Have a deep view into what people are curious about.

🔗 Soviet Union 🔗 Russia 🔗 Russia/technology and engineering in Russia 🔗 Spaceflight 🔗 Russia/science and education in Russia 🔗 Russia/history of Russia

Sputnik 1 ( or ; "Satellite-1", or "PS-1", Простейший Спутник-1 or Prosteyshiy Sputnik-1, "Elementary Satellite 1") was the first artificial Earth satellite. The Soviet Union launched it into an elliptical low Earth orbit on 4 October 1957, orbiting for three weeks before its batteries died, then silently for two more months before falling back into the atmosphere. It was a 58 cm (23 in) diameter polished metal sphere, with four external radio antennas to broadcast radio pulses. Its radio signal was easily detectable by radio amateurs, and the 65° inclination and duration of its orbit made its flight path cover virtually the entire inhabited Earth. The satellite's unanticipated success precipitated the American Sputnik crisis and triggered the Space Race, a part of the Cold War. The launch was the beginning of a new era of political, military, technological, and scientific developments. The name "Sputnik" is Russian for spouse/traveling companion or satellite when interpreted in an astronomical context.

Tracking and studying Sputnik 1 from Earth provided scientists with valuable information. The density of the upper atmosphere could be deduced from its drag on the orbit, and the propagation of its radio signals gave data about the ionosphere.

Sputnik 1 was launched during the International Geophysical Year from Site No.1/5, at the 5th Tyuratam range, in Kazakh SSR (now known as the Baikonur Cosmodrome). The satellite travelled at about 29,000 kilometres per hour (18,000 mph; 8,100 m/s), taking 96.2 minutes to complete each orbit. It transmitted on 20.005 and 40.002 MHz, which were monitored by radio operators throughout the world. The signals continued for 21 days until the transmitter batteries ran out on 26 October 1957. Sputnik burned up on 4 January 1958 while reentering Earth's atmosphere, after three months, 1440 completed orbits of the Earth, and a distance travelled of about 70 million km (43 million mi).

🔗 Geology

The Chesapeake Bay impact crater was formed by a bolide that impacted the eastern shore of North America about 35.5 ± 0.3 million years ago, in the late Eocene epoch. It is one of the best-preserved "wet-target" impact craters in the world.

Continued slumping of sediments over the rubble of the crater has helped shape the Chesapeake Bay.

🔗 Lists 🔗 Psychology

A list of 'effects' that have been noticed in the field of psychology.

🔗 Mathematics

In mathematics, Euler's identity (also known as Euler's equation) is the equality

${\displaystyle e^{i\pi }+1=0}$

where

e is Euler's number, the base of natural logarithms,

i is the imaginary unit, which by definition satisfies i² = −1, and

π is pi, the ratio of the circumference of a circle to its diameter.

Euler's identity is named after the Swiss mathematician Leonhard Euler. It is considered to be an exemplar of mathematical beauty as it shows a profound connection between the most fundamental numbers in mathematics.

🔗 Physics

The Einstein–Szilard or Einstein refrigerator is an absorption refrigerator which has no moving parts, operates at constant pressure, and requires only a heat source to operate. It was jointly invented in 1926 by Albert Einstein and his former student Leó Szilárd, who patented it in the U.S. on November 11, 1930 (U.S. Patent 1,781,541). The three working fluids in this design are water, ammonia and butane. The Einstein refrigerator is a development of the original three-fluid patent by the Swedish inventors Baltzar von Platen and Carl Munters.

🔗 Biography 🔗 France 🔗 Biography/science and academia 🔗 Biography/Actors and Filmmakers

Louis Aimé Augustin Le Prince (28 August 1841 – disappeared 16 September 1890, declared dead 16 September 1897) was a French artist and the inventor of an early motion-picture camera, possibly the first person to shoot a moving picture sequence using a single lens camera and a strip of (paper) film. He has been credited as the "Father of Cinematography", but his work did not influence the commercial development of cinema—owing at least in part to the great secrecy surrounding it.

A Frenchman who also worked in the United Kingdom and the United States, Le Prince's motion-picture experiments culminated in 1888 in Leeds, England. In October of that year, he filmed moving-picture sequences of family members in Roundhay Garden and his son playing the accordion, using his single-lens camera and Eastman's paper negative film. At some point in the following eighteen months he also made a film of Leeds Bridge. This work may have been slightly in advance of the inventions of contemporaneous moving-picture pioneers, such as the British inventors William Friese-Greene and Wordsworth Donisthorpe, and was years in advance of that of Auguste and Louis Lumière and William Kennedy Dickson (who did the moving image work for Thomas Edison).

Le Prince was never able to perform a planned public demonstration of his camera in the US because he mysteriously vanished; he was last known to be boarding a train on 16 September 1890. Multiple conspiracy theories have emerged about the reason for his disappearance, including: a murder set up by Edison, secret homosexuality, disappearance in order to start a new life, suicide because of heavy debts and failing experiments, and a murder by his brother over their mother's will. No conclusive evidence exists for any of these theories. In 2004, a police archive in Paris was found to contain a photograph of a drowned man bearing a strong resemblance to Le Prince who was discovered in the Seine just after the time of his disappearance, but it has been claimed that the body was too short to be Le Prince.

In early 1890, Edison workers had begun experimenting with using a strip of celluloid film to capture moving images. The first public results of these experiments were shown in May 1891. However, Le Prince's widow and son Adolphe were keen to advance Louis's cause as the inventor of cinematography. In 1898, Adolphe appeared as a witness for the defence in a court case brought by Edison against the American Mutoscope Company. This suit claimed that Edison was the first and sole inventor of cinematography, and thus entitled to royalties for the use of the process. Adolphe was involved in the case but was not allowed to present his father's two cameras as evidence, although films shot with cameras built according to his father's patent were presented. Eventually the court ruled in favour of Edison. A year later that ruling was overturned, but Edison then reissued his patents and succeeded in controlling the US film industry for many years.

🔗 Systems 🔗 Politics 🔗 Socialism 🔗 Sociology 🔗 Globalization

World-systems theory (also known as world-systems analysis or the world-systems perspective) is a multidisciplinary, macro-scale approach to world history and social change which emphasizes the world-system (and not nation states) as the primary (but not exclusive) unit of social analysis.

"World-system" refers to the inter-regional and transnational division of labor, which divides the world into core countries, semi-periphery countries, and the periphery countries. Core countries focus on higher skill, capital-intensive production, and the rest of the world focuses on low-skill, labor-intensive production and extraction of raw materials. This constantly reinforces the dominance of the core countries. Nonetheless, the system has dynamic characteristics, in part as a result of revolutions in transport technology, and individual states can gain or lose their core (semi-periphery, periphery) status over time. This structure is unified by the division of labour. It is a world-economy rooted in a capitalist economy. For a time, certain countries become the world hegemon; during the last few centuries, as the world-system has extended geographically and intensified economically, this status has passed from the Netherlands, to the United Kingdom and (most recently) to the United States.

World-systems theory has been examined by many political theorists and sociologists to explain the reasons for the rise and fall of nations, income inequality, social unrest, and imperialism.

🔗 India 🔗 Languages

Languages spoken in India belong to several language families, the major ones being the Indo-Aryan languages spoken by 78.05% of Indians and the Dravidian languages spoken by 19.64% of Indians. Languages spoken by the remaining 2.31% of the population belong to the Austroasiatic, Sino-Tibetan, Tai-Kadai and a few other minor language families and isolates. India (780) has the world's second highest number of languages, after Papua New Guinea (839).

Article 343 of the Indian constitution stated that the official language of the Union should become Hindi in Devanagari script instead of the extant English. Later, a constitutional amendment, The Official Languages Act, 1963, allowed for the continuation of English alongside Hindi in the Indian government indefinitely until legislation decides to change it. The form of numerals to be used for the official purposes of the Union are "the international form of Indian numerals", which are referred to as Arabic numerals in most English-speaking countries. Despite the misconceptions, Hindi is not the national language of India. The Constitution of India does not give any language the status of national language.

The Eighth Schedule of the Indian Constitution lists 22 languages, which have been referred to as scheduled languages and given recognition, status and official encouragement. In addition, the Government of India has awarded the distinction of classical language to Kannada, Malayalam, Odia, Sanskrit, Tamil and Telugu. Classical language status is given to languages which have a rich heritage and independent nature.

According to the Census of India of 2001, India has 122 major languages and 1599 other languages. However, figures from other sources vary, primarily due to differences in definition of the terms "language" and "dialect". The 2001 Census recorded 30 languages which were spoken by more than a million native speakers and 122 which were spoken by more than 10,000 people. Two contact languages have played an important role in the history of India: Persian and English. Persian was the court language during the Mughal period in India. It reigned as an administrative language for several centuries until the era of British colonisation. English continues to be an important language in India. It is used in higher education and in some areas of the Indian government. Hindi, the most commonly spoken language in India today, serves as the lingua franca across much of North and Central India. Bengali is the second most spoken and understood language in the country with a significant amount of speakers in Eastern and North- eastern regions. However, there have been concerns raised with Hindi being imposed in South India, most notably in the state of Tamil Nadu and Karnataka. Maharashtra, West Bengal, Assam, Punjab and other non-Hindi regions have also started to voice concerns about Hindi.