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Fundamental interaction

Fundamental interaction
Fundamental interactions, also called fundamental forces or interactive forces, are modeled in fundamental physics as patterns of relations in physical systems, evolving over time, that appear not reducible to relations among entities more basic. Four fundamental interactions are conventionally recognized: gravitational, electromagnetic, strong nuclear, and weak nuclear. Everyday phenomena of human experience are mediated via gravitation and electromagnetism. In modern physics, gravitation is the only fundamental interaction still modeled as classical/continuous (versus quantum/discrete). Beyond the Standard Model, some theorists work to unite the electroweak and strong interactions within a Grand Unified Theory (GUT). Overview of the fundamental Interaction[edit] An overview of the various families of elementary and composite particles, and the theories describing their interactions. The interaction of any pair of fermions in perturbation theory can then be modeled thus: Related:  Leseliste

Calculator Tab • Free Online Scientific Calculator table of contents calculator Quick start Calculator Tab is a free online scientific calculator which works like your regular calculator. This calculator follows the standard order of operations. . button. Calculator Tab will not allow you to make ambiguous enteries and will tell you, what is not allowed if you try to make such an entry. the entry of will generate an error telling you, that you first need to enter a number before continuing with the calculation. will be ignored and you can continue with your calculation as though you had not entered it. Features unlimited long-term memory storagepop-up version (for working with other documents)saving of settings between sessionshighlighting of the last valid functionpossibility of switching between comma and point as decimal separatorsambiguous input filter Using the memory function There are two possibilities to store a value in the memory bank:1. button you can quickly store the displayed value in the memory bank. Negative numbers .2. and .

Elementary particle In particle physics, an elementary particle or fundamental particle is a particle whose substructure is unknown, thus it is unknown whether it is composed of other particles.[1] Known elementary particles include the fundamental fermions (quarks, leptons, antiquarks, and antileptons), which generally are "matter particles" and "antimatter particles", as well as the fundamental bosons (gauge bosons and Higgs boson), which generally are "force particles" that mediate interactions among fermions.[1] A particle containing two or more elementary particles is a composite particle. Everyday matter is composed of atoms, once presumed to be matter's elementary particles—atom meaning "indivisible" in Greek—although the atom's existence remained controversial until about 1910, as some leading physicists regarded molecules as mathematical illusions, and matter as ultimately composed of energy.[1][2] Soon, subatomic constituents of the atom were identified. Overview[edit] Main article: Standard Model

Graviton Theory[edit] The three other known forces of nature are mediated by elementary particles: electromagnetism by the photon, the strong interaction by the gluons, and the weak interaction by the W and Z bosons. The hypothesis is that the gravitational interaction is likewise mediated by an – as yet undiscovered – elementary particle, dubbed as the graviton. Gravitons and renormalization[edit] When describing graviton interactions, the classical theory (i.e., the tree diagrams) and semiclassical corrections (one-loop diagrams) behave normally, but Feynman diagrams with two (or more) loops lead to ultraviolet divergences; that is, infinite results that cannot be removed because the quantized general relativity is not renormalizable, unlike quantum electrodynamics. Comparison with other forces[edit] Unlike the force carriers of the other forces, gravitation plays a special role in general relativity in defining the spacetime in which events take place. Gravitons in speculative theories[edit]

Angular frequency Angular frequency ω (in radians per second), is larger than frequency ν (in cycles per second, also called Hz), by a factor of 2π. This figure uses the symbol ν, rather than f to denote frequency. In physics, angular frequency ω (also referred to by the terms angular speed, radial frequency, circular frequency, orbital frequency, radian frequency, and pulsatance) is a scalar measure of rotation rate. Angular frequency (or angular speed) is the magnitude of the vector quantity angular velocity. The term angular frequency vector is sometimes used as a synonym for the vector quantity angular velocity.[1] where: ω is the angular frequency or angular speed (measured in radians per second), T is the period (measured in seconds), Units[edit] In SI units, angular frequency is normally presented in radians per second, even when it does not express a rotational value. Examples[edit] A sphere rotating around an axis. Circular motion[edit] Oscillations of a spring[edit] where k is the spring constant

Spin (physics) In quantum mechanics and particle physics, spin is an intrinsic form of angular momentum carried by elementary particles, composite particles (hadrons), and atomic nuclei.[1][2] Spin is a solely quantum-mechanical phenomenon; it does not have a counterpart in classical mechanics (despite the term spin being reminiscent of classical phenomena such as a planet spinning on its axis).[2] Spin is one of two types of angular momentum in quantum mechanics, the other being orbital angular momentum. Orbital angular momentum is the quantum-mechanical counterpart to the classical notion of angular momentum: it arises when a particle executes a rotating or twisting trajectory (such as when an electron orbits a nucleus).[3][4] The existence of spin angular momentum is inferred from experiments, such as the Stern–Gerlach experiment, in which particles are observed to possess angular momentum that cannot be accounted for by orbital angular momentum alone.[5] where h is the Planck constant.

Tests of general relativity The very strong gravitational fields that must be present close to black holes, especially those supermassive black holes which are thought to power active galactic nuclei and the more active quasars, belong to a field of intense active research. Observations of these quasars and active galactic nuclei are difficult, and interpretation of the observations is heavily dependent upon astrophysical models other than general relativity or competing fundamental theories of gravitation, but they are qualitatively consistent with the black hole concept as modelled in general relativity. As a consequence of the equivalence principle, Lorentz invariance holds locally in freely falling reference frames. Classical tests[edit] Albert Einstein proposed three tests of general relativity, subsequently called the classical tests of general relativity, in 1916:[1] The chief attraction of the theory lies in its logical completeness. Perihelion precession of Mercury[edit] Deflection of light by the Sun[edit]

Why does current lead the voltage in capacitor? Best way is to consider an uncharged cap. A switch is closed & current enters the cap. The current is full value, a constant current source or a constant voltage source plus a resistor. At time t = 0+, the current i is maximum value, if the voltage source value is V, & resistance is R, then i(t=0+) = V/R. Another thought is that current in a cap can change quickly/abruptly but voltage in a cap changes gradually/slowly. But changing cap voltage is changing its energy, needing work to be done. In the ac domain. i = C*dv/dt. Did I help? Claude

Antimatter In particle physics, antimatter is material composed of antiparticles, which have the same mass as particles of ordinary matter but have opposite charge and other particle properties such as lepton and baryon number. Encounters between particles and antiparticles lead to the annihilation of both, giving rise to varying proportions of high-energy photons (gamma rays), neutrinos, and lower-mass particle–antiparticle pairs. Setting aside the mass of any product neutrinos, which represent released energy which generally continues to be unavailable, the end result of annihilation is a release of energy available to do work, proportional to the total matter and antimatter mass, in accord with the mass-energy equivalence equation, E=mc2.[1] Antiparticles bind with each other to form antimatter just as ordinary particles bind to form normal matter. For example, a positron (the antiparticle of the electron) and an antiproton can form an antihydrogen atom. History of the concept Notation Positrons

Gravity Probe B - Special & General Relativity Questions and Answers It is true that, given enough energy, you could be propelled so fast that 1 year back home would pass for you in a few minutes; a ride across the Milky Way covering 100,000 light years could be done in a few seconds; or even a ride across the visible universe of 14 billion light years could be done in a second or less...given an ultimate source of power to get you to those speeds. For a photon, or any other particle traveling at ESSENTIALLY the speed of light, any arbitrarily long distance could be traversed in less than a second....but eternity is different. For you to get boosted to a speed where 'eternity would pass in an instant' you would travel essentially an infinite distance, and the energy you would need to accelerate you would be infinite as well. For a photon, it is a completely meaningless exercise to ask how fast time passes for a photon, and in some sense in the 'rest frame' of such a massless particle, time is meaningless. All answers are provided by Dr.

Generalized Ohm's Law and Impedance Next: Impedance and Generalized Ohm's Up: Chapter 3: AC Circuit Previous: Sinusoidal Functions In the following discussion about AC circuit analysis, all sinusoidal variables (currents and voltages) are assumed to be of the same frequency. In general, arithmetic operations of sinusoidal functions are not convenient as they will involve using trigonometric identities. However, we can consider such sinusoidal functions as real (or imaginary) parts of some rotating vectors in the complex plane, and their arithmetic operations (addition, multiplication, etc.) can be more conveniently carried out (review of complex arithmetic). However, we can consider the phasor The sum of the two sinusoidal function can now be found as the real part of the rotating vector sum: The addition can be more easily carried out in the phasor form as vectors in the complex plane, than in the time domain. Specifically, consider two sinusoidal functions where and When multiplied by and then taking the real part: or Example

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