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Equation 2 · Part 1 · Decoherence: The Quiet Selection That Makes the World Look Solid

Symbol x

xx
xx

What this part means

x is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

Its job in the formula

x is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

The passage around this formula

…particular observable, typically position. States that are eigenstates, or near-eigenstates, of that monitored observable are left almost undisturbed by the scattering; a photon that reflects off an object localized at x still tells you, afterward, that the object was at x , and nothing about the interaction has to change for that to remain true on the next scattering event. A superposition of two well-separated positions, by contrast, is not an eigenstate of position, and the environment cannot scatter off it…

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A variable is a named place for a value. Its letter is a local label: x can mean position in one formula and a data point in another.

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Sources cited in the article section

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