Passive Alien Civilization Detection with Neutrinos

How do you track an advanced civilization or a spacecraft across light-years of space?Traditional search methods rely on light or radio waves, which can be easily blockedor scattered by intervening matter. This paper explores a fundamentally dierent ap-proach: tracking neutrinosnearly invisible particles that pass through entire plan-ets without stopping. Current neutrino detectors are massive underground tanks ofwater or ice, but they are wholly inecient for deep-space technosignature searches.To address this, we introduce a novel detector design based on ultra-dense Osmiumor Tungsten crystal spheres. Rather than detecting light, the system exploits Co-herent Elastic Neutrino-Nucleus Scattering (CEνNS) and reads out acoustic crystalvibrations (phonons) via superconducting Transition Edge Sensors (TES), while AI-assisted acoustic ngerprinting reconstructs the directional origin of each event.