Reflections in time instead of space:
Walk through a maze of mirrors, you'll soon come face to face with yourself. Your nose meets your nose, your fingertips touch at their phantom twins, stopped abruptly by a boundary of glass.
Most of the time, a reflection needs no explanation. The collision of light with the mirror's surface is almost intuitive, its rays set on a new path through space with the same ease as a ball bouncing off a wall.
For over sixty years, however, physicists have considered a subtly different kind of reflection. One that occurs not through the three dimensions of space, but in time.
Now researchers from the City University of New York's Advanced Science Research Center (CUNY ASRC) have turned the theory of 'time reflections' into practice, providing the first experimental evidence of its manipulation across the electromagnetic spectrum.
[...] Put aside thoughts of TARDIS-like technologies rewriting history. This kind of time reflection is even weirder. And, it seems, actually possible after all.
By the 1970s, it was becoming clear that there was an analog for spatial reflection in the time component of a quantum wave of light. Change the medium a wave is traveling through quickly enough, in just the right way, and the temporal component of the wave will change with it.
The effect of this reflection in time isn't going to rip a hole in reality. But It will shift the frequency of the wave, in ways technology could exploit across varied fields like imaging, analogue computing, and optical filtering.
Strangely, the 'echo' of altered frequency is also a reversal of the signal. If it was an echo of your voice counting one to ten, you'd hear each number spoken backwards, from ten back to one, in a chipmunk squeak.
[...] The team shone a mix of frequencies through a purposefully designed metal strip roughly 6 meters in length, loaded with switches and capacitors. Triggered at the same moment, the capacitors unloaded their charge, swiftly altering the impedance of the metamaterial as the signal passed through.
This shock change created an echo in the broad range of light waves, demonstrating a reflection in their temporal properties.
[...] "The exotic electromagnetic properties of metamaterials have so far been engineered by combining in smart ways many spatial interfaces," says physicist Shixiong Yin, one of the study's lead authors.
"Our experiment shows that it is possible to add time interfaces into the mix, extending the degrees of freedom to manipulate waves."
Journal Reference:
Moussa, H., Xu, G., Yin, S. et al. Observation of temporal reflection and broadband frequency translation at photonic time interfaces. Nat. Phys. (2023). https://doi.org/10.1038/s41567-023-01975-y
(Score: 1) by shrewdsheep on Friday March 24 2023, @12:03PM (1 child)
I would kindly ask some soylentils to add some explanation. How does this go beyond some simple wave manipulation? If spoken text is reversed, where is the "buffer" that stores the informaion?
(Score: 4, Interesting) by HiThere on Friday March 24 2023, @01:48PM
Judging from the summary, the buffer that stores the signal is a strip of space, that holds onto the leading edge of the signal until the entire signal is past, and then releases in with momentum intact. (When I said space, I was actually talking about stuff distributed through space. E.g. they mentioned that this involved lots of capacitors.)
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(Score: 2) by Tork on Friday March 24 2023, @05:54PM
🏳️🌈 Proud Ally 🏳️🌈
(Score: 0) by Anonymous Coward on Friday March 24 2023, @08:18PM (1 child)
Can we make an echo pedal out of this thing or what?
(Score: 2) by sjames on Friday March 24 2023, @09:56PM
Yes, but only if you want to record "The Chipmunks go Psychedelic".