What Kills Schrödinger’s Cat? Scientists Just Ruled Out a 60-Year-Old Theory

Key Points:

• An experiment conducted deep underground at Italy's INFN Gran Sasso National Laboratory found no evidence of the faint electromagnetic radiation predicted by Károlyházy’s 1960s model, which suggests spacetime fluctuations cause gravity-induced quantum decoherence.
• The absence of this signal effectively rules out this specific gravity-based explanation for why quantum superpositions disappear in everyday objects, though it does not eliminate other gravitational mechanisms that might contribute to decoherence.
• The study used a high-purity germanium detector shielded by rock, copper, and lead to minimize background radiation, enabling a sensitive search for the weak radiation that would indicate spacetime fluctuations affecting charged particles.
• These results narrow the field of viable theories connecting gravity and quantum mechanics, advancing the quest to understand the fundamental relationship between these two pillars of physics and bringing quantum gravity concepts closer to experimental testability.
• Supported by the Foundational Questions Institute, the research highlights how increasingly precise experiments are beginning to test longstanding theoretical ideas about the quantum nature of spacetime and gravity.