Negative time experiment clears peer review as photons appear to leave an atom cloud before entering — groundbreaking quantum 'negative time' proven after 1 million test runs

A University of Toronto experiment demonstrating that photons can spend a negative amount of time inside a cloud of atoms has passed peer review and been published in Physical Review Letters. Led by Aephraim Steinberg, the research found that photons can appear to exit a cloud of rubidium atoms before entering it, with the atoms reporting the same negative time when probed. The study, conducted over 70 hours with 1 million test runs, showed that the effect is explained by standard physics and does not involve faster-than-light signaling. While this discovery showcases an unexpected quantum property, it does not suggest the possibility of time travel or immediate practical applications. Future research will focus on measuring the positive excitation time of scattered photons that do not pass through the atom cloud.