|
Timeline Of United States Discoveries
Timeline of United States discoveries encompasses the breakthroughs of human thought and knowledge of new scientific findings, phenomena, places, things, and what was previously unknown to exist. From a historical stand point, the timeline below of United States discoveries dates from the 18th century to the current 21st century, which have been achieved by discoverers who are either native-born or naturalized citizens of the United States. With an emphasis of discoveries in the fields of astronomy, physics, chemistry, medicine, biology, geology, paleontology, and archaeology, United States citizens acclaimed in their professions have contributed much. For example, the "Bone Wars," beginning in 1877 and ending in 1892, was an intense period of rivalry between two American paleontologists, Edward Drinker Cope and Othniel Charles Marsh, who initiated several expeditions throughout North America in the pursuit of discovering, identifying, and finding new species of dinosaur fossils ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Othniel Charles Marsh & Edward Drinker Cope Bw
Othniel (; he, עָתְנִיאֵל בֶּן קְנַז, ''ʿOṯnīʾēl ben Qenaz'') was the first of the biblical judges. The etymology of his name is uncertain, but may mean "God/He is my strength" or "God has helped me". Family The Hebrew Bible refers to Othniel as "Othniel the son of Kenaz, the brother of Caleb". The expression is inconclusive in Hebrew, and has been taken to mean either that Othniel himself was the brother of Caleb, or that Othniel's father Kenaz was the brother of Caleb. The Talmud argues that Othniel was Caleb's brother. When Caleb promises the hand of his daughter Achsah to whoever conquers the land of Debir, it is Othniel who rises to the challenge, thus becoming Caleb's son-in-law. Campaign as a Judge The historical reality of events described in the Book of Judges is the subject of ongoing dispute among scholars, who vary in their opinions about how much of the book is historical. As to the story of Othniel in particular, biblical scholar Marc Z ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar System" and "solar system" structures in theinaming guidelines document. The name is commonly rendered in lower case ('solar system'), as, for example, in the ''Oxford English Dictionary'' an''Merriam-Webster's 11th Collegiate Dictionary''. is the gravity, gravitationally bound system of the Sun and the objects that orbit it. It Formation and evolution of the Solar System, formed 4.6 billion years ago from the gravitational collapse of a giant interstellar molecular cloud. The solar mass, vast majority (99.86%) of the system's mass is in the Sun, with most of the Jupiter mass, remaining mass contained in the planet Jupiter. The four inner Solar System, inner system planets—Mercury (planet), Mercury, Venus, Earth and Mars—are terrest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johnston Atoll
Johnston Atoll is an Unincorporated territories of the United States, unincorporated territory of the United States, currently administered by the United States Fish and Wildlife Service (USFWS). Johnston Atoll is a National Wildlife Refuge and part of the Pacific Remote Islands Marine National Monument. It is closed to public entry, and limited access for management needs is only granted by Letter of Authorization from the United States Air Force and a Special Use Permit from the U.S. Fish and Wildlife Service. For nearly 70 years, the isolated atoll was under the control of the United States Armed Forces, U.S. military. During that time, it was variously used as a naval refueling depot, an Johnston Island Air Force Base, airbase, a testing site for nuclear and biological weapons, a secret missile base, and a site for the storage and disposal of chemical weapons and Agent Orange. Those activities left the area environmentally contaminated, and monitoring continues. The island i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benjamin Franklin
Benjamin Franklin ( April 17, 1790) was an American polymath who was active as a writer, scientist, inventor, statesman, diplomat, printer, publisher, and political philosopher. Encyclopædia Britannica, Wood, 2021 Among the leading intellectuals of his time, Franklin was one of the Founding Fathers of the United States, a drafter and signer of the United States Declaration of Independence, and the first United States Postmaster General. As a scientist, he was a major figure in the American Enlightenment and the history of physics for his studies of electricity, and for charting and naming the current still known as the Gulf Stream. As an inventor, he is known for the lightning rod, bifocals, and the Franklin stove, among others. He founded many civic organizations, including the Library Company, Philadelphia's first fire department, and the University of Pennsylvania. Isaacson, 2004, p. Franklin earned the title of "The First American" for his early and indefa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conserved Quantity
In mathematics, a conserved quantity of a dynamical system is a function of the dependent variables, the value of which remains constant along each trajectory of the system. Not all systems have conserved quantities, and conserved quantities are not unique, since one can always produce another such quantity by applying a suitable function, such as adding a constant, to a conserved quantity. Since many laws of physics express some kind of conservation, conserved quantities commonly exist in mathematical models of physical systems. For example, any classical mechanics model will have mechanical energy as a conserved quantity as long as the forces involved are conservative. Differential equations For a first order system of differential equations :\frac = \mathbf f(\mathbf r, t) where bold indicates vector quantities, a scalar-valued function ''H''(r) is a conserved quantity of the system if, for all time and initial conditions in some specific domain, :\frac = 0 Note that by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negative Charge
Electric charge is the physical property of matter that causes charged matter to experience a force when placed in an electromagnetic field. Electric charge can be ''positive'' or ''negative'' (commonly carried by protons and electrons respectively). Like charges repel each other and unlike charges attract each other. An object with an absence of net charge is referred to as neutral. Early knowledge of how charged substances interact is now called classical electrodynamics, and is still accurate for problems that do not require consideration of quantum effects. Electric charge is a conserved property; the net charge of an isolated system, the amount of positive charge minus the amount of negative charge, cannot change. Electric charge is carried by subatomic particles. In ordinary matter, negative charge is carried by electrons, and positive charge is carried by the protons in the nuclei of atoms. If there are more electrons than protons in a piece of matter, it will have a neg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positive Charge
Electric charge is the physical property of matter that causes charged matter to experience a force when placed in an electromagnetic field. Electric charge can be ''positive'' or ''negative'' (commonly carried by protons and electrons respectively). Like charges repel each other and unlike charges attract each other. An object with an absence of net charge is referred to as neutral. Early knowledge of how charged substances interact is now called classical electrodynamics, and is still accurate for problems that do not require consideration of quantum effects. Electric charge is a conserved property; the net charge of an isolated system, the amount of positive charge minus the amount of negative charge, cannot change. Electric charge is carried by subatomic particles. In ordinary matter, negative charge is carried by electrons, and positive charge is carried by the protons in the nuclei of atoms. If there are more electrons than protons in a piece of matter, it will have a neg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Charge
Electric charge is the physical property of matter that causes charged matter to experience a force when placed in an electromagnetic field. Electric charge can be ''positive'' or ''negative'' (commonly carried by protons and electrons respectively). Like charges repel each other and unlike charges attract each other. An object with an absence of net charge is referred to as neutral. Early knowledge of how charged substances interact is now called classical electrodynamics, and is still accurate for problems that do not require consideration of quantum effects. Electric charge is a conserved property; the net charge of an isolated system, the amount of positive charge minus the amount of negative charge, cannot change. Electric charge is carried by subatomic particles. In ordinary matter, negative charge is carried by electrons, and positive charge is carried by the protons in the nuclei of atoms. If there are more electrons than protons in a piece of matter, it will have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charge Conservation
In physics, charge conservation is the principle that the total electric charge in an isolated system never changes. The net quantity of electric charge, the amount of positive charge minus the amount of negative charge in the universe, is always '' conserved''. Charge conservation, considered as a physical conservation law, implies that the change in the amount of electric charge in any volume of space is exactly equal to the amount of charge flowing into the volume minus the amount of charge flowing out of the volume. In essence, charge conservation is an accounting relationship between the amount of charge in a region and the flow of charge into and out of that region, given by a continuity equation between charge density \rho(\mathbf) and current density \mathbf(\mathbf). This does not mean that individual positive and negative charges cannot be created or destroyed. Electric charge is carried by subatomic particles such as electrons and protons. Charged particles can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar And Planetary Laboratory
The Lunar and Planetary Laboratory (LPL) is a research center for planetary science located in Tucson, Arizona. It is also a graduate school, constituting the Department of Planetary Sciences at the University of Arizona. LPL is one of the world's largest programs dedicated exclusively to planetary science in a university setting. The Lunar and Planetary Lab collection is held at the University of Arizona Special Collections Library. Background LPL was founded in 1960 by astronomer Gerard Kuiper. Kuiper had long been a pioneer in observing the Solar System, especially the Moon, at a time when this was unfashionable among astronomers. Among his contributions are the discovery of Miranda and Nereid, the detection of carbon dioxide on Mars and of methane on Titan, and the prediction of the Kuiper Belt. Kuiper came to Tucson looking for greater independence than he had enjoyed at the University of Chicago, the chance to build a community dedicated to solar system studies, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Arizona
The University of Arizona (Arizona, U of A, UArizona, or UA) is a public land-grant research university in Tucson, Arizona. Founded in 1885 by the 13th Arizona Territorial Legislature, it was the first university in the Arizona Territory. The university is part of the Association of American Universities and the Universities Research Association. In the former, it is the only member from the state of Arizona. The university is classified among "R1: Doctoral Universities – Very High Research Activity". The University of Arizona is one of three universities governed by the Arizona Board of Regents. , the university enrolled 49,471 students in 19 separate colleges/schools, including the University of Arizona College of Medicine in Tucson and Phoenix and the James E. Rogers College of Law, and is affiliated with two academic medical centers ( Banner – University Medical Center Tucson and Banner – University Medical Center Phoenix). In 2021, University of Arizona acquired ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peter Smith (physicist)
Peter H. Smith is a Professor Emeritus (he retired in 2013) at the Lunar and Planetary Laboratory of the University of Arizona, where he holds the inaugural Thomas R. Brown Distinguished Chair in Integrative Science. He is also the principal investigator for the $420 million robotic explorer Phoenix which landed at the north pole of the planet Mars on May 25, 2008. Peter H. Smith's papers are held at the University of Arizona Special Collections Library. Early life and education Peter H. Smith was born December 2, 1947 in New York and was raised in Tucson, Arizona. Smith's father was Hugh H. Smith, a virologist who was part of the team at the Rockefeller Foundation who developed a vaccine for yellow fever in 1930's. After his retirement from the Rockefeller Foundation, Hugh H. Smith worked at the University of Arizona and founded the Tucson Society of Tropical Medicine. Smith's mother was an opera singer. Smith went to Tucson High School and received his bachelor's degree in p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> University Of Arizona")