Scientists Just Spotted Evidence of ‘Negative Time’

Quantum physicists from the University of Toronto have uncovered evidence suggesting the existence of "negative time" through their study of photon behavior—a revelation highlighting the peculiar nature of the quantum world. The research commenced over seven years ago as scientists sought to explore atomic excitation, wherein photons absorbed within a material experience a time delay—termed a group delay—before departing due to their interaction with the material's atoms.

In a 2022 study detailed in PRX Quantum, these scientists experimented by propelling photons through a cloud predominantly made up of ultracold rubidium atoms to observe atomic excitation nuances. Interestingly, some photons were observed to exit the atomic cloud quicker than anticipated, giving rise to the notion of "negative time" as it seemed like they exited before entering.

This breakthrough obtained further examination in a follow-up paper on arXiv—which was shortly explored by physicist Josiah Sinclair of the University of Toronto along with a co-author from Griffith University in Australia. As inspected in articles by Spektrum der Wissenschaft, it's suggested these photons, described as "fuzzy" quantum objects, possess a probabilistic absorption and remission, hinting at the strange potential visibility of a negative temporal transition instance amidst photon trajectory and atomic excitation.

The initial observation led to acknowledging that constructing a quantum clock how much time is traversed by atoms in an excited state might yield an apparent retrogression of time instead. While these findings won't necessarily unravel prevailing notions about time or challenge Einstein's relativity constraints fully, the notion indeed underscores the idiosyncrasies inherent in the quantum realm, extending questions surrounding photons and optics intercharacteristics.

Earlier, SSP wrote about how do we see pictures in our brain.