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Galactic Habitable Zone
In astrobiology and planetary astrophysics, the galactic habitable zone is the region of a galaxy in which life might most likely develop. The concept of a galactic habitable zone analyzes various factors, such as metallicity (the presence of elements heavier than hydrogen and helium) and the rate and density of major catastrophes such as supernovae, and uses these to calculate which regions of a galaxy are more likely to form terrestrial planets, initially develop simple life, and provide a suitable environment for this life to evolve and advance. According to research published in August 2015, very large galaxies may favor the birth and development of habitable planets more than smaller galaxies such as the Milky Way. In the case of the Milky Way, its galactic habitable zone is commonly believed to be an annulus (chubby ring) with an outer radius of about and an inner radius close to the Galactic Center (with both radii lacking hard boundaries). Galactic habitable-zone theory h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrobiology
Astrobiology, and the related field of exobiology, is an interdisciplinary scientific field that studies the origins, early evolution, distribution, and future of life in the universe. Astrobiology is the multidisciplinary field that investigates the deterministic conditions and contingent events with which life arises, distributes, and evolves in the universe. Astrobiology makes use of molecular biology, biophysics, biochemistry, chemistry, astronomy, physical cosmology, exoplanetology, geology, paleontology, and ichnology to investigate the possibility of life on other worlds and help recognize biospheres that might be different from that on Earth. The origin and early evolution of life is an inseparable part of the discipline of astrobiology. Astrobiology concerns itself with interpretation of existing scientific data, and although speculation is entertained to give context, astrobiology concerns itself primarily with hypotheses that fit firmly into existing scientific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harlow Shapley
Harlow Shapley (November 2, 1885 – October 20, 1972) was an American scientist, head of the Harvard College Observatory (1921–1952), and political activist during the latter New Deal and Fair Deal. Shapley used Cepheid variable stars to estimate the size of the Milky Way Galaxy and the Sun's position within it by using parallax.Bart J. Bok. Harlow Shapely 1885–1972 A Biographical Memoir. National Academy of Sciences In 1953 he proposed his "liquid water belt" theory, now known as the concept of a habitable zone.Richard J. Hugget, ''uGeoecology: an evolutionary approach''. p. 10 Background Shapley was born on a farm five miles outside Nashville, Missouri, to Willis and Sarah (née Stowell) Shapley. He went to school in Jasper, Missouri, but not beyond elementary school. He worked as a journalist after studying at home and covering crime stories as a newspaper reporter for the ''Daily Sun'' in Chanute, Kansas, and intermittently for the ''Times'' of Joplin, Missouri. In Chanu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Washington
The University of Washington (UW, simply Washington, or informally U-Dub) is a public research university in Seattle, Washington. Founded in 1861, Washington is one of the oldest universities on the West Coast; it was established in Seattle approximately a decade after the city's founding. The university has a 703 acre main campus located in the city's University District, as well as campuses in Tacoma and Bothell. Overall, UW encompasses over 500 buildings and over 20 million gross square footage of space, including one of the largest library systems in the world with more than 26 university libraries, art centers, museums, laboratories, lecture halls, and stadiums. The university offers degrees through 140 departments, and functions on a quarter system. Washington is the flagship institution of the six public universities in Washington state. It is known for its medical, engineering, and scientific research. Washington is a member of the Association of American Universiti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guillermo Gonzalez (astronomer)
Guillermo Gonzalez (born 1963) is an astronomer, a proponent of the pseudoscientific principle of intelligent design, and a research scientist at the University of Alabama-Huntsville. He is a senior fellow of the Discovery Institute's Center for Science and Culture, considered the hub of the intelligent design movement, and a fellow with the International Society for Complexity, Information and Design, which also promotes intelligent design. Education, work and academics Gonzalez obtained a BS in 1987 in physics and astronomy from University of Arizona and his Ph.D. in astronomy from the University of Washington in 1993. He has done post-doctoral work at the University of Texas, Austin and the University of Washington. He has received fellowships, grants and awards from NASA, the University of Washington, Sigma Xi, and the National Science Foundation. He supports the Galactic habitable zone concept, which was coined in 1986 by L.S. Marochnik and L.M. Mukhin, who defined the zone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Why Complex Life Is Uncommon In The Universe
Why may refer to: * Causality, a consequential relationship between two events * Reason (argument), a premise in support of an argument, for what reason or purpose * Grounding (metaphysics), a topic in metaphysics regarding how things exist in virtue of more fundamental things. * Why?, one of the Five Ws used in journalism Music Artists * Why? (American band), a hip hop/indie rock band formed in Oakland, California, in 2004 ** Yoni Wolf, formerly known by the stage name Why? * Why (Canadian band), a rock band formed in Winnipeg, Manitoba, in 1993 * Why?, a 1990s UK folk band, two members of which formed Quench in 2001 Albums * ''Why'' (Baby V.O.X album) or the title song, 2000 * ''Why?'' (Ginger Baker album) or the title song, 2014 * ''Why'' (Prudence Liew album) or the title song, 1987 * ''Why?'' (They Might Be Giants album), 2015 * ''Why?'', by Jacob Whitesides, 2016 * ''Why'', by Moahni Moahna, 1996 * ''Why?'', by the MonaLisa Twins, 2022 EPs * ''Why'' (Discharge EP) o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metazoan
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a Symmetry in biology#Bilateral symmetry, bilat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peter Ward (paleontologist)
Peter Douglas Ward (born 1949) is an American paleontologist and professor at the University of Washington, Seattle, and Sprigg Institute of Geobiology at the University of Adelaide. He has written numerous popular science works for a general audience and is also an adviser to the Microbes Mind Forum. In 2000, along with his co-author Donald E. Brownlee, he co-originated the term '' Rare Earth'' and developed the Medea hypothesis alleging that multicellular life is ultimately self-destructive. Life and work His parents, Joseph and Ruth Ward, moved to Seattle following World War II. Ward grew up in the Seward Park neighborhood of Seattle, attending Franklin High School, and he spent time during summers at a family summer cabin on Orcas Island. Ward's academic career has included teaching posts and professional connections with Ohio State University, the NASA Astrobiology Institute, the University of California, McMaster University (where he received his PhD in 1976), and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Donald E
Donald is a masculine given name derived from the Gaelic name ''Dòmhnall''.. This comes from the Proto-Celtic *''Dumno-ualos'' ("world-ruler" or "world-wielder"). The final -''d'' in ''Donald'' is partly derived from a misinterpretation of the Gaelic pronunciation by English speakers, and partly associated with the spelling of similar-sounding Germanic names, such as ''Ronald''. A short form of ''Donald'' is ''Don''. Pet forms of ''Donald'' include ''Donnie'' and ''Donny''. The feminine given name ''Donella'' is derived from ''Donald''. ''Donald'' has cognates in other Celtic languages: Modern Irish ''Dónal'' (anglicised as ''Donal'' and ''Donall'');. Scottish Gaelic ''Dòmhnall'', ''Domhnull'' and ''Dòmhnull''; Welsh '' Dyfnwal'' and Cumbric ''Dumnagual''. Although the feminine given name ''Donna'' is sometimes used as a feminine form of ''Donald'', the names are not etymologically related. Variations Kings and noblemen Domnall or Domhnall is the name of many ancie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Russian Space Research Institute
The Russian Space Research Institute (russian: Институт космических исследований Российской академии наук, Space Research Institute of the Russian Academy of Sciences, SRI RAS, Russian abbreviation: ИКИ РАН, IKI RAN) is the leading organization of the Russian Academy of Sciences on space exploration to benefit fundamental science. It was formerly known as the Space Research Institute of the USSR Academy of Sciences (Russian abbr.: ИКИ АН СССР, IKI AN SSSR). It is usually known by the shorter name Space Research Institute and especially by the initialism IKI. The institute is located in Moscow with a staff of 289 scientists. It conducts scientific research in the fields of astrophysics, planetary science, solar physics, Sun-Earth relations, cosmic plasma, and geophysics. IKI also develops and tests space technologies in collaboration with the Russian Academy of Sciences and the Federal Space Agency. History I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wallace Hampton Tucker
Wallace Hampton Tucker is an American astrophysicist who specializes in high-energy astrophysics, an award-winning playwright, and an active environmentalist. Early life Tucker was born in McAlester, Oklahoma. He’s a part of the Choctaw tribe. He attended and graduated from McAlester High School where he met his future wife, Karen. Shortly after their graduation, they eloped. Education Tucker attended the University of Oklahoma and where he earned his bachelor's degree in mathematics and Master's in physics. He continued his education from there and received his Ph.D. in physics from the University of California, San Diego in 1966.Geiogamah, Hanay, & Darby, Jaye T. (1999). ''Stories of Our Ways: An Anthology of American Indian Plays''. Regents of the University of California. He has been active in environmental work, helping to found and lead two nonprofit organizations in Southern California: the Fallbrook Land Conservancy (FLC) and the San Diego Land Conservation Coalition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Galactic Nucleus
An active galactic nucleus (AGN) is a compact region at the center of a galaxy that has a much-higher-than-normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not produced by stars. Such excess non-stellar emission has been observed in the radio, microwave, infrared, optical, ultra-violet, X-ray and gamma ray wavebands. A galaxy hosting an AGN is called an "active galaxy". The non-stellar radiation from an AGN is theorized to result from the accretion of matter by a supermassive black hole at the center of its host galaxy. Active galactic nuclei are the most luminous persistent sources of electromagnetic radiation in the universe, and as such can be used as a means of discovering distant objects; their evolution as a function of cosmic time also puts constraints on models of the cosmos. The observed characteristics of an AGN depend on several properties such as the mass of the central black hole, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seyfert Galaxy
Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei (very luminous, distant and bright sources of electromagnetic radiation) with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, their host galaxies are clearly detectable. Seyfert galaxies account for about 10% of all galaxies and are some of the most intensely studied objects in astronomy, as they are thought to be powered by the same phenomena that occur in quasars, although they are closer and less luminous than quasars. These galaxies have supermassive black holes at their centers which are surrounded by accretion discs of in-falling material. The accretion discs are believed to be the source of the observed ultraviolet radiation. Ultraviolet emission and absorption lines provide the best diagnostics for the composition of the surrounding material. Seen in visible light, most Seyfert galaxies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
