1919 In Science
The year 1919 in science and technology involved some significant events, listed below. Astronomy * April – George Ellery Hale and collaborators publish their discovery that the magnetic polarity of sunspot pairs reverses on an 11-year solar cycle and that the polarity varies by hemisphere, which becomes known as Hale's law. * The International Astronomical Union is established in Paris. Chemistry * June 1 – The term ''covalence'' in relation to chemical bonding is first used by Irving Langmuir. * F. W. Aston discovers multiple stable isotopes for neon. History of science * Leonard Eugene Dickson begins publication of ''History of the Theory of Numbers''. Mathematics * Viggo Brun proves Brun's theorem ''B''2 for twin primes. * G. H. Hardy rediscovers Pisot–Vijayaraghavan numbers in the context of Diophantine approximation. Medicine * Dr George Newman is appointed as the first Chief Medical Officer to the Ministry of Health in England and Wales. Physics * May 29 � ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Viggo Brun
Viggo Brun (13 October 1885 – 15 August 1978) was a Norwegian professor, mathematician and number theorist. Contributions In 1915, he introduced a new method, based on Legendre's version of the sieve of Eratosthenes, now known as the '' Brun sieve'', which addresses additive problems such as Goldbach's conjecture and the twin prime conjecture. He used it to prove that there exist infinitely many integers ''n'' such that ''n'' and ''n''+2 have at most nine prime factors, and that all large even integers are the sum of two numbers with at most nine prime factors. He also showed that the sum of the reciprocals of twin primes converges to a finite value, now called Brun's constant: by contrast, the sum of the reciprocals of all primes is divergent. He developed a multi-dimensional continued fraction algorithm in 1919–1920 and applied this to problems in musical theory. He also served as praeses of the Royal Norwegian Society of Sciences and Letters in 1946. Biography ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Solar Eclipse Of May 29, 1919
A total solar eclipse occurred at the Moon's descending node of orbit on Thursday, May 29, 1919, with a magnitude of 1.0719. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. Occurring only 19 hours after perigee (on May 28, 1919, at 18:09 UTC), the Moon's apparent diameter was larger. This specific total solar eclipse was significant because it helped prove Einstein's theory of relativity. The eclipse was the subject of the Eddington experiment: two groups of British astronomers went to Brazil and the west coast of Africa to take pictures of the stars in the sky once the Moon covere ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Arthur Eddington
Sir Arthur Stanley Eddington, (28 December 1882 – 22 November 1944) was an English astronomer, physicist, and mathematician. He was also a philosopher of science and a populariser of science. The Eddington limit, the natural limit to the luminosity of stars, or the radiation generated by accretion onto a compact object, is named in his honour. Around 1920, he foreshadowed the discovery and mechanism of nuclear fusion processes in stars, in his paper "The Internal Constitution of the Stars".The Internal Constitution of the Stars A. S. Eddington The Scientific Monthly Vol. 11, No. 4 (Oct., 1920), pp. 297–303 At that time, the source of stellar energy was a complete mystery; Eddington was the first to correctly speculate that the source was fusion of hydrogen into helium. Eddington wrote a number of articles that announced and explained Einstein's theory of general relativity to the English-speaking world. World War I had severed many lines of scientific communication, and ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
General Relativity
General relativity, also known as the general theory of relativity, and as Einstein's theory of gravity, is the differential geometry, geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics. General theory of relativity, relativity generalizes special relativity and refines Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time in physics, time, or four-dimensional spacetime. In particular, the ''curvature of spacetime'' is directly related to the energy and momentum of whatever is present, including matter and radiation. The relation is specified by the Einstein field equations, a system of second-order partial differential equations. Newton's law of universal gravitation, which describes gravity in classical mechanics, can be seen as a prediction of general relativity for the almost flat spacetime geometry around stationary mass ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Albert Einstein
Albert Einstein (14 March 187918 April 1955) was a German-born theoretical physicist who is best known for developing the theory of relativity. Einstein also made important contributions to quantum mechanics. His mass–energy equivalence formula , which arises from special relativity, has been called "the world's most famous equation". He received the 1921 Nobel Prize in Physics for . Born in the German Empire, Einstein moved to Switzerland in 1895, forsaking his German citizenship (as a subject of the Kingdom of Württemberg) the following year. In 1897, at the age of seventeen, he enrolled in the mathematics and physics teaching diploma program at the Swiss ETH Zurich, federal polytechnic school in Zurich, graduating in 1900. He acquired Swiss citizenship a year later, which he kept for the rest of his life, and afterwards secured a permanent position at the Swiss Patent Office in Bern. In 1905, he submitted a successful PhD dissertation to the University of Zurich. In 19 ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
England And Wales
England and Wales () is one of the Law of the United Kingdom#Legal jurisdictions, three legal jurisdictions of the United Kingdom. It covers the constituent countries England and Wales and was formed by the Laws in Wales Acts 1535 and 1542. The substantive law of the jurisdiction is English law. The Welsh devolution, devolved Senedd (Welsh Parliament; ) – previously named the National Assembly for Wales – was created in 1999 under the Government of Wales Act 1998 and provides a degree of Self-governance, self-government in Wales. The powers of the legislature were expanded by the Government of Wales Act 2006, which allows it to pass Welsh law, its own laws, and the Act also formally separated the Welsh Government from the Senedd. There is currently no Devolved English parliament, equivalent body for England, which is directly governed by the parliament and government of the United Kingdom. History of jurisdiction During the Roman occupation of Britain, the area of presen ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Department Of Health (United Kingdom)
The Department of Health and Social Care (DHSC) is a Departments of the Government of the United Kingdom, ministerial department of the Government of the United Kingdom. It is responsible for government policy on health and adult social care matters in England, along with a few elements of the same matters which are not otherwise devolved to the Scottish Government, Welsh Government or Northern Ireland Executive. It oversees the English National Health Service (NHS). The department is led by the Secretary of State for Health and Social Care with three ministers of state and three parliamentary under-secretaries of state. The department develops policies and guidelines to improve the quality of care and to meet patient expectations. It carries out some of its work through Quango, arms-length bodies (ALBs), including executive non-departmental public bodies such as NHS England and the NHS Digital, and executive agencies such as the UK Health Security Agency and the Medicines and He ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Chief Medical Officer (United Kingdom)
In the United Kingdom, a chief medical officer (CMO) is the most senior government advisor on matter relating to health. There are four chief medical officers in the United Kingdom who are appointed to advise their respective governments: * His Majesty's Government (CMO for England and medical advisor to the United Kingdom government) * Scottish Government * Welsh Government * Northern Ireland Executive Each CMO is assisted by one or more deputy chief medical officers, and complemented by a chief nursing officer. The chief medical officer is a qualified medical doctor whose medical speciality traditionally was public health medicine, and whose work focused on the health of communities rather than health of individuals. More recently, some appointees have been senior clinicians without training in public health medicine. In the UK, the CMO is one of the chief professional officers who advise the government in their respective health and social care disciplines. The CMO has ind ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
George Newman (doctor)
Sir George Newman (23 October 1870 – 26 May 1948) was an English public health physician, Quaker, the first Chief Medical Officer to the Ministry of Health in England, and wrote a seminal treatise on the social problems causing infant mortality. Biography George Newman was born in Leominster, Herefordshire, the fourth of six children of Henry Stanley Newman and Mary Anna Pumphrey. His father was a Quaker who undertook several missionary journeys, including one to India, and edited '' The Friend'', a Quaker journal. Newman was educated at two Quaker schools, Sidcot School in North Somerset (1881–1885) and Bootham School in York (1885–1887). He initially planned to become a missionary, but then decided to study medicine, starting at the University of Edinburgh Medical School and continuing at King's College London. After qualifying he studied for his MD at Edinburgh, receiving the gold medal for his year, before winning a scholarship to study public health and gaining his ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Diophantine Approximation
In number theory, the study of Diophantine approximation deals with the approximation of real numbers by rational numbers. It is named after Diophantus of Alexandria. The first problem was to know how well a real number can be approximated by rational numbers. For this problem, a rational number ''p''/''q'' is a "good" approximation of a real number ''α'' if the absolute value of the difference between ''p''/''q'' and ''α'' may not decrease if ''p''/''q'' is replaced by another rational number with a smaller denominator. This problem was solved during the 18th century by means of simple continued fractions. Knowing the "best" approximations of a given number, the main problem of the field is to find sharp upper and lower bounds of the above difference, expressed as a function of the denominator. It appears that these bounds depend on the nature of the real numbers to be approximated: the lower bound for the approximation of a rational number by another rational number i ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |