Detection: non-EM channel (neutrino / gravitational-wave SETI).
hypothesisdetection_strategyScientific Instrumentation & Sensor Data
Signal via neutrinos or gravitational waves (near-zero terrestrial background); detect by re-mining IceCube / LIGO / pulsar-timing archives for modulated or directionally-clustered anomalies.
Relaxes the assumption observation/command uses EM. Neutrino comms + GWs are physically real (we detect GWs). SETI is ~entirely EM; detectors are tuned for astrophysical templates, not engineered modulation. HYPOTHESIS.