running through Greenwich.

primary; → meridian.

prime number
  عدد ِ نخست   
'adad-e naxost

Fr.: nombre premier   

A number which is divisible by no whole number other than itself and one.

prime; → number.

prime vertical
  هجین ِ نخستی   
hajin-e noxosti

Fr.: premier vertical   

The great circle through the observer's zenith that intersects the horizon at the west and east points. → vertical circle.

primary; → vertical.

primeval atom
  اتم ِ نخستین   
atom-e naxostin

Fr.: atome primitif   

Lemaître's (1931) name for the early dense Universe, which later became known as the → Big Bang theory.

From L. primaevus "early in life," from primus "first," → prime, + aevum "an age," + → -al; → atom.