kb/data/en.wikipedia.org/wiki/Glossary_of_physics-11.md

title	chunk	source	category	tags	date_saved	instance
Glossary of physics	12/13	https://en.wikipedia.org/wiki/Glossary_of_physics	reference	science, encyclopedia	2026-05-05T07:51:11.278375+00:00	kb-cron

stiffness The rigidity of an object, i.e. the extent to which it resists deformation in response to an applied force.

strain The transformation of a body from a reference configuration to a current configuration. A configuration is a set containing the positions of all particles of the body.

strain hardening

strength of materials

stress

1. An applied force or system of forces that tends to strain or deform a physical body.
2. A measure of the internal forces acting within a deformable body.
3. A quantitative measure of the average force per unit area of a surface within a body on which internal forces act.

stress–strain curve

string duality

string theory

strong interaction Also strong force and strong nuclear force.

structural load

subatomic particle Any particle that is smaller than an atom.

sublimation The physical process by which matter is transformed directly from the solid phase to the gas phase without passing through an intermediate liquid phase. Sublimation is an endothermic phase transition that occurs at temperatures and pressures below a substance's triple point in its phase diagram.

superconductivity

superconductor A phenomenon of exactly zero electrical resistance and expulsion of magnetic fields occurring in certain materials when cooled below a characteristic critical temperature.

superhard material

superposition principle

supersymmetry (SUSY)

surface tension

== T ==

temperature A physical property of matter that quantitatively expresses the common notions of hot and cold.

tensile modulus

tensile strength

tesla (T)

test particle

theoretical physics A branch of physics that employs mathematical models and abstractions of physical objects and systems in order to rationalize, explain, and predict natural phenomena, as opposed to experimental physics, which relies on data generated by experimental observations.

theory of everything (ToE)

theory of relativity

thermal conduction

thermal equilibrium A state in which there is no net flow of thermal energy between two physical systems when the systems are connected by a path permeable to heat. A system may also be said to be in thermal equilibrium with itself if the temperature within the system is spatially and temporally uniform. Systems in thermodynamic equilibrium are always in thermal equilibrium, but the converse is not always true.

thermal radiation

thermionic emission

thermodynamic equilibrium

thermodynamic free energy

thermodynamics

thermometer An instrument used to measure temperature.

third law of thermodynamics

threshold frequency

torque Also moment or moment of force. The tendency of a force to rotate an object about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist to an object.

total internal reflection

toughness The ability of a material to absorb energy and plastically deform without fracturing. Material toughness is defined as the amount of energy per unit volume that a material can absorb before rupturing. It is also defined as the resistance to fracture of a material when stressed.

trajectory The path that a moving object follows through space as a function of time.

transducer

transmission medium

transverse wave

trigonometry A branch of mathematics that studies triangles and the relationships between their sides and the angles between these sides.

trimean

triple point The temperature and pressure at which the three phases (gas, liquid, and solid) of a given substance coexist in thermodynamic equilibrium.

truncated mean

== U ==

unbalanced forces When there is unbalanced force(s); and as such, the object changes its state of motion. The object is not at equilibrium and subsequently accelerates.

uncertainty principle Any of a variety of mathematical inequalities asserting a fundamental limit to the precision with which certain pairs of physical properties of a particle, such as position x and momentum p, cannot be known simultaneously.

unified atomic mass unit One dalton: one-twelfth the mass of an isolated neutral atom of the isotope 126C in its ground state.

uniform motion

uniform circular motion

unit vector

utility frequency The frequency of the oscillations of alternating current (AC) in an electric power grid transmitted from a power plant to the end-user.

== V ==

vacuum An area of space which contains no matter.

valence electron An electron that is associated with an atom and can participate in the formation of a chemical bond.

valence shell The outermost electron shell of an atom.

valley of stability

Van de Graaff generator

variable capacitor

variable resistor

vector Any quantity that has both magnitude and direction.

vector space A mathematical structure formed by a collection of elements called vectors, which may be added together and multiplied ("scaled") by numbers called scalars.

velocity (

    v
  

{\displaystyle v}

) A vector quantity defined as the rate of change of the position of an object with respect to a given frame of reference. Velocity specifies both an object's speed and direction of motion (e.g. 60 kilometres per hour to the north).

virtual image

virtual particle

viscoelasticity

viscosity

visible light A form of electromagnetic radiation generally defined as the range of wavelengths visible to the average human eye.

volt (V) The SI derived unit for electric potential, electric potential difference, and electromotive force, defined as the difference in electric potential between two points of a conducting wire when an electric current of one ampere dissipates one watt of power between those two points.

Volta potential

voltage

voltmeter An instrument used for measuring the difference in electric potential between two points in an electric circuit. Analog voltmeters move a pointer across a scale in proportion to the voltage of the circuit.

volt per metre

volume

== W ==

W and Z bosons

watt (W) A derived unit of power in the International System of Units (SI) defined as one joule per second. The watt measures the rate of energy conversion or transfer.

wave A disturbance or oscillation that travels through spacetime accompanied by a transfer of energy.

wave equation

wave function

wave function collapse

wave–particle duality

wavelength A measure of the distance traversed by a single spatial period of a sinusoidal wave, i.e. the distance over which the wave's shape repeats.