Portal:Technology and applied sciences/Selected articles
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[edit] Selected articles
The selected are what we believe to be the best articles in Wikipedia related to technology. Prior to being listed here, articles are reviewed at Portal:Technology/Selected article candidates for style, prose, completeness, accuracy and neutrality according to our selected article criteria.
[edit] Usage
- Add a new selected article to the next available subpage.
- Update "max=" to new total for its {{Random portal component}} on the main page.
[edit] Selected articles list
[edit] 35 mm film
35 mm film is the basic film gauge most commonly used for both still photography and motion pictures, and remains relatively unchanged since its introduction in 1892 by William Dickson and Thomas Edison, using film stock supplied by George Eastman. The photographic film is cut into strips 35 mm (about 1 3/8 inches) wide — hence the name. The standard negative pulldown is four perforations per frame along both edges, which makes for exactly 16 frames per foot.
A wide variety of largely proprietary gauges were used by the numerous different camera and projection systems independently invented around the late 19th century and early 20th century, ranging from 13 mm to 75 mm (0.51–2.95 in). Its longevity is largely because its size allows for a relatively good tradeoff between the cost of the film stock and the quality of the images captured. Additionally, the ubiquity of 35 mm movie projectors in commercial movie theaters makes it the only motion picture format, film or video, which can be played in almost any cinema in the world.
[edit] Nuclear weapon
A nuclear weapon is a tool employed to injure, defeat, or destroy an adversary. It derives its destructive force from nuclear reactions of fission or fusion. As a result, even a nuclear weapon with a small yield is significantly more powerful than the largest conventional explosives, and a single weapon is capable of destroying an entire city.
In the history of warfare, nuclear weapons have been used only twice, both during the closing days of World War II. The first event occurred on the morning of August 6, 1945, when the United States dropped a uranium gun-type device code-named "Little Boy" on the Japanese city of Hiroshima. The 2nd event occurred 3 days later when the United States dropped a plutonium implosion-type device code-named "Fat Man" on the city of Nagasaki. The use of these weapons, which resulted in the immediate deaths of around 100,000 to 200,000 people and even more over time, was and remains controversial.
Since the Hiroshima and Nagasaki bombings, nuclear weapons have been detonated on over 2,000 occasions for testing and demonstration purposes. The only countries known to have detonated such weapons are (chronologically) the United States,Soviet Union, United Kingdom, France, People's Republic of China, India, Pakistan, and North Korea.
