When Quantum Meets Gravity, Weirdness Fades ✛
Quantum contextuality means a particle's properties aren't fixed until measured, like an ocean wave whose height depends on your measuring stick. To merge quantum theory with gravity, some physicists propose making the rules slightly nonlinear. Linear evolution is like two ripples passing through each other undisturbed; nonlinearity makes them crash and fuse, so a particle’s own state influences its future — much as spacetime curves back on itself. This also orders entropy, making outcomes more predictable.
New research reveals that three popular nonlinear models (by Deutsch, Schrödinger-Newton, and others) actually erase contextuality, forcing the wave to always read the same. If experiments keep showing contextuality, these gravity-inspired modifications are ruled out. Surprisingly, this erasure would make the universe clockwork-predictable, and it suggests why we never see quantum superpositions: nonlinearity collapses the fog. This means we can test quantum-gravity ideas today, without a full theory.
The Schrödinger-Newton equation imagines that every particle is pulled by its own gravity, which would make large objects collapse into one location, explaining why we never see a basketball in two places at once.
Nonlinear quantum mechanics forcing collapse mirrors the famous Schrödinger's cat, and resonates with films like 'Coherence' where parallel realities clash and merge.