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1916 In Science
The year 1916 involved a number of significant events in science and technology, some of which are listed below. Astronomy * Barnard's Star is discovered by Edward Emerson Barnard. * Harlow Shapley finds that the spectrum of S Sagittae and other Cepheid variables varies with brightness, recording it as spectral type F0 leading to maximum, F4 at maximum, and G3 just before minimum brightness. Chemistry * Gilbert N. Lewis and Irving Langmuir formulate an electron shell model of chemical bonding. * The Born–Haber cycle, an approach to analyze reaction energies, is developed by German scientists Max Born and Fritz Haber. * Sydney Chapman and David Enskog systematically develop a kinetic theory of gases. * Jan Czochralski invents a method for growing single crystals of metals. Mathematics * Ludwig Bieberbach presents the Bieberbach conjecture. * Wacław Sierpiński gives the first example of an absolutely normal number and describes the Sierpinski carpet. Medicine * 1 Janu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sydney Chapman (astronomer)
Sydney Chapman (29 January 1888 – 16 June 1970) was a British mathematician and geophysicist. His work on the kinetic theory of gases, solar-terrestrial physics, and the Earth's ozone layer has inspired a broad range of research over many decades. Education and early life Chapman was born in Eccles, near Salford in England and began his advanced studies at a technical institute, now the University of Salford, in 1902. In 1904 at age 16, Chapman entered the University of Manchester. He competed for a scholarship to the university offered by his home county, and was the last student selected. Chapman later reflected, "I sometimes wonder what would have happened if I'd hit one place lower." He initially studied engineering in the department headed by Osborne Reynolds. Chapman was taught mathematics by Horace Lamb, the Beyer professor of mathematics, and J. E. Littlewood, who came from Cambridge in Chapman's final year at Manchester. Although he graduated with an engineeri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birth Control
Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent pregnancy. Birth control has been used since ancient times, but effective and safe methods of birth control only became available in the 20th century. Planning, making available, and using human birth control is called family planning. Some cultures limit or discourage access to birth control because they consider it to be morally, religiously, or politically undesirable. The World Health Organization and United States Centers for Disease Control and Prevention provide guidance on the safety of birth control methods among women with specific medical conditions. The most effective methods of birth control are sterilization by means of vasectomy in males and tubal ligation in females, intrauterine devices (IUDs), and implantable birth control. This is followed by a number of hormone-based methods including contraceptive pills, patches, vaginal r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family Planning
Family planning is the consideration of the number of children a person wishes to have, including the choice to have no children, and the age at which they wish to have them. Things that may play a role on family planning decisions include marital situation, career or work considerations, or financial situations. If sexually active, family planning may involve the use of Birth control, contraception (birth control) and other techniques to control the timing of Human reproduction, reproduction. Other aspects of family planning aside from contraception include sex education, prevention and management of sexually transmitted infections, pre-conception counseling and pregnancy#Management, management, and infertility management.World Health Organization. (n.d.)Sexual and Reproductive Health. Retrieved on 30 October 2019. Family planning, as defined by the United Nations and the World Health Organization, encompasses services leading up to conception. Abortion is another form of family ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Margaret Sanger
Margaret Sanger ( Higgins; September 14, 1879September 6, 1966) was an American birth control activist, sex educator, writer, and nurse. She opened the first birth control clinic in the United States, founded Planned Parenthood, and was instrumental in the development of the first birth control pill. Sanger is regarded as a founder and leader of the Birth control movement in the United States, birth control movement. In the early 1900s, contraceptives, abortion, and even birth control literature were illegal in much of the U.S. Working as a nurse in the slums of New York City, Sanger often treated mothers desperate to avoid conceiving additional children, many of whom had resorted to unsafe abortions, back-alley abortions. Sanger was a First-wave feminism, first-wave feminist and believed that women should be able to decide if and when to have children, leading her to campaign for the legalization of contraceptives. As an adherent of the Eugenics in the United States, eugenics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Transfusion
Blood transfusion is the process of transferring blood products into a person's Circulatory system, circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used whole blood, but modern medical practice commonly uses only components of the blood, such as red blood cells, blood plasma, plasma, platelets, and other clotting factors. White blood cells are transfused only in very rare circumstances, since granulocyte transfusion has limited applications. Whole blood has come back into use in the Major trauma, trauma setting. Red blood cells (RBC) contain hemoglobin and supply the Cell (biology), cells of the body with oxygen. White blood cells are not commonly used during transfusions, but they are part of the immune system and also fight infections. Plasma is the "yellowish" liquid part of blood, which acts as a buffer and contains proteins and other important substances needed for the body's overall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Army Medical Corps
The Royal Army Medical Corps (RAMC) was a specialist corps in the British Army which provided medical services to all Army personnel and their families, in war and in peace. On 15 November 2024, the corps was amalgamated with the Royal Army Dental Corps and Queen Alexandra's Royal Army Nursing Corps to form the Royal Army Medical Service. History Origins Medical services in the British armed services date from the formation of the British Army#The Founding of the Army, Standing Regular Army after the English Restoration, Restoration of Charles II of England, Charles II in 1660. Prior to this, from as early as the 13th century there are records of surgeons and physicians being appointed by the English army to attend in times of war; but this was the first time a career was provided for a Medical Officer (MO), both in peacetime and in war. For much of the next two hundred years, army medical provision was mostly arranged on a regimental basis, with each battalion arranging its o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Normal Number
In mathematics, a real number is said to be simply normal in an integer base b if its infinite sequence of digits is distributed uniformly in the sense that each of the b digit values has the same natural density 1/b. A number is said to be normal in base b if, for every positive integer n, all possible strings n digits long have density b−''n''. Intuitively, a number being simply normal means that no digit occurs more frequently than any other. If a number is normal, no finite combination of digits of a given length occurs more frequently than any other combination of the same length. A normal number can be thought of as an infinite sequence of coin flips ( binary) or rolls of a die ( base 6). Even though there ''will'' be sequences such as 10, 100, or more consecutive tails (binary) or fives (base 6) or even 10, 100, or more repetitions of a sequence such as tail-head (two consecutive coin flips) or 6-1 (two consecutive rolls of a die), there will also be equally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wacław Sierpiński
Wacław Franciszek Sierpiński (; 14 March 1882 – 21 October 1969) was a Polish mathematician. He was known for contributions to set theory (research on the axiom of choice and the continuum hypothesis), number theory, theory of functions, and topology. He published over 700 papers and 50 books. Three well-known fractals are named after him (the Sierpiński triangle, the Sierpiński carpet, and the Sierpiński curve), as are Sierpiński numbers and the associated Sierpiński problem. Early life and education Sierpiński was born in 1882 in Warsaw, Congress Poland, to a doctor father Konstanty and mother Ludwika (''née'' Łapińska). His abilities in mathematics were evident from childhood. He enrolled in the Department of Mathematics and Physics at the University of Warsaw in 1899 and graduated five years later. In 1903, while still at the University of Warsaw, the Department of Mathematics and Physics offered a prize for the best essay from a student on Vorono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bieberbach Conjecture
In complex analysis, de Branges's theorem, or the Bieberbach conjecture, is a theorem that gives a necessary condition on a holomorphic function in order for it to map the open unit disk of the complex plane injectively to the complex plane. It was posed by and finally proven by . The statement concerns the Taylor coefficients a_n of a univalent function, i.e. a one-to-one holomorphic function that maps the unit disk into the complex plane, normalized as is always possible so that a_0=0 and a_1=1. That is, we consider a function defined on the open unit disk which is holomorphic and injective ('' univalent'') with Taylor series of the form :f(z)=z+\sum_ a_n z^n. Such functions are called ''schlicht''. The theorem then states that : , a_n, \leq n \quad \textn\geq 2. The Koebe function (see below) is a function for which a_n=n for all n, and it is schlicht, so we cannot find a stricter limit on the absolute value of the nth coefficient. Schlicht functions The normalization ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ludwig Bieberbach
Ludwig Georg Elias Moses Bieberbach (; 4 December 1886 – 1 September 1982) was a German mathematician and leading representative of National Socialist German mathematics (" Deutsche Mathematik"). Biography Born in Goddelau, near Darmstadt, he studied at Heidelberg and under Felix Klein at Göttingen, receiving his doctorate in 1910. His dissertation was titled ''On the theory of automorphic functions'' (). He began working as a Privatdozent at Königsberg in 1910 and as Professor ordinarius at the University of Basel in 1913. He taught at the University of Frankfurt in 1915 and the University of Berlin from 1921–45. Bieberbach wrote a habilitation thesis in 1911 about groups of Euclidean motions – identifying conditions under which the group must have a translational subgroup whose vectors span the Euclidean space – that helped solve Hilbert's 18th problem. He worked on complex analysis and its applications to other areas in mathematics. He is known for his wor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
