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1872 In Science
The year 1872 in science and technology involved some significant events, listed below. Chemistry * Robert Chesebrough patents Vaseline in the United States * Eugen Baumann rediscovers polyvinyl chloride * Charles-Adolphe Wurtz discovers the aldol reaction Conservation * March 1 – Yellowstone National Park is established in the United States, the world's first national park Exploration * December 21 – ''Challenger'' expedition: sails from Portsmouth in England on the 4-year scientific expedition that lays the foundation for the science of oceanography Mathematics * Richard Dedekind publishes ''Stetigkeit und irrationale Zahlen'', a theory of irrational numbers * Felix Klein produces the Erlangen program on geometries Medicine * February 15 – George Huntington makes the first detailed description of Huntington's disease, in Middleport, Ohio * Moritz Kaposi describes Kaposi's sarcoma and the manifestations of systemic lupus erythematosus * Ferdinand Monoyer proposes the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science
Science is a systematic endeavor that builds and organizes knowledge in the form of 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 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 physical world based on natural causes. After the fall of the Western Roman Empire, knowledge of 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 Islamic Golden Age and later by the efforts of Byzantine Greek scholars who brought Greek ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irrational Number
In mathematics, the irrational numbers (from in- prefix assimilated to ir- (negative prefix, privative) + rational) are all the real numbers that are not rational numbers. That is, irrational numbers cannot be expressed as the ratio of two integers. When the ratio of lengths of two line segments is an irrational number, the line segments are also described as being '' incommensurable'', meaning that they share no "measure" in common, that is, there is no length ("the measure"), no matter how short, that could be used to express the lengths of both of the two given segments as integer multiples of itself. Among irrational numbers are the ratio of a circle's circumference to its diameter, Euler's number ''e'', the golden ratio ''φ'', and the square root of two. In fact, all square roots of natural numbers, other than of perfect squares, are irrational. Like all real numbers, irrational numbers can be expressed in positional notation, notably as a decimal number. In the cas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ludwig Boltzmann
Ludwig Eduard Boltzmann (; 20 February 1844 – 5 September 1906) was an Austrian physicist and philosopher. His greatest achievements were the development of statistical mechanics, and the statistical explanation of the second law of thermodynamics. In 1877 he provided the current definition of entropy, S = k_ \ln \Omega \!, where Ω is the number of microstates whose energy equals the system's energy, interpreted as a measure of statistical disorder of a system. Max Planck named the constant the Boltzmann constant. Statistical mechanics is one of the pillars of modern physics. It describes how macroscopic observations (such as temperature and pressure) are related to microscopic parameters that fluctuate around an average. It connects thermodynamic quantities (such as heat capacity) to microscopic behavior, whereas, in classical thermodynamics, the only available option would be to measure and tabulate such quantities for various materials. Biography Childhood and educatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Power
In optics, optical power (also referred to as dioptric power, refractive power, focusing power, or convergence power) is the degree to which a lens (optics), lens, mirror, or other optical system converges or diverges light. It is equal to the Multiplicative inverse, reciprocal of the focal length of the device: . High optical power corresponds to short focal length. The SI unit for optical power is the inverse metre (m−1), which is commonly called the dioptre. Converging lenses have positive optical power, while diverging lenses have negative power. When a lens is immersed in a medium (optics), refractive medium, its optical power and focal length change. For two or more thin lenses close together, the optical power of the combined lenses is approximately equal to the sum of the optical powers of each lens: . Similarly, the optical power of a single lens is roughly equal to the sum of the powers of each surface. These approximations are commonly used in optometry. An human ey ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioptre
A dioptre (British spelling) or diopter (American spelling) is a unit of measurement with dimension of reciprocal length, equivalent to one reciprocal metre, 1 dioptre = 1 m−1. It is normally used to express the optical power of a lens or curved mirror, which is a physical quantity equal to the reciprocal of the focal length, expressed in metres. For example, a 3-dioptre lens brings parallel rays of light to focus at metre. A flat window has an optical power of zero dioptres, as it does not cause light to converge or diverge. Dioptres are also sometimes used for other reciprocals of distance, particularly radii of curvature and the vergence of optical beams. The main benefit of using optical power rather than focal length is that the thin lens formula has the object distance, image distance, and focal length all as reciprocals. Additionally, when relatively thin lenses are placed close together their powers approximately add. Thus, a thin 2.0-dioptre lens placed close to a t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systemic Lupus Erythematosus
Lupus, technically known as systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Common symptoms include painful and swollen joints, fever, chest pain, hair loss, mouth ulcers, swollen lymph nodes, feeling tired, and a red rash which is most commonly on the face. Often there are periods of illness, called flares, and periods of remission during which there are few symptoms. The cause of SLE is not clear. It is thought to involve a mixture of genetics combined with environmental factors. Among identical twins, if one is affected there is a 24% chance the other one will also develop the disease. Female sex hormones, sunlight, smoking, vitamin D deficiency, and certain infections are also believed to increase a person's risk. The mechanism involves an immune response by autoantibodies against a person's own tissues. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Who Named It?
''Whonamedit?'' is an online English-language dictionary of medical eponyms and the people associated with their identification. Though it is a dictionary, many eponyms and persons are presented in extensive articles with comprehensive bibliographies. The dictionary is hosted in Norway and maintained by medical historian Ole Daniel Enersen Ole Daniel Enersen (born March 14, 1943, in Oslo, Norway) is a Norwegian climber, photographer, journalist, writer, and medical historian. In 1965 he made the first ascent of the Trollveggen mountain in Romsdalen, Norway, along with Leif Norman .... References External links * Medical websites Medical dictionaries Eponyms {{online-dict-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaposi's Sarcoma
Kaposi's sarcoma (KS) is a type of cancer that can form masses in the skin, in lymph nodes, in the mouth, or in other organs. The skin lesions are usually painless, purple and may be flat or raised. Lesions can occur singly, multiply in a limited area, or may be widespread. Depending on the sub-type of disease and level of immune suppression, KS may worsen either gradually or quickly. Except for Classical KS where there is generally no immune suppression, KS is caused by a combination of immune suppression (such as due to HIV/AIDS) and infection by Human herpesvirus 8 (HHV8 – also called KS-associated herpesvirus (KSHV)). Four sub-types are described: classic, endemic, immunosuppression therapy-related (also called iatrogenic), and epidemic (also called AIDS-related). Classic KS tends to affect older men in regions where KSHV is highly prevalent (Mediterranean, Eastern Europe, Middle East), is usually slow-growing, and most often affects only the legs. Endemic KS is most commo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moritz Kaposi
Moritz Kaposi ( hu, Kaposi Mór, ; 23 October 1837 in Kaposvár, Hungary – 6 March 1902 in Vienna, Austria-Hungary) was a Hungarian physician and dermatologist who discovered the skin tumor that received his name (Kaposi's sarcoma). Biography Early life and name Born to a Jewish family, originally his surname was Kohn; but, with his conversion to the Catholic faith, he changed it to Kaposi in 1871, in reference to his town of birth. One purported reason behind this is that he wanted to marry a daughter of current dermatology chairman, Ferdinand Ritter von Hebra, and advance in the society, which he could not have done being of Jewish faith. This seems unlikely because he married Martha Hebra and converted to Catholicism several years prior to changing his name, by which time he was already well established in the Vienna University faculty and a close associate of her father, Ferdinand. A more plausible explanation is based on his own comments to colleagues that he changed his ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of The History Of The Neurosciences
''Journal of the History of the Neurosciences'' is a British academic journal founded in 1992. It covers the history of neuroscience Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions and disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, development .... The journal contains a combination of original articles, book reviews, and two unique types of columns called "NEUROwords" and the "Neurognostics" Questions and Answers. References External links International Society for the History of the Neurosciences Publications established in 1992 History of medicine journals Neurology journals Neuroscience journals Quarterly journals {{Sci-hist-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Huntington's Disease
Huntington's disease (HD), also known as Huntington's chorea, is a neurodegenerative disease that is mostly inherited. The earliest symptoms are often subtle problems with mood or mental abilities. A general lack of coordination and an unsteady gait often follow. It is also a basal ganglia disease causing a hyperkinetic movement disorder known as chorea. As the disease advances, uncoordinated, involuntary body movements of chorea become more apparent. Physical abilities gradually worsen until coordinated movement becomes difficult and the person is unable to talk. Mental abilities generally decline into dementia. The specific symptoms vary somewhat between people. Symptoms usually begin between 30 and 50 years of age but can start at any age. The disease may develop earlier in each successive generation. About eight percent of cases start before the age of 20 years, and are known as ''juvenile HD'', which typically present with the slow movement symptoms of Parkinson's d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Huntington
George Huntington (April 9, 1850 – March 3, 1916) was an American physician who contributed a classic clinical description of the disease that bears his name – Huntington's disease. Huntington described this condition in the first of only two scientific papers he ever wrote. He wrote this paper when he was 22, a year after receiving his medical degree from Columbia University in New York. He first read the paper before the Meigs and Mason Academy of Medicine in Middleport, Ohio on February 15, 1872 and then published it in the Medical and Surgical Reporter of Philadelphia on April 13, 1872. Huntington's father and grandfather, George Lee Huntington (1811–1881) and Abel Huntington (1778–1858), were also physicians in the same family practice. Their longitudinal observations combined with his own were invaluable in precisely describing this hereditary disease in multiple generations of a family in East Hampton (town), New York, East Hampton on Long Island. In a 1908 revi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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