Schrödinger's Cat and Gravity-Induced Decoherence

Scientists have recently ruled out a 60-year-old physics theory proposed by Frigyes Károlyházy, which suggested that constant fluctuations in spacetime cause quantum decoherence and destroy quantum superpositions in macroscopic objects. Researchers from the VIP Collaboration at INFN-LNF conducted an underground experiment at the INFN Gran Sasso National Laboratory using a high-purity germanium crystal over a 62-day measurement period. The primary objective of the experiment was to detect faint electromagnetic radiation that electrically charged particles would theoretically emit if Károlyházy's gravity-induced decoherence model were accurate. After accounting for background radiation, the researchers found no trace of the predicted signal, thereby excluding this specific model and establishing rigorous new constraints on gravity-induced decoherence theories. While this specific hypothesis was disproven, the finding does not completely eliminate the possibility that gravity plays a role in quantum decoherence. The results narrow the search parameters for a unified theory connecting general relativity with quantum mechanics, demonstrating that precision physics experiments can now test once-speculative theoretical concepts. The study's conclusions advance the field of fundamental physics by pushing the boundaries of what can be tested experimentally, bringing researchers closer to understanding the interplay between gravity and quantum mechanics. Future sensitivity improvements in similar precision instruments will likely continue to test remaining theories involving spacetime uncertainty and minimum length scales.