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:
× 396
The result of sampling the property of a system
× 381
Object moving through space due to the exertion of a force.
× 380
the transmission of current with no resistive losses, and is one of the most active areas of condensed matter physics research.
× 367
for questions relating to what, if anything, the quantum mechanical formalism and experimental results say about the way the world works.
× 365
standards of measurement used for different types of quantities.
× 360
Change in the direction of propagation of a wave when its transmitting medium changes.
× 359
the unit of measurement for electronic potential, from one point location to another.
× 358
The historical development of physics concepts: who did what and when.
× 355
A nucleus made of protons and neutrons surrounded by a cloud of electrons equal in number to the protons.
× 354
for questions seeking a single specific paper or a short, non-open-ended list of references, like "What paper first discovered X?", "Where can I find the original derivation of X?", or "W…
× 352 × 351
The double slit experiment involves passing light through two parallel slits to demonstrate that the light from one slit interferes with that from the other.
× 346
The tendency of a force to rotate an object about an arbitrary axis.
× 345
The study of the composition or dynamics of the gaseous layers around planets, often applied to questions on Earth's atmosphere but can be applicable to all planets & moons in the solar system.
× 343
Celestial body that orbits following an elliptical path around a star or stellar remnant.
× 333
The temperature-dependant emission of electromagnetic waves. Combine this tag with [tag:thermodynamics] for a macroscopic view or [tag:quantum-mechanics] for a microscopic explanation.
× 329
A unitary linear operator which resolves a function on $\mathbb{R}^N$ into a linear superposition of "plane wave functions". Most often used in physics for calcalating the response of a time shift inv…
× 326
"Faster-than-light", also known as superluminal velocities, refers to any sort of travel at a speed greater than the speed of light. Prohibited in mainstream physics due to the Special theory of …
× 326
A region of space devoid of any fluid molecules resulting in a zero pressure in ideal cases. In practice, even space has a small but finite number of molecules.
× 325
Use this for questions pertaining to curvature of manifolds. Does not need to be specific to general relativity, but also for curvature of e.g. a [tag:calabi-yau] manifold.
× 324
for questions about the quantum mechanical measurement problem, such as e.g. the wavefunction collapse/decoherence. DO NOT USE THIS TAG for non-quantum measurements.
× 319
Subdiscipline of theoretical physics which consists in the study of physics problems using numerical algorithms. PLEASE NOTE that questions about computational methods and/or programming are OFF-TOPIC…
× 317
energy transferred from one system to another by thermal interaction. In contrast to work, heat is always accompanied by a transfer of entropy. Heat flow is characteristic of macroscopic objec…
× 317
Study of macroscopic and microscopic phenomena in chemical systems in terms of physical laws and concepts [thermodynamics, statistical mechanics, kinetic theory, quantum mechanics...].
× 315
is used in situations where the question is either about how some term or concept is define or where the validity of an answer depends on a subtle definition of some term or concept…
× 311 × 310
the rate of repetitive aspect in the amplitude over a given dimension.
× 310
For questions about probability, probability theory, probability distributions, expected values and related matters. Purely mathematical questions should be asked on Math.SE.
× 306
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.
× 306
questions concerning measurements, experiments, and activities that demonstrate physics and are safe to do at home, require at most one tool or ingredient not readily available, and can be interpreted…
× 305
the practice of separating a signal by frequency (or sometimes energy or momentum) and analyzing the resulting spectrum.
× 304
An object such as a metal coil or air-filled tube which provides a force opposing the direction of deformation.
× 304
Circular motion about a central point or axis
× 304
A subset of [tag:fluid-dynamics] concerning primarily forces such as lift and drag generated on bodies as they move through gasses or as gasses move through the body (typically air).
× 303
Path integral formulation (Due to Feynman) is a major formulation of Quantum Mechanics along with Matrix mechanics (Due to Heisenberg and Pauli), Wave Mechanics (Due to Schrodinger), and Variational M…
× 301
A gas that behaves as randomly moving, non-interacting molecules. This allows a simplified equation of state.