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Tony Bell (physicist)
Anthony Raymond Bell One or more of the preceding sentences incorporates text from the royalsociety.org website where: (born 9 June 1952) is a British physicist. He is a professor of physics at the University of Oxford and the Rutherford Appleton Laboratory. He is a senior research fellow at Somerville College, Oxford. Early life and education Anthony Raymond Bell was born on 9 June 1952 in Lincoln, England, to Raymond and Muriel Bell. He was educated at Leeds Modern School and Churchill College, Cambridge, where he studied natural sciences and later gained a PhD in radio astronomy in 1977 for research investigating supernova remnants. Career and research Following his PhD, Bell worked on radar signal processing with Marconi Electronic Systems before moving to the Central Laser Facility as a laser-plasma theorist. In 1985 he was appointed a lecturer at Imperial College London. In 2007, following two years with the Methodist Church, he was jointly appointed at the Cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lincoln, England
Lincoln () is a cathedral city, a non-metropolitan district, and the county town of Lincolnshire, England. In the 2021 Census, the Lincoln district had a population of 103,813. The 2011 census gave the Lincoln Urban Area, urban area of Lincoln, including North Hykeham and Waddington, Lincolnshire, Waddington, a population of 115,000. Roman Britain, Roman ''Lindum Colonia'' developed from an Iron Age settlement on the River Witham. Landmarks include Lincoln Cathedral (English Gothic architecture; for over 200 years the world's tallest building) and the 11th-century Norman architecture, Norman Lincoln Castle. The city hosts the University of Lincoln, Bishop Grosseteste University, Lincoln City F.C., Lincoln City FC and Lincoln United F.C., Lincoln United FC. Lincoln is the largest settlement in Lincolnshire, with the towns of Grimsby second largest and Scunthorpe third. History Earliest history: ''Lincoln'' The earliest origins of Lincoln can be traced to remains of an Iron Ag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supernova Remnant
A supernova remnant (SNR) is the structure resulting from the explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar material it sweeps up and shocks along the way. There are two common routes to a supernova: either a massive star may run out of fuel, ceasing to generate fusion energy in its core, and collapsing inward under the force of its own gravity to form a neutron star or a black hole; or a white dwarf star may accrete material from a companion star until it reaches a critical mass and undergoes a thermonuclear explosion. In either case, the resulting supernova explosion expels much or all of the stellar material with velocities as much as 10% the speed of light (or approximately 30,000 km/s). These speeds are highly supersonic, so a strong shock wave forms ahead of the ejecta. That heats the upstream plasma up to temperatures well above mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Astronomical Society
(Whatever shines should be observed) , predecessor = , successor = , formation = , founder = , extinction = , merger = , merged = , type = NGO, learned society , status = Registered charity , purpose = To promote the sciences of astronomy & geophysics , professional_title = Fellow of the Royal Astronomical Society (FRAS) , headquarters = Burlington House , location = Piccadilly, London , coords = , region_served = , services = , membership = , language = , general = , leader_title = Patron , leader_name = King Charles III , leader_title2 = President , leader_name2 = Mike Edmunds , leader_title3 = Executive Director , leader_name3 = Philip Diamond , leader_title4 = , leader_name4 = , key_peop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Institute Of Physics
The Institute of Physics (IOP) is a UK-based learned society and professional body that works to advance physics education, research and application. It was founded in 1874 and has a worldwide membership of over 20,000. The IOP is the Physical Society for the UK and Ireland and supports physics in education, research and industry. In addition to this, the IOP provides services to its members including careers advice and professional development and grants the professional qualification of Chartered Physicist (CPhys), as well as Chartered Engineer (CEng) as a nominated body of the Engineering Council. The IOP's publishing company, IOP Publishing, publishes 85 academic titles. History The Institute of Physics was formed in 1960 from the merger of the Physical Society, founded as the Physical Society of London in 1874, and the Institute of Physics, founded in 1918. The Physical Society of London had been officially formed on 14 February 1874 by Frederick Guthrie, following ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pair Production
Pair production is the creation of a subatomic particle and its antiparticle from a neutral boson. Examples include creating an electron and a positron, a muon and an antimuon, or a proton and an antiproton. Pair production often refers specifically to a photon creating an electron–positron pair near a nucleus. As energy must be conserved, for pair production to occur, the incoming energy of the photon must be above a threshold of at least the total rest mass energy of the two particles created. (As the electron is the lightest, hence, lowest mass/energy, elementary particle, it requires the least energetic photons of all possible pair-production processes.) Conservation of energy and momentum are the principal constraints on the process. All other conserved quantum numbers (angular momentum, electric charge, lepton number) of the produced particles must sum to zero thus the created particles shall have opposite values of each other. For instance, if one particle has electric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positron
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. It has an electric charge of +1 '' e'', a spin of 1/2 (the same as the electron), and the same mass as an electron. When a positron collides with an electron, annihilation occurs. If this collision occurs at low energies, it results in the production of two or more photons. Positrons can be created by positron emission radioactive decay (through weak interactions), or by pair production from a sufficiently energetic photon which is interacting with an atom in a material. History Theory In 1928, Paul Dirac published a paper proposing that electrons can have both a positive and negative charge. This paper introduced the Dirac equation, a unification of quantum mechanics, special relativity, and the then-new concept of electron spin to explain the Zeeman effect. The paper did not explicitly predict a new particle but did allow for electrons having either positive or negative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron
The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no known components or substructure. The electron's mass is approximately 1/1836 that of the proton. Quantum mechanical properties of the electron include an intrinsic angular momentum ( spin) of a half-integer value, expressed in units of the reduced Planck constant, . Being fermions, no two electrons can occupy the same quantum state, in accordance with the Pauli exclusion principle. Like all elementary particles, electrons exhibit properties of both particles and waves: They can collide with other particles and can be diffracted like light. The wave properties of electrons are easier to observe with experiments than those of other particles like neutrons and protons because electrons have a lower mass and hence a longer de Broglie wavele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inertial Confinement Fusion
Inertial confinement fusion (ICF) is a fusion energy process that initiates nuclear fusion reactions by compressing and heating targets filled with thermonuclear fuel. In modern machines, the targets are small spherical pellets about the size of a pinhead typically containing a mixture of about 10 milligrams of deuterium 2H and tritium 3H. To compress and heat the fuel, energy is deposited in the outer layer of the target using high-energy beams of photons, electrons or ions, although almost all ICF devices used lasers. The beams heat the outer layer, which explodes outward. This produces a reaction force against the remainder of the target, which accelerates it inwards and compresses the fuel. This process also creates shock waves that travel inward through the target. Sufficiently powerful shock waves can compress and heat the fuel at the center such that fusion occurs. ICF is one of two major branches of fusion energy research, the other is magnetic confinement fusion. When ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particle Acceleration
In a compressible sound transmission medium - mainly air - air particles get an accelerated motion: the particle acceleration or sound acceleration with the symbol a in metre/second2. In acoustics or physics, acceleration (symbol: ''a'') is defined as the rate of change (or time derivative) of velocity. It is thus a vector quantity with dimension length/time2. In SI units, this is m/s2. To accelerate an object (air particle) is to change its velocity over a period. Acceleration is defined technically as "the rate of change of velocity of an object with respect to time" and is given by the equation \mathbf = \frac where *''a'' is the acceleration vector *''v'' is the velocity vector expressed in m/s *''t'' is time expressed in seconds. This equation gives ''a'' the units of m/(s·s), or m/s2 (read as "metres per second per second", or "metres per second squared"). An alternative equation is: \mathbf = \frac where *\mathbf is the average acceleration (m/s2) *\mathbf is the init ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Field
A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to the magnetic field. A permanent magnet's magnetic field pulls on ferromagnetic materials such as iron, and attracts or repels other magnets. In addition, a nonuniform magnetic field exerts minuscule forces on "nonmagnetic" materials by three other magnetic effects: paramagnetism, diamagnetism, and antiferromagnetism, although these forces are usually so small they can only be detected by laboratory equipment. Magnetic fields surround magnetized materials, and are created by electric currents such as those used in electromagnets, and by electric fields varying in time. Since both strength and direction of a magnetic field may vary with location, it is described mathematically by a function assigning a vector to each point of space, cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monthly Notices Of The Royal Astronomical Society
''Monthly Notices of the Royal Astronomical Society'' (MNRAS) is a peer-reviewed scientific journal covering research in astronomy and astrophysics. It has been in continuous existence since 1827 and publishes letters and papers reporting original research in relevant fields. Despite the name, the journal is no longer monthly, nor does it carry the notices of the Royal Astronomical Society. History The first issue of MNRAS was published on 9 February 1827 as ''Monthly Notices of the Astronomical Society of London'' and it has been in continuous publication ever since. It took its current name from the second volume, after the Astronomical Society of London became the Royal Astronomical Society (RAS). Until 1960 it carried the monthly notices of the RAS, at which time these were transferred to the newly established ''Quarterly Journal of the Royal Astronomical Society'' (1960–1996) and then to its successor journal ''Astronomy & Geophysics'' (since 1997). Until 1965, MNRAS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmic Ray
Cosmic rays are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own galaxy, and from distant galaxies. Upon impact with Earth's atmosphere, cosmic rays produce showers of secondary particles, some of which reach the surface, although the bulk is deflected off into space by the magnetosphere or the heliosphere. Cosmic rays were discovered by Victor Hess in 1912 in balloon experiments, for which he was awarded the 1936 Nobel Prize in Physics. Direct measurement of cosmic rays, especially at lower energies, has been possible since the launch of the first satellites in the late 1950s. Particle detectors similar to those used in nuclear and high-energy physics are used on satellites and space probes for research into cosmic rays. Data from the Fermi Space Telescope (2013) have been interpreted as evidenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
