A simple tub of flowing liquid can mimic the spooky quantum correlations once thought to exist only in the subatomic world.
April 23, 2026
Original Paper
Quantum Correlations in Classical Systems
arXiv · 2604.19940
The Takeaway
Quantum mechanics is usually defined by Bell-type violations that prove particles are entangled. This experiment shows that a classical fluid splitter can produce the exact same energy patterns and statistical signatures. It suggests that the boundary between the weird quantum world and the normal classical world is thinner than we believed. These correlations might be emergent properties of large groups of moving parts rather than a unique law of nature. This shifts our understanding of reality by showing that classical physics can be just as counterintuitive as quantum physics.
From the abstract
A classical fluid splitter produces the same patterns of energy redistribution as a Stern-Gerlach quantum device, with rotationally invariant coefficients of correlation between molecular paths. Alternative settings express a cosine squared relationship, leading to Tsirelson-type Bell violations with outcome independence. This result confirms the Correspondence Principle of quantum mechanics, where individual detection events express system-level properties according to Born's Rule. Kochen-Speck