quantum foundations — interactive demo
No experiment distinguishes many-worlds from Bohmian mechanics or Copenhagen — they're the same physics, differently narrated. Objective collapse models are different: they modify the Schrödinger equation itself, and that difference is measurable.
Every interpretation built on exact unitary evolution — many-worlds, Bohmian mechanics, relational QM, QBism, Copenhagen-without-collapse — predicts identical interference statistics. They differ only in the story attached to the same equations. Objective collapse models (GRW, CSL, Diósi-Penrose) are the one family that departs from the Schrödinger equation itself, adding a real stochastic term that should show up as interference decaying faster than ordinary environmental noise can explain.
The key mechanism is amplification with mass: for a rigid body of N nucleons held in superposition well beyond the model's coherence length rC, the collapse rate scales as
which is why a single atom never visibly collapses while a cat would — and why the frontier of these experiments is pushing to exactly the nanoparticle mass range where N² finally produces a rate big enough to beat vacuum and cooling noise.
Set a mass, a separation, and a collapse model, then compare the predicted interference visibility over time against pure unitary evolution.
N ≈ 1.0e6 nucleons
20 nm · rC = 100 nm
0.01 Hz · state-of-art vacuum + cooling
V at t=5s, unitary
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V at t=5s, collapse
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