Evidence of ‘Negative Time’ Found

 First time in history: Evidence of ‘Negative Time’ Found in Quantum Physics         

Physicists showed that photons can seem to exit a material before entering it, revealing observational evidence of negative time. According to scientists at the University of Toronto, “negative time”, which was previously considered an illusion, has turned out to be measurable through quantum mechanics. This discovery contests previous assumptions and raises piquing curiosity as well as skepticism regarding the question of what quantum reality is. “It took a positive amount of time, but our experiment observing that photons can make atoms seem to spend a *negative* amount of time in the excited state is up!” wrote Aephraim Steinberg, a physicist at the University of Toronto, about the new study, which was uploaded to the preprint server arXiv.org and has not yet been peer-reviewed.

For decades, ‘negative time’ has been treated as a freakish concept, thought of as due to distortions in the way light waves interact with materials. However, the latest experiments have acted as a substantial challenge to these notions, as conducted by Aephraim Steinberg and Daniela Angulo in research they describe in a preprint on arXiv focusing on how photons interact with atoms. They measure the length of time atoms absorb then emit light, ”exciting” them temporarily. Amazingly, some of these times appeared to be shorter than zero. Steinberg explained that the results would not allow time travel or breaches of the physical laws as normally understood. Instead, it demonstrated how quantum mechanics constantly defied everyday intuition. “This is tough stuff, even for us to talk about with other physicists,” he admitted. The term ‘negative time’ has become a touchstone against which the unusualness of their observations can be gauged and meaningful debates about the intricacies of quantum phenomena sparked.

Quantum Physics

Quantum physicists are familiar with wonky, seemingly nonsensical phenomena: atoms and molecules sometimes act as particles, sometimes as waves; particles can be connected to one another by a “spooky action at a distance,” even over great distances; and quantum objects can detach themselves from their properties like the Cheshire Cat from Alice’s Adventures in Wonderland detaches itself from its grin. Now research have revealed another oddball quantum outcome: photons, wave-particles of light, can spend a negative amount of time zipping through a cloud of chilled atoms. In other words, photons can seem to exit a material before entering it. These tests were held in a kind of basement laboratory full of lasers, mirrors and wires, and were directed at careful measurement of photon’s behaviour. When photons pass due to a material, they are absorbed and emitted and momentarily change the state of the atoms involved.

By analysing the duration of interaction, Angulo’s team picked up intervals that were beyond what one would expect; it was as though the photons had exited the material before having entirely entered it. Contradiction is a far cry from breaching the tenets of image time for special relativity-there’s simply nothing that moves faster than light forward. It illustrates, thus, the probabilistic characteristics of quantum mechanics, through which time behaves more like an arbitrary group of outcomes. The studies highlight how naturally fuzzy particles like photons are, defining multiple states-almost simultaneous-creating scenarios contrary to linear timelines. The idea for this work emerged in 2017. At the time, Steinberg and a lab colleague, then doctoral student Josiah Sinclair, were interested in the interaction of light and matter, specifically a phenomenon called atomic excitation: when photons pass through a medium and get absorbed, electrons swirling around atoms in that medium jump to higher energy levels. When these excited electrons lapse to their original state, they release that absorbed energy as reemitted photons, introducing a time delay in the light’s observed transit time through the medium.

Some scientists are still skeptical to this day, but the group from the University of Toronto reassures that “Our data are solid,” according to Steinberg. “We’re not trying to rewrite physics,” he added. We’re really highlighting the weirdness of quantum measurements and their deviation from classical expectations. It has already caused heated discussions in the scientific world. Prominent physicist Sabine Hossenfelder dismissed the terminology of negative time as misleading, referring to it as mere phase shifts in the path of the photon, and not as a property of time. The critique marks the great divisiveness of the concept. But Steinberg and Angulo would not apologize anything for it. They contended that the interpretation empty explanations do not reflect the true diverse possibilities of their observations that may offer new windows to quantum behaviour.

Sinclair’s team wanted to measure that time delay (which is sometimes technically called a “group delay”) and learn whether it depends on the fate of that photon: Was it scattered and absorbed inside the atomic cloud, or was it transmitted with no interaction whatsoever? “At the time, we weren’t sure what the answer was, and we felt like such a basic question about something so fundamental should be easy to answer,” Sinclair says. “But the more people we talked to, the more we realized that while everyone had their own intuition or guess, there was no expert consensus on what the right answer would be.” Because the nature of these delays can be so strange and counterintuitive, some researchers had written the phenomenon off as effectively meaningless for describing any physical property associated with light. Granted, they may not have “great technology” in mind for now, but it fills holes in our understanding of light and matter interaction-an opening to also other fields such as quantum computing and telecommunications.

 “We made our choice of words in reporting the results,” said Steinberg. “The data speaks for itself, and we’re ready to refine our interpretations as we get more attuned to what’s going on.” The term ‘negative time’ has brought to challenge the perception of conventional thinking and calls for further exploration. Though practical applications seem far away, the experiments will provide further insights into quantum phenomena. This finding demonstrates how practical applications seem far away, the experiments will provide further insights into quantum phenomena. This finding demonstrates how quantum physics can seemingly go against common sense and how break less science is willing to take risks in exploration"

To understand the nonsensical finding, you can think of photons as the fuzzy quantum objects they are, in which any given photon’s absorption and reemission through an atomic excitation is not guaranteed to occur over a certain fixed amount of time; rather, it takes place across a smeared-out, probabilistic range of temporal values. As demonstrated by the team’s experiments, these values can encompass instances when an individual photon’s transit time is instantaneous—or, bizarrely, when it concludes before the atomic excitation has ceased, which gives a negative value. Experiment can be understood by considering the two ways a photon can be transmitted. In one, the photon wears blinders of sorts and ignores the atom entirely, leaving without even a nod. In the other, it interacts with the atom, boosting it to a higher energy level, before getting reemitted. In other words, the time in which the photons were absorbed by atoms is negative. Even though the phenomenon is astonishing, it has no impact on our understanding of time itself, but it does illustrate once again that the quantum world still has surprises in store.