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Hans Friedrich Geitel
Hans Friedrich Karl Geitel (16 July 1855 in Braunschweig – 15 August 1923 in Wolfenbüttel) was a German physicist. He is credited with coining the phrase "atomic energy." Biography Through the relocation of his family, his father was a forester, Hans Geitel came to Blankenburg in 1861 and grew up in close proximity to Julius Elster. He attended school and high school together with Elster. A lifelong friendship developed between the two of them, their interest in science became a shared field of activity. During their studies both spent two years in Heidelberg and Berlin. In 1879 Geitel got his teaching degree in Braunschweig and accepted a position as teacher at the then called Herzogliche Große Schule (translation: Ducal Great School) in Wolfenbüttel. In 1881 Geitel succeeded in getting Julius Elster to the school as well. There they intensified their joint researches. Karl Bergwitz (1875–1958), who continued their research, was one of their students there. In 1892 Geitel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Göttingen
The University of Göttingen, officially the Georg August University of Göttingen, (german: Georg-August-Universität Göttingen, known informally as Georgia Augusta) is a public research university in the city of Göttingen, Germany. Founded in 1734 by George II, King of Great Britain and Elector of Hanover, and starting classes in 1737, the Georgia Augusta was conceived to promote the ideals of the Enlightenment. It is the oldest university in the state of Lower Saxony and the largest in student enrollment, which stands at around 31,600. Home to many noted figures, it represents one of Germany's historic and traditional institutions. According to an official exhibition held by the University of Göttingen in 2002, 44 Nobel Prize winners had been affiliated with the University of Göttingen as alumni, faculty members or researchers by that year alone. The University of Göttingen was previously supported by the German Universities Excellence Initiative, holds memberships ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientists From Braunschweig
A scientist is a person who conducts scientific research to advance knowledge in an area of the natural sciences. In classical antiquity, there was no real ancient analog of a modern scientist. Instead, philosophers engaged in the philosophical study of nature called natural philosophy, a precursor of natural science. Though Thales (circa 624-545 BC) was arguably the first scientist for describing how cosmic events may be seen as natural, not necessarily caused by gods,Frank N. Magill''The Ancient World: Dictionary of World Biography'', Volume 1 Routledge, 2003 it was not until the 19th century that the term ''scientist'' came into regular use after it was coined by the theologian, philosopher, and historian of science William Whewell in 1833. In modern times, many scientists have advanced degrees in an area of science and pursue careers in various sectors of the economy such as academia, industry, government, and nonprofit environments.'''' History The roles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1923 Deaths
Nineteen or 19 may refer to: * 19 (number), the natural number following 18 and preceding 20 * one of the years 19 BC, AD 19, 1919, 2019 Films * ''19'' (film), a 2001 Japanese film * ''Nineteen'' (film), a 1987 science fiction film Music * 19 (band), a Japanese pop music duo Albums * ''19'' (Adele album), 2008 * ''19'', a 2003 album by Alsou * ''19'', a 2006 album by Evan Yo * ''19'', a 2018 album by MHD * ''19'', one half of the double album ''63/19'' by Kool A.D. * ''Number Nineteen'', a 1971 album by American jazz pianist Mal Waldron * ''XIX'' (EP), a 2019 EP by 1the9 Songs * "19" (song), a 1985 song by British musician Paul Hardcastle. * "Nineteen", a song by Bad4Good from the 1992 album '' Refugee'' * "Nineteen", a song by Karma to Burn from the 2001 album ''Almost Heathen''. * "Nineteen" (song), a 2007 song by American singer Billy Ray Cyrus. * "Nineteen", a song by Tegan and Sara from the 2007 album '' The Con''. * "XIX" (song), a 2014 song by Slipk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1855 Births
Events January–March * January 1 – Ottawa, Ontario, is incorporated as a city. * January 5 – Ramón Castilla begins his third term as President of Peru. * January 23 ** The first bridge over the Mississippi River opens in modern-day Minneapolis, a predecessor of the Father Louis Hennepin Bridge. ** The 8.2–8.3 Wairarapa earthquake claims between five and nine lives near the Cook Strait area of New Zealand. * January 26 – The Point No Point Treaty is signed in the Washington Territory. * January 27 – The Panama Railway becomes the first railroad to connect the Atlantic and Pacific Oceans. * January 29 – Lord Aberdeen resigns as Prime Minister of the United Kingdom, over the management of the Crimean War. * February 5 – Lord Palmerston becomes Prime Minister of the United Kingdom. * February 11 – Kassa Hailu is crowned Tewodros II, Emperor of Ethiopia. * February 12 – Michigan State University (the "pioneer" l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermionic Emission
Thermionic emission is the liberation of electrons from an electrode by virtue of its temperature (releasing of energy supplied by heat). This occurs because the thermal energy given to the charge carrier overcomes the work function of the material. The charge carriers can be electrons or ions, and in older literature are sometimes referred to as thermions. After emission, a charge that is equal in magnitude and opposite in sign to the total charge emitted is initially left behind in the emitting region. But if the emitter is connected to a battery, the charge left behind is neutralized by charge supplied by the battery as the emitted charge carriers move away from the emitter, and finally the emitter will be in the same state as it was before emission. The classical example of thermionic emission is that of electrons from a hot cathode into a vacuum (also known as thermal electron emission or the Edison effect) in a vacuum tube. The hot cathode can be a metal filament, a coated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photomultiplier Tube
Photomultiplier tubes (photomultipliers or PMTs for short) are extremely sensitive detectors of light in the ultraviolet, visible, and near-infrared ranges of the electromagnetic spectrum. They are members of the class of vacuum tubes, more specifically vacuum phototubes. These detectors multiply the current produced by incident light by as much as 100 million times or 108 (i.e., 160 dB),Decibels are power ratios. Power is proportional to I2 (current squared). Thus a current gain of 108 produces a power gain of 1016, or 160 dB in multiple dynode stages, enabling (for example) individual photons to be detected when the incident flux of light is low. The combination of high gain, low noise, high frequency response or, equivalently, ultra-fast response, and large area of collection has maintained photomultipliers an essential place in low light level spectroscopy, confocal microscopy, Raman spectroscopy, fluorescence spectroscopy, nuclear and particle physics, astronomy, medical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoelectric Effect
The photoelectric effect is the emission of electrons when electromagnetic radiation, such as light, hits a material. Electrons emitted in this manner are called photoelectrons. The phenomenon is studied in condensed matter physics, and solid state and quantum chemistry to draw inferences about the properties of atoms, molecules and solids. The effect has found use in electronic devices specialized for light detection and precisely timed electron emission. The experimental results disagree with classical electromagnetism, which predicts that continuous light waves transfer energy to electrons, which would then be emitted when they accumulate enough energy. An alteration in the intensity of light would theoretically change the kinetic energy of the emitted electrons, with sufficiently dim light resulting in a delayed emission. The experimental results instead show that electrons are dislodged only when the light exceeds a certain frequency—regardless of the light's intensity or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Braunschweig University Of Technology
Braunschweig () or Brunswick ( , from Low German ''Brunswiek'' , Braunschweig dialect: ''Bronswiek'') is a city in Lower Saxony, Germany, north of the Harz Mountains at the farthest navigable point of the river Oker, which connects it to the North Sea via the rivers Aller and Weser. In 2016, it had a population of 250,704. A powerful and influential centre of commerce in medieval Germany, Brunswick was a member of the Hanseatic League from the 13th until the 17th century. It was the capital city of three successive states: the Principality of Brunswick-Wolfenbüttel (1269–1432, 1754–1807, and 1813–1814), the Duchy of Brunswick (1814–1918), and the Free State of Brunswick (1918–1946). Today, Brunswick is the second-largest city in Lower Saxony and a major centre of scientific research and development. History Foundation and early history The date and circumstances of the town's foundation are unknown. Tradition maintains that Brunswick was created through the mer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honorary Degree
An honorary degree is an academic degree for which a university (or other degree-awarding institution) has waived all of the usual requirements. It is also known by the Latin phrases ''honoris causa'' ("for the sake of the honour") or ''ad honorem '' ("to the honour"). The degree is typically a doctorate or, less commonly, a master's degree, and may be awarded to someone who has no prior connection with the academic institution or no previous postsecondary education. An example of identifying a recipient of this award is as follows: Doctorate in Business Administration (''Hon. Causa''). The degree is often conferred as a way of honouring a distinguished visitor's contributions to a specific field or to society in general. It is sometimes recommended that such degrees be listed in one's curriculum vitae (CV) as an award, and not in the education section. With regard to the use of this honorific, the policies of institutions of higher education generally ask that recipients ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photocell
Photodetectors, also called photosensors, are sensors of light or other electromagnetic radiation. There is a wide variety of photodetectors which may be classified by mechanism of detection, such as photoelectric or photochemical effects, or by various performance metrics, such as spectral response. Semiconductor-based photodetectors typically photo detector have a p–n junction that converts light photons into current. The absorbed photons make electron–hole pairs in the depletion region. Photodiodes and photo transistors are a few examples of photo detectors. Solar cells convert some of the light energy absorbed into electrical energy. Types Photodetectors may be classified by their mechanism for detection: * Photoemission or photoelectric effect: Photons cause electrons to transition from the conduction band of a material to free electrons in a vacuum or gas. * Thermal: Photons cause electrons to transition to mid-gap states then decay back to lower bands, inducing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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