An exploration of quantum entanglement and the ways in which it
contradicts our everyday assumptions about the ultimate nature of
reality.
Quantum physics is
notable for its brazen defiance of common sense. (Think of
Schrödinger's Cat, famously both dead and alive.) An especially
rigorous form of quantum contradiction occurs in experiments with
entangled particles. Our common assumption is that objects have
properties whether or not anyone is observing them, and the
measurement of one can't affect the other. Quantum
entanglement—called by Einstein “spooky action at a
distance”—rejects this assumption, offering impeccable reasoning
and irrefutable evidence of the opposite. Is quantum entanglement
mystical, or just mystifying? In this volume in the MIT Press
Essential Knowledge series, Jed Brody equips readers to decide for
themselves. He explains how our commonsense assumptions impose
constraints—from which entangled particles break free.
Brody explores such
concepts as local realism, Bell's inequality, polarization, time
dilation, and special relativity. He introduces readers to imaginary
physicists Alice and Bob and their photon analyses; points out that
it's easier to reject falsehood than establish the truth; and reports
that some physicists explain entanglement by arguing that we live in
a cross-section of a higher-dimensional reality. He examines a
variety of viewpoints held by physicists, including quantum
decoherence, Niels Bohr's Copenhagen interpretation, genuine
fortuitousness, and QBism. This relatively recent interpretation, an
abbreviation of “quantum Bayesianism,” holds that there's no such
thing as an absolutely accurate, objective probability “out there,”
that quantum mechanical probabilities are subjective judgments, and
there's no “action at a distance,” spooky or otherwise.