Night
Night (also described as nighttime, unconventionally spelled as "nite") is the period of ambient darkness from sunset to sunrise during each 24-hour day, when the Sun is below the horizon. The exact time when night begins and ends depends on the location and varies throughout the year, based on factors such as season and latitude.
The word can be used in a different sense as the time between bedtime and morning. In common communication, it is a farewell (sometimes lengthened to "good night"), mainly when someone is going to sleep or leaving.[1]
Astronomical night is the period between astronomical
The opposite of night is
Natural illumination at night is still provided by a combination of moonlight, planetary light, starlight, zodiacal light, gegenschein, and airglow. In some circumstances, aurorae, lightning, and bioluminescence can provide some illumination. The glow provided by artificial lighting is sometimes referred to as light pollution because it can interfere with observational astronomy and ecosystems.
Duration and geography
On Earth, an average night is shorter than daytime due to two factors. Firstly, the Sun's apparent disk is not a point, but has an angular diameter of about 32 arcminutes (32'). Secondly, the atmosphere refracts sunlight so that some of it reaches the ground when the Sun is below the horizon by about 34'. The combination of these two factors means that light reaches the ground when the center of the solar disk is below the horizon by about 50'. Without these effects, daytime and night would be the same length on both equinoxes, the moments when the Sun appears to contact the celestial equator. On the equinoxes, daytime actually lasts almost 14 minutes longer than night does at the equator, and even longer towards the poles.
at nightThe
In the region within either polar circle, the variation in daylight hours is so extreme that part of summer sees a period without night intervening between consecutive days, while part of winter sees a period without daytime intervening between consecutive nights.[2]
Beyond Earth
The phenomenon of day and night is due to the rotation of a
Effects on life
Biological
The disappearance of sunlight, the primary
Social
The first constant electric light was demonstrated in 1835.[4] As artificial lighting has improved, especially after the Industrial Revolution, nighttime activity has increased and become a significant part of the economy in most places. Many establishments, such as nightclubs, bars, convenience stores, fast-food restaurants, gas stations, distribution facilities, and police stations now operate 24 hours a day or stay open as late as 1 or 2 a.m. Even without artificial light, moonlight sometimes makes it possible to travel or work outdoors at night.
Cultural and psychological
Night is often associated with danger and evil, because of the psychological connection of night's all-encompassing darkness to the fear of the unknown and darkness's hindrance of a major sensory system (the sense of sight). Nighttime is naturally associated with vulnerability and danger for human physical survival. Criminals, animals, and other potential dangers can be concealed by darkness. Midnight has a particular importance in human imagination and culture.
The belief in magic often includes the idea that magic and magicians are more powerful at night. Séances of spiritualism are usually conducted closer to midnight. Similarly, mythical and folkloric creatures such as vampires, ghosts and werewolves are described as more active at night. In almost all cultures, legendary stories warn of the night's dangers.
The cultural significance of the night in
People who prefer nocturnal activity are called
See also
- Earth's shadow
- Night aviation regulations in the US
- Night sky
- Nocturne
- Olbers' paradox
Further reading
Culture
- "International Night Studies Network". the CISAN-UNAM (México), the Center for Interdisciplinary Research on Montreal, McGill (Canada), the Institut de Géoarchitecture and the IDA-Brest (France). Archived from the original on 15 May 2021. Retrieved 23 May 2021.
{{cite web}}: CS1 maint: bot: original URL status unknown (link) - Shaw, Robert (2 February 2018). The Nocturnal City (Ebook). .
...This book looks at the relationship between night and society in contemporary cities..
References
- ^ "Definition of good night". merriam-webster.com. Retrieved 31 December 2019.
- ^ "Day Length". University Of Guelph. Archived from the original on 27 May 2021. Retrieved 27 May 2021.
- ^ Seidelmann, P. K.; Abalakin, V. K.; Bursa, M.; Davies, M. E.; et al. (2001). "Report of the IAU/IAG Working Group on Cartographic Coordinates and Rotational Elements of the Planets and Satellites: 2000". HNSKY Planetarium Program. Archived from the original on 26 December 2018. Retrieved 2 February 2007.
- ^ Matulka, Rebecca; Wood, Daniel (22 November 2013). "The History of the Light Bulb". Department of Energy. Archived from the original on 25 May 2021. Retrieved 25 May 2021.
- ^ "Nightlife – Definition of nightlife by Merriam-Webster". merriam-webster.com.
- MoMA. Retrieved May 23, 2021.
- ISBN 9780191025266. Retrieved 26 May 2021. The source doesn't state whether the location "painted in the depths" had natural light or no natural light.
- ^ Klein, Stefan (2008). Time. p. 20.
External links
Quotations related to 
The dictionary definition of 
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