Quantum Time Bends Our Reality

Craig: so scientists have discovered that quantum time works different than regular time. and in fact, there is what we call negative time, and time can actually flow backwards in quantum time, which starts bending my mind, never mind our reality. what's going on here, john?

Jon: yeah. so we did kind of cover something similar to this, but this is different. this is negative time. but the concept of negative time, it's a paradox in quantum physics, which obviously challenges our conventional understanding of time. so quantum challenges everything. okay? just put it that way. so this is cool because, researchers at u of t have demonstrated that under certain conditions, photon can appear to exit a material before they enter it, which leads to measurements of negative time. so it's linked to the group delay effect where light interacts with atoms in the material causing it to be emitted before it seems to have entered. so, it's not about time travel. okay? it's not about violating the laws of physics. it's more about highlighting peculiarities of quantum mechanics. so in quantum systems, time can appear to behave differently than in classical physics, which we've talked about. we've covered. you have to throw out all your understanding of physics. and in classical physics, time always moves forward. so in this experiment, in this research that they did, this has implications for our understanding of quantum phenomena, and it could lead to insights specifically relating to quantum computing and theoretical physics. but, what do you think about this, craig?

Craig: i've this was the thing that took me the longest to read and understand and, you know, negative time doesn't mean particles literally travel backward in time like science fiction. instead, it refers to wave packet tunneling through quantum barriers exhibiting negative duration.

Jon: yes.

Craig: alright. so what's actually happening is a complex reorganization of probabilities. the wave function, which describes the quantum state, reorganizes itself in ways, that make it appear as if time flows backwards even though causality remains intact. so, you know, the example is think of it as a car chase by the fbi helicopters through a tunnel. in a classical world, the car enters one end and exits the other. but in the quantum world, probabilities allow parts of the car to appear on the exit side before the whole vehicle has even entered the tunnel as if the car's presence is leaked through space. yeah. so now we get into the weirdness, retrocausality. can the future influence the past? so one of the most mind bending aspects of quantum time is retrocausality, the idea of that future events might influence past ones. while this seems to violate everything we know about cause and effect, quantum mechanics suggest it might be possible.

Jon: yeah. but just to put things into perspective and question anything, this does not imply time travel at all. this just shows that quantum mechanics can exhibit behaviors that seem counterintuitive from the classical physics perspective. so, it could help us to understand the quantum reality much much more deeper, but, has nothing to do with time travel. it's for those of you thinking that.

Craig: so quantum entanglement and bidirectional time. entangled quantum systems imply bidirectional time correlations. wheeler's famous delayed choice experiments demonstrates how post measurement selection appears to alter previous interactions. so we're gonna talk a little bit about that again. and so okay. so something i do now affects something that happened before. it's not time travel, but it affects the result in the quantum state. physicist, lee smolin proposed that quantum twin theory using hidden variables to avoid faster than light signaling rather than physical backward causal causation. this theory suggests a restructuring of shared quantum pass. so, you know, this is why things start to, you know, go we're really not talking about time travel. we're talking about quantum tunneling, the ability for particles to pass through energy barriers that classically couldn't overcome, reveals fascinating insights about times symmetry at the quantum level. so steinberg's groundbreaking experiments with cold atoms showed that noninvasive measurement effectively stops time for tunneling particles. using weak measurement techniques, his team tracked particles as they tunneled through barriers, something previously thought impossible without disrupting the quantum state. so john wheeler's delayed choice thought experiment suggests that the act of measurement can influence how a particle behaved in the past. the paradox emerges from quantum experiments where the experimental setup is changed after a particle has already decided whether it behaves as a wave or a particle. yeah.

Jon: yeah. and this is cool because it's gonna help to develop more efficient quantum algorithms, and it's gonna all obviously improve our ability to control quantum states, and, obviously, in turn, lead to breakthroughs in cryptography, simulation, and definitely optimization. so this is really cool. i really like this.

Craig: yeah. and i wanna understand it more because it's it's mind bending as it is. you know? despite the theoretical nature, quantum time concepts are finding practical implications or applications in cutting edge technologies like you're talking about. quantum computer leverage super positioning and entanglement to perform calculations in ways that classical computers cannot. the time symmetry properties of quantum systems are being exploited to develop more efficient quantum algorithms like you mentioned. and you gotta wonder if it's utilizing some of these concepts when, i can't remember. i think it was willow who's who did ten thousand years worth of research in a few minutes, and they thought, well, maybe it attacked it. it leveraged the multiverse. maybe it was leveraging some of these, time stopping, reverse time, things as well. quantum cryptography and temporal security. so quantum key distribution systems using principles of quantum measurement to create unhackable communication channels. the temporal aspect of quantum measurement ensures that any eavesdropping attempt disturbs the quantum state in detectable ways. so, quantum time challenges are deeply held belief that time flows linearly from past to future. if particles can exhibit negative tunneling times or if measurement choices can influence past events, is time fundamentally different than we've always assumed? what do you think?

Jon: i don't know. it's tough because, like, i obviously, if you're you're getting to the quantum level, you throw out everything. you throw out all your understanding. but, yeah, i'm i'm not. i don't know.

Craig: quantum is magic.

Jon: quantum is magic.

Craig: yeah. you can say what you want. we're gonna explain it eventually. any significantly advanced technology can, appear as magic. right?

Jon: yeah.

Craig: so quantum gravity and time, the holy grail of theoretical physics reconciling quantum mechanics and general relativity centers largely around resolving incompatible treatments of time. so quantum time forces us to reconsider our most basic assumptions that time flows uniformly forward. the evidence from quantum mechanics suggest a more complex picture, one where time can bend, branch, and even appear to run backwards under certain conditions. i'd love to hear what you think about this. is quantum time gonna change our reality, or is it just gonna change computing? how do you translate this into the future technologies and where we're going with quantum computing? i'd love to hear some feedback on what you think is happening here. any last words, john?

Jon: no. i always love the new discoveries. i love that this is a u of t research, and, yeah, it's great.

Craig: and, yeah, this article, with the well researched is on toronto slarks dot com, it's, if you're listening to this in the podcast, just click on the show notes. it'll take you right to this page. it's, the podcast page where this is at, and we'd love to have you leave a comment.