Editing Darkness (section)

==Scientific==

===Perception===
The perception of darkness differs from the mere absence of light that sometimes lead to afterimages. In perceiving, the eye is active, and the part of the retina that is unstimulated produces a complementary afterimage.<ref>{{cite book |first1=David T. |last1=Horner |title=Demonstrations of Color Perception and the Importance of Contours, Handbook for Teaching Introductory Psychology |volume=2 |page=217 |publisher=Psychology Press |location=Texas |year=2000 |quote="Afterimages are the complementary hue of the adapting stimulus and trichromatic theory fails to account for this fact" |url=https://books.google.com/books?id=qyjYzloWfoMC&q=retina%20that%20is%20unstimulated%20produces%20a%20complementary%20afterimage&pg=PA216 |isbn=9780805836547 }}{{Dead link|date=January 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

===Physics===
{{See also|Light|Heat death of the universe}}
In terms of physics, an object is said to be dark when it absorbs [[photon]]s, causing it to appear dim compared to other objects.  For example, matte black paint does not reflect much visible light and appears dark, whereas white paint reflects much light and appears bright.<ref>{{cite journal
  | author = Mantese, Lucymarie
  | title = Photon-Driven Localization: How Materials Really Absorb Light
  | publisher = American Physical Society
  | date = March 2000
  | bibcode = 2000APS..MAR.E2001M
  | journal    = American Physical Society, Annual March Meeting
 | pages = E2.001
 }}
</ref> For more information, see [[color]]. An object may appear dark, but it may be bright at a frequency that humans cannot perceive.

A dark area has limited light sources, making things hard to see. Exposure to alternating light and darkness (night and day) has caused several evolutionary adaptations to darkness.  When a [[vertebrate]], like a human, enters a dark area, its [[pupil]]s dilate, allowing more light to enter the eye and improving [[night vision]]. Also, the light detecting cells in the human eye ([[rods and cones]]) will regenerate more unbleached [[rhodopsin]] when adapting to darkness.

One scientific measure of darkness is the [[Bortle Dark-Sky Scale|Bortle scale]], which indicates the night [[Sky brightness|sky's and stars' brightness]] at a particular location, and the observability of celestial objects at that location.<ref>{{Cite book |last=Mizon |first=Bob |url=https://books.google.com/books?id=0j6lDAAAQBAJ&pg=PA9 |title=Finding a Million-Star Hotel: An Astro-Tourist's Guide to Dark Sky Places |date=2016-07-04 |publisher=Springer |isbn=978-3-319-33855-2 |pages=9–16 |language=en}}</ref>

The material known as [[Vantablack]] is one of the darkest substances known, absorbing up to 99.965% of visible light (at 663&nbsp;nm if the light is perpendicular to the material), and was developed by Surrey NanoSystems in the United Kingdom.<ref name="NBCNews">{{cite web |last=Coldewey |first=Devin |date=15 July 2014 |title=Vantablack: U.K. Firm Shows Off 'World's Darkest Material' |url=http://www.nbcnews.com/science/science-news/vantablack-u-k-firm-shows-worlds-darkest-material-n155581 |url-status=live |archive-url=https://web.archive.org/web/20140719140154/https://www.nbcnews.com/science/science-news/vantablack-u-k-firm-shows-worlds-darkest-material-n155581 |archive-date=19 July 2014 |access-date=19 July 2014 |website=[[NBC News]]}}</ref><ref>[[Guinness World Records]]: [https://www.guinnessworldrecords.com/world-records/darkest-manmade-substance/ ''Darkest manmade substance''], 19 October 2015</ref> The name is a compound of the acronym VANTA (vertically aligned nanotube arrays) and the color black.<ref>{{Cite book |last1=Rossing |first1=Thomas D. |url=https://books.google.com/books?id=7_XHDwAAQBAJ&pg=PA172 |title=Light Science: Physics and the Visual Arts |last2=Chiaverina |first2=Christopher J. |date=2020-01-03 |publisher=Springer Nature |isbn=978-3-030-27103-9 |pages=172 |language=en}}</ref>

===Technical===
The color of a [[pixel|point]], on a standard 24-bit [[computer display]], is defined by three RGB (red, green, blue) values, each ranging from 0–255. When the red, green, and blue components of a pixel are fully illuminated (255,255,255), the pixel appears white; when all three components are unilluminated (0,0,0), the pixel appears black.<ref>{{Cite book |last=Kruegle |first=Herman |url=https://books.google.com/books?id=DaQY8CrmqFcC&pg=PA259 |title=CCTV Surveillance: Video Practices and Technology |date=2011-03-15 |publisher=Elsevier |isbn=978-0-08-046818-1 |pages=259 |language=en}}</ref>