A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.

Type to find tags:
× 119 × 119 × 119 × 118
A smaller body orbiting a larger, primary body, where the primary body is not a star.
× 117
a type of boundary such that any information past this boundary is inaccessible to the observer it is defined for. Common examples are the Schwarzschild radius of a black hole (whi…
× 116 × 115
the electromagnetic radiation in the microwave band which can be observed throughout the whole universe, not connected to any astronomical object. Its spectrum…
× 114
Theory, experiments and calculations related the physics of plasmas, i.e., matter constituted by ionized atoms.
× 113
The motion of fluids (gases, liquids and granular material).
× 112
a set of agreed, stipulated, or generally accepted norms. It typically helps common efficiency or understanding but is not required, as opposed to a strict standard or protocol.
× 112
A rank-2 tensor in relativity, which expresses the flux of energy-momentum along timelike and spacelike axes. Also known as the energy-momentum tensor. In the Einstein field equations, it is the sourc…
× 110
× 110 × 109
for questions on information theory applied to physics, especially in the fields of statistical mechanics and thermodynamics, the black hole information paradox, complexity of dynamical a…
× 109 × 108
× 108 × 107 × 107 × 107
× 107
Gaseous layer around a planet, dwarf planet, or a star.
× 107
Techniques and methods for computing, estimating, or placing bounds on the errors of expressions (formulas) based on knowledge of error distributions, error intervals or bounds of variables and parame…
× 107 × 107
the study of electric circuits and electrical components, and the design of useful devices. Some questions in this tag may be more appropriate for the [Electrical Engineering(http://ele…
× 106 × 106
a new kind of order in quantum matter, which corresponds to pattern of long-range quantum entanglement. See http://en.wikipedia.org/wiki/Topological_order
× 106 × 105
A fundamental and empirical law quantifying the electrostatic force between two charges.
× 105
any force responsible for maintaining an object on a curved path around a fixed center. In introductory coursework this is usually "uniform circular motion" and yields several simple and useful relati…
× 104 × 104 × 104
Radiation that comes from pair production quantum effects in close vicinity to an event horizon, leading to the potential for eventual evaporation of black holes. Two mirror particles are created wit…
× 103 × 103 × 103 × 102