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Ronald Wilfred Gurney
Ronald Wilfred (or Wilfrid) Gurney (1898, in Cheltenham, England – 14 April 1953, in New York, New York) was a British theoretical physicist and research pupil of William Lawrence Bragg at the Victoria University of Manchester during the 1920s and 1930s, Bristol University during the 1930s and later in the US, where he died. Radioactive decay processes Whilst at the Palmer Physical Laboratory at Princeton University from 1926 to 1928, he discovered alpha decay via quantum tunnelling, together with Edward Condon and independently of George Gamow. In the early 1900s, radioactive materials were known to have characteristic exponential decay rates or half lives. At the same time, radiation emissions were known to have certain characteristic energies. By 1928, Gamow had solved the theory of the alpha decay of a nucleus via quantum tunnelling and the problem was also solved independently by Gurney and Condon. Books *''Elementary quantum mechanics'', Cambridge ng.The University Press ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cheltenham
Cheltenham (), also known as Cheltenham Spa, is a spa town and borough on the edge of the Cotswolds in the county of Gloucestershire, England. Cheltenham became known as a health and holiday spa town resort, following the discovery of mineral springs in 1716, and claims to be the most complete Regency town in Britain. The town hosts several festivals of culture, often featuring nationally and internationally famous contributors and attendees; they include the Cheltenham Literature Festival, the Cheltenham Jazz Festival, the Cheltenham Science Festival, the Cheltenham Music Festival, the Cheltenham Cricket Festival and the Cheltenham Food & Drink Festival. In steeplechase horse racing, the Gold Cup is the main event of the Cheltenham Festival, held every March. History Cheltenham stands on the small River Chelt, which rises nearby at Dowdeswell and runs through the town on its way to the Severn. It was first recorded in 803, as ''Celtan hom''; the meaning has not been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans Bethe
Hans Albrecht Bethe (; July 2, 1906 – March 6, 2005) was a German-American theoretical physicist who made major contributions to nuclear physics, astrophysics, quantum electrodynamics, and solid-state physics, and who won the 1967 Nobel Prize in Physics for his work on the theory of stellar nucleosynthesis. For most of his career, Bethe was a professor at Cornell University.Available at www.JamesKeckCollectedWorks.or are the class notes taken by one of his students at Cornell from the graduate courses on Nuclear Physics and on Applications of Quantum Mechanics he taught in the spring of 1947. During World War II, he was head of the Theoretical Division at the secret Los Alamos National Laboratory, Los Alamos laboratory that developed the first atomic bombs. There he played a key role in calculating the critical mass of the weapons and developing the theory behind the implosion method used in both the Trinity test and the "Fat Man" weapon dropped on Nagasaki in August ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alumni Of The Victoria University Of Manchester
Alumni (singular: alumnus (masculine) or alumna (feminine)) are former students of a school, college, or university who have either attended or graduated in some fashion from the institution. The feminine plural alumnae is sometimes used for groups of women. The word is Latin and means "one who is being (or has been) nourished". The term is not synonymous with "graduate"; one can be an alumnus without graduating (Burt Reynolds, alumnus but not graduate of Florida State, is an example). The term is sometimes used to refer to a former employee or member of an organization, contributor, or inmate. Etymology The Latin noun ''alumnus'' means "foster son" or "pupil". It is derived from PIE ''*h₂el-'' (grow, nourish), and it is a variant of the Latin verb ''alere'' "to nourish".Merriam-Webster: alumnus .. Separate, but from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academics Of The University Of Bristol
An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary or tertiary higher learning (and generally also research or honorary membership). The name traces back to Plato's school of philosophy, founded approximately 385 BC at Akademia, a sanctuary of Athena, the goddess of wisdom and skill, north of Athens, Greece. Etymology The word comes from the ''Academy'' in ancient Greece, which derives from the Athenian hero, ''Akademos''. Outside the city walls of Athens, the gymnasium was made famous by Plato as a center of learning. The sacred space, dedicated to the goddess of wisdom, Athena, had formerly been an olive grove, hence the expression "the groves of Academe". In these gardens, the philosopher Plato conversed with followers. Plato developed his sessions into a method of teaching philosophy and in 387 BC, established what is known today as the Old Academy. By extension, ''academia'' has come to mean the accumulation, dev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1953 Deaths
Events January * January 6 – The Asian Socialist Conference opens in Rangoon, Burma. * January 12 – Estonian émigrés found a Estonian government-in-exile, government-in-exile in Oslo. * January 14 ** Marshal Josip Broz Tito is chosen President of Socialist Federal Republic of Yugoslavia, Yugoslavia. ** The Central Intelligence Agency, CIA-sponsored Robertson Panel first meets to discuss the Unidentified flying object, UFO phenomenon. * January 15 – Georg Dertinger, foreign minister of East Germany, is arrested for spying. * January 19 – 71.1% of all television sets in the United States are tuned into ''I Love Lucy'', to watch Lucy give birth to Little Ricky, which is more people than those who tune into Dwight Eisenhower's inauguration the next day. This record has yet to be broken. * January 20 – Dwight D. Eisenhower is First inauguration of Dwight D. Eisenhower, sworn in as the 34th President of the United States. * January 24 ** Mau Mau Upr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1898 Births
Events January–March * January 1 – New York City annexes land from surrounding counties, creating the City of Greater New York as the world's second largest. The city is geographically divided into five boroughs: Manhattan, Brooklyn, Queens, The Bronx and Staten Island. * January 13 – Novelist Émile Zola's open letter to the President of the French Republic on the Dreyfus affair, '' J'Accuse…!'', is published on the front page of the Paris daily newspaper ''L'Aurore'', accusing the government of wrongfully imprisoning Alfred Dreyfus and of antisemitism. * February 12 – The automobile belonging to Henry Lindfield of Brighton rolls out of control down a hill in Purley, London, England, and hits a tree; thus he becomes the world's first fatality from an automobile accident on a public highway. * February 15 – Spanish–American War: The USS ''Maine'' explodes and sinks in Havana Harbor, Cuba, for reasons never fully established, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gurney Equations
The Gurney equations are a set of mathematical formulas used in explosives engineering to relate how fast an explosive will accelerate an adjacent layer of metal or other material when the explosive detonates. This determines how fast fragments are released by military explosives, how quickly shaped charge explosives accelerate their liners inwards, and in other calculations such as explosive welding where explosives force two metal sheets together and bond them. The equations were first developed in the 1940s by Ronald Gurney and have been expanded on and added to significantly since that time. The original paper by Gurney analyzed the situation of an exploding shell or bomb, a mass of explosives surrounded by a solid shell. Other researchers have extended similar methods of analysis to other geometries. All of the equations derived based on Gurney's methods are collectively called "Gurney equations". Underlying physics When an explosive adjacent to a layer of a metallic or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mott–Gurney Law
Space charge is an interpretation of a collection of electric charges in which excess electric charge is treated as a continuum of charge distributed over a region of space (either a volume or an area) rather than distinct point-like charges. This model typically applies when charge carriers have been emitted from some region of a solid—the cloud of emitted carriers can form a space charge region if they are sufficiently spread out, or the charged atoms or molecules left behind in the solid can form a space charge region. Space charge only occurs in dielectric media (including vacuum) because in a conductive medium the charge tends to be rapidly neutralized or screened. The sign of the space charge can be either negative or positive. This situation is perhaps most familiar in the area near a metal object when it is heated to incandescence in a vacuum. This effect was first observed by Thomas Edison in light bulb filaments, where it is sometimes called the Edison effect. Space ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nevill Francis Mott
Sir Nevill Francis Mott (30 September 1905 – 8 August 1996) was a British physicist who won the Nobel Prize for Physics in 1977 for his work on the electronic structure of magnetic and disordered systems, especially amorphous semiconductors. The award was shared with Philip W. Anderson and J. H. Van Vleck. The three had conducted loosely related research. Mott and Anderson clarified the reasons why magnetic or amorphous materials can sometimes be metallic and sometimes insulating. Education and early life Mott was born in Leeds to Lilian Mary Reynolds and Charles Francis Mott and grew up first in the village of Giggleswick, in the West Riding of Yorkshire, where his father was Senior Science Master at Giggleswick School. His mother also taught Maths at the School. The family moved (due to his father's jobs) first to Staffordshire, then to Chester and finally Liverpool, where his father had been appointed Director of Education. Mott was at first educated at home by hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jagdish Mehra
Jagdish Mehra (April 8, 1931 – September 14, 2008) was an Indian-American historian of science. Academic career Mehra was educated at Allahabad University, the Max Planck Institut für Physik and the University of California at Los Angeles and obtained a Ph.D. in theoretical physics at the University of Neuchatel. He subsequently taught at Purdue University, Southeastern Massachusetts University, the University of Geneva, the Solvay Institute in Brussels, Rice University, the University of Houston and the International Center for Theoretical Physics. He is particularly well known for a book in 6 volumes on The Historical Development of Quantum Theory,Mehra, J. and Rechenberg, H. The Historical Development of Quantum Theory, Volumes 1-6. New York: Springer-Verlag which he wrote with Helmut Rechenberg. He also wrote a biography of Richard Feynman. He also wrote a book on the controversy surrounding the exact role David Hilbert played in the development of the gravitation the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exponential Decay
A quantity is subject to exponential decay if it decreases at a rate proportional to its current value. Symbolically, this process can be expressed by the following differential equation, where is the quantity and (lambda) is a positive rate called the exponential decay constant, disintegration constant, rate constant, or transformation constant: :\frac = -\lambda N. The solution to this equation (see derivation below) is: :N(t) = N_0 e^, where is the quantity at time , is the initial quantity, that is, the quantity at time . Measuring rates of decay Mean lifetime If the decaying quantity, ''N''(''t''), is the number of discrete elements in a certain set, it is possible to compute the average length of time that an element remains in the set. This is called the mean lifetime (or simply the lifetime), where the exponential time constant, \tau, relates to the decay rate constant, λ, in the following way: :\tau = \frac. The mean lifetime can be looked at as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theoretical Physicist
Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena. This is in contrast to experimental physics, which uses experimental tools to probe these phenomena. The advancement of science generally depends on the interplay between experimental studies and theory. In some cases, theoretical physics adheres to standards of mathematical rigour while giving little weight to experiments and observations.There is some debate as to whether or not theoretical physics uses mathematics to build intuition and illustrativeness to extract physical insight (especially when normal experience fails), rather than as a tool in formalizing theories. This links to the question of it using mathematics in a less formally rigorous, and more intuitive or heuristic way than, say, mathematical physics. For example, while developing special relativity, Albert Einstein was concerned with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
