A lot of science depends on filtering things out. When researchers collect data, they usually begin with some idea of what they are looking for, which means anything that interferes with that target can get labeled as noise. Sometimes that is obviously the right call. A faulty sensor reading or electrical interference does not suddenly become scientifically interesting just because it showed up in the data. But there are also cases where the line between signal and noise becomes harder to draw, especially when the “irrelevant” part of an experiment keeps showing up in a way that is too consistent to ignore. A famous example comes from the 1960s, when Arno Penzias and Robert Wilson were working with a large radio antenna in New Jersey. They kept detecting a faint microwave hiss that seemed to come from every direction. At first, it looked like an annoying problem with the equipment. They checked the antenna carefully and tried to account for possible interference, but the signal stayed....