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Mauri Valtonen
Mauri Valtonen (born 1945) is a Finnish astronomer and professor at the University of Turku. His fields of scientific interest include active galaxies, cosmology, and the three-body problem. Valtonen completed a Ph.D. from Cambridge University in 1975. He served as Director of Tuorla Observatory from 1980 to 2002 and returned to this position again in 2007. In 2008, Valtonen led a research team which argued that delay in the periodic outbursts from the nucleus of the active galaxy OJ 287 confirmed Albert Einstein's general theory of relativity General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the differential geometry, geometric scientific theory, theory of gravitation published by Albert Einstein in 1915 and is the current descr ....M. Valtonen et al. (2008) A massive binary black-hole system in OJ 287 and a test of general relativity ''Nature'', 452, 851-853 References Books by Mauri Valtonen *Valtonen, M. & Kartt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Finland
Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland across Estonia to the south. Finland covers an area of with a population of 5.6 million. Helsinki is the capital and largest city, forming a larger metropolitan area with the neighbouring cities of Espoo, Kauniainen, and Vantaa. The vast majority of the population are ethnic Finns. Finnish, alongside Swedish, are the official languages. Swedish is the native language of 5.2% of the population. Finland's climate varies from humid continental in the south to the boreal in the north. The land cover is primarily a boreal forest biome, with more than 180,000 recorded lakes. Finland was first inhabited around 9000 BC after the Last Glacial Period. The Stone Age introduced several differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomer
An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, galaxies – in either observational astronomy, observational (by analyzing the data) or theoretical astronomy. Examples of topics or fields astronomers study include planetary science, Sun, solar astronomy, the Star formation, origin or stellar evolution, evolution of stars, or the galaxy formation and evolution, formation of galaxies. A related but distinct subject is physical cosmology, which studies the Universe as a whole. Types Astronomers usually fall under either of two main types: observational astronomy, observational and theoretical astronomy, theoretical. Observational astronomers make direct observations of Astronomical object, celestial objects and analyze the data. In contrast, theoretical astronomers create and investigate C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Turku
sv, Åbo universitet , latin_name = Universitas Aboensis , image_name = University of Turku.svg , motto = ''Vapaan kansan lahja vapaalle tieteelle'' , established = 1920 , type = Public University , endowment = , administrative_staff = 3,412 , rector = Jukka Kola , students = 20,768 , undergrad = 8,247 , postgrad = 6,244 , doctoral = 1,984 , city = Turku , country = Finland , campus = Urban , free_label = , free = , colors = , colours = , mascot = , affiliations = Coimbra Group, UArctic , website Official Website (in English) , motto_lang = fin , mottoeng = The gift of a free nation to free science ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Galaxies
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
