: External factors like nearby electronic infrastructure or even passing trains can create detectable magnetic disturbances. 2. How Magnetic Fields Disrupt Detectors

Intense or correlated magnetic noise directly limits the "reach" of GW astronomy:

In gravitational wave (GW) detectors, intense or fluctuating magnetic fields create "magnetic noise" that can mimic or obscure the incredibly faint signals from cosmic events like black hole mergers. This noise is a critical challenge for current interferometers like LIGO and Virgo , and it is expected to be a primary limiting factor for next-generation detectors like the Einstein Telescope . 1. Primary Sources of Magnetic Noise