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 24 of 32: from “quasimolecular” to “resilience”.
- quasimolecular adj Having some characteristics of a molecule; relating to a quasimolecule
- quasineutral adj Whose bulk is more significant in terms of interactions than its edges, where boundary layer effects may occur.
- quasiparticle noun Any entity that has some characteristics of a distinct particle, but comprises a grouping of multiple particles
- quasiperiodic adj Having two unrelated periods.
- quasipotential noun A complex function of momentum and energy applied to an individual attractor in a complex system of multiple attractors
- quasistatic adj In a state of dynamic equilibrium
- quasiuniversality noun The state of being quasiuniversal; the property of existing or holding true in virtually all conditions.
- quench noun The abnormal termination of operation of a superconducting magnet, occurring when part of the superconducting coil enters the normal…
- quenching noun The extinction of any of several physical properties.
- quintessence noun A hypothetical form of dark energy postulated to explain observations of an accelerating universe.
- Rabi problem noun A problem concerning the response of an atom to an applied harmonic electric field, with an applied frequency very close to the atom's…
- race noun A race condition; a bug or problem that occurs when two or more components attempt to use the same resource at the same time.
- race condition noun A flaw in a system or process whereby the output or result is unexpectedly and critically dependent on the sequence or timing of other…
- radial distribution function noun A function which specifies the average density of atoms, molecules etc in three dimensions from a given point.
- radiance noun The flux of radiation emitted per unit solid angle in a given direction by a unit area of a source.
- radiancy noun The amount of energy emitted, flux.
- radiant heat noun Heat or warmth transferred directly to people and objects in a space via infrared radiation, similar to the sun's warmth, rather than…
- radiation belt noun A region of high-energy charged particles which partly surrounds a planet or star, trapped by its magnetic field and characterized by…
- radiation dose noun The amount of radiation that reaches something from a radioactive source, or the effect that that amount has; it can be measured in several…
- radiation pressure noun The pressure exerted by electromagnetic radiation on an object on which it impinges, as a consequence of its momentum.
- radiative recombination noun the capture of a free electron by an atom and the subsequent emission of a photon having the same energy
- radiator noun A type of antenna.
- radio wave noun Electromagnetic radiation having a wavelength between about .5 centimeters and 30,000 meters; used for the broadcasting of radio and…
- radioactive tracer noun A radioactive isotope which, when injected into a chemically similar substance, or artificially attached to a biological or physical…
- radiocarbon dating noun A method of estimating the age of an artifact or biological vestige based on the relative amounts of the different isotopes of carbon…
- radiochemical adj Of or pertaining to radiochemistry
- radioelectricity noun All the phenomena related to electromagnetic waves
- radiometry noun The branch of science that deals with the detection and measurement of radiant electromagnetic energy.
- radion noun The radius modulus of an extra dimension in a compactification. Coined in 1998 by Nima Arkani-Hamed, Savas Dimopoulos, and John…
- radiophotoluminescence noun the luminescence observed when some minerals or glasses, having been exposed to ionizing radiation, are subsequently exposed to ultraviolet…
- radiophysics noun The physics of ionizing radiation.
- radius of gyration noun Given a body B, the distance from a given axis of rotation at which a point mass of the same mass as B would have the same moment of…
- rail noun A conductor maintained at a fixed electrical potential relative to ground, to which other circuit components are connected.
- Raman effect noun the inelastic scattering of photons with subsequent change in frequency and phase; employed in Raman spectroscopy
- Randall-Sundrum model noun A model describing the universe as a five-dimensional anti-de Sitter space where the elementary particles (except the graviton) are…
- random access memory noun Computer memory, usually volatile, that stores program and data values during operation and in which each word of memory may be directly…
- rapidity noun A measure of the velocity of a particle in a beam relative to the beam's axis
- raster noun A scanning pattern of parallel lines that form the display of an image projected on a cathode-ray tube of a television set or display…
- rate of change noun A value that results from dividing the change in a function of a variable by the corresponding change in the variable
- ratemeter noun Any of several devices that measure the average rate of radioactive emissions over a specified time interval.
- ratiometric adj Describing any system in which an output is directly proportional to an input
- ray of light noun A path that a photon or a group of photons takes through space, visible as a column of light.
- rayleigh noun A unit of brightness (of the sky at night) equal to 10¹⁰/4π quanta per square meter per second per steradian
- Rayleigh's resolution limit noun The minimum angular separation between two point sources that an optical system can resolve, limited by diffraction.
- Rayleigh-Bénard convection noun A type of natural convection, occurring in a planar horizontal layer of fluid heated from below, in which the fluid develops a regular…
- reabsorption noun The subsequent absorption of emitted radiation.
- react verb To return an impulse or impression; to resist the action of another body by an opposite force
- reactance noun The opposition to the change in flow of current in an alternating current circuit, due to inductance and capacitance; the imaginary part of…
- reaction drive noun A propulsion system for a slow-than-light spacecraft that moves by expelling matter in the opposite direction of travel.
- reactive adj Characterized by induction or capacitance rather than resistance.
- reactor noun An electrical component with reactance
- reballing noun The process of reapplying the balls (protruding contacts) on a ball grid array.
- rebit noun Any of an arbitrary number of quantum mechanical binary states that are maximally entangled with every other one (in the real-vector-space…
- receptacle noun A contact device installed at an outlet for the connection of an attachment plug (typically by receiving the plug's prongs) to supply…
- reception noun The act or ability to receive radio or similar signals.
- recollision noun A repeat collision between two particles (such as an electron and an ion) which have collided before.
- recombination energy noun The energy released when two oppositely charged fragments of an atom or molecule recombine to form a neutral compound
- reconductor verb To replace the cable or wire on an electric circuit, typically a high-voltage transmission line, usually to afford a greater…
- rectify verb To convert (alternating current) into direct current.
- red noun One of the three color charges for quarks.
- red hydrogen noun hydrogen produced by using the waste heat from nuclear reactors to power high-temperature catalytic splitting
- redshift noun An increase in the wavelength of a photon or of light, corresponding to a lower frequency and a shift toward the red end of the…
- redward adj Toward the red end of the spectrum
- redwards adj Towards the red end of the spectrum
- reemit verb To emit something (especially radiation) that has previously been absorbed.
- reflectron noun A time-of-flight mass spectrometer that uses a static electric field to reverse the direction of travel of the ions entering it.
- refract verb Of a medium, substance, object, etc.: to deflect the course of (light rays), esp. when they enter the medium, etc., at an oblique angle; to…
- refraction noun The turning or bending of any wave, such as a light or sound wave, when it passes from one medium into another of different optical density.
- regenerative braking noun A form of braking used on some electric vehicles in conjunction with the main braking system, where kinetic energy from braking is…
- regional converter noun A tool used to change the plug shape to match the outlets in a different region or country.
- regular black hole noun A mathematical formulation for a black hole which does not contain a singularity. The environment outside the event horizon is the same as…
- relative atomic mass noun The ratio of the average mass per atom of the naturally occurring form of an element to 1/12 of the mass of a carbon-12 atom. Symbol Aᵣ…
- relative density noun A dimensionless measure which is the ratio of the mass of a substance to that of some reference substance (chiefly an equal volume of water…
- relativistic adj Of or relating to relativity.
- relativistic mechanics noun The mechanics of objects moving at speeds comparable to the speed of light; per special and general relativity.
- relativity noun Ellipsis of principle of relativity (“the principle that the laws of physics should be the same for all observers”).
- relaxation noun The transition of a nucleus, atom or molecule from a higher energy level to a lower one; the opposite of excitation
- relaxation time noun The characteristic time for a system to reach an equilibrium condition after a disturbance.
- relaxed adj Without physical tension; in a state of equilibrium.
- relay noun An electrical actuator that allows a relatively small electrical voltage or current to control a larger voltage or current.
- reluctance noun That property of a magnetic circuit analogous to resistance in an electric circuit.
- remanence noun The magnetization left behind in a medium after an external magnetic field is removed.
- renormalization noun Any of several techniques in statistical mechanics and quantum electrodynamics used to construct mathematical relationships between…
- renormalization group noun A mathematical apparatus that allows systematic investigation of the changes of a physical system as viewed at different distance scales.
- renormalize verb To subject to renormalization
- repeater noun An electronic device that receives a weak or low-level signal and retransmits it at a higher level or higher power.
- repel verb To force away by means of a repulsive force.
- repellent adj Tending or able to repel; driving back.
- repetition time noun The amount of time from the application of an excitation pulse to the application of the next pulse.
- rephase verb To return to being in phase.
- repose noun Chiefly in the form point of repose, position of repose, etc.: absence of motion; equilibrium; (countable) a position where an object is…
- reptation noun A creeping thermal motion of entangled linear polymers
- repulsion noun The repulsive force acting between bodies of the same electric charge or magnetic polarity.
- repulsive adj Having the capacity to repel.
- repump verb To use a laser to raise an electron (in an atom or ion etc) back to a previous high state.
- reseat verb To plug (something) back into its socket.
- reserve buoyancy noun The ability of a ship, boat, or other vessel to stay afloat even if loaded with additional weight; the additional buoyancy of a vessel…
- reset button noun A button that resets something.
- residual-current device noun An automatic circuit breaker that rapidly disconnects an electric circuit when the imbalance of the currents going through it exceeds a…
- resilience noun The physical property of material that can resume its shape after being stretched or deformed; elasticity.