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Barometers
A barometer is a scientific instrument that is used to measure air pressure in a certain environment. Pressure tendency can forecast short term changes in the weather. Many measurements of air pressure are used within surface weather analysis to help find surface troughs, pressure systems and frontal boundaries. Barometers and pressure altimeters (the most basic and common type of altimeter) are essentially the same instrument, but used for different purposes. An altimeter is intended to be used at different levels matching the corresponding atmospheric pressure to the altitude, while a barometer is kept at the same level and measures subtle pressure changes caused by weather and elements of weather. The average atmospheric pressure on the earth's surface varies between 940 and 1040 hPa (mbar). The average atmospheric pressure at sea level is 1013 hPa (mbar). Etymology The word ''barometer'' is derived from the Ancient Greek (), meaning "weight", and (), meaning "measu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barometer
A barometer is a scientific instrument that is used to measure air pressure in a certain environment. Pressure tendency can forecast short term changes in the weather. Many measurements of air pressure are used within surface weather analysis to help find surface troughs, pressure systems and frontal boundaries. Barometers and pressure altimeters (the most basic and common type of altimeter) are essentially the same instrument, but used for different purposes. An altimeter is intended to be used at different levels matching the corresponding atmospheric pressure to the altitude, while a barometer is kept at the same level and measures subtle pressure changes caused by weather and elements of weather. The average atmospheric pressure on the earth's surface varies between 940 and 1040 hPa (mbar). The average atmospheric pressure at sea level is 1013 hPa (mbar). Etymology The word '' barometer'' is derived from the Ancient Greek (), meaning "weight", and (), meaning "me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver and was formerly named hydrargyrum ( ) from the Greek words, ''hydor'' (water) and ''argyros'' (silver). A heavy, silvery d-block element, mercury is the only metallic element that is known to be liquid at standard temperature and pressure; the only other element that is liquid under these conditions is the halogen bromine, though metals such as caesium, gallium, and rubidium melt just above room temperature. Mercury occurs in deposits throughout the world mostly as cinnabar ( mercuric sulfide). The red pigment vermilion is obtained by grinding natural cinnabar or synthetic mercuric sulfide. Mercury is used in thermometers, barometers, manometers, sphygmomanometers, float valves, mercury switches, mercury relays, fluorescent lamps and other devices, though concerns about the element's toxicity have led to mercury thermometers and sphygmomanometers being largely p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siphon
A siphon (from grc, σίφων, síphōn, "pipe, tube", also spelled nonetymologically syphon) is any of a wide variety of devices that involve the flow of liquids through tubes. In a narrower sense, the word refers particularly to a tube in an inverted "U" shape, which causes a liquid to flow upward, above the surface of a reservoir, with no pump, but powered by the fall of the liquid as it flows down the tube under the pull of gravity, then discharging at a level lower than the surface of the reservoir from which it came. There are two leading theories about how siphons cause liquid to flow uphill, against gravity, without being pumped, and powered only by gravity. The traditional theory for centuries was that gravity pulling the liquid down on the exit side of the siphon resulted in reduced pressure at the top of the siphon. Then atmospheric pressure was able to push the liquid from the upper reservoir, up into the reduced pressure at the top of the siphon, like in a barome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altitude
Altitude or height (also sometimes known as depth) is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The exact definition and reference datum varies according to the context (e.g., aviation, geometry, geographical survey, sport, or atmospheric pressure). Although the term ''altitude'' is commonly used to mean the height above sea level of a location, in geography the term elevation is often preferred for this usage. Vertical distance measurements in the "down" direction are commonly referred to as depth. In aviation In aviation, the term altitude can have several meanings, and is always qualified by explicitly adding a modifier (e.g. "true altitude"), or implicitly through the context of the communication. Parties exchanging altitude information must be clear which definition is being used. Aviation altitude is measured using either mean sea level (MSL) or local ground level (above ground leve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niccolò Zucchi
Niccolò Zucchi (; December 6, 1586 – May 21, 1670) was an Italian Jesuit, astronomer, and physicist. As an astronomer he may have been the first to see the belts on the planet Jupiter (on May 17, 1630), and reported spots on Mars in 1640. His "''Optica philosophia experimentis et ratione a fundamentis constituta''", published in 1652–56, described his 1616 experiments using a curved mirror instead of a lens as a telescope objective, which may be the earliest known description of a reflecting telescope. In his book he also demonstrated that phosphors generate rather than store light. He also published two other works on mechanics and machines. Biography Niccolò Zucchi was fourth of eight children born into the noble family of Pierre Zucchi and Francoise Giande Marie. Three of his sisters became nuns, three of his brothers became Jesuits, and one brother became a secular priest. The Jesuit order Niccolò studied rhetoric in Piacenza and philosophy and theology in Parma. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure Altimeter
An altimeter or an altitude meter is an instrument used to measure the altitude of an object above a fixed level. The measurement of altitude is called altimetry, which is related to the term bathymetry, the measurement of depth under water. The most common unit for altimeter calibration worldwide is hectopascals (hPa), except for North America (other than Canada ) and Japan where inches of mercury (inHg) are used. To obtain an accurate altitude reading in either feet or meters, the local barometric pressure must be calibrated correctly using the barometric formula. History The scientific principles behind the altimeter were first written by Rev. Alexander Bryce a Scottish minister and astronomer in 1772 who realised that the principles of a barometer could be adjusted to measure height. Pressure altimeter Altitude can be determined based on the measurement of atmospheric pressure. The greater the altitude, the lower the pressure. When a barometer is supplied with a nonlinear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blaise Pascal
Blaise Pascal ( , , ; ; 19 June 1623 – 19 August 1662) was a French mathematician, physicist, inventor, philosopher, and Catholic writer. He was a child prodigy who was educated by his father, a tax collector in Rouen. Pascal's earliest mathematical work was on conic sections; he wrote a significant treatise on the subject of projective geometry at the age of 16. He later corresponded with Pierre de Fermat on probability theory, strongly influencing the development of modern economics and social science. In 1642, while still a teenager, he started some pioneering work on calculating machines (called Pascal's calculators and later Pascalines), establishing him as one of the first two inventors of the mechanical calculator. Like his contemporary René Descartes, Pascal was also a pioneer in the natural and applied sciences. Pascal wrote in defense of the scientific method and produced several controversial results. He made important contributions to the study of fluid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Athanasius Kircher
Athanasius Kircher (2 May 1602 – 27 November 1680) was a German Jesuit scholar and polymath who published around 40 major works, most notably in the fields of comparative religion, geology, and medicine. Kircher has been compared to fellow Jesuit Roger Joseph Boscovich and to Leonardo da Vinci for his enormous range of interests, and has been honoured with the title "Master of a Hundred Arts".Woods, p. 108. He taught for more than 40 years at the Roman College, where he set up a wunderkammer. A resurgence of interest in Kircher has occurred within the scholarly community in recent decades. Kircher claimed to have deciphered the hieroglyphic writing of the ancient Egyptian language, but most of his assumptions and translations in this field were later found to be incorrect. He did, however, correctly establish the link between the ancient Egyptian and the Coptic languages, and some commentators regard him as the founder of Egyptology. Kircher was also fascina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michelangelo Ricci
Michelangelo Ricci (1619–1682) was an Italian mathematician and a Cardinal of the Roman Catholic Church. Biography Michelangelo Ricci was born on 30 January 1619 in Rome, then capital of the Papal States, to a family of low social standing that originated in Bergamo. He studied theology and law in Rome, where he was a contemporary of René-François de Sluse. He also studied mathematics under Benedetto Castelli who himself had been a student of Galileo Galilei. He was a friend of Evangelista Torricelli, kept close links with contemporary scientific culture, and played an important role in the development of the Galilean school. Like de Sluze, he spent his entire career in the Roman Catholic Church and served the pope in various roles on several occasions. A trained theologian, he acted as consultant to various Congregations of the Roman Curia. Having suffered from epilepsy since his birth, he was (according to canon law of the time) disqualified from ordination. Nonethe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre Petit (engineer)
Pierre Petit (8 December 1594His birth year is sometimes given as 1598. – 20 August 1677) was a French astronomer, physicist, mathematician and instrument maker. Petit was born in Montluçon. He succeeded his father in his municipal office (''Contrôleur de l'élection''), but went to Paris in 1633 to dedicate himself to the sciences. He was a member of the circle around Marin Mersenne, and knew Etienne Pascal, Blaise Pascal, and René Descartes. Later he was a member of the academy of Montmor. On 4 April 1667 he became a fellow of The Royal Society.Database of all Royal Society fellows fro About Us at the Royal Society official site He also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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