In physics, particularly in quantum physics, a system observable is a measurable operator, or gauge, where the property of the system state can be determined by some sequence of physical operations. For example, these operations might involve submitting the system to various electromagnetic fields and eventually reading a value off some gauge. In systems governed by classical mechanics, any experimentally observable value can be shown to be given by a real-valued function on the set of all possible system states.

Physically meaningful observables must also satisfy transformation laws which relate observations performed by different observers in different frames of reference. These transformation laws are automorphisms of the state space, that is bijective transformations which preserve some mathematical property.

Read more about ObservableQuantum Mechanics, Incompatibility of Observables in Quantum Mechanics

Other articles related to "observable, observables":

Quantum Channel - Examples - Observable
... An observable associates a numerical value to a quantum mechanical effect ... is called a POVM.) In the Heisenberg picture, the corresponding observable map Ψ maps a classical observable to the quantum mechanical one In other words, one integrate f ...
Incompatibility of Observables in Quantum Mechanics
... between classical quantities and quantum mechanical observables is that the latter may not be simultaneously measurable ... expresses a dependence of measurement results on the order in which measurements of observables and are performed ... Observables corresponding to non-commutative operators are called incompatible ...
Observable Subgroup
... In mathematics, in the representation theory of algebraic groups, an observable subgroup is an algebraic subgroup of a linear algebraic group whose every finite-dimensional rational representation arises as ... case the base field is closed, is that K is an observable subgroup of G if and only if the quotient variety G/K is a quasi-affine variety ... Some basic facts about observable subgroups Every normal algebraic subgroup of an algebraic group is observable ...
Cosmic Web - Matter Content
... The observable universe contains between 1022 and 1024 stars (between 10 sextillion and 1 septillion stars) ... the currently observable universe is home to of order 6 x 1022 stars" These stars are organized in more than 100 to 200 billion (up to 1 trillion depending on ... Two approximate calculations give the number of atoms in the observable universe to be close to 1080 ...
Descriptive Psychiatry
... Descriptive psychiatry is based on the study of observable symptoms and behavioral phenomena rather than underlying psychodynamic processes ... In descriptive psychiatry, the clinical psychiatrist focuses on empirically observable behaviors and conditions, such as words spoken or actions taken ... Its focus on observable symptoms contrasts with dynamic psychiatry's emphasis on emotional processes and the mental mechanisms underlying them ...

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