Tags
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.
Tensor calculus (tensor analysis) is a systematic extension of vector calculus to multivector and tensor fields in a form that is independent of the choice of coordinates on the relevant manifold, but…
2566 questions
The path a body takes while moving through space under the influence of the gravitational forces of other bodies
2520 questions
Questions asking "What is a good book about X?" or more generally, "What should I read to learn about X?", typically where there is not a single authoritative reference. Please READ THE GUIDANCE IN ME…
2504 questions
The term "harmonic oscillator" is used to describe any system with a "linear" restoring force that tends to return the system to an equilibrium state. There is both a classical harmonic oscillator and…
2454 questions
A gauge theory has internal degrees of freedom that do not affect the foretold physical outcomes of the theory. The theory has a Lie group of *continuous symmetries* of these internal degrees of freed…
2399 questions
A model of the basic particles and forces featuring six quarks, three charged leptons, three massless neutral leptons and four fundamental force carrying bosons. The twelve fermions are arranged into …
2356 questions
just because your question involves math! If your question is on simplification of a mathematical expression, please ask it at math.stackexchange.com. Mathematical physics is the m…
2353 questions
Quantum electrodynamics (QED) is the quantum field theory believed to describe electromagnetic interaction. It is the simplest example of a quantum gauge theory, where the gauge group is abelian, U(1)…
2341 questions
Group theory is a branch of abstract algebra. A group is a set of objects, together with a binary operation, that satisfies four axioms. The set must be closed under the operation and contain an ident…
2298 questions
The time rate of change of the position of an object
2269 questions
Time is defined operationally to be that which is measured by clocks. The SI unit of time is the second, which is defined to be
2268 questions
Use this for questions relating to the proper use of physics terminology or nomenclature.
2260 questions
Concerns the application of the laws of physics to analyze common situations encountered in everyday life.
2237 questions
used in situations where the question is either about how some term or concept is defined or where the validity of an answer depends on a subtle definition of some term or concep…
2180 questions
Voltage is the unit of measurement for electronic potential, from one point location to another.
2177 questions
Quantum entanglement is 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…
2049 questions
The expansion of the universe is a phenomenon wherein, at scales much larger than galaxies, the distance between objects grows over time. This phenomenon is often described as "expansion of space", al…
2003 questions
The science dealing with objects and phenomena located beyond Earth. In particular, this applies to observations and data. At its core, astronomy is the physically informed cataloging and classifying …
1974 questions
The ability of an object to store electric charge.
1964 questions
for questions relating to collision which is the interaction between two or more bodies that results in physical contact and an exchange of momentum between the bodies involved. When it ha…
1939 questions
The Hamiltonian formalism is 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…
1926 questions
Two Hydrogen atoms covalently bonded to one Oxygen atom. One of the more common compounds on the surface of the earth.
1910 questions
A pictorial device which analyzes forces present on any body with the use of vectors. Allows easier grasping of problems involving either objects at equilibrium or in motion. Can be used to predict pr…
1909 questions
for questions which relates with the renormalization, an ensemble of techniques which serves to treat the infinities which appear in quantum field theory or statistical mechanics. Renormal…
1905 questions
Semiconductor physics is 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…
1860 questions
Differentiation is the set of techniques and results from Differential Calculus, concerning the calculation of derivatives of functions or distributions.
1843 questions
The bridge between theoretical and experimental physics which utilizes numerical analysis, specifically through the use of software, to solve problems in physics. This tag is NOT intended for use in s…
1829 questions
Scattering is 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…
1798 questions
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).
1796 questions
The central term in the hamiltonian formalism. Can be interpreted as an energy input, or "true" energy.
1786 questions
A convention is 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.
1779 questions
for questions relating to reflection, the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it origina…
1776 questions
The universe refers to the cosmos; all of space-time and that which exists as part of it. Alternatively, it can refer to the observable universe, which only contains the part we can see. Questions tag…
1764 questions
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 calculating the response of a time shift inv…
1762 questions
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 Calabi-Yau manifold.
1744 questions
for questions regarding to torque, which is a measure of the increase in angular momentum over time.
1711 questions