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BlackBlack can mean several things:
Color or light
Black can be defined as the absence of visible light. For example collapsed stars, which due to their intense gravity can neither reflect nor emit light, are called "black holes". Pigments that absorb light rather than reflect it back to your eye "look black". Conversely, the combination of all colors of light is called white.
On a browser that supports visual formatting in Cascading Style Sheets, the following box should appear in black:
In terms of pigment, however, black is the combination of all (pigment) colors. If equal proportions of primary pigments are mixed, the result reflects little light and so is "black".
This creates two opposite yet complementary definitions of black. Black is the lack of all colors of light, or the combination of all colors of pigment. See also Primary colors and Primary pigments.
This can be explained as follows: The red pigment, for example, absorbs all light except red light; red light is reflected, and thus our eye sees the pigmented object as red. When many pigments are combined, whatever would have been reflected by one of the pigments is absorbed by the others. Thus no light escapes. (No visible light, that is; ultraviolet, for example, might still be reflected, unless some kind of "ultraviolet pigment" were added.)
The term black is also used for people with dark skin color, usually of sub-Saharan African origin (in fact the color of the skin is not black, but any of a variety of shades of brown).
Some argue that there is a scientific consensus against race as a biological category, that "blackness" is merely a social construct as some people who call themselves "black" are also of European, Native American and/or Asian descent.
In many countries, there is still a strong (though weakening) social stigma against those persons identifying themselves as part of more than one perceived racial category. Hence, it may be truer to say that people who perceive themselves or are perceived by others as a member of an black cultural group are often called "black".
The term "negro" was widely used until the 1960s, and remains a constituent part of the names of several African Americans organizations. Nowadays, the term is derogatory and inappropriate. The derived term "nigger", once used widely to refer to people of African descent in a derogatory way, is now almost always considered to be extremely offensive. The exception where some African-Americans have sought to reclaim the term from its racist history by transmuting it to the variant "nigga" by using this to identify themselves in a non-derogatory way. Nevertheless, this term is always considered offensive when used by someone who is perceived as not being of African ancestry.
Some people of African descent are referred to as being "white" because they have an especially light complexion or European-looking features. This is sometimes called by the slang term of passing.
United States usage
In the USA, African Americans are commonly called, and call themselves, "black".
United Kingdom usage
In the United Kingdom, the term "black" refers to people of Afro-Caribbean or African descent. It is sometimes used to refer to all non-white people, especially in a political context. This has also been the case in South Africa.
Australian usage
Australian Aborigines are also commonly called black.
Canadian usage
Canadians use the term Black Canadian.
Usage, symbolism, colloquial expressions
In Western societies black is most often used with a negative connotation, with a few notable exceptions. For instance, a "black day" would be used in these cultures to refer to a sad or tragic day. However, to say one's accounts are "in the black" is used to mean that one is free of debt (a very positive thing in a capitalist society).
In arguments things can be black or white, or shades of gray, the intensity used as an analogue for things such as truthfulness or right and wrong. (Note that when referring to the intensity of pigment or light, black is always the complete lack of intensity.)
In Western cultures and their colonial offshoots, the color black is often used in painting, film, and literature to evoke a sense of the unknown or of death. In these cultures, the color black is often seen as the color of mourning, though this convention is less strict than in earlier times, when widows and widowers were expected to wear black for a year after the death of their spouses.
However, in other cultures, such as the Maasai tribes of Kenya and Tanzania, the color black is associated with rain clouds and is thus a symbol of life and prosperity.
The national rugby team of New Zealand is called the All Blacks, in reference to their black outfits.
Soccer referees traditionally wear all black outfits, although nowadays the rules have changed and referees are seen wearing outfits in different colors.
Color coordinates
- RGB:
- CMYK:
- (canonical)
- (ideal inks, theoretical only)
- C: 255
- M: 255
- Y: 255
- K: 0
- (registration black)
- C: 255
- M: 255
- Y: 255
- K: 255
- HSV:
- H: 0 (or any other value)
- S: 0 (or any other value)
- V: 0
hex triplet:#000000
People whose surname is or was Black include
See also: , The Black family in the Harry Potter books
Black Army: a supporter club for AIK, Stockholm, Sweden.
The athletic teams which represent the country of New Zealand often have the word "black" in their names. For example, the All Blacks are the country's national rugby union team; less well-known, the Tall Blacks represent New Zealand in basketball.
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Hawking Radiation
Classically, black holes are black. Quantum mechanically, black holes radiate, with a radiation known as Hawking radiation, after the British physicist Stephen Hawking who first proposed it.
http://casa.colorado.edu/~ajsh/hawk.html
Geometry Around Black Holes
An exhibition on relativistic computer dynamics used to present the theory of black holes.
http://www.astro.ku.dk/~cramer/RelViz/text/exhib1
Kerr's Rotating Black Holes.
A brief mathematical description of this phenomenon and diagrams of the mathematical results.
http://www.astro.ku.dk/~cramer/RelViz/text/exhib4/exhib4.html
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An overview of the effects on light in the presence of a black hole.
http://www.astro.ku.dk/~cramer/RelViz/text/exhib3/exhib3.html
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A set of notes on aspects of black holes.
http://www.astro.ku.dk/~cramer/RelViz/text/exhib1/exhib1.html
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A review of the theory and history of black holes.
http://www.suite101.com/article.cfm/advanced_physics/28145
Modern Research by Eduard Westra
Research done about low mass black holes. On the level of 2nd year astronomy students.
http://www.astro.rug.nl/~westra/aoz
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An overview of modern research in black holes without the use of mathematical equations.
http://www.geocities.com/autotheist/Physics/bh.htm
Cambridge Relativity - Black Holes
An overview of black holes and information on current research from Cambridge
http://www.damtp.cam.ac.uk/user/gr/public/bh_home.html
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Physicists may soon create artificial analogs of black holes in the laboratory.
http://sciencenews.org/20000205/fob4.asp
Schwarzschild's Spacetime
A site explaining the Schwarzschild solution and how it leads to black holes.
http://www.phy.syr.edu/courses/modules/LIGHTCONE/schwarzschild.html
Schwarzschild Geometry
The Schwarzschild geometry describes the spacetime geometry of empty space surrounding any spherical mass.
http://casa.colorado.edu/~ajsh/schwp.html
Stringy Black Holes
A set of lecture notes with a section on black holes, as well as current work in string theory.
http://www-th.phys.rug.nl/~schaar/htmlreport/report.html
SETI@home Listens to the Dying Gasps of Black Holes
Visit this site to find out more and get involved.
http://www.planetary.org/html/UPDATES/seti/SETI@home/Update_110501.htm
FAQ to SCI.PHYSICS on Black Holes
An FAQ list by Matt McIrvin containing basic questions and answers related to black holes.
http://antwrp.gsfc.nasa.gov/htmltest/gifcity/bh_pub_faq.html
The Net Advance of Physics: Black Holes
A set of links to numerous black holes resources on the Web. A great starting point to finding some advanced papers on the topic.
http://web.mit.edu/afs/athena.mit.edu/user/r/e/redingtn/www/netadv/bh.html
Do Black Holes Exist ?
Science popularization article on black holes.
http://www.freehomepages.com/pgostrov/e3.html
About Astronomy and Space - Black Holes
Find articles, information, and web sites about these theoretical cellestial objects, formed when a massive star collapses from its own gravity.
http://space.about.com/cs/blackholes/index.htm
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http://arxiv.org/abs/gr-qc/0304052
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http://arxiv.org/abs/gr-qc/9808035
Higher Dimensional Chern-Simons Theories and Topological Black Holes
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http://arxiv.org/abs/gr-qc/9803002
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http://arxiv.org/abs/gr-qc/9804039
Introduction to Black Hole Microscopy
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http://arxiv.org/abs/hep-th/9510026
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http://arxiv.org/abs/astro-ph/9801252
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http://arxiv.org/abs/hep-th/9801025
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http://arxiv.org/abs/gr-qc/9805066
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Portal linking to sites about very high density objects: black holes, neutron stars.
http://www.galacticsurf.com/trounoirGB.htm
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http://www.gothosenterprises.com/black_holes/
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