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:
× 125
The quark model postulates that the hadrons such as protons and neutrons have an inner structure; quarks.
× 123 × 122
World's largest particle accelerator built by the CERN (European Organization for Nuclear Research) near the Franco-Swiss frontier near Geneva, Switzerland. It is designed to collide beams of protons…
× 122
× 121 × 121
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.
× 121
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…
× 120
The motion of fluids (gases, liquids and granular material).
× 120
Theory, experiments and calculations related the physics of plasmas, i.e., matter constituted by ionized atoms.
× 120
A smaller body orbiting a larger, primary body, where the primary body is not a star.
× 120
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…
× 118
× 115
the electromagnetic radiation in the microwave band which can be observed throughout the whole universe, not connected to any astronomical object. Its spectrum…
× 115
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…
× 115
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…
× 115
× 113
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…
× 113
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…
× 113 × 112
× 112 × 112 × 111 × 111
× 111 × 110
A fundamental and empirical law quantifying the electrostatic force between two charges.
× 110 × 110
× 109 × 109
Numbers of the form $\{z= x+ i\,y:\;x,\, y\in\mathbb{R}\}$ where $i^2 = -1$. Useful especially as quantum mechanics, where system states take complex vector values.
× 108
A specific reference frame that describes its coordinates in a manner that does not depend on time and is isotropic.
× 108
× 108
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
× 107 × 107
for questions about singularities in physical quantities. Use the tag "singularity" for general relativistic singularities such as those inside black holes and at the Big Bang.
× 107
a branch of mechanics that deals with the analysis of the kinematics and the mechanical behavior of materials modeled as a continuous mass rather than as discrete particles.