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Friedrich Ernst Dorn
Friedrich Ernst Dorn (27 July 1848 – 16 December 1916) was a German physicist who was the first to discover that a radioactive substance, later named radon, is emitted from radium. Life and work Dorn was born in Guttstadt (Dobre Miasto), Province of Prussia (nowadays Warmia in Poland), and died in Halle, Province of Saxony. He was educated at Königsberg and went on to teach at the university level. In 1885, at Halle University, Dorn took over the position of personal ''ordinarius'' professor for theoretical physics from Anton Oberbeck. Since Dorn was already an ''ordinarius'' professor, he was allowed to assume the title so as to not appear as having been demoted. In 1895, Dorn succeeded Hermann Knoblauch at Halle as the ''ordinarius'' professor for experimental physics and director of the physics institute. Dorn's previous duties were assumed by Carl Schmidt, who had been a Privatdozent and was called as an ''extraordinarius'' professor for theoretical physics. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dobre Miasto
Dobre Miasto (; german: Guttstadt ; literally Good City) is a town in Poland, in the Warmian-Masurian Voivodeship with 9,857 inhabitants as of December 2021. It is situated in the northwestern part of the Masurian Lake District in the heart of the historical region of Warmia. It is also the seat of Dobre Miasto Commune which consists of the main town and 21 village administrative divisions, with a total population of 16,014. History Middle Ages Dobre Miasto was founded on the place of a destroyed Old Prussian settlement. It received German town privileges on 26 December 1329. The name of the town was spelled in different ways: Guddestat, Godenstat, Gudinstat, Gutberg, Gutenstat, Guthenstadt, Guthinstadt. The Latin name of the region ( Pogesania) was derived from the Old Prussian word ''gudde'' (a bush/thicket). It is possible that the name of the town originated from this word. The Teutonic Order changed the Old Prussian pronunciation of the name into ''Guttstadt''. However, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermann Knoblauch
Karl Hermann Knoblauch (; 11 April 1820 – 30 June 1895) was a German physicist. He is most notable for his studies of radiant heat. He was one of the six founding members of the Deutsche Physikalische Gesellschaft at Berlin on 14 January 1845. Knoblauch's father was a well-to-do silk fabrics manufacturer in Berlin. Despite pressure from his father to enter the family business, Knoblauch in his early 20s opted to study mathematics and science at the University of Berlin. There he became one of the star students in the laboratory of Gustav Magnus. Knoblauch's doctorate, completed in Berlin in 1847, described valuable experiments that established some of the optical properties of radiant heat (a.k.a. infrared radiation). In an article describing these experiments Knoblauch wrote that experimental facts are "the only permanent things in science", while abstract models are "transitory" and should be treated with caution and kept separate from the facts, a view that Magnus maintained a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periodic Table
The periodic table, also known as the periodic table of the (chemical) elements, is a rows and columns arrangement of the chemical elements. It is widely used in chemistry, physics, and other sciences, and is generally seen as an icon of chemistry. It is a graphic formulation of the periodic law, which states that the properties of the chemical elements exhibit an approximate periodic dependence on their atomic numbers. The table is divided into four roughly rectangular areas called blocks. The rows of the table are called periods, and the columns are called groups. Elements from the same group of the periodic table show similar chemical characteristics. Trends run through the periodic table, with nonmetallic character (keeping their own electrons) increasing from left to right across a period, and from down to up across a group, and metallic character (surrendering electrons to other atoms) increasing in the opposite direction. The underlying reason for these trends is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectrum
A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors in visible light after passing through a prism. As scientific understanding of light advanced, it came to apply to the entire electromagnetic spectrum. It thereby became a mapping of a range of magnitudes (wavelengths) to a range of qualities, which are the perceived "colors of the rainbow" and other properties which correspond to wavelengths that lie outside of the visible light spectrum. Spectrum has since been applied by analogy to topics outside optics. Thus, one might talk about the " spectrum of political opinion", or the "spectrum of activity" of a drug, or the "autism spectrum". In these uses, values within a spectrum may not be associated with precisely quantifiable numbers or definitions. Such uses imply a broad range of condition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Mass
The atomic mass (''m''a or ''m'') is the mass of an atom. Although the SI unit of mass is the kilogram (symbol: kg), atomic mass is often expressed in the non-SI unit dalton (symbol: Da) – equivalently, unified atomic mass unit (u). 1 Da is defined as of the mass of a free carbon-12 atom at rest in its ground state. The protons and neutrons of the nucleus account for nearly all of the total mass of atoms, with the electrons and nuclear binding energy making minor contributions. Thus, the numeric value of the atomic mass when expressed in daltons has nearly the same value as the mass number. Conversion between mass in kilograms and mass in daltons can be done using the atomic mass constant m_= = 1\ \rm . The formula used for conversion is: :1\ = m_ = 1.660\ 539\ 066\ 60(50)\times 10^\ \mathrm , where M_ is the molar mass constant, N_ is the Avogadro constant, and M(^\mathrm) is the experimentally determined molar mass of carbon-12. The relative isotopic mass (see ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radioisotope
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferred to one of its electrons to release it as a conversion electron; or used to create and emit a new particle (alpha particle or beta particle) from the nucleus. During those processes, the radionuclide is said to undergo radioactive decay. These emissions are considered ionizing radiation because they are energetic enough to liberate an electron from another atom. The radioactive decay can produce a stable nuclide or will sometimes produce a new unstable radionuclide which may undergo further decay. Radioactive decay is a random process at the level of single atoms: it is impossible to predict when one particular atom will decay. However, for a collection of atoms of a single nuclide the decay rate, and thus the half-life (''t''1/2) for t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frederick Soddy
Frederick Soddy FRS (2 September 1877 – 22 September 1956) was an English radiochemist who explained, with Ernest Rutherford, that radioactivity is due to the transmutation of elements, now known to involve nuclear reactions. He also proved the existence of isotopes of certain radioactive elements. In 1921 he received the Nobel Prize in Chemistry "for his contributions to our knowledge of the chemistry of radioactive substances, and his investigations into the origin and nature of isotopes". Soddy was a polymath who mastered chemistry, nuclear physics, statistical mechanics, finance and economics. Biography Soddy was born at 6 Bolton Road, Eastbourne, England, the son of Benjamin Soddy, corn merchant, and his wife Hannah Green. He went to school at Eastbourne College, before going on to study at University College of Wales at Aberystwyth and at Merton College, Oxford, where he graduated in 1898 with first class honours in chemistry. He was a researcher at Oxford from 189 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernest Rutherford
Ernest Rutherford, 1st Baron Rutherford of Nelson, (30 August 1871 – 19 October 1937) was a New Zealand physicist who came to be known as the father of nuclear physics. ''Encyclopædia Britannica'' considers him to be the greatest experimentalist since Michael Faraday (1791–1867). Apart from his work in his homeland, he spent a substantial amount of his career abroad, in both Canada and the United Kingdom. In early work, Rutherford discovered the concept of radioactive half-life, the radioactive element radon, and differentiated and named alpha and beta radiation. This work was performed at McGill University in Montreal, Quebec, Canada. It is the basis for the Nobel Prize in Chemistry he was awarded in 1908 "for his investigations into the disintegration of the elements, and the chemistry of radioactive substances", for which he was the first Oceanian Nobel laureate, and the first to perform the awarded work in Canada. In 1904, he was elected as a member to the Am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thorium
Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90. Thorium is silvery and tarnishes black when it is exposed to air, forming thorium dioxide; it is moderately soft and malleable and has a high melting point. Thorium is an electropositive actinide whose chemistry is dominated by the +4 oxidation state; it is quite reactive and can ignite in air when finely divided. All known thorium isotopes are unstable. The most stable isotope, 232Th, has a half-life of 14.05 billion years, or about the age of the universe; it decays very slowly via alpha decay, starting a decay chain named the thorium series that ends at stable 208 Pb. On Earth, thorium and uranium are the only significantly radioactive elements that still occur naturally in large quantities as primordial elements. Thorium is estimated to be over three times as abundant as uranium in the Earth's crust, and is chiefly refined from monazite sands as a by-product of extracti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Privatdozent
''Privatdozent'' (for men) or ''Privatdozentin'' (for women), abbreviated PD, P.D. or Priv.-Doz., is an academic title conferred at some European universities, especially in German-speaking countries, to someone who holds certain formal qualifications that denote an ability (''facultas docendi'') and permission to teach (''venia legendi'') a designated subject at the highest level. To be granted the title Priv.-Doz. by a university, a recipient has to fulfill the criteria set by the university which usually require excellence in research, teaching, and further education. In its current usage, the title indicates that the holder has completed their habilitation and is therefore granted permission to teach and examine students independently without having a professorship. Conferment and roles A university faculty can confer the title to an academic who has a higher doctoral degree - usually in the form of a habilitation. The title, ''Privatdozent'', as such does not imply a sala ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Schmidt (chemist)
Carl Ernst Heinrich Schmidt ( – ), also known in Russia as Karl Genrikhovich Schmidt (russian: Карл Ге́нрихович Шмидт, translit=Karl Génrichovič Šmidt), was a Baltic German Baltic Germans (german: Deutsch-Balten or , later ) were ethnic German inhabitants of the eastern shores of the Baltic Sea, in what today are Estonia and Latvia. Since their coerced resettlement in 1939, Baltic Germans have markedly declined ... chemist from the Governorate of Livonia, a part of the Russian Empire. Biography Schmidt received his Doctor of Philosophy, PhD in 1844 from the University of Gießen under Justus von Liebig. In 1845, he first announced the presence in the test of some Ascidians of what he called "tunicine", a substance very similar to cellulose. Tunicine now is regarded as cellulose and correspondingly a remarkable substance to find in an animal. In 1850, Schmidt had been named Professor of Pharmacy at Tartu, Dorpat (Tartu) and in 1851 he was appoi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Munich
The Ludwig Maximilian University of Munich (simply University of Munich or LMU; german: Ludwig-Maximilians-Universität München) is a public research university in Munich, Germany. It is Germany's List of universities in Germany, sixth-oldest university in continuous operation. Originally University of Ingolstadt, established in Ingolstadt in 1472 by Louis IX, Duke of Bavaria, Duke Ludwig IX of Bavaria-Landshut, the university was moved in 1800 to Landshut by Maximilian I Joseph of Bavaria, King Maximilian I of Bavaria when the city was threatened by the French, before being relocated to its present-day location in Munich in 1826 by Ludwig I of Bavaria, King Ludwig I of Bavaria. In 1802, the university was officially named Ludwig-Maximilians-Universität by King Maximilian I of Bavaria in honor of himself and Ludwig IX. LMU is currently the second-largest university in Germany in terms of student population; in the 2018/19 winter semester, the university had a total of 51,606 m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
