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Mechanics

Quantum mechanics

Classical mechanics

Fluid mechanics

Solid mechanics

Statistical mechanics

Rate of change of velocity

Action (physics)

Physical quantity of dimension energy × time

Action principles

Variational principle for physical systems that minimizes the action of the system

AdS/CFT correspondence

Duality between theories of gravity on anti-de Sitter space and conformal field theories

Branch of dynamics concerned with studying the motion of air

Analytical mechanics

Concerned with the relationship between motion of bodies and its causes, namely the forces acting on the bodies and the properties of the bodies (particularly mass and moment of inertia)

Angle of Repose

Book by Wallace Stegner

Angular acceleration

Rate of change of angular velocity

Angular displacement

Displacement measured angle-wise when a body is showing circular or rotational motion

Angular frequency

Rate of change of the phase angle

Angular momentum operator

Quantum mechanical operator related to rotational symmetry

Angular velocity

Physical quantity

Archimedes' principle

Buoyancy principle in fluid dynamics

Science of the motion of projectiles

Bernoulli's principle

Principle relating to fluid dynamics

Boltzmann distribution

Probability distribution of energy states of a system

Calculation rule in quantum mechanics

Bose–Einstein statistics

Description of the behaviour of bosons

Physics of bouncing balls

System where a particle is subject to a potential such that the particle has a tendency to remain localised in one or more regions of space

Layer of fluid in the immediate vicinity of a bounding surface

Bra–ket notation

Notation for quantum states

Liability of breakage from stress without significant plastic deformation

Measure of how incompressible / resistant to compressibility a substance is

Upward force that opposes the weight of an object immersed in fluid

Canonical coordinates

Sets of coordinates on phase space which can be used to describe a physical system

Canonical ensemble

Ensemble of possible states of a mechanical system at a fixed temperature

Force resulting from the quantisation of a field

Cauchy stress tensor

Representation of mechanical stress at every point within a deformed 3D object

Cavendish experiment

Experiment to measure the gravitational force

Unique point where the weighted relative position of the distributed mass sums to zero

Central force on an object is a force that is directed along the line joining the object and the origin

Centrifugal force

Type of inertial force

Centripetal force

Force that makes a body follow a curved path

Circular motion

Object movement along a circular path

Circulation (physics)

Line integral of the fluid velocity around a closed curve

Classical mechanics

Description of large objects' physics

An instance of two or more bodies physically contacting each other within short period of time

Compressible flow

Branch of fluid mechanics

Compression (physics)

Application of inward ("pushing") forces to a material or structure

Compton wavelength

Quantum mechanical property of particles

Computational fluid dynamics

Branch of fluid mechanics that uses numerical analysis and data structures to solve and analyze problems that involve fluid flows

Conformal field theory

Quantum field theory enjoying conformal symmetry

Conservation of mass

Scientific law that a closed system's mass remains constant

Conservative force

Force with the property that the work done in moving a particle between two points is independent of the path taken

Contact mechanics

Study of the deformation of solids that touch each other

Continuum mechanics

Branch of physics which studies the behavior of materials modeled as continuous masses

Fluid flow that occurs due to heterogeneous fluid properties and body forces.

Copenhagen interpretation

Probabilistic interpretation of quantum mechanics involving wavefunction collapse

A force on objects moving within a reference frame that rotates with respect to an inertial frame.

Correspondence principle

Physics principle that quantum theories reproduce classical physics in the limit of large quantum numbers, formulated by Niels Bohr in 1920

Small crystal which forms under certain conditions

Mathematical law of motion

Davisson–Germer experiment

Deformation (engineering)

In engineering, any changes in the shape or size of an object

Deformation (physics)

Transformation of a body from a reference configuration to a current configuration

Degrees of freedom (mechanics)

Number of independent parameters needed to define the state of a mechanical system

Delta potential

Model of an energy potential in quantum mechanics

Mass per unit volume

Density of states

Describes the number of states per interval of energy at each energy level available to be occupied in a system

Movement of molecules, atoms, or ions from a region of high concentration to a region of low concentration

Diffusion equation

Equation that describes density changes of a material that is diffusing in a medium

Relativistic quantum mechanical wave equation

Displacement (geometry)

Vector relating the initial and the final positions of a moving point

Distribution function (physics)

Function of position and velocity which gives the number of particles per unit volume in single-particle phase space

Double-slit experiment

Physics experiment

Retarding force on a body moving in a fluid

Material ability to undergo significant plastic deformation before rupture

Dynamics (mechanics)

Branch of physics studying forces and their effect on motion

Ehrenfest theorem

Theorem that the time evolution of the expectation value of a quantum observable is proportional to that of the commutator between the observable and the Hamiltonian (plus that of any explicit time dependence of the operator, if any)

Elastic collision

Collision in which kinetic energy is conserved

Elastic modulus

Physical property that measures stiffness of material

Elasticity (physics)

Physical property when materials or objects return to original shape after deformation

Electron diffraction

Bending of electron beams due to electrostatic interactions with matter

Entropy (statistical thermodynamics)

Entropy in statistics

Equations for a falling body

Mathematical description of a body in free fall

Equations of motion

Equations that describe the behavior of a physical system

Region in space consisting of points at the same potential

Euler equations (fluid dynamics)

Set of quasilinear hyperbolic equations governing adiabatic and inviscid flow

Euler–Lagrange equation

Second-order partial differential equation whose solutions are the functions for which a given functional is stationary

Quantum states with more energy than the lowest possible amount

Expectation value (quantum mechanics)

Expected value of a quantum measurement

Fatigue (material)

The initiation and propagation of cracks in a material due to cyclic loading

Concept in quantum mechanics referring to the energy difference between the highest and lowest occupied single-particle states in a quantum system of non-interacting fermions at absolute zero temperature

Fermi–Dirac statistics

Statistical description for the behavior of fermions

Fictitious force

A force on objects moving within a reference frame that rotates with respect to an inertial frame.

Finite potential well

Quantum mechanics concept

Finite strain theory

Flight International

British aviation magazine

Flow measurement

Quantification of bulk fluid movement

Vector field which is used to mathematically describe the motion of a continuum

Substance which continuously deforms under an applied shear stress, including liquids and gases

Aspects of fluid mechanics involving flow

Fluid mechanics

Branch of physics concerned with the mechanics of fluids (liquids, gases, and plasmas)

Force (disambiguation)

Topics referred to by the same term

Force field (physics)

Region of space in which a force acts

Fourth, fifth, and sixth derivatives of position

Higher derivatives of the position vector with respect to time

Fracture toughness

Stress intensity factor at which a crack's propagation increases drastically

Frame of reference

Abstract coordinate system and the set of physical reference points that uniquely fix (locate and orient) the coordinate system and standardize measurement (s)

Free body diagram

Diagram showing applied forces and moments on a physical body

Motion of a body subject only to gravity

Particle that, in some sense, is not bound by an external force, or equivalently not in a region where its potential energy varies

Force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other

Galilean invariance

Low velocity approximation for special relativity

Galilean transformation

Transform between the coordinates of two reference frames which differ only by constant relative motion within the constructs of Newtonian physics

Generalized coordinates

Parameters that describe the configuration of the system relative to some reference configuration

g-factor (physics)

Relation between observed magnetic moment of a particle and the related unit of magnetic moment

Grand canonical ensemble

Statistical ensemble of particles in thermodynamic equilibrium

Granular convection

Movement in granular material

Gravitational field

Direction and intensity of gravity in every point of space

Gravitational potential

Scalar potential that describes a gravitational field

Lowest energy state of quantum-mechanical system

Gyromagnetic ratio

Ratio of magnetic moment to angular momentum

Hamiltonian (quantum mechanics)

Quantum operator for the sum of energies of a system

Hamiltonian mechanics

Branch of analytical mechanics

Harmonic oscillator

Physical system that responds to a restoring force inversely proportional to displacement

Physical law: force needed to deform a spring scales linearly with distance

Hydrostatic equilibrium

Property of fluid mechanics

Impact (mechanics)

High force or shock applied over a short time period when two or more bodies collide

Impulse (physics)

Integral of a force over a time interval

Incompressible flow

Fluid flow in which density remains constant

Indistinguishable particles

Concept in quantum mechanics of perfectly substitutable particles

Inelastic collision

Collision where energy is lost to heat, so that kinetic energy is not conserved

Fundamental principle of classical physics

Inertial frame of reference

Fundamental concept of classical mechanics

Interpretations of quantum mechanics

Set of statements which attempt to explain how quantum mechanics informs our understanding of nature

Introduction to quantum mechanics

Non-technical introduction to quantum physics

Rate of change of acceleration with time.

Kepler conjecture

Mathematical theorem about sphere packing

Branch of physics describing the motion of objects or groups of objects without considering its cause

Energy of a moving physical body

Lagrangian mechanics

Formulation of classical mechanics

Flow where fluid particles follow smooth paths in layers

Force perpendicular to flow of surrounding fluid

Type of motion in which the path of the moving object is a straight line

Manab Adhikar Sangram Samiti

Human rights NGO in Assam

Many-worlds interpretation

Interpretation of quantum mechanics which denies the collapse of the wavefunction

Mass flow (life sciences)

Movement of fluids down a pressure or temperature gradient

Mass of a substance which passes per unit of time

Mathematical formulation of quantum mechanics

Mathematical structures that allow quantum mechanics to be explained

Aspect of wave–particle duality

Maxwell–Boltzmann distribution

Specific probability distribution function, important in physics

Maxwell–Boltzmann statistics

Statistical distribution used in many-particle mechanics

Maxwell's demon

Thought experiment of 1867

Measurement in quantum mechanics

Interaction of a quantum system with a classical observer

Measurement problem

In quantum mechanics, the problem of how or whether wave function collapse occurs during measurement

Mechanical advantage

Measure of the force amplification achieved by using a tool, mechanical device or machine system

Mechanical equilibrium

In classical mechanics, a particle is in mechanical equilibrium if the net force on that particle is zero

Mechanical resonance

Tendency of a mechanical system

Science concerned with physical bodies subjected to forces or displacements

Microcanonical ensemble

Ensemble of states with an exactly specified total energy

Microstate (statistical mechanics)

Specific microscopic configuration of a thermodynamic system

Molecular diffusion

The thermal motion of liquid or gas particles at temperatures above absolute zero

Moment (physics)

Concept in physics

Moment of inertia

Scalar measure of the rotational inertia with respect to a fixed axis of rotation

Conserved physical quantity related to the motion of a body

Momentum operator

Operator in quantum mechanics

Change in position of an object over time

Navier–Stokes equations

Equations describing the motion of viscous fluid substances

Problem in physics and celestial mechanics

Newtonian dynamics

Formulation of physics

Newtonian fluid

Fluid in which the viscous stresses arising from its flow, at every point, are linearly proportional to the local strain rate—the rate of change of its deformation over time; the simplest mathematical model of fluid that account for viscosity

Newton's law of universal gravitation

Classical mechanics physical law

Newton's laws of motion

Physical laws in classical mechanics

Non-inertial reference frame

Frame of reference

Non-Newtonian fluid

Fluid that does not follow Newton's Law of Viscosity

Force exerted on an object by a body with which it is in contact, and vice versa

Pattern of motion in which all parts of the system move sinusoidally with the same frequency and with a fixed phase relation

In physics, a dynamic variable that can be measured

Operator (physics)

Function acting on the space of physical states in physics

Repetitive variation of some measure about a central value

Chemical process

Parity (physics)

Symmetry of physical systems under mirror reflections.

Particle in a box

Physical model in quantum mechanics which is analytically solvable

Particle statistics

Particular description of multiple particles in statistical mechanics

Partition function (statistical mechanics)

Function in thermodynamics and statistical physics

Path integral formulation

Formal sum or integral over all histories of a quantum system

Pauli exclusion principle

Quantum mechanics principle

Perpetual motion (disambiguation)

Topics referred to by the same term

Perturbation theory

Mathematical methods used to find an approximate solution to a problem which cannot be solved exactly

Piezoelectricity

Electric charge that accumulates in certain solids

Type of liquid flow within a closed conduit

Planck postulate

Principle of quantum physics

Plasticity (physics)

The deformation of a solid material undergoing non-reversible changes of shape in response to applied forces

Mathematical abstraction modeling objects with zero extent, heavily used in physics to understand nature

Poisson's ratio

Parameter of elastic materials: ratio of transverse strain to axial strain

Position (geometry)

Vector representing the position of a point with respect to a fixed origin

Position and momentum spaces

Physical spaces representing position and momentum, Fourier transform duals

Position operator

Operator in quantum mechanics

Potential energy

Energy held by an object because of its position relative to other objects

Concept in quantum mechanics

Power (physics)

Rate at which energy is transferred, used, or transformed

Periodic change in the direction of a rotation axis

Probability amplitude

Complex number whose squared absolute value is a probability

Any object thrown by an exertion of an unbalanced force in an inertial frame of reference

Projectile motion

Motion of an object given an initial velocity which then follows a path determined entirely by gravity

Quantization (physics)

Procedure to construct a quantum system whose classical limit corresponds to a given classical system

Aspect of physics

Quantum chromodynamics

Theory of the strong nuclear interactions

Quantum electrodynamics

Relativistic quantum field theory of electromagnetism

Quantum entanglement

Correlation between measurements of quantum subsystems, even when spatially separated

Quantum field theory

Theoretical framework combining classical field theory, special relativity, and quantum mechanics

Quantum fluctuation

Random change in the energy inside a (typically sub-microscopic) volume

Fluctuation of spacetime on very small scales

Quantum gravity

Field of theoretical physics

Quantum harmonic oscillator

Important, well-understood quantum mechanical model

Quantum indeterminacy

The apparent lack of definite state before measurement of quantum systems

Quantum mechanics

Description of physical properties at the atomic and subatomic scale

Notation for conserved quantities in physics and chemistry

Quantum potential

Quantum mechanical statistic

Mathematical entity to describe the probability of each possible measurement on a system

Quantum superposition

Principle of quantum mechanics

Quantum tunnelling

Quantum mechanical phenomenon

Radiation pressure

Pressure exerted upon any surface exposed to electromagnetic radiation

Reaction (physics)

Part of Newton's laws

"effective" inertial mass appearing in the two-body problem of Newtonian mechanics; quantity which allows the two-body problem to be solved as if it were a one-body problem

Relativistic mechanics

Theory of motion and forces for objects close to the speed of light

Relativistic quantum mechanics

Quantum mechanics taking into account particles near or at the speed of light

Restoring force

Physical force acting to bring a system back toward equilibrium

Resultant force

Single force representing the combination of all forces acting on a physical body

Reynolds number

Ratio of inertial to viscous forces acting on a liquid

Study of the flow of matter, primarily in a liquid state

Physical object which does not deform when forces or moments are exerted on it

Rigid body dynamics

Study of the effects of forces on undeformable bodies

Type of motion that combines rotation and translation of an object with respect to a surface with which it is in contact

Movement of an object around an axis

Scalar potential

When potential energy difference depends only on displacement

Schrödinger equation

Linear partial differential equation whose solution describes the quantum-mechanical system.

Schrödinger's cat

Thought experiment devised by the physicist Erwin Schrödinger

Ratio of shear stress to the shear strain

Component of stress coplanar with a material cross section

Shearing (physics)

Shock (mechanics)

Sudden transient acceleration

Simple harmonic motion

To and fro periodic motion in science and engineering

Branch of soil physics and applied mechanics that describes the behavior of soils

Solid mechanics

Branch of mechanics concerned with solid materials and their behaviors

Speed (disambiguation)

Topics referred to by the same term

Branch of mechanics concerned with balance of forces in nonmoving systems

Stationary state

In quantum mechanics

Statistical mechanics

Physics of large number of particles' statistical behavior

State of a system or a process in which the variables which define the behavior of the system or the process are unchanging in time

Stern–Gerlach experiment

Physical experiment that demonstrated the quantization of angular momentum

Resistance to deformation in response to force

Strength of materials

Behavior of solid objects subject to stresses and strains

Stress (mechanics)

Physical quantity that expresses internal forces in a continuous material

Surface tension

Tendency of a liquid surface to shrink to reduce surface area

Symmetry in quantum mechanics

Properties underlying modern physics

Tension (physics)

Pulling force transmitted axially – Opposite of compression

Study of an Partical

A force that stretches a body along the line towards the center of mass of another body due to a gradient in gravitational field

Physics concept

Torsion (mechanics)

Twisting of an object due to an applied torque

Material ability to absorb energy and plastically deform without fracturing

Path of a moving object

Motion characterized by chaotic changes in pressure and flow velocity

Two-body problem

Motion problem in classical mechanics

Uncertainty principle

Foundational principle in quantum physics

Vector potential

A vector field whose curl is a given vector field

Vector that measures the rate of change in position over time of a moving point

Mechanical oscillations about an equilibrium point

Physics theorem

Resistance of a fluid to shear deformation

Volumetric flow rate

Volume of fluid which passes per unit time

Pseudovector field in continuum mechanics

Mathematical description of the quantum state of a system

Wave function collapse

Process by which a quantum system takes on a definitive state

Wave–particle duality

Concept in quantum mechanics

Instrument to measure the weight of an object

Force on a mass due to gravity

WKB approximation

Solution method for linear differential equations

Process of energy transfer to an object via force application through displacement

Work (thermodynamics)

Form of energy defined in the first law of thermodynamics

Young's modulus

Mechanical property that measures stiffness of a solid material

Zero-point energy

Lowest possible energy of a quantum system or field