Page "EPR paradox" Paragraph 19

That paper, " Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?

", authored by Einstein, Podolsky and Rosen in 1935, condensed the philosophical discussion into a physical argument.

They claim that given a specific experiment, in which the outcome of a measurement is known before the measurement takes place, there must exist something in the real world, an " element of reality ", that determines the measurement outcome.

They postulate that these elements of reality are local, in the sense that each belongs to a certain point in spacetime.

Each element may only be influenced by events which are located in the backward light cone of its point in spacetime ( i. e. the past ).

These claims are founded on assumptions about nature that constitute what is now known as local realism.