Quantum Theory: Only the results of a measurement can be copied.

The GUM provides a way to express the perceived quality of the result of a measurement.

Schrödinger's cat and Wigner's friend are links in the chain from microscopic object to my knowing the result of a measurement made upon that object.

These findings, sometimes referred to as the faster-than-light neutrino anomaly, were subsequently determined-subject to further confirmation-to be the result of a measurement error.

The state vector is inherently defined as a probabilistic mathematical object such that the result of a measurement is one outcome OR another outcome.

The possible results of a measurement are the eigenvalues of the operator-which explains the choice of self-adjoint operators, for all the eigenvalues must be real.

Werner Heisenberg maintained that wave function collapse-the destruction of quantum superposition-occurs when the result of a measurement is registered in the mind of an observer.

According to one interpretation, as the result of a measurement the wave function containing the probability information for a system collapses from a given initial state to a particular eigenstate.

The latter is the claim that the world is mind-independent: that even if the results of a measurement do not pre-exist the act of measurement, that does not require that they are the creation of the observer.

I have several times spoken of an"instantaneous effect upon B as a result of a measurement made on A. Is this not in flagrant contradiction to Einstein's rule that signals do not travel faster than the velocity of light?

A core concept in metrology is metrological traceability, defined by the BIPM as "the property of the result of a measurement or the value of a standard whereby it can be related to stated references, usually national or international standards, through an unbroken chain of comparisons, all having stated uncertainties."

The level of traceability establishes the level of comparability of the measurement: whether the result of a measurement can be compared to the previous one, a measurement result a year ago, or to the result of a measurement performed anywhere else in the world.

Rather than express the result by providing an estimate of the measurand along with information about systematic and random error values (in the form of an "error analysis"), the GUM approach is to express the result of a measurement as an estimate of the measurand along with an associated measurement uncertainty.