Fr.: nombre de Fermat premier
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
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.
naxost, naxostin, naxosti
1) Of the first importance; of the highest rank.
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.
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.
Fr.: méridien origine
The meridian at which longitude is defined to be 0°. The meridian running through Greenwich.
Fr.: nombre premier
A number which is divisible by no whole number other than itself and one.
Fr.: premier vertical
The great circle through the observer's zenith that intersects the horizon at the west and east points. → vertical circle.
Fr.: atome primitif
Lemaître's (1931) name for the early dense Universe, which later became known as the → Big Bang theory.