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Unit 731 (Japanese: 731部隊, Hepburn: Nana-san-ichi Butai), short for Manchu Detachment 731 and also known as the Kamo Detachment: 198 and the Ishii Unit, was a covert biological and chemical warfare research and development unit of the Imperial Japanese Army that engaged in lethal human experimentation and biological weapons manufacturing during the Second Sino-Japanese War (1937–1945 ...
Lawrence Wong Shyun Tsai [b] (born 18 December 1972) is a Singaporean politician, economist and former civil servant who has been serving as the fourth prime minister of Singapore since 15 May 2024 and the minister for finance since 2021. A member of the governing People's Action Party, he has been the Member of Parliament (MP) representing the ...
Post-traumatic organic. v. t. e. Antisocial personality disorder ( ASPD or APD) is a personality disorder characterized by a limited capacity for empathy and a long-term pattern of disregard or violation of the rights of others. [3] [4] Other notable symptoms include impulsivity, reckless behavior (including substance abuse ), a lack of remorse ...
Novak Djokovic (Serbian: Новак Ђоковић, Novak Đoković, pronounced [nôʋaːk dʑôːkoʋitɕ] ⓘ;[6] born 22 May 1987) is a Serbian professional tennis player who is currently ranked world No. 1 in singles by the Association of Tennis Professionals (ATP). Djokovic has been ranked No. 1 for a record total of 427 weeks in a record ...
- Etymology
- Occurrence
- Causes
- Interaction of The Solar Wind with Earth
- Auroral Particle Acceleration
- Historically Significant Events
- Historical Views and Folklore
- Extraterrestrial Aurorae
- See Also
- Further Reading
The term aurora borealis was coined by Galileo in 1619, from the Roman Aurora, goddess of the dawn and the Greek name for the north wind (Boreas). The word aurora is derived from the name of the Roman goddess of the dawn, Aurora, who travelled from east to west announcing the coming of the sun. Ancient Greek poets used the corresponding name Eosmet...
Most auroras occur in a band known as the "auroral zone", which is typically 3° to 6° (approximately 330–660 km) wide in latitude and between 10° and 20° from the geomagnetic poles at all local times (or longitudes), most clearly seen at night against a dark sky. A region that currently displays an aurora is called the "auroral oval", a band displa...
A full understanding of the physical processes which lead to different types of auroras is still incomplete, but the basic cause involves the interaction of the solar wind with Earth's magnetosphere. The varying intensity of the solar wind produces effects of different magnitudes but includes one or more of the following physical scenarios. 1. A qu...
Earth is constantly immersed in the solar wind, a flow of magnetized hot plasma (a gas of free electrons and positive ions) emitted by the Sun in all directions, a result of the two-million-degree temperature of the Sun's outermost layer, the corona. The solar wind reaches Earth with a velocity typically around 400 km/s, a density of around 5 ions/...
Just as there are many types of aurora, there are many different mechanisms that accelerate auroral particles into the atmosphere. Electron aurora in Earth's auroral zone (i.e. commonly visible aurora) can be split into two main categories with different immediate causes: diffuse and discrete aurora. Diffuse aurora appear relatively structureless t...
The discovery of a 1770 Japanese diary in 2017 depicting auroras above the ancient Japanese capital of Kyoto suggested that the storm may have been 7% larger than the Carrington event, which affected telegraph networks. The auroras that resulted from the Carrington event on both 28 August and 2 September 1859, are thought to be the most spectacular...
The earliest datable record of an aurora was recorded in the Bamboo Annals, a historical chronicle of the history of ancient China, in 977 or 957 BC.An aurora was described by the Greek explorer Pytheas in the 4th century BC. Seneca wrote about auroras in the first book of his Naturales Quaestiones, classifying them, for instance, as pithaei ('barr...
Both Jupiter and Saturn have magnetic fields that are stronger than Earth's (Jupiter's equatorial field strength is 4.3 gauss, compared to 0.3 gauss for Earth), and both have extensive radiation belts. Auroras have been observed on both gas planets, most clearly using the Hubble Space Telescope, and the Cassini and Galileo spacecraft, as well as on...
Procter, Henry Richardson (1878). "Aurora Polaris" . Encyclopædia Britannica. Vol. III (9th ed.). pp. 90–99.Chree, Charles (1911). "Aurora Polaris" . Encyclopædia Britannica. Vol. 2 (11th ed.). pp. 927–934.These two both include detailed descriptions of historical observations and descriptions.Stern, David P. (1996). "A Brief History of Magnetospheric Physics During the Space Age". Reviews of Geophysics. 34 (1): 1–31. Bibcode:1996RvGeo..34....1S. doi:10.1029/95rg03508.Stern, David P.; Peredo, Mauricio. "The Exploration of the Earth's Magnetosphere". phy6.org.Anthropology is a global discipline involving humanities, social sciences and natural sciences. Anthropology builds upon knowledge from natural sciences, including the discoveries about the origin and evolution of Homo sapiens, human physical traits, human behavior, the variations among different groups of humans, how the evolutionary past of Homo sapiens has influenced its social organization ...
The United Nations Educational, Scientific and Cultural Organization ( UNESCO) [a] is a specialized agency of the United Nations (UN) with the aim of promoting world peace and security through international cooperation in education, arts, sciences and culture. [2] [3] It has 194 member states and 12 associate members, [4] as well as partners in ...
