This page gathers the 3,177 dictionary entries belonging to the domain “Physics”, as labelled by Wiktionary. Each word leads to its full entry: definitions, etymology, pronunciation, examples. Page 4 of 32: from “black hole” to “capacitance”.
- black hole noun A region of spacetime that exerts a gravitational pull strong enough that no matter or energy, not even light, can escape it.
- black noise noun Technical silence; noise that has a frequency spectrum of predominantly zero power level over all frequencies except for a few narrow bands…
- black start noun The process of restoring an electric power station or part of an electric grid to operation without relying on the external electric power…
- blackbody noun a theoretical body, approximated by a hole in a hollow black sphere, that absorbs all incident electromagnetic radiation and reflects none…
- blip noun A small dot registered on electronic equipment, such as a radar or oscilloscope screen.
- blivet noun An electronic signal that is normally high or on, but goes low for a very short period and then returns to high. A low going spike.
- Bloch oscillation noun In solid-state physics, the oscillation of a particle (e.g. an electron) confined in a periodic potential when a constant force is acting…
- blow a fuse verb To overload a circuit sufficiently that a fuse protecting it melts away (or informally a circuit breaker trips), stopping current from…
- blowable adj That can cease to function when overloaded.
- blue adj Having a colour charge of blue.
- blue shift noun Alternative form of blueshift.
- blueshift noun A decrease in the wavelength of a photon or of light, corresponding to a higher frequency and a shift toward the blue end of the…
- board finger noun A part used in printed circuit boards to form the traces of the edge connector which plug into matching sockets.
- body contact noun A conductive connection between body and active parts of electrical equipment resulting from a fault.
- Bogoliubov transformation noun An isomorphism of either the canonical commutation relation algebra or canonical anticommutation relation algebra. It is often used to…
- bogolon noun A collective excitation, in a Bose-Einstein condensate, that has some characteristics of a particle.
- Bohmian mechanics noun a version or interpretation of quantum mechanics which uses pilot waves instead of the Copenhagen interpretation.
- boiling point noun The temperature at which a liquid boils, with the vapor pressure equal to the given external pressure.
- boiling-point elevation noun The phenomenon that the boiling point of a liquid (a solvent) will be higher when another compound is added.
- bombard verb To direct at a substance an intense stream of high-energy particles, usually sub-atomic or made of at most a few atoms.
- bombardment noun The incidence of an intense stream of high-energy particles directed at a substance.
- bond verb To make a reliable electrical connection between two conductors (or any pieces of metal that may potentially become conductors).
- bond dissociation energy noun The change in enthalpy that occurs when a specific chemical bond is broken; a measure of the strength of the bond
- bond energy noun The sum of the bond dissociation energies of all the bonds in a molecule
- boojum noun A geometric pattern sometimes observed on the surface of superfluid helium-3.
- boom noun The longest element of a Yagi-Uda antenna, on which the other, smaller antennae are transversally mounted.
- boost noun A coordinate transformation that changes velocity.
- booster noun A motor-generator set used for voltage regulation in direct current electrical power circuits.
- bootstrap model noun Any of a class of theories that use very general consistency criteria to determine the form of a quantum theory from some assumptions on…
- boron-10 noun A stable isotope, 105B, having five protons and five neutrons, that makes up about 20% of natural boron; it is a good absorber of slow…
- boron-11 noun A stable isotope, 115B, having five protons and six neutrons, that makes up about 80% of natural boron.
- Borromean nucleus noun An atomic nucleus comprising three bound components in which any subsystem of two components is unbound.
- borrowed neutral noun A wiring practice where the neutral conductor from one circuit is improperly shared or borrowed by another separate circuit, common in…
- bosenova noun A very small, supernova-like explosion, which can be induced in a Bose-Einstein condensate by suitably changing its magnetic field.
- boson noun A particle with totally symmetric composite quantum states, which exempts them from the Pauli exclusion principle, and that hence obeys…
- bottom noun Ellipsis of bottom quark.
- bottom quark noun A quark having a fractional electric charge of -1/3 and a mass of about 4,100 to 4,400 MeV.
- bottomness noun A quantum number of quarks and hadrons, determined by the number(s) of bottom quarks & antiquarks present. Symbol B.
- bounce verb To turn power to (a device) off and back on; to reset; to reboot.
- bounceless adj That does not require debouncing.
- bound state noun A composite of two or more particles that behaves as a single particle.
- bow shock noun A shock wave formed by the bow of an object travelling at supersonic speed.
- bra-ket noun The scalar product of two vectors (and optionally an operator), in Hilbert space, where the left (row) vector is a bra and the right…
- Bragg peak noun A maximum in the graph of energy loss of a high-energy particle, as it travels through matter, just before it comes to rest.
- Bragg plane noun A plane in reciprocal space which bisects a reciprocal lattice vector, scriptstyle mathbf K, at right angles.
- Bragg scattering noun the diffraction phenomenon exhibited by a crystal bombarded with X-rays in such a way that each plane of the crystal lattice acts as a…
- brane noun A hypothetical object extending across a number of (often specified) spatial dimensions, with strings in string theory seen as…
- braneworld noun A world that is a brane, with its own limited set of dimensions, in any of several brane cosmology theories.
- breadboard noun A device used to build a (usually temporary) prototype of an electronic circuit and for experimenting with circuit designs. Both solder and…
- breakdown noun The sudden (and usually damaging) transition of an electrical insulator to a conductor when subjected to a sufficiently strong voltage…
- breaker noun Ellipsis of circuit breaker.
- breakout adj Splitting a signal into several signals.
- breakpoint noun The point where surface water waves are breaking in, e.g., oceans or lakes.
- breather noun A spatially localized, time-periodic excitation in a one-dimensional lattice.
- breezer noun A bound state of solitons and antisolitons.
- Breit-Wheeler process noun A proposed physical process in which a positron-electron pair is created from the collision of two photons; the simplest mechanism by which…
- bremsstrahlung noun The electromagnetic radiation produced by the deceleration of a charged particle, such as an electron, when it is deflected by another…
- brewster noun A unit of stress optical coefficient which is equal to 10⁻¹² m²/N or 10⁻¹² Pa⁻¹. Symbol: B.
- brick-wall limiter noun A limiter circuit that completely cuts off signals above a specified threshold, rather than merely attenuating the peaks.
- bricking noun The state of an electronic device being rendered completely unusable by a failed or corrupted firmware or software change.
- bridge noun An unintended solder connection between two or more components or pins.
- Brillouin zone noun A uniquely defined primitive cell forming part of the reciprocal lattice, involved in calculations regarding waves in a periodic medium…
- bring up verb To check (a newly-assembled printed circuit board) for errors.
- bringup noun The process of checking newly-assembled printed circuit boards for defects and ensuring they run as expected.
- Brownian adj Pertaining to motion caused by the random vibration of molecules (Brownian motion).
- Brownian ratchet noun An apparent perpetual motion machine, the subject of a thought experiment, that would consist of a tiny paddle wheel and a ratchet, and…
- brownout noun A period of low alternating current line voltage, causing a reduction in illumination.
- BTE noun Initialism of Boltzmann transport equation.
- buck verb To output a voltage that is lower than the input voltage.
- bucket brigade noun A discrete-time analogue delay line that moves a signal along a line of capacitors, one step at each clock cycle.
- bulger noun A capacitor with a bulging top.
- buncher noun A circuit that causes electrons or other charged particles in a particle beam to group together.
- bunchlet noun A very short burst of subatomic particles in the beam of a particle accelerator.
- buoyancy noun The upward force on a body immersed or partly immersed in a fluid.
- burn verb To be converted to another element in a nuclear fusion reaction, especially in a star.
- burn in noun A process by which an image becomes permanently imprinted on an electronic display such as a monitor.
- burn time noun The amount of time in which which the propellant charge of a rocket engine is completely consumed.
- burnup noun A measure of the consumption of fuel in a nuclear reactor.
- burst mode noun A mode in which data is transmitted repeatedly without separate transactions.
- bus noun An electrical conductor or interface serving as a common connection for two or more circuits or components.
- bushing noun A lining for an opening through which a conductor passes, providing insulation and mechanical protection for the conductor.
- Cabibbo-Kobayashi-Maskawa matrix noun In the Standard Model, a unitary matrix that specifies the mismatch of quantum states of quarks when they propagate freely and when they…
- cable core noun Central part or the innermost part of a power cable which carries electric current and is surrounded by various layers of insulation.
- calcium-40 noun The major stable isotope of calcium, 4020Ca, with 20 protons and 20 neutrons; it amounts to almost 97% of natural calcium.
- calcium-42 noun A stable isotope of calcium, 4220Ca, with 20 protons and 22 neutrons; it amounts to about 0.6% of the element in nature
- calcium-43 noun A stable isotope of calcium, 4320Ca, with 20 protons and 23 neutrons; it amounts to about 0.1% of the element in nature
- calcium-44 noun A stable isotope of calcium, 4420Ca, with 20 protons and 24 neutrons; it amounts to about 2% of the element in nature
- calcium-45 noun A radioactive isotope of calcium, 4520Ca, with 20 protons and 25 neutrons, and a half-life of 162.6 days; it is used as a tracer in…
- calcium-46 noun A rare stable isotope of calcium, 4620Ca, with 20 protons and 26 neutrons; it amounts to only 0.004% of the element in nature
- calcium-48 noun A naturally-occurring isotope of calcium, 4820Ca, with 20 protons and 28 neutrons. It decays very slowly, with a half-life of 4.3x10¹⁹…
- californium-252 noun An isotope of californium, 25298Cf, with a half-life of 2.6 years; it is popular as a source of neutrons.
- calligraphic projection noun A system for displaying or projecting an image composed of a beam of light or electrons directly tracing the image, as opposed to sweeping…
- calomel electrode noun A reference electrode or half-cell consisting of mercury, mercurous chloride and potassium chloride; used in pH meters and voltmeters.
- calorie noun A non-SI unit of energy, equivalent to 4.184 joules, that can raise the temperature of a gram of water by one degree Celsius. This unit was…
- calorific adj Relating to or producing heat or other energy.
- calorimeter noun An apparatus for measuring the heat generated or absorbed by either a chemical reaction, change of phase or some other physical change.
- calorimetry noun The science of measuring the heat absorbed or evolved during the course of a chemical reaction or change of state.
- caloritronics noun The generation and control of currents of heat, especially by means of the degree of freedom of electron spin
- cap noun A capacitor.
- capacitance noun The property of an electric circuit or its element that permits it to store charge, defined as the ratio of stored charge to potential over…