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Hilbrand J. Groenewold
Hilbrand Johannes "Hip" Groenewold (1910–1996) was a Dutch theoretical physicist who pioneered the largely operator-free formulation of quantum mechanics in phase space known as phase space formulation, phase-space quantization. Biography Groenewold was born on 29 June 1910 in Muntendam in the province of Groningen (province), Groningen. He graduated from the University of Groningen, with a major in physics and minors in mathematics and mechanics in 1934. After a visit to Cambridge to interact with John von Neumann (1934–5) on the links between classical and quantum mechanics, and a checkered career working with Frits Zernike in Groningen, then Leiden, the Hague, De Bilt, and several addresses in the North of the Netherlands during World War II, he earned his Ph.D. degree in 1946, under the tutelage of Léon Rosenfeld at Utrecht University. In 1951, he obtained a position in Groningen in theoretical physics, first as a lecturer, then as a senior lecturer, and finally as a pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muntendam
Muntendam is a village in the municipality of Midden-Groningen, in the Dutch province of Groningen. Until 1990 it was a separate municipality, which boasted the title 'reddest (most socialist) municipality in the Netherlands', with a council of 11 containing 7 PvdA (Labour Party) members and 2 CPN (Communist Party) members. (However, nearby Reiderland had had a vast CPN majority since WWII, so the claim is rather too strong). When a new mayor had to be appointed in 1980 (at the time a municipality had no say in the matter), it was assumed that it would become a PvdA mayor as it had always been. However, the then minister of the interior, Hans Wiegel of the right-wing VVD, decided that this very left-wing part of the Netherlands needed a change and appointed a D66 (left of centre) mayor. This led to a cold reception and the first time a Dutch Dutch commonly refers to: * Something of, from, or related to the Netherlands * Dutch people () * Dutch language () Dutch may also refe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Utrecht University
Utrecht University (UU; nl, Universiteit Utrecht, formerly ''Rijksuniversiteit Utrecht'') is a public research university in Utrecht, Netherlands. Established , it is one of the oldest universities in the Netherlands. In 2018, it had an enrollment of 31,801 students, and employed 7,191 faculty and staff. In 2018, 525 PhD degrees were awarded and 6,948 scientific articles were published. The 2018 budget of the university was €857 million. Utrecht University counts a number of distinguished scholars among its alumni and faculty, including 12 Nobel Prize laureates and 13 Spinoza Prize laureates. Utrecht University has been placed consistently in the top 100 universities in the world by prominent international ranking tables. The university is ranked as the best university in the Netherlands by the Shanghai Ranking of World Universities 2022, ranked 14th in Europe and 54th in the world. The university's motto is "Sol Iustitiae Illustra Nos", which means ''May the Sun of Righteous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1910 Births
Year 191 ( CXCI) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Apronianus and Bradua (or, less frequently, year 944 ''Ab urbe condita''). The denomination 191 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Parthia * King Vologases IV of Parthia dies after a 44-year reign, and is succeeded by his son Vologases V. China * A coalition of Chinese warlords from the east of Hangu Pass launches a punitive campaign against the warlord Dong Zhuo, who seized control of the central government in 189, and held the figurehead Emperor Xian hostage. After suffering some defeats against the coalition forces, Dong Zhuo forcefully relocates the imperial capital from Luoyang to Chang'an. Before leaving, Dong Zhuo orders his troops to loot the tombs of the Ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Catastrophic Risk
A global catastrophic risk or a doomsday scenario is a hypothetical future event that could damage human well-being on a global scale, even endangering or destroying modern civilization. An event that could cause human extinction or permanently and drastically curtail humanity's potential is known as an "existential risk." Over the last two decades, a number of academic and non-profit organizations have been established to research global catastrophic and existential risks, formulate potential mitigation measures and either advocate for or implement these measures. Definition and classification Defining global catastrophic risks The term global catastrophic risk "lacks a sharp definition", and generally refers (loosely) to a risk that could inflict "serious damage to human well-being on a global scale". Humanity has suffered large catastrophes before. Some of these have caused serious damage but were only local in scope—e.g. the Black Death may have resulted in the de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Existential Risk And The Future Of Humanity
Existentialism ( ) is a form of philosophical inquiry that explores the problem of human existence and centers on human thinking, feeling, and acting. Existentialist thinkers frequently explore issues related to the meaning, purpose, and value of human existence, and the role of personal agency in transforming one's life. In the view of an existentialist, the individual's starting point is phenomenological, grounded in the immediate direct experience of life. Key concepts include "existential angst", a sense of dread, disorientation, confusion, or anxiety in the face of an apparently meaningless or absurd world, and also authenticity, courage, and human-heartedness. Existentialism is associated with several 19th- and 20th-century European philosophers who shared an emphasis on the human subject, despite often profound differences in thought. Among the earliest figures associated with existentialism are philosophers Søren Kierkegaard and Friedrich Nietzsche and novelist Fyod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toby Ord
Toby David Godfrey Ord (born July 1979) is an Australian philosopher. He founded Giving What We Can in 2009, an international society whose members pledge to donate at least 10% of their income to effective charities, and is a key figure in the effective altruism movement, which promotes using reason and evidence to help the lives of others as much as possible. He is a senior research fellow at the University of Oxford's Future of Humanity Institute, where his work is focused on existential risk. His book on the subject '' The Precipice: Existential Risk and the Future of Humanity'' was published in March 2020. Early life and education Ord was born in Melbourne, Australia, in 1979. He later attended the University of Melbourne, where he initially studied computer science. On completing his first degree, he switched to studying philosophy to pursue his interest in ethics, later stating: "At this stage I knew that I wanted to make a large positive difference in the world and it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canonical Quantization
In physics, canonical quantization is a procedure for quantizing a classical theory, while attempting to preserve the formal structure, such as symmetries, of the classical theory, to the greatest extent possible. Historically, this was not quite Werner Heisenberg's route to obtaining quantum mechanics, but Paul Dirac introduced it in his 1926 doctoral thesis, the "method of classical analogy" for quantization, and detailed it in his classic text. The word ''canonical'' arises from the Hamiltonian approach to classical mechanics, in which a system's dynamics is generated via canonical Poisson brackets, a structure which is ''only partially preserved'' in canonical quantization. This method was further used in the context of quantum field theory by Paul Dirac, in his construction of quantum electrodynamics. In the field theory context, it is also called the second quantization of fields, in contrast to the semi-classical first quantization of single particles. History When ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Léon Van Hove
Léon Charles Prudent Van Hove (10 February 1924 – 2 September 1990) was a Belgian physicist and a Director General of CERN. He developed a scientific career spanning mathematics, solid state physics, elementary particle and nuclear physics to cosmology. Biography Van Hove studied mathematics and physics at the Université Libre de Bruxelles (ULB). In 1946 he received his PhD in mathematics at the ULB. From 1949 to 1954 he worked at the Institute for Advanced Study in Princeton, New Jersey by virtue of his meeting with Robert Oppenheimer. Later he worked at the Brookhaven National Laboratory and was a professor and Director of the Theoretical Physics Institute at the University of Utrecht in the Netherlands. In the 1950s he laid the theoretical foundations for the analysis of inelastic neutron scattering in terms of the dynamic structure factor. In 1958, he was awarded the Francqui Prize in Exact Sciences. In 1959, he received an invitation to become the head of the Theory D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Dirac
Paul Adrien Maurice Dirac (; 8 August 1902 – 20 October 1984) was an English theoretical physicist who is regarded as one of the most significant physicists of the 20th century. He was the Lucasian Professor of Mathematics at the University of Cambridge, a professor of physics at Florida State University and the University of Miami, and a 1933 Nobel Prize recipient. Dirac made fundamental contributions to the early development of both quantum mechanics and quantum electrodynamics. Among other discoveries, he formulated the Dirac equation which describes the behaviour of fermions and predicted the existence of antimatter. Dirac shared the 1933 Nobel Prize in Physics with Erwin Schrödinger "for the discovery of new productive forms of atomic theory". He also made significant contributions to the reconciliation of general relativity with quantum mechanics. Dirac was regarded by his friends and colleagues as unusual in character. In a 1926 letter to Paul Ehrenfest, Albert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poisson Bracket
In mathematics and classical mechanics, the Poisson bracket is an important binary operation in Hamiltonian mechanics, playing a central role in Hamilton's equations of motion, which govern the time evolution of a Hamiltonian dynamical system. The Poisson bracket also distinguishes a certain class of coordinate transformations, called ''canonical transformations'', which map canonical coordinate systems into canonical coordinate systems. A "canonical coordinate system" consists of canonical position and momentum variables (below symbolized by q_i and p_i, respectively) that satisfy canonical Poisson bracket relations. The set of possible canonical transformations is always very rich. For instance, it is often possible to choose the Hamiltonian itself H =H(q, p, t) as one of the new canonical momentum coordinates. In a more general sense, the Poisson bracket is used to define a Poisson algebra, of which the algebra of functions on a Poisson manifold is a special case. There are ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commutator
In mathematics, the commutator gives an indication of the extent to which a certain binary operation fails to be commutative. There are different definitions used in group theory and ring theory. Group theory The commutator of two elements, and , of a group , is the element : . This element is equal to the group's identity if and only if and commute (from the definition , being equal to the identity if and only if ). The set of all commutators of a group is not in general closed under the group operation, but the subgroup of ''G'' generated by all commutators is closed and is called the ''derived group'' or the ''commutator subgroup'' of ''G''. Commutators are used to define nilpotent and solvable groups and the largest abelian quotient group. The definition of the commutator above is used throughout this article, but many other group theorists define the commutator as :. Identities (group theory) Commutator identities are an important tool in group theory. The expr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum
In physics, a quantum (plural quanta) is the minimum amount of any physical entity (physical property) involved in an interaction. The fundamental notion that a physical property can be "quantized" is referred to as "the hypothesis of quantization". This means that the magnitude of the physical property can take on only discrete values consisting of integer multiples of one quantum. For example, a photon is a single quantum of light (or of any other form of electromagnetic radiation). Similarly, the energy of an electron bound within an atom is quantized and can exist only in certain discrete values. (Atoms and matter in general are stable because electrons can exist only at discrete energy levels within an atom.) Quantization is one of the foundations of the much broader physics of quantum mechanics. Quantization of energy and its influence on how energy and matter interact (quantum electrodynamics) is part of the fundamental framework for understanding and describing nature. E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
