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Otto Hahn (petrologist)
Otto Hahn (1828 – 1904) was a German petrologist, geologist, lawyer and author. His father was Johann Franz Gottlieb Hahn (1789 – 1844). His great-grandfather was Christian Tobias Hahn (1759 – 1837), who was the half-brother of Philipp Matthäus Hahn. Hahn started his career as a lawyer. He eventually left the legal profession for the natural sciences. The University of Tübingen awarded him a doctorate for his participation in the Eozoön canadense controversy. He was an active member of The New Church (Swedenborgian) and was a Neptunist. He published ''Die Urzelle'' in 1879. His book ''Die Meteorite (Chondrite) und ihre Organismen'', published the following year in 1880, was a major work in the field of meteoritics that included 142 black and white photomicrographs of chondrite thin sections. In this latter work Hahn proposed the theory that the chondrites consist entirely of fossilized organic remains of life-forms, namely, fossilized sponges, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otto Hahn (1828 - 1904)
Otto Hahn (; 8 March 1879 – 28 July 1968) was a German chemist who was a pioneer in the fields of radioactivity and radiochemistry. He is referred to as the father of nuclear chemistry and father of nuclear fission. Hahn and Lise Meitner discovered radioactive isotopes of radium, thorium, protactinium and uranium. He also discovered the phenomena of atomic recoil and nuclear isomerism, and pioneered rubidium–strontium dating. In 1938, Hahn, Meitner and Fritz Strassmann discovered nuclear fission, for which Hahn alone, was awarded the 1944 Nobel Prize for Chemistry. Nuclear fission was the basis for nuclear reactors and nuclear weapons. A graduate of the University of Marburg, which awarded him a doctorate in 1901, Hahn studied under Sir William Ramsay at University College London and at McGill University in Montreal under Ernest Rutherford, where he discovered several new radioactive isotopes. He returned to Germany in 1906; Emil Fischer placed a forme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sponge
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells. Sponges have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes. Sponges were first to branch off the evolutionary tree from the last common ancestor of all animals, making them the sister group of all other animals. Etymology The term ''sponge'' derives from the Ancient Greek word ( 'sponge'). Overview Sponges are similar to other animals in that they are multicell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anton Rzehak
Anton Rzehak (26 May 1855 in Nový Dvůr, part of Nikolčice – 31 March 1923 in Brno) was a Moravian geologist, paleontologist and prehistorian. He studied chemistry and geology at the University of Technology in Brno, where from 1880 to 1884, he worked as an assistant to Alexander Makowsky (1833–1908).Rzehak, Anton (1855-1923), Geologe, Paläontologe und Prähistoriker Österreichisches Biographisches Lexikon und biographische Dokumentation In 1883, the two men published a geological map of the environs of Brno. From 1884 to 1905 he taught classes in chemistry and natural history at a secondary school in Brno, and meanwhile, obtained an associate professorship for paleontology and applied geography (1902). In 1905, he was named chair of |
Friedrich August Von Quenstedt
Friedrich August von Quenstedt (July 10, 1809 – December 21, 1889), was a German geologist and palaeontologist. Life Von Quenstedt was born at Eisleben in Saxony, and educated at the Humboldt University of Berlin. After a period as assistant in the mineralogical museum, he was appointed associate professor (1837) and then professor (1841) of mineralogy and geognosy at the Eberhard Karls Universität Tübingen. Work His earlier work related chiefly to crystallography and mineralogy, on which subjects he published text-books that were widely used. However, he also became distinguished for his researches on palaeontology, and especially for those on the fossils of the Jurassic system. In 1845, he devised a trinomial system of nomenclature for Jurassic ammonites, which has caused some difficulty for later taxonomists.J.H. Callomon, D. T. Donovan, & M. K. Howarth "F. A. Quenstedt's Trinominal Nomenclature of Jurassic Ammonites" ''Palaeontology'' 47 (4) 1063 (2004) He investigate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gustav Karl Wilhelm Hermann Karsten
Gustav Karl Wilhelm Hermann Karsten (6 November 1817, in Stralsund – 10 July 1908, in Zoppot) was a German botanist and geologist. Born in Stralsund, he followed the example of Alexander von Humboldt and traveled 1844-56 the northern part of South America ( Venezuela, Ecuador and Colombia). From 1856 to 1868, he was a professor at the agricultural college in Berlin, afterwards serving as a professor of plant physiology at the University of Vienna (1868–72). In 1881, at the suggestion of David Friedrich Weinland, Karsten became convinced of the correctness of Otto Hahn's organic theory of the chondrites and, as a result, wrote an essay entitled "Die Meteorite und ihre Organismen" in which he declared his support for Hahn's theory. He died 1908 in Berlin- Grunewald. As a taxonomist, he was the binomial author of many botanical species. Selected bibliography * ''Florae Columbiae ...'' 1859–1869. (Vol. 1Digital edition/ Vol. 2Digital editionby the University and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelm Von Gümbel
Ritter (i. e. personal knight) Karl Wilhelm von Gümbel (11 February 1823 – 18 June 1898), German geologist, was born at Dannenfels, in the Palatinate of the Rhine, and is known chiefly by his researches on the geology of Bavaria. He was the brother of bryologist Wilhelm Theodor Gümbel (1812–1858). He received a practical and scientific education in mining at Munich and Heidelberg, taking the degree of Ph.D. at Munich in 1862; and he was engaged for a time at the colliery of St Ingbert and as a surveyor in that district. In 1851, when the Geological Survey of Bavaria was instituted, Gumbel was appointed chief geologist; in 1863 he was made honorary professor of geognosy and surveying at the university of Munich, and in 1879, Oberberg director of the Bavarian mining department with which the Geological Survey was incorporated. His geological map of Bavaria appeared in 1858, and the official memoir descriptive of the detailed work, entitled ''Geognoslische Beschreibun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Friedrich Weinland
David Friedrich Weinland (30 August 1829 in Grabenstetten – 19 September 1915 in Hohenwittlingen) was a German zoologist and novelist. The son of a pastor, Weinland attended the Protestant Seminary in Maulbronn from 1843 to 1847. He studied theology at the University of Tübingen 1847–51, followed by two semester of studying natural sciences. He earned his PhD in 1852. then worked as an assistant at the Zoological Museum in Berlin. From 1855 he conducted scientific investigations in Canada, Mexico and the Caribbean (especially Haiti) and worked for three years in Louis Agassiz's microscopical laboratory at Harvard University. In 1859 he returned to Germany as director of the Frankfurt Zoological Garden; in this capacity he edited the journal "''Der Zoologische Garten''". and contributed significantly to the enthusiasm for founding zoos, which spread among the middle classes. Following the publication of Otto Hahn's 1880 work, ''Die Meteorite (Chondrite) und ihre O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chondrites (genus)
''Chondrites'' is a trace fossil ichnogenus, preserved as small branching burrows of the same diameter that superficially resemble the roots of a plant. The origin of these structures is currently unknown. ''Chondrites'' is found in marine sediments from the Cambrian period of the Paleozoic onwards. It is especially common in sediments that were deposited in reduced-oxygen environments. Morphology There are four recognized ''Chondrites'' ichnospecies, however, aberrant forms of unknown taxonomic affinity have been discovered. The fossils are made of infilled dendritic rootlike burrows. The branching angles are 30° to 40°, while a shaft diameter varies between 0.1 mm and 10 mm, remaining constant within a single system. ''Chondrites'' is classified as a fodinichnion. Occurrence First appearing during the Cambrian, ''Chondrites'' is still produced today. It is one of the most common ichnotaxa throughout the fossil record and is widely distributed in all types of marin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichnotaxon
An ichnotaxon (plural ichnotaxa) is "a taxon based on the fossilized work of an organism", i.e. the non-human equivalent of an artifact. ''Ichnotaxa'' comes from the Greek ίχνος, ''ichnos'' meaning ''track'' and ταξις, ''taxis'' meaning ''ordering''.Definition o'ichno'at dictionary.com. Ichnotaxa are names used to identify and distinguish morphologically distinctive ichnofossils, more commonly known as trace fossils. They are assigned genus and species ranks by ichnologists, much like organisms in Linnaean taxonomy. These are known as ichnogenera and ichnospecies, respectively. "Ichnogenus" and "ichnospecies" are commonly abbreviated as "igen." and "isp.". The binomial names of ichnospecies and their genera are to be written in italics. Most researchers classify trace fossils only as far as the ichnogenus rank, based upon trace fossils that resemble each other in morphology but have subtle differences. Some authors have constructed detailed hierarchies up to ichnosu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron–nickel Alloy
An iron–nickel alloy or nickel–iron alloy, abbreviated FeNi or NiFe, is a group of alloys consisting primarily of the elements nickel (Ni) and iron (Fe). It is the main constituent of the "iron" planetary cores and iron meteorites. In chemistry, the acronym NiFe refers to an iron–nickel catalyst or component involved in various chemical reactions, or the reactions themselves; in geology, it refers to the main constituents of telluric planetary cores (including Earth's). Some manufactured alloys of iron–nickel are called ''nickel steel'' or '' stainless steel''. Depending on the intended use of the alloy, these are usually fortified with small amounts of other metals, such as chromium, cobalt, molybdenum, and titanium. Astronomy and geology Iron and nickel are the most abundant elements produced during the final stage of stellar nucleosynthesis in massive stars. Heavier elements require other forms of nucleosynthesis, such as during a supernova or neutron star merg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungus
A fungus (plural, : fungi or funguses) is any member of the group of Eukaryote, eukaryotic organisms that includes microorganisms such as yeasts and Mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as a Kingdom (biology), kingdom, separately from the other eukaryotic kingdoms, which by one traditional classification include Plantae, Animalia, Protozoa, and Chromista. A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of motility, mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single gro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petrifaction
In geology, petrifaction or petrification () is the process by which organic material becomes a fossil through the replacement of the original material and the filling of the original pore spaces with minerals. Petrified wood typifies this process, but all organisms, from bacteria to vertebrates, can become petrified (although harder, more durable matter such as bone, beaks, and shells survive the process better than softer remains such as muscle tissue, feathers, or skin). Petrifaction takes place through a combination of two similar processes: permineralization and replacement. These processes create replicas of the original specimen that are similar down to the microscopic level. Processes Permineralization One of the processes involved in petrifaction is permineralization. The fossils created through this process tend to contain a large amount of the original material of the specimen. This process occurs when groundwater containing dissolved minerals (most commonly q ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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