| slovo | definícia |
black hole
(encz) | black hole,černá díra |
black hole
(gcide) | black hole \black" hole`\
A dungeon or dark cell in a prison; a military lock-up or
guardroom; -- now commonly with allusion to the cell (the
Black Hole) in a fort at Calcutta (called the {Black Hole of
Calcutta}), into which 146 English prisoners were thrust by
the nabob Suraja Dowla on the night of June 20, 1765, and in
which 123 of the prisoners died before morning from lack of
air.
[1913 Webster]
A discipline of unlimited autocracy, upheld by rods,
and ferules, and the black hole. --H. Spencer.
[1913 Webster]
2. (Physics, Astron.) An astronomical object whose mass is so
condensed that the gravitational force does not allow
anything, even light, to escape from its outer limit (the
event horizon). The existence of such objects was first
proposed from theoretical considerations. Because light
cannot escape from such objects, they have not yet been
detected with certainty (1998), but several "candidates"
have been observed whose properties strongly suggest that
they are black holes. Some theorists suggest that the
centers of many galaxies may have large black holes at
their cores. See also escape velocity.
[PJC]
3. [from the astronomical black hole.] a place into which
things may enter, but can never emerge. [Fig., Jocose] "He
was so disorganized his office was a black hole."
[PJC] |
black hole
(wn) | black hole
n 1: a region of space resulting from the collapse of a star;
extremely high gravitational field |
black hole
(foldoc) | black hole
1. An expression which depends on its own value or a technique
to detect such expressions. In graph reduction, when the
reduction of an expression is begun, the root of the
expression can be overwritten with a black hole. If the
expression depends on its own value, e.g.
x = x + 1
then it will try to evaluate the black hole which will usually
print an error message and abort the program. A secondary
effect is that, once the root of the expression has been
black-holed, parts of the expression which are no longer
required may be freed for garbage collection.
Without black holes the usual result of attempting to evaluate
an expression which depends on itself would be a stack
overflow. If the expression is evaluated successfully then
the black hole will be updated with the value.
Expressions such as
ones = 1 : ones
are not black holes because the list constructor, : is lazy so
the reference to ones is not evaluated when evaluating ones to
WHNF.
2. Where an electronic mail message or news aritcle has
gone if it disappears mysteriously between its origin and
destination sites without returning a bounce message.
Compare bit bucket.
[Jargon File]
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black hole
(jargon) | black hole
n.,vt.
[common] What data (a piece of email or netnews, or a stream of TCP/IP
packets) has fallen into if it disappears mysteriously between its origin
and destination sites (that is, without returning a bounce message). “I
think there's a black hole at foovax!” conveys suspicion that site foovax
has been dropping a lot of stuff on the floor lately (see {drop on the
floor}). The implied metaphor of email as interstellar travel is
interesting in itself. Readily verbed as blackhole: “That router is
blackholing IDP packets.” Compare bit bucket and see RBL.
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| | podobné slovo | definícia |
Black Hole of Calcutta
(gcide) | black hole \black" hole`\
A dungeon or dark cell in a prison; a military lock-up or
guardroom; -- now commonly with allusion to the cell (the
Black Hole) in a fort at Calcutta (called the {Black Hole of
Calcutta}), into which 146 English prisoners were thrust by
the nabob Suraja Dowla on the night of June 20, 1765, and in
which 123 of the prisoners died before morning from lack of
air.
[1913 Webster]
A discipline of unlimited autocracy, upheld by rods,
and ferules, and the black hole. --H. Spencer.
[1913 Webster]
2. (Physics, Astron.) An astronomical object whose mass is so
condensed that the gravitational force does not allow
anything, even light, to escape from its outer limit (the
event horizon). The existence of such objects was first
proposed from theoretical considerations. Because light
cannot escape from such objects, they have not yet been
detected with certainty (1998), but several "candidates"
have been observed whose properties strongly suggest that
they are black holes. Some theorists suggest that the
centers of many galaxies may have large black holes at
their cores. See also escape velocity.
[PJC]
3. [from the astronomical black hole.] a place into which
things may enter, but can never emerge. [Fig., Jocose] "He
was so disorganized his office was a black hole."
[PJC] |
black hole of calcutta
(wn) | Black Hole of Calcutta
n 1: a dungeon (20 feet square) in a fort in Calcutta where as
many as 146 English prisoners were held overnight by Siraj-
ud-daula; the next morning only 23 were still alive |
|