Concepts in physics

geometric object that has magnitude (or length) and direction

In physics, spacetime, also called the space-time continuum, is a mathematical model that fuses the three dimensions of space and the one dimension of time into a single four-dimensional continuum. Spacetime diagrams are useful in visualizing and understanding relativistic effects, such as how different observers perceive where and when events occur.

the basic algebraic structure of linear algebra; a module over a field, such that its elements can be added together or scaled by elements of the field

theory of particle physics based on Yang–Mills theory with gauge group SU(3)×SU(2)×U(1) and spontaneous symmetry breaking

physical theory of quantized one-dimensional objects with conformal symmetry, which can describe gravitation, gauge theory and other phenomena

property of binary operations, for which changing the order of the operands does not change the result

quantum mechanical principle that two identical fermions cannot occupy the same quantum state simultaneously

thumb|The spectrum in a rainbow

singular aggregation of tangible substance(s) such as matter or radiation, with overall properties

region in a substance throughout which all physical properties are essentially uniform; region of material that is chemically uniform, physically distinct, (often) mechanically separable

right|thumb|300px|The second-order Cauchy stress tensor \mathbf{T} describes the stress experienced by a material at a given point. For any unit vector \mathbf{v}, the product \mathbf{T} \cdot \mathbf{v} is a vector, denoted \mathbf{T}(\mathbf{v}), that quantifies the force per area along the plane perpendicular to \mathbf{v}. This image shows, for cube faces perpendicular to \mathbf{e}_1, \mathbf{e}_2, \mathbf{e}_3, the corresponding stress vectors \mathbf{T}(\mathbf{e}_1), \mathbf{T}(\mathbf{e}_2), \mathbf{T}(\mathbf{e}_3) along those faces. Because the stress tensor takes one vector as inpu

In fluid dynamics, turbulence or turbulent flow is fluid motion exhibiting chaotic changes in pressure and flow velocity. It is in contrast to laminar flow, which occurs when a fluid flows in parallel layers with no disruption between those layers.

elastic scattering of light, or other electromagnetic radiation, by particles of size much smaller than the wavelength of the radiation

Supersymmetry is a theoretical framework in physics that suggests the existence of a symmetry between particles with integer spin (bosons) and particles with half-integer spin (fermions). It proposes that for every known particle, there exists a partner particle with different spin properties. There have been multiple experiments on supersymmetry that have failed to provide evidence that it exists in nature. If evidence is found, supersymmetry could help explain certain phenomena, such as the nature of dark matter and the hierarchy problem in particle physics.

statistical description for the behaviour of bosons

system of nonlinear partial differential equations describing the motion of viscous fluids

portion of the physical universe chosen for analysis; everything outside the system is known as the environment

ideal property of waves that enables stationary (i.e. temporally and spatially constant) interference

lowest possible energy of a quantum system or field

pictorial representations of the behavior of subatomic particles

particle with no physical extent, either an idealization or a feature of elementary particles

system in which the change of the output is not proportional to the change of the input

thumb|Supercooled water, still in liquid state thumb|Start of solidification as a result of leaving the state of rest Supercooling, also known as undercooling, is the process of lowering the temperature of a liquid below its freezing point without it becoming a solid. Per the established international definition, supercooling means "cooling a substance below the normal freezing point without solidification". While it can be achieved by different physical means, the postponed solidification is most often due to the absence of seed crystals or nuclei around which a crystal structure can form. Th

physical law that differentiable symmetries correspond to conservation laws

In special relativity, a four-vector (or 4-vector, sometimes Lorentz vector) is an element of a four-dimensional vector space object with four components, which transform under Lorentz transformations with respect to a change of basis. Its magnitude is determined by an indefinite quadratic form, the preservation of which defines the Lorentz transformations, which include spatial rotations and boosts (a change by a constant velocity to another reference frame).

thumb|upright=1.2|Self-organization in micron-sized Nb3O7(OH) cubes during a Hydrothermal synthesis|hydrothermal treatment at 200 °C. Initially [[amorphous cubes gradually transform into ordered 3D meshes of crystalline nanowires as summarized in the model below.]]

abstract space whose coordinates are the dynamic variables of the studied system

process by which a quantum system takes on a definitive state

transient fluctuations of physical fields with existence limited and required by the uncertainty-principle

length scale on which objects or phenomena are large enough to be visible almost practically with the naked eye

symmetric rank (0, 2) tensor field on a smooth manifold

general equation that relates the time-averaged total kinetic energy of a stable system consisting of N particles, bound by potential forces, with that of the time-averaged total potential energy

formal sum or integral over all histories of a quantum system

Two-dimensional rotation can occur in two possible directions, or senses of rotation. Clockwise motion (abbreviated CW) proceeds in the same direction as a clock's hands relative to the observer: from the top to the right, then down and then to the left, and back up to the top. The opposite sense of rotation or revolution is (in Commonwealth English) anticlockwise (ACW) or (in North American English) counterclockwise (CCW). Three-dimensional rotation can have similarly defined senses when considering the corresponding angular velocity vector.

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

feature of a system that is preserved under some transformation

a vector field whose curl is a given vector field

spatially nonlocal causation: the concept that an object can be directly influenced by one that is not adjacent to it

involutive transformation on real-valued convex functions of one real variable

mathematical model of a system based on the use of a linear operator

statistical distribution used in many-particle mechanics

bilinear differential operation on scalar fields on a symplectic (or, more generally, Poisson) manifold

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

scale of objects and events smaller than those that can easily be seen by the naked eye, requiring a lens or microscope to see them clearly

uniformity of a material or system at every point

concept

classification scheme for hadrons

In physics and mathematics, an ansatz (; , meaning: "initial placement of a tool at a work piece", plural ansatzes or, from German, ansätze ; ) is an educated guess or an additional assumption made to help solve a problem, and which may later be verified to be part of the solution by its results.

(scientific contexts) mass refers loosely to the amount of "matter" in an object (though "matter" may be difficult to define), whereas weight refers to the force exerted on an object by gravity

mathematical model used in general relativity

Classification scheme of hadrons

point along a standing wave where the wave has minimum amplitude

Frame-dragging is an effect on spacetime, predicted by Albert Einstein's general theory of relativity, that is due to non-static stationary distributions of mass–energy. A stationary field is one that is in a steady state, but the masses causing that field may be non-static ⁠— rotating, for instance. More generally, the subject that deals with the effects caused by mass–energy currents is known as gravitoelectromagnetism, which is analogous to the magnetism of classical electromagnetism.

approximation method where the behavior of a single particle can be treated assuming all other influences are averaged

hypothesis that typical physical systems studied in statistical mechanics are ergodic, such that time averages equal phase space averages

point at a distance from the curve equal to the radius of curvature lying on the normal vector

conceptual link between natural phenomena that temporally follow one another because one is the cause of the other

gradual quantitative transition without abrupt change

incomplete, Lorentz-invariant gauge condition setting the four-divergence of the electromagnetic four-potential to zero

quantity in the theory of relativity which is invariant under a Lorentz transformation