Deutsche Digitale Bibliothek Einführung in die Theoretische Physik - Ein Lehrbuch in mehreren Bänden – Wikibooks, Sammlung freier Lehr-, Sach- und Fachbücher Einführung in die Theoretische Physik - Ein Lehrbuch in mehreren Bänden Aus Wikibooks Wechseln zu: Navigation, Suche Dieses mehrbändige Werk steht im Regal Physik sowie im Regal Maschinenbau. Hier gibt es eine PDF-Version [1]. Von „ Kategorie: Mehrbändiges Werk Navigationsmenü Meine Werkzeuge Namensräume Varianten Ansichten Mehr Navigation Mitmachen Werkzeuge Sprachen Drucken/exportieren Diese Seite wurde zuletzt am 21.
Wikileaks - WikiLeaks Light-time correction Light-time correction is a displacement in the apparent position of a celestial object from its true position (or geometric position) caused by the object's motion during the time it takes its light to reach an observer. Light-time correction occurs in principle during the observation of any moving object, because the speed of light is finite. The magnitude and direction of the displacement in position depends upon the distance of the object from the observer and the motion of the object, and is measured at the instant at which the object's light reaches the observer. Light-time correction can be applied to any object whose distance and motion are known. Calculation[edit] A calculation of light-time correction usually involves an iterative process. Discovery[edit] The effect of the finite speed of light on observations of celestial objects was first recognised by Ole Rømer in 1675, during a series of observations of eclipses of the moons of Jupiter. References[edit] P.
Tests of special relativity Special relativity is a physical theory that plays a fundamental role in the description of all physical phenomena, as long as gravitation is not significant. Many experiments played (and still play) an important role in its development and justification. The strength of the theory lies in its unique ability to correctly predict to high precision the outcome of an extremely diverse range of experiments. Repeats of many of those experiments are still being conducted with steadily increased precision, with modern experiments focusing on effects such as at the Planck scale and in the neutrino sector. Their results are consistent with the predictions of special relativity. Collections of various tests were given by Jakob Laub,[1] Zhang,[2] Mattingly,[3] Clifford Will,[4] and Roberts/Schleif.[5] Special relativity is restricted to flat spacetime, i.e., to all phenomena without significant influence of gravitation. Experiments paving the way to relativity[edit] First-order experiments[edit]
Dimensional analysis Dimensional analysis is routinely used as a check on the plausibility of derived equations and computations. It is also used to categorize types of physical quantities and units based on their relationship to or dependence on other units. Great principle of similitude[edit] The basic principle of dimensional analysis was known to Isaac Newton (1686) who referred to it as the "Great Principle of Similitude".[1] James Clerk Maxwell played a major role in establishing modern use of dimensional analysis by distinguishing mass, length, and time as fundamental units, while referring to other units as derived.[2] The 19th-century French mathematician Joseph Fourier made important contributions[3] based on the idea that physical laws like F = ma should be independent of the units employed to measure the physical variables. Definition[edit] The term dimension is more abstract than scale unit: mass is a dimension, while kilograms are a scale unit (choice of standard) in the mass dimension.
Electric field Electric field lines emanating from a point positive electric charge suspended over an infinite sheet of conducting material. Qualitative description[edit] An electric field that changes with time, such as due to the motion of charged particles producing the field, influences the local magnetic field. That is: the electric and magnetic fields are not separate phenomena; what one observer perceives as an electric field, another observer in a different frame of reference perceives as a mixture of electric and magnetic fields. For this reason, one speaks of "electromagnetism" or "electromagnetic fields". In quantum electrodynamics, disturbances in the electromagnetic fields are called photons. Definition[edit] Electric Field[edit] Consider a point charge q with position (x,y,z). Notice that the magnitude of the electric field has dimensions of Force/Charge. Superposition[edit] Array of discrete point charges[edit] Electric fields satisfy the superposition principle. Continuum of charges[edit]
Vector From Wikipedia, the free encyclopedia Vector may refer to: In mathematics and physics[edit] In computer science[edit] In biology[edit] In business[edit] In entertainment[edit] Fictional characters and elements[edit] Other uses[edit] See also[edit] Quantum electrodynamics In particle physics, quantum electrodynamics (QED) is the relativistic quantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and special relativity is achieved. QED mathematically describes all phenomena involving electrically charged particles interacting by means of exchange of photons and represents the quantum counterpart of classical electromagnetism giving a complete account of matter and light interaction. History[edit] The first formulation of a quantum theory describing radiation and matter interaction is attributed to British scientist Paul Dirac, who (during the 1920s) was first able to compute the coefficient of spontaneous emission of an atom.[2] Difficulties with the theory increased through the end of 1940. QED has served as the model and template for all subsequent quantum field theories. Feynman's view of quantum electrodynamics[edit] Introduction[edit] or
Tensor Cauchy stress tensor, a second-order tensor. The tensor's components, in a three-dimensional Cartesian coordinate system, form the matrix whose columns are the stresses (forces per unit area) acting on the e1, e2, and e3 faces of the cube. Tensors are used to represent correspondences between sets of geometric vectors. For example, the Cauchy stress tensor T takes a direction v as input and produces the stress T(v) on the surface normal to this vector for output thus expressing a relationship between these two vectors, shown in the figure (right). Because they express a relationship between vectors, tensors themselves must be independent of a particular choice of coordinate system. Tensors are important in physics because they provide a concise mathematical framework for formulating and solving physics problems in areas such as elasticity, fluid mechanics, and general relativity. Definition[edit] There are several approaches to defining tensors. As multidimensional arrays[edit] as, .