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:
× 288
the quantum field theory believed to describe the electromagnetic interaction (and with some extension the weak nuclear force).
× 287
physics taught and learned. Teaching strategies, class examples and demonstrations; learning resources, career advice, etc. For explicit problems, use the 'homework' tag instead.
× 282
Use this for questions relating to the proper use of physics terminology or nomenclature.
× 279
The statement that a property of a system does not change if the system is isolated.
× 272
an ensemble of techniques which serves to treat the infinities which appear in quantum field theory or statistical mechanics.
× 267 × 251
A system of coordinates used as the basis for describing the position and motion of objects
× 245
The study of how the properties of matter arise from its structure at all scales and of how processing can be used to modify those properties (often in pursuit of a specific application).
× 243
a process in which energetic particles or energetic waves travel through a medium or space. The particles or waves radiate (i.e., travel outward in all directions) from a source.
× 241
The time rate of change of the position of an object
× 239
A fundamental property of matter which causes it to experience electromagnetic forces.
× 235
a general term for several physical processes in which radiation of some sort changes direction due to an interaction with a particle. Scattering can be classified by the type of radiati…
× 234
for questions relating to what, if anything, the quantum mechanical formalism and experimental results say about the way the world works.
× 232 × 231
a formalism in Classical Mechanics. Besides Lagrangian Mechanics, it is an effective way of reformulating classical mechanics in a simple way. Very useful in Quantum Mecha…
× 229
× 226
the mechanism by which quantum correlations between two sub-systems survive even after being physically separated from an interaction region. The correlations could in principl…
× 225
used to describe any system with a "linear" restoring force that tends to return the system to a equilibrium state. There is both a classical harmonic oscillator and …
× 225
for Heisenberg quantum mechanical uncertainty principle.
× 224
× 220
The near-vacuum extending between the planets and stars, containing small amounts of gas and dust. Also called outer space to refer to the physical universe beyond the Earth's atmosphere.
× 219 × 218
Applies also to pre-Hilbert spaces, rigged Hilbert spaces, and spaces with negative norm or zero-norm states.
× 217
× 217 × 216
The result of sampling the property of a system
× 210
Celestial body that orbits following an elliptical path around a star or stellar remnant.
× 210
The historical development of physics concepts: who did what and when.
× 209
According to the current cosmological theories, it's the model that explains the early life of the universe, starting from a rapid expansion of hot and dense matter.
× 208
A nucleus made of protons and neutrons surrounded by a cloud of electrons equal in number to the protons.
× 208
The union of special (SR) and general (GR) relativity. Use this tag if both SR and GR apply.
× 207
the branch of solid state physics that focuses on specific properties of semiconductors. It studies dynamics of different perturbations (mainly electrons and holes) in the sem…
× 205
just because your question involves math! If your question is on simplification of a mathematical expression, please ask it at math.stackexchange.com The mathematics tag covers non…
× 204
Geometric object with magnitude (length) and direction.
× 200
the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus. It is primarily concerned with the arrangement of electrons around the nucleus and t…
× 199