Optics: A strip or annulus of material, such as glass or film, whose density
increases progressively from one end to the other. The function of the wedge is to
weaken the light beam in an optical system.

A binary star in which the presence of an unresolved
companion is revealed by small oscillations in
the movement of the visible component caused by the gravitational
influence of the unseen component.

A crystal device made of two → quartz
→ prisms
with equal acute angles assembled in a rhombus
that is used in analyzing → polarized light.
The wedge-shaped prisms are placed against each other and can be displaced along
their plane of contact by a → micrometer.
Thus they form a parallel plate of variable thickness allowing
the optical retardation to be adjusted.

Jacques Babinet (1794-1872), French physicist; → compensator.

1a) General:A box or enclosed space for storing grain, coal, or
the like.
1b) Electronics: In a → CCD detector,
a square or rectangular group of adjacent → pixels
used collectively to transport the → electron charges.
1c) In a statistical → histogram, the range of
→ distribution → intervals.
The bin widths (or the number of bins) affect a histogram.
2) To place in a → bin; to create → binning.

M.E. binne, O.E. binn(e) "manger, crib,"
perhaps from O.Celt. *benna, akin to
Welsh benn "a cart, especially one with a woven wicker body."
The same Celtic word seems to be preserved in It. benna
"dung cart," Fr. benne
"a sort of box for transporting materials, especially in mines,"
Du. benne "large basket," from L.L. benna.

Bâvin "a basket, more precisely a small basket which
contains the cotton to be spun;" bâvinidan infinitive from bâvin.

General: Characterized by or consisting of two parts or
components. Math.: Of or relating to a system of numeration having 2 as
its base. Astro.: Physically associated pair of astronomical objects.

Binary, from L.L. binarius, from bini "two-by-two,"
from bis "twice, two times;" cf. Av. biš- "twice,"
bi- "two," Mod.Pers. do "two,"
PIE *dwo- "two."

Dorin, from Mid.Pers. dorin "double, pair,"
from do (Av. dva-, Skt. dvi-, Gk. duo,
L. duo, E. two, Der. zwei, Fr. deux)
"two" + rin "time, turn." Dodoyi "two-by-two," from do, → two.

binary arithmetic

حساب ِ درین، ~ دودویی

hesâb-e dorin, ~ dodoi (#)

Fr.: arithmétique binaire

A system of calculation in which the only numerals used are 0 and 1.
All the real numbers are represented in terms of powers of 2.

A member of a population of double objects in the main → Asteroid Belt
or the → Kuiper Belt which are
gravitationally bound together. So far about 200 such binary systems have been identified,
while their number is increasing.
243 Ida was the first binary asteroid to be discovered during
the Galileo spacecraft flyby in 1993. Other examples are
→ Antiope and
Kalliope in the main belt and QG_{298} in the Kuiper Belt.
The importance of these objects resides in the fact that
systems with well measured orbital parameters allow the total mass to be estimated. If
the sizes of the components are known then their densities can be accurately calculated.
Density is an important parameter since it yields information about composition and
internal structure.

The fraction of stars that have at least one
→ companion. It is at least 50%.
The binary fraction appears to increase with increasing
→ primary star
mass, at least among the more massive stars:
the → O stars and → B stars
have a companion frequency of at least 70%, while for the
→ G stars the binary frequency is around 50%
and the → M stars may have an
even lower binary frequency of around 30-40%. Brown dwarfs
are rare as companions to lower-main-sequence stars, although
brown-dwarf binaries appear not to be rare. An increase in binary
frequency with mass would be expected if most stars form in
→ multiple systems
that disintegrate, since the more massive stars
would then preferentially remain in binaries while the less massive
ones would preferentially be ejected as single stars (see Richard
B. Larson, 2001, in IAU Symposium 200, p. 93 and references
therein).

A → numeral system that has 2 as its base and uses
only two digits, 0 and 1. The positional value of each digit in a binary number
is twice the place value of the digit of
its right side. Each binary digit is known as a bit. The decimal numbers from 0 to 10
are thus in binary 0, 1, 10, 11, 100, 101, 110, 111, 1000, 1001, and 1010.
And, for example, the binary number 11101_{2} represents the decimal number
(1 × 2^{4}) + (1 × 2^{3})
+ (1 × 2^{2}) + (0 × 2^{1}) + (1 × 2^{0}),
or 29. In electronics, binary numbers are the flow of information in the form
of zeros and ones used by computers. Computers use it to manipulate and store all of
their data including numbers, words, videos, graphics, and music.

A mathematical operation that combines two numbers, quantities, sets, etc.,
to give a third. For example, multiplication of two numbers is a binary operation.
A binary operation * on a set S is → commutative
if a * b = b * a for all a, b∈ S.
A binary operation * on a set S is → associative
if (a * b) * c = a * (b * c) for all a, b, c∈ S.

A pulsar in a → binary system, the companion of which often
being a → neutron star or a
→ white dwarf. The only known binary system with two pulsars
components is the → double pulsar.
As of 2010 about 70 binary pulsars have been identified. They are
ideal laboratories for testing and studying the effects predicted by
→ general relativity, such as
→ spin precession,
→ Shapiro time delay, and
→ gravitational waves.
The prototype, called PSR 1913+16, was discovered in 1974 by
Russell A. Hulse and Joseph H. Taylor, Jr., who received
the Nobel Prize for Physics in 1993.
→ Hulse-Taylor pulsar.