‘It’s a Mess’: A Brain-Bending Trip to Quantum Theory’s 100th Birthday Party
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Summary
This year marks the 100th anniversary of the birth of quantum mechanics, a theory that upended the simple, concrete view of reality that physics had seemed to confirm during the 1800s.
Helgoland, an island in the North Sea, played host to a conference where young physicists tried to make sense of their new theory.
It was there that Werner Heisenberg first realized that atomic phenomena — which are too small to observe directly — cannot be exactly described in terms of the positions and moments of particles.
Later in the 20th century, the physicist John Bell showed that if the particles really do have predetermined properties in any classical sense, those properties can be “nonlocal,” meaning they depend on the state of faraway particles.
Today, researchers are still trying to make sense of what quantum mechanics means.
Some take the perspective that ψ — the wavefunction that describes the quantum state — captures our ignorance about an otherwise classical world.
Others insist that ψ itself is real, in some nontrivial way that’s still being debated.
And some physicists think quantum mechanics is about making decisions — not a description of reality at all.
