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Kenneth L. Nordtvedt
Kenneth Leon Nordtvedt is an American physicist. He was born on April 16, 1939, in Chicago, Illinois. Nordtvedt graduated from the Massachusetts Institute of Technology (1960) and Stanford University (Ph.D., 1964) and was a junior fellow in the Harvard Society of Fellows (1963–1965). Soon after witnessing the Sputnik spacecraft cross the Boston sky in fall of 1957, he became a part-time student employee for the Mars Probe project at the MIT Instrumentation Lab, and in early 1960s was staff physicist at the same Laboratory's project to develop the Apollo Mission's navigation and guidance system. Works Theories of gravity In 1968 Nordtvedt calculated how and to what degree the gravitational-to-inertial mass ratio of gravitationally compact bodies—bodies with significant gravitational binding energy—will generally differ from one in gravity theories other than general relativity, and he then showed how lunar laser ranging data could be used to measure that key ratio to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chicago, Illinois
(''City in a Garden''); I Will , image_map = , map_caption = Interactive Map of Chicago , coordinates = , coordinates_footnotes = , subdivision_type = Country , subdivision_name = United States , subdivision_type1 = State , subdivision_type2 = Counties , subdivision_name1 = Illinois , subdivision_name2 = Cook and DuPage , established_title = Settled , established_date = , established_title2 = Incorporated (city) , established_date2 = , founder = Jean Baptiste Point du Sable , government_type = Mayor–council , governing_body = Chicago City Council , leader_title = Mayor , leader_name = Lori Lightfoot ( D) , leader_title1 = City Clerk , leader_name1 = Anna Valencia ( D) , unit_pref = Imperial , area_footnotes = , ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montana State Legislature
The Montana State Legislature is the state legislature of the U.S. state of Montana. It is composed of the 100-member Montana House of Representatives and the 50-member Montana Senate. The Montana Constitution dictates that the legislature meet in regular session for no longer than 90 days in each odd-numbered year. The primary work of the legislature is to pass a balanced biennial budget which must then be approved by the governor. If the governor vetoes a bill, the legislature may override the veto by a two-thirds vote. Since the beginning of statehood for Montana, the Legislature has been split along party lines fairly consistently and evenly. Since adoption of the current state constitution in 1972, which mandated single-member legislative districts for the first time in the state's history, the Montana Senate has been controlled by Democrats in 9 sessions and Republicans in 16 sessions. During the same period, the Montana House has been controlled by Democrats in 8 sessi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fellows Of The American Physical Society
The American Physical Society honors members with the designation ''Fellow'' for having made significant accomplishments to the field of physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which .... The following lists are divided chronologically by the year of designation. * List of American Physical Society Fellows (1921–1971) * List of American Physical Society Fellows (1972–1997) * List of American Physical Society Fellows (1998–2010) * List of American Physical Society Fellows (2011–) References {{reflist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Relativity Theorists
American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, people who self-identify their ancestry as "American" ** American English, the set of varieties of the English language native to the United States ** Native Americans in the United States, indigenous peoples of the United States * American, something of, from, or related to the Americas, also known as "America" ** Indigenous peoples of the Americas * American (word), for analysis and history of the meanings in various contexts Organizations * American Airlines, U.S.-based airline headquartered in Fort Worth, Texas * American Athletic Conference, an American college athletic conference * American Recordings (record label), a record label previously known as Def American * American University, in Washington, D.C. Sports teams Soccer * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Geneticists
American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, people who self-identify their ancestry as "American" ** American English, the set of varieties of the English language native to the United States ** Native Americans in the United States, indigenous peoples of the United States * American, something of, from, or related to the Americas, also known as "America" ** Indigenous peoples of the Americas * American (word), for analysis and history of the meanings in various contexts Organizations * American Airlines, U.S.-based airline headquartered in Fort Worth, Texas * American Athletic Conference, an American college athletic conference * American Recordings (record label), a record label previously known as Def American * American University, in Washington, D.C. Sports teams Soccer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
21st-century American Physicists
The 1st century was the century spanning AD 1 ( I) through AD 100 ( C) according to the Julian calendar. It is often written as the or to distinguish it from the 1st century BC (or BCE) which preceded it. The 1st century is considered part of the Classical era, epoch, or historical period. The 1st century also saw the appearance of Christianity. During this period, Europe, North Africa and the Near East fell under increasing domination by the Roman Empire, which continued expanding, most notably conquering Britain under the emperor Claudius (AD 43). The reforms introduced by Augustus during his long reign stabilized the empire after the turmoil of the previous century's civil wars. Later in the century the Julio-Claudian dynasty, which had been founded by Augustus, came to an end with the suicide of Nero in AD 68. There followed the famous Year of Four Emperors, a brief period of civil war and instability, which was finally brought to an end by Vespasian, ninth Roman emper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1939 Births
This year also marks the start of the Second World War, the largest and deadliest conflict in human history. Events Below, the events of World War II have the "WWII" prefix. January * January 1 ** Third Reich *** Jews are forbidden to work with Germans. *** The Youth Protection Act was passed on April 30, 1938 and the Working Hours Regulations came into effect. *** The Jews name change decree has gone into effect. ** The rest of the world *** In Spain, it becomes a duty of all young women under 25 to complete compulsory work service for one year. *** First edition of the Vienna New Year's Concert. *** The company of technology and manufacturing scientific instruments Hewlett-Packard, was founded in a garage in Palo Alto, California, by William (Bill) Hewlett and David Packard. This garage is now considered the birthplace of Silicon Valley. *** Sydney, in Australia, records temperature of 45 ˚C, the highest record for the city. *** Philipp Etter took over as Swiss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scalar–tensor Theory
In theoretical physics, a scalar–tensor theory is a field theory that includes both a scalar field and a tensor field to represent a certain interaction. For example, the Brans–Dicke theory of gravitation uses both a scalar field and a tensor field to mediate the gravitational interaction. Tensor fields and field theory Modern physics tries to derive all physical theories from as few principles as possible. In this way, Newtonian mechanics as well as quantum mechanics are derived from Hamilton's ''principle of least action''. In this approach, the behavior of a system is not described via forces, but by functions which describe the energy of the system. Most important are the energetic quantities known as the Hamiltonian function and the Lagrangian function. Their derivatives in space are known as Hamiltonian density and the Lagrangian density. Going to these quantities leads to the field theories. Modern physics uses field theories to explain reality. These fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parameterized Post-Newtonian Formalism
In physics, precisely in the study of the theory of general relativity and many alternatives to it, the post-Newtonian formalism is a calculational tool that expresses Einstein's (nonlinear) equations of gravity in terms of the lowest-order deviations from Newton's law of universal gravitation. This allows approximations to Einstein's equations to be made in the case of weak fields. Higher-order terms can be added to increase accuracy, but for strong fields, it may be preferable to solve the complete equations numerically. Some of these post-Newtonian approximations are expansions in a small parameter, which is the ratio of the velocity of the matter forming the gravitational field to the speed of light, which in this case is better called the speed of gravity. In the limit, when the fundamental speed of gravity becomes infinite, the post-Newtonian expansion reduces to Newton's law of gravity. The parameterized post-Newtonian formalism or PPN formalism, is a version of this formu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nordtvedt Effect
In theoretical astrophysics, the Nordtvedt effect refers to the relative motion between the Earth and the Moon that would be observed if the gravitational self-energy of a body contributed differently to its gravitational mass than to its inertial mass. If observed, the Nordtvedt effect would violate the strong equivalence principle, which indicates that an object's movement in a gravitational field does not depend on its mass or composition. No evidence of the effect has been found. The effect is named after Kenneth L. Nordtvedt, who first demonstrated that some theories of gravity suggest that massive bodies should fall at different rates, depending upon their gravitational self-energy. Nordtvedt then observed that if gravity did in fact violate the strong equivalence principle, then the more-massive Earth should fall towards the Sun at a slightly different rate than the Moon, resulting in a polarization of the lunar orbit. To test for the existence (or absence) of the Nord ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galileo's Leaning Tower Of Pisa Experiment
Between 1589 and 1592, the Italian scientist Galileo Galilei (then professor of mathematics at the University of Pisa) is said to have dropped two spheres of different masses from the Leaning Tower of Pisa to demonstrate that their time of descent was independent of their mass, according to a biography by Galileo's pupil Vincenzo Viviani, composed in 1654 and published in 1717. The basic premise had already been demonstrated by Italian experimenters a few decades earlier. According to the story, Galileo discovered through this experiment that the objects fell with the same acceleration, proving his prediction true, while at the same time disproving Aristotle's theory of gravity (which states that objects fall at speed proportional to their mass). Most historians consider it to have been a thought experiment rather than a physical test. Background The 6th-century Byzantine Greek philosopher and Aristotelian commentator John Philoponus argued that the Aristotelian assertion that o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternatives To General Relativity
Founded in 1994, Alternatives, Action and Communication Network for International Development, is a non-governmental, international solidarity organization based in Montreal, Quebec, Canada. Alternatives works to promote justice and equality amongst individuals and communities worldwide. Active in over 35 countries, Alternatives supports local, community-based initiatives working towards the greater economic, social, and political rights of people and communities affected by poverty, discrimination, exploitation, and violence. The organization publishes the ''Le Journal des Alternatives'' newsletter, a publication inserted every three months in Montreal's French paper ''Le Voir''. Alternatives also publishes the ''Alternatives International Journal'', a monthly publication in English distributed electronically. Alternatives Montreal is the headquarters of an International Federation consisting of nine NGOs spread across the world. Alternative-Niger, Alternatives Asia (New Del ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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