|
Wheeler–Feynman Absorber Theory
The Wheeler–Feynman absorber theory (also called the Wheeler–Feynman time-symmetric theory), named after its originators, the physicists Richard Feynman and John Archibald Wheeler, is a theory of electrodynamics based on a relativistic correct extension of action at a distance electron particles. The theory postulates no independent electromagnetic field. Rather, the whole theory is encapsulated by the Lorentz-invariant action S of particle trajectories a^\mu(\tau),\,\, b^\mu(\tau),\,\, \cdots defined as S = -\sum_ m_a c \int \sqrt + \sum_ \frac \int \int \delta(ab_\mu ab^\mu) \, da_\nu db^\nu, where ab_\mu \equiv a_\mu - b_\mu. The absorber theory is invariant under time-reversal transformation, consistent with the lack of any physical basis for microscopic time-reversal symmetry breaking. Another key principle resulting from this interpretation, and somewhat reminiscent of Mach's principle and the work of Hugo Tetrode, is that elementary particles are not self-intera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Feynman
Richard Phillips Feynman (; May 11, 1918 – February 15, 1988) was an American theoretical physicist. He is best known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics, the physics of the superfluidity of supercooled liquid helium, and in particle physics, for which he proposed the parton model. For his contributions to the development of quantum electrodynamics, Feynman received the Nobel Prize in Physics in 1965 jointly with Julian Schwinger and Shin'ichirō Tomonaga. Feynman developed a pictorial representation scheme for the mathematical expressions describing the behavior of subatomic particles, which later became known as Feynman diagrams and is widely used. During his lifetime, Feynman became one of the best-known scientists in the world. In a 1999 poll of 130 leading physicists worldwide by the British journal ''Physics World'', he was ranked the seventh-greatest physicist of all time. He assisted in the Manhatt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation Resistance
Radiation resistance is that part of an antenna's feedpoint electrical resistance caused by the emission of radio waves from the antenna. A radio transmitter applies a radio frequency alternating current to an antenna, which radiates the energy of the current as radio waves. Because the antenna is absorbing the energy it is radiating from the transmitter, the antenna's input terminals present a resistance to the current from the transmitter. Radiation resistance is an ''effective'' resistance, due to the power carried away from the antenna as radio waves. Unlike conventional ohmic resistance, radiation resistance is not an opposition to current (resistivity) of the imperfect conducting materials the antenna is made of. The radiation resistance (\ R_\mathsf\ ) is conventionally defined as the value of electrical resistance that ''would'' dissipate the same amount of power as heat, as is dissipated by the radio waves emitted from the antenna. From Joule's law, it is equal to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Journal Of Theoretical Physics
The ''International Journal of Theoretical Physics'' is a peer-reviewed scientific journal of physics published by Springer Science+Business Media since 1968. According to the ''Journal Citation Reports'', the journal has a June 2023 real-time impact factor of 4.6 and publishes both original research and review articles. The editor-in-chief is Andreas Wipf ( Friedrich-Schiller-University Jena). Scope and indexing The journal covers the following areas: general relativity, quantum theory with relativistic quantum field theory, quantum measurement theory, quantum geometry and quantum logic. Services abstracting and indexing this journal include Chemical Abstracts Service, Mathematical Reviews, Science Citation Index, Scopus Scopus is a scientific abstract and citation database, launched by the academic publisher Elsevier as a competitor to older Web of Science in 2004. The ensuing competition between the two databases has been characterized as "intense" and is c ..., and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John G
John is a common English name and surname: * John (given name) * John (surname) John may also refer to: New Testament Works * Gospel of John, a title often shortened to John * First Epistle of John, often shortened to 1 John * Second Epistle of John, often shortened to 2 John * Third Epistle of John, often shortened to 3 John People * John the Baptist (died ), regarded as a prophet and the forerunner of Jesus Christ * John the Apostle (died ), one of the twelve apostles of Jesus Christ * John the Evangelist, assigned author of the Fourth Gospel, once identified with the Apostle * John of Patmos, also known as John the Divine or John the Revelator, the author of the Book of Revelation, once identified with the Apostle * John the Presbyter, a figure either identified with or distinguished from the Apostle, the Evangelist and John of Patmos Other people with the given name Religious figures * John, father of Andrew the Apostle and Saint Peter * Pope John ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Relativity
General relativity, also known as the general theory of relativity, and as Einstein's theory of gravity, is the differential geometry, geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics. General theory of relativity, relativity generalizes special relativity and refines Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time in physics, time, or four-dimensional spacetime. In particular, the ''curvature of spacetime'' is directly related to the energy and momentum of whatever is present, including matter and radiation. The relation is specified by the Einstein field equations, a system of second-order partial differential equations. Newton's law of universal gravitation, which describes gravity in classical mechanics, can be seen as a prediction of general relativity for the almost flat spacetime geometry around stationary mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time (magazine)
''Time'' (stylized in all caps as ''TIME'') is an American news magazine based in New York City. It was published Weekly newspaper, weekly for nearly a century. Starting in March 2020, it transitioned to every other week. It was first published in New York City on March 3, 1923, and for many years it was run by its influential co-founder, Henry Luce. A European edition (''Time Europe'', formerly known as ''Time Atlantic'') is published in London and also covers the Middle East, Africa, and, since 2003, Latin America. An Asian edition (''Time Asia'') is based in Hong Kong. The South Pacific edition, which covers Australia, New Zealand, and the Pacific Islands, is based in Sydney. Since 2018, ''Time'' has been owned by Salesforce founder Marc Benioff, who acquired it from Meredith Corporation. Benioff currently publishes the magazine through the company Time USA, LLC. History 20th century ''Time'' has been based in New York City since its first issue published on March 3, 1923 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proceedings Of The Royal Society A
''Proceedings of the Royal Society'' is the main research journal of the Royal Society. The journal began in 1831 and was split into two series in 1905: * Series A: for papers in physical sciences and mathematics. * Series B: for papers in life sciences. Many landmark scientific discoveries are published in the Proceedings, making it one of the most important science journals in history. The journal contains several articles written by prominent scientists such as Paul Dirac, Werner Heisenberg, Ernest Rutherford, Erwin Schrödinger, William Lawrence Bragg, Lord Kelvin, J.J. Thomson, James Clerk Maxwell, Dorothy Hodgkin and Stephen Hawking. In 2004, the Royal Society began '' The Journal of the Royal Society Interface'' for papers at the interface of physical sciences and life sciences. History The journal began in 1831 as a compilation of abstracts of papers in the '' Philosophical Transactions of the Royal Society'', the older Royal Society publication, that began in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hoyle–Narlikar Theory Of Gravity
The Hoyle–Narlikar theory of gravity is a Machian and conformal theory of gravity proposed by Fred Hoyle and Jayant Narlikar that originally fits into the quasi steady state model of the universe. The gravitational constant ''G'' is arbitrary and is determined by the mean density of matter in the universe. The theory was inspired by the Wheeler–Feynman absorber theory for electrodynamics. When Richard Feynman, as a graduate student, lectured on the Wheeler–Feynman absorber theory in the weekly physics seminar at Princeton, Albert Einstein was in the audience and stated at question time that he was trying to achieve the same thing for gravity. Stephen Hawking showed in 1965 that the theory is incompatible with an expanding universe, because the Wheeler–Feynman advanced solution would diverge. However, at that time the accelerating expansion of the universe was not known, which resolves the divergence issue because of the cosmic event horizon. The Hoyle–Narlikar theor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jayant Narlikar
Jayant Vishnu Narlikar (19 July 1938 – 20 May 2025) was an Indian astrophysicist who performed research on alternative cosmology. He was also an author who wrote textbooks on cosmology, popular science books, and science fiction novels and short stories. Narlikar studied at Banaras Hindu University and Cambridge University, where he obtained his PhD in 1963 working with Fred Hoyle. After postdoctoral work in Cambridge, in 1972 he was appointed a professor at the Tata Institute of Fundamental Research. In 1988, he became the first director of the Inter-University Centre for Astronomy and Astrophysics (IUCAA). Early life Narlikar was born in Kolhapur, India, on 19 July 1938, into an academic family. His father, Vishnu Vasudev Narlikar, was a mathematician and theoretical physicist who was a professor and head of department at Banaras Hindu University (BHU), Varanasi. His mother, Sumati Narlikar, was a scholar of Sanskrit. His maternal uncle, V. S. Huzurbazar, was a stati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fred Hoyle
Sir Fred Hoyle (24 June 1915 – 20 August 2001) was an English astronomer who formulated the theory of stellar nucleosynthesis and was one of the authors of the influential B2FH paper, B2FH paper. He also held controversial stances on other scientific matters—in particular his rejection of the "Big Bang" theory (a term coined by him on BBC Radio) in favor of the "steady-state model", and his promotion of panspermia as the origin of life on Earth. He spent most of his working life at St John's College, Cambridge and served as the founding director of the Institute of Astronomy, Cambridge, Institute of Theoretical Astronomy at Cambridge. Hoyle also wrote science fiction novels, short stories and radio plays, co-created television serials, and co-authored twelve books with his son, Geoffrey Hoyle. Biography Early life Hoyle was born near Bingley in Gilstead, West Riding of Yorkshire, England. His father Ben Hoyle was a violinist and worked in the wool trade in Bradford, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Dirac
Paul Adrien Maurice Dirac ( ; 8 August 1902 – 20 October 1984) was an English mathematician and Theoretical physics, theoretical physicist who is considered to be one of the founders of quantum mechanics. Dirac laid the foundations for both quantum electrodynamics and quantum field theory. He was the Lucasian Professor of Mathematics at the University of Cambridge and a professor of physics at Florida State University. Dirac shared the 1933 Nobel Prize in Physics with Erwin Schrödinger for "the discovery of new productive forms of atomic theory". Dirac graduated from the University of Bristol with a first class honours Bachelor of Science degree in electrical engineering in 1921, and a first class honours Bachelor of Arts degree in mathematics in 1923. Dirac then graduated from the University of Cambridge with a PhD in physics in 1926, writing the first ever thesis on quantum mechanics. Dirac made fundamental contributions to the early development of both quantum mechanic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Max Abraham
Max Abraham (; 26 March 1875 – 16 November 1922) was a German physicist known for his work on electromagnetism and his opposition to the theory of relativity. Biography Abraham was born in Danzig, Imperial Germany (now Gdańsk in Poland) to a family of Jewish merchants. His father was Moritz Abraham and his mother was Selma Moritzsohn. Attending the University of Berlin, he studied under Max Planck. He graduated in 1897. For the next three years, Abraham worked as Planck's assistant. From 1900 to 1909, Abraham worked at Göttingen as a privatdozent, an unpaid lecturing position. Abraham developed his theory of the electron in 1902, in which he hypothesized that the electron was a perfect sphere with a charge divided evenly around its surface. Abraham's model was competing with that developed by Hendrik Lorentz (1899, 1904) and Albert Einstein (1905) which seem to have become more widely accepted; nevertheless, Abraham never gave up his model, since he considered it wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
