TOULON, France — A neutrino telescope anchored 2,450 metres beneath the Mediterranean Sea has put one of the foundations of Einstein’s theory of relativity to one of its most unusual tests — and found no cracks. The international KM3NeT collaboration reports that an analysis of 5,828 atmospheric neutrino events recorded by its KM3NeT/ORCA detector found no evidence that Lorentz invariance, the principle that the laws of physics are the same for every observer, is violated. The result, published in the Journal of Cosmology and Astroparticle Physics on November 4, 2026, sets new experimental limits on how large any such violation could be — including the first direct constraints on possible flavour-dependent effects involving muon and tau neutrinos. The finding is a null result, and the researchers are the first to say so. But in fundamental physics, a careful null result is far from a failure: it is a successful stress test. Every time a theory as central as relativity survives...