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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 Jan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science
Science is a systematic endeavor that Scientific method, builds and organizes knowledge in the form of Testability, testable explanations and predictions about the universe. Science may be as old as the human species, and some of the earliest archeological evidence for scientific reasoning is tens of thousands of years old. The earliest written records in the history of science come from Ancient Egypt and Mesopotamia in around 3000 to 1200 Common Era, BCE. Their contributions to mathematics, astronomy, and medicine entered and shaped Greek natural philosophy of classical antiquity, whereby formal attempts were made to provide explanations of events in the Universe, physical world based on natural causes. After the fall of the Western Roman Empire, knowledge of History of science in classical antiquity, Greek conceptions of the world deteriorated in Western Europe during the early centuries (400 to 1000 CE) of the Middle Ages, but was preserved in the Muslim world during the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Enskog
250px David Enskog (22 April 1884, Västra Ämtervik, Sunne – 1 June 1947, Stockholm) was a Swedish mathematical physicist. Enskog helped develop the kinetic theory of gases by extending the Maxwell–Boltzmann equations. Biography After undergraduate studies at Uppsala University he received a licentiate degree in physics in 1911, working on gas diffusion under professor Gustaf Granqvist, who was an experimentalist. Enskog did not wish to continue with experimental physics, however, and transferred to professor Carl Wilhelm Oseen for his Ph.D. From 1913, Enskog worked as a high school teacher in mathematics and physics to support himself and his family, while continuing his research and thesis writing in his free time. In 1917 he completed his thesis on kinetic theory of gases at Uppsala. As his thesis was considered obscure and difficult to grasp, he received a rather mediocre grade on it, which did not qualify him to become a docent, which was the essential next s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brownsville, Brooklyn
Brownsville is a residential neighborhood in eastern Brooklyn in New York City. The neighborhood is generally bordered by Crown Heights to the northwest; Bedford–Stuyvesant and Cypress Hills to the north; East New York to the east; Canarsie to the south; and East Flatbush to the west. The area that comprises Brownsville has 58,300 residents as of the 2010 United States Census, with an estimated population of 128,369 residents in 2019. Founded in its current incarnation in 1858, Brownsville was initially a settlement composed of Jewish factory workers. The neighborhood underwent a major demographic change in the 1950s that saw an influx of African-American residents. Since the late 20th century, Brownsville has consistently held one of the highest poverty and crime rates of any neighborhood in New York City. Brownsville is part of Brooklyn Community District 16, and its primary ZIP Code is 11212. It is patrolled by the 73rd Precinct of the New York City Police Department ... [...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 unwanted 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 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 oral pills, patches, vaginal rings ... [...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, financial situations. If sexually active, family planning may involve the use of contraception and other techniques to control the timing of reproduction. Family planning has been of practice since the 16th century by the people of Djenné in West Africa, when physicians advised women to space their births at three-year intervals. Others aspects of family planning aside from contraception include sex education, prevention and management of sexually transmitted infections, pre-conception counseling and 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 W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Margaret Sanger
Margaret Higgins Sanger (born Margaret Louise Higgins; September 14, 1879September 6, 1966), also known as Margaret Sanger Slee, was an American birth control activist, sex educator, writer, and nurse. Sanger popularized the term "birth control", opened the first birth control clinic in the United States, and established organizations that evolved into the Planned Parenthood Federation of America. Sanger used her writings and speeches primarily to promote her way of thinking. She was prosecuted for her book ''Family Limitation'' under the Comstock Act in 1914. She feared the consequences of her writings, so she fled to Britain until public opinion had quieted. Sanger's efforts contributed to several judicial cases that helped legalize contraception in the United States. Due to her connection with Planned Parenthood, Sanger is frequently criticized by opponents of abortion. However, Sanger drew a sharp distinction between birth control and abortion and was opposed to abortions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Transfusion
Blood transfusion is the process of transferring blood products into a person's 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, white blood cells, plasma, clotting factors and platelets. Red blood cells (RBC) contain hemoglobin, and supply the cells of the body with oxygen. White blood cells are not commonly used during transfusion, 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 important substances needed for the body's overall health. Platelets are involved in blood clotting, preventing the body from bleeding. Before these components were known, doctors believed that blood was homogeneous. Because of this scientific misunderstanding, many patients died ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Army Medical Corps
The Royal Army Medical Corps (RAMC) is a specialist corps in the British Army which provides medical services to all Army personnel and their families, in war and in peace. The RAMC, the Royal Army Veterinary Corps, the Royal Army Dental Corps and Queen Alexandra's Royal Army Nursing Corps form the Army Medical Services. History Origins Medical services in the British armed services date from the formation of the Standing Regular Army after the Restoration of 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 own hospital facilities and medical supplies. An element of oversight was provided by the appoin ... [...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 ma ... [...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. Educational background Sierpiński enrolled in the Department of Mathematics and Physics at the University of Warsaw in 1899 and graduated four 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 Voronoy's contribution to number theory. Sierpiński was awarded a gold medal for his essay, thus laying the foundation for his first major mathematical contribution. Unwilling for his work to b ... [...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 in 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 normalizat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
