physics -
the science of matter and energy and their interactions.
≡natural philosophy
↔phase space - (physics)
an ideal space in which the coordinate dimensions represent the variables that are required to describe a system or substance; "a multidimensional phase space".
↔containment - (physics)
a system designed to prevent the accidental release of radioactive material from a reactor.
↔hodoscope - (physics)
scientific instrument that traces the path of a charged particle.
↔magnet - (physics)
a device that attracts iron and produces a magnetic field.
↔meniscus - (physics)
the curved upper surface of a nonturbulent liquid in a vertical tube.
↔nuclear reactor, reactor - (physics)
any of several kinds of apparatus that maintain and control a nuclear reaction for the production of energy or artificial elements.
↔metastability -
the quality of a physical system that persists in its existing equilibrium when undisturbed (or only slightly disturbed) but able to pass to a more stable equilibrium when sufficiently disturbed.
↔isotropy, symmetry - (physics)
the property of being isotropic; having the same value when measured in different directions.
↔wave-particle duality, duality - (physics)
the property of matter and electromagnetic radiation that is characterized by the fact that some properties can be explained best by wave theory and others by particle theory.
↔absorption factor, absorptivity - (physics)
the property of a body that determines the fraction of the incident radiation or sound flux absorbed or absorbable by the body.
↔reluctivity - (physics)
the resistance of a material to the establishment of a magnetic field in it.
↔rest mass - (physics)
the mass of a body as measured when the body is at rest relative to an observer, an inherent property of the body.
↔relativistic mass - (physics)
the mass of a body in motion relative to the observer: it is equal to the rest mass multiplied by a factor that is greater than 1 and that increases as the magnitude of the velocity increases.
↔gravitational mass - (physics)
the mass of a body as measured by its gravitational attraction for other bodies.
↔inertial mass - (physics)
the mass of a body as determined by the second law of motion from the acceleration of the body when it is subjected to a force that is not due to gravity.
↔mass energy - (physics)
the mass of a body regarded relativistically as energy.
↔flux density, flux - (physics)
the number of changes in energy flow across a given surface per unit area.
↔absorbance, optical density, photographic density, transmission density - (physics)
a measure of the extent to which a substance transmits light or other electromagnetic radiation.
↔quantum - (physics)
the smallest discrete quantity of some physical property that a system can possess (according to quantum theory).
↔attracter, attractor - (physics)
a point in the ideal multidimensional phase space that is used to describe a system toward which the system tends to evolve regardless of the starting conditions of the system.
↔Bose-Einstein statistics - (physics)
statistical law obeyed by a system of particles whose wave function is not changed when two particles are interchanged (the Pauli exclusion principle does not apply).
↔Dalton's law of partial pressures, law of partial pressures, Dalton's law - (chemistry and physics)
law stating that the pressure exerted by a mixture of gases equals the sum of the partial pressures of the gases in the mixture; the pressure of a gas in a mixture equals the pressure it would exert if it occupied the same volume alone at the same temperature.
↔Boltzmann distribution law, Maxwell-Boltzmann distribution law - (physics)
a
law expressing the distribution of energy among the molecules of a gas in thermal equilibrium.
↔Fermi-Dirac statistics - (physics)
law obeyed by a systems of particles whose wave function changes when two particles are interchanged (the Pauli exclusion principle applies).
↔Charles's law, Gay-Lussac's law, law of volumes - (physics)
the density of an ideal gas at constant pressure varies inversely with the temperature.
↔Hooke's law - (physics)
the principle that (within the elastic limit) the stress applied to a solid is proportional to the strain produced.
↔Kirchhoff's laws - (physics)
two laws governing electric networks in which steady currents flow: the sum of all the currents at a point is zero and the sum of the voltage gains and drops around any closed circuit is zero.
↔law of gravitation, Newton's law of gravitation - (physics)
the law that states any two bodies attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
↔law of thermodynamics - (physics)
a law governing the relations between states of energy in a closed system.
↔mass-energy equivalence - (physics)
the principle that a measured quantity of mass is equivalent (according to relativity theory) to a measured quantity of energy.
↔Planck's law - (physics)
the basis of quantum theory; the energy of electromagnetic waves is contained in indivisible quanta that have to be radiated or absorbed as a whole; the magnitude is proportional to frequency where the constant of proportionality is given by Planck's constant.
2. physics - the physical properties, phenomena, and laws of something; "he studied the physics of radiation"
≡physical science
↔natural science -
the sciences involved in the study of the physical world and its phenomena.
↔acoustics -
the study of the physical properties of sound
