Two teams of radio telescopes pointed their antennas at two gas clouds: one at the very center of the Milky Way, the other in its quiet outskirts. Both clouds contain methanol molecules — an alcohol that acts as a tiny pendulum in space: it absorbs and emits radio waves at strictly defined frequencies. These frequencies depend on how much heavier the proton is compared to the electron. If that ratio changes even slightly, the pendulum starts ticking differently.
In the central cloud, the ticking shifted. Frequencies that are most sensitive to particle mass moved, while those that barely feel it stayed put. In the outskirts cloud, no such shift was seen. The difference is tiny, about three parts in ten million, but it's there and doesn't look like a random measurement error.
What could make molecules at the galaxy's center tick differently? The authors suggest dark matter. There's more of it at the center, and it could slightly alter the Higgs field — the one that gives mass to particles. Then protons and electrons would weigh slightly differently in different parts of the universe, and molecular frequencies would change along with them.
If this is confirmed, the constants of nature would no longer be constant. They would depend on the environment, like temperature or pressure. And then clocks made of molecules in different corners of the galaxy would show different times.
Methanol is the same alcohol found in windshield washer fluid. In space, its molecules serve as natural 'quantum clocks': they emit radio waves that can be used to check particle masses.
In the series 'The Expanse', an alien protomolecule changes the laws of physics in a local region — here's a similar idea, but with the Higgs field and dark matter.