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Physics terms glossary page 3

Physics terms explained in plain English. 735 words and meanings, most familiar first.

Word	Meaning
diffusion noun	The scattering of light by reflection from a rough surface, or by passage through a translucent medium.
digression noun	An elongation, a deflection or deviation from a mean position or expected path.
dipole noun	Any object (such as a magnet, polar molecule or antenna) that is oppositely charged at two points (or poles).
directivity noun	A measure of the performance of an antenna compared to an isotropic antenna; the ratio of the maximum value of radiation intensity to the average radiation intensity.
discriminator noun	Any of several electronic devices that convert some property of a signal into an amplitude whose value is proportional to the difference between the value of the input signal and that of a standard.
dissipation noun	A loss of energy, usually as heat, from a dynamic system.
ductility noun	Ability of a material to be drawn out longitudinally to a reduced section without fracture under the action of a tensile force.
excitation noun	A transition of a nucleus, atom or molecule to an excited state by the absorption of a quantum of energy; the opposite of relaxation
ferromagnet noun	A ferromagnetic material
fissile adjective	Capable of sustaining a nuclear fission chain reaction.
flatlander noun	An inhabitant of or observer in a universe with two spatial dimensions.
flavorless adjective	Without flavor.
fluoresce verb	To emit electromagnetic radiation, especially visible light, when absorbing radiation of some other wavelength.
fluorescence noun	The emission of light (or other electromagnetic radiation) by a material when stimulated by the absorption of radiation or of a subatomic particle.
formalism noun	A particular mathematical or scientific theory or description of a given state or effect.
fugacity noun	A measure of the relative stability of different phases of a substance under the same conditions.
gravimeter noun	An instrument used to measure local variations in the gravitational field.
handedness noun	The property that distinguishes an asymmetric object from its mirror image. For example, the essential difference between a left and right glove.
helicon noun	A low-frequency electromagnetic wave observed in various plasmas.
heterogeneous adjective	Having more than one phase (solid, liquid, gas) present in a system or process.
hybridize verb	To combine atomic orbitals mathematically to form hybrid orbitals.
hydrostatic adjective	Of or relating to hydrostatics.
immiscible adjective	Of two or more liquids that are not mutually soluble: unmixable.
impedance noun	A measure of the opposition to the flow of an alternating current in a circuit; the aggregation of its resistance, and inductive and capacitive reactances; the ratio of voltage to current treated as complex quantities.
implantation noun	The insertion of ions into the crystal structure of another material through ion bombardment.
imponderable noun	An imponderable substance or body; specifically, in the plural, a name formerly applied to heat, light, electricity, and magnetism.
incandescence noun	The emission of visible light by a hot body
inductance noun	The property of an electric circuit by which a voltage is induced in it by a changing magnetic field.
inductive adjective	Of, relating to, or arising from inductance.
inexact adjective	Having a path-dependent integral
intermolecular adjective	From one molecule to another; between molecules
interstitial noun	An interstitial discontinuity in a crystal.
ionization noun	Any process that leads to the dissociation of a neutral atom or molecule into charged particles ions; the state of being ionized.
isometric adjective	Taking place at constant volume because of being confined by rigid boundaries.
jounce noun	The fourth derivative of the position vector with respect to time; the time derivative of jerk.
ket noun	A column vector, in Hilbert space, especially as representing the state of a quantum mechanical system; the complex conjugate of a bra (a row vector); a ket vector. Symbolised by \|...〉.
kinesis noun	Any energy that creates/controls movement.
luminal adjective	Of or pertaining to the nature of light
luminescence noun	Any emission of light that cannot be attributed merely to the temperature of the emitting body.
luminosity noun	The ratio of luminous flux to radiant flux at the same wavelength; the luminosity factor
macroscopic adjective	Having an appreciable mass.
magnetize verb	To make magnetic.
magnetometer noun	An instrument used to measure the intensity and direction of a magnetic field, especially at points on the Earth's surface; sometimes used as metal detector.
maser noun	A device for the coherent amplification or generation of electromagnetic radiation (especially of microwave frequency) by the use of excitation energy in resonant atomic or molecular systems
materialization noun	The conversion of energy into mass
mesic adjective	Of or pertaining to mesons; mesonic.
micron noun	The thousandth part of one millimeter; the millionth part of a meter.
miscible adjective	Able to be mixed together in all proportions.
modulation noun	The process of applying a signal to a carrier.
modulus noun	A coefficient that expresses how much of a certain property is possessed by a certain substance.
monopole noun	A magnetic monopole.
multiplier noun	Any of several devices used to enhance a signal
nucleonics noun	The study of nucleons, or of atomic nuclei
observable noun	Any physical property that can be observed and measured directly and not derived from other properties
occlusion noun	The absorption of a gas or liquid by a substance such as a metal.
overtone noun	A tone whose frequency is an integer multiple of another; a member of the harmonic series.
parity noun	Symmetry of interactions under spatial inversion.
permeability noun	A quantitative measure of the degree of magnetization of a material in the presence of an applied magnetic field (measured in newtons per ampere squared in SI units).
perturb verb	To slightly modify the motion of an object.
perturbation noun	Variation in an orbit due to the influence of external bodies
phenomenology noun	The use of theoretical models to make predictions that can be tested through experiments.
photometer noun	Any of several instruments used to measure various aspects of the intensity of light.
plenum noun	A space that is completely filled with matter.
polarization noun	The production of polarized light; the direction in which the electric field of an electromagnetic wave points
polychromatic adjective	Composed of more than one wavelength.
polyphase adjective	Of, pertaining to, or consisting of multiple phases of matter
ponderable adjective	Having a detectable amount of matter; having a measurable mass.
potentiality noun	Quantum potential.
precession noun	The wobbling motion of the axis of a spinning body when there is an external force acting on the axis.
propagator noun	A function that represents the quantum propagation of a subatomic particle
quadrature noun	The condition in which the phase angle between two alternating quantities is 90°.
quantize verb	To limit the number of possible values of a quantity, or states of a system, by applying the rules of quantum mechanics
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.
rapidity noun	A measure of velocity relative to the speed of light

Word	Meaning
reflectivity noun	The property or quality of being reflective.
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.
relativistic adjective	Of or relating to relativity.
retardation noun	Deceleration; reduction in the magnitude of velocity.
scalar adjective	Relating to particles with a spin (quantum angular momentum) of 0 (known as spin 0).
semiconductor noun	A substance with electrical properties intermediate between a good conductor and a good insulator.
shadowgraph noun	An optical technique of visualizing patterns of fluid flow by using differences in refractive index
singlet noun	A multiplet having a single member, especially a single spectroscopic peak.
slowness noun	A unit, the reciprocal of velocity, that delineates the amount of time required for an object to travel a given distance.
solidus noun	The line in a phase diagram marking the temperatures and pressures below which a given substance is a stable solid.
speckle noun	The random distribution of light when it is scattered by a rough surface.
sputter verb	To cause surface atoms or electrons of a solid to be ejected by bombarding it with heavy atoms or ions.
sublimate verb	To change state from a solid to a gas without passing through the liquid state.
superconductivity noun	The property of a material whereby it has no resistance to the flow of an electric current.
supergroup noun	A generalization of groups, used in the study of supersymmetry.
susceptibility noun	Electric susceptibility, a measure of how easily a dielectric polarizes in response to an external electric field (compare permittivity).
tailwind noun	A wind that blows in the same direction as the course taken by an aircraft, sailing ship, bird, etc.
tensor noun	A mathematical object that describes linear relations on scalars, vectors, matrices and other algebraic objects, and is represented as a multidimensional array.
thermodynamic adjective	Of, or relating to thermodynamics.
tortuosity noun	A property of curve being tortuous, commonly used to describe diffusion in porous media.
transduction noun	The conversion of energy (especially light energy) into another form, especially in a biological process such as photosynthesis or in a transducer.
translational adjective	Relating to movement of a body in a straight line.
triplet noun	A triquark.
ultrashort adjective	Having a wavelength of between 1 and 10 metres
uncharged adjective	Not carrying an overall electric charge; neutral.
vernier noun	A secondary system of force application for the attitude control of a spacecraft; for example a vernier thruster.
viscosity noun	A quantity expressing the magnitude of internal friction in a fluid, as measured by the force per unit area resisting uniform flow.
wiggler noun	A magnet designed to make a beam of charged particles follow a curving path in an accelerator.
dalton noun	The atomic mass unit
faraday noun	The quantity of electricity required to deposit or liberate 1 gram equivalent weight of a substance during electrolysis; approximately −96,487 coulombs.
pp noun	Proton and proton (used attributively to describe a collision or other interaction of these two particles)
tachyon noun	A flaw in a physical theory that predicts the existence of tachyons or similar paradoxical results. Compare with ghost.
absorbance noun	A logarithmic measure of the amount of light that is absorbed when passing through a substance; the capacity of a substance to absorb light of a given wavelength; optical density.
absorbency noun	The ratio of the absorbance or optical density of a substance to that of a similar body of pure solvent.
aclinic adjective	Without inclination or dipping.
actinism noun	That property of electromagnetic radiation that leads to the production of photochemical effects
actinometer noun	A device used to measure the heating power of electromagnetic radiation, especially that of solar radiation.
adsorb verb	To accumulate on a surface, by adsorption
aeroelasticity noun	The scientific study of the effect of aerodynamic loads on structures.
aeromechanics noun	The branch of mechanics that deals with the motion of gases; it comprises aerostatics and aerodynamics
aerostatics noun	The study of gases in equilibrium and of balloons or aircraft in varying atmospheric conditions
aerothermodynamics noun	The scientific study of the thermodynamic properties of gases, especially when travelling at a high velocity.
allobar noun	Any form of an element having a different isotopic composition to that of the natural element, and thus a different atomic weight.
altocumulus noun	A fleecy cloud formation consisting of large whitish or greyish globular cloudlets with shaded portions, often grouped in flocks or rows. (Abbreviated Ac.)
altostratus noun	A principal medium-level cloud type in the form of a gray or bluish (never white) sheet or layer of striated, fibrous, or uniform appearance.
amperage noun	The electric current; charge transmitted per unit time, measured in amperes.
amperometric adjective	That involves measurement of an electric current during a process such as titration
anergy noun	Dilute or disorganized energy, which cannot be transformed into work.
anisotropic adjective	Having properties that differ according to the direction of measurement; exhibiting anisotropy.
antiferromagnet noun	An antiferromagnetic material
antiferromagnetic adjective	Exhibiting antiferromagnetism.
antimagnetic adjective	Unable to be magnetized; unaffected by a magnetic field.
antineutron noun	The antiparticle corresponding to a neutron.
antinodal adjective	Of, pertaining to, or located at an antinode
antinode noun	A region of maximum amplitude situated between adjacent nodes of a vibrating body, such as a string.
antiproton noun	The antiparticle of the proton, having a negative electric charge.
aperiodic adjective	That does not have a periodic vibration
attenuator noun	Any device that attenuates a signal, but especially an electronic device that reduces the amplitude of a signal
axion noun	A hypothetical subatomic particle postulated to resolve certain symmetry problems concerning the strong nuclear force.
azeotrope noun	A mixture of two or more substances whose liquid and gaseous forms have the same composition (at a certain pressure); the substances cannot be separated by normal distillation.
backscattering noun	The scattering of waves, particles, or signals back in the direction of their source.
barye noun	A unit of pressure under the CGS system; symbol Ba; equal to 1 dyne per square centimeter. 1 Ba = 0.1 Pa = 0.1 N/m2 = 1x10-6 bar.
betatron noun	A form of cyclotron used to accelerate electrons to high speed.
bilinear adjective	Of or pertaining to a Möbius transformation (type of conformal map representable as the ratio of two linear functions).
bioelectricity noun	Any form of electricity generated within an organism, especially by a muscle or nerve
bioenergetics noun	The study of the energy transformations that take place in living organisms.
biomechanics noun	The branch of biophysics that deals with the mechanics of the human or animal body; especially concerned with muscles and the skeleton.
birefringence noun	The splitting of a ray of light into two parallel rays of perpendicular polarization by passage through an optically anisotropic medium; the property of a material that light passing through it is so split.
blackbody noun	A theoretical body, approximated by a hole in a hollow black sphere, that absorbs all incident electromagnetic radiation and reflects none; it has a characteristic emission spectrum
bolometer noun	A sensitive device for detecting and measuring the energy of electromagnetic radiation.
calorics noun	The study of heat flow and heat transfer.
calorific adjective	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.
calutron noun	A form of mass spectrometer used to separate the isotopes of uranium.

Meanings from Wiktionary (CC BY-SA 4.0). Sources