Posted on 03/14/2023 8:15:04 AM PDT by Red Badger
Time Reflections Visualization
Illustration of the experimental platform used to realize time reflections. (Andrea Alu)
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.
"This has been really exciting to see, because of how long ago this counterintuitive phenomenon was predicted, and how different time-reflected waves behave compared to space-reflected ones," says physicist Andrea Alù, founding director of the CUNY ASRC Photonics Initiative.
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.
Time Reflections Diagram Circuit A control signal (in green) activates a set of switches along a metal strip. The electromagnetic impedance of the metamaterial is abruptly changed, causing a forward-propagating signal (in blue) to be partially time-reflected (in red), with all its frequencies converted. (Andrea Alu) 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.
Equivalents in acoustics and magnetism have been experimented with before, as has a limited investigation of narrow frequencies in electromagnetic temporal reflection using a computer setup.
Exploring the phenomenon on a less-constrained level would require uniform and sudden variations across the whole electromagnetic field of a material, something experimentalists assumed would demand too much energy to make work.
Until now, it seems.
"Using a sophisticated metamaterial design, we were able to realize the conditions to change the material's properties in time both abruptly and with a large contrast," says Alù.
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.
Metamaterials are artificial constructs that have no equivalent in the natural world. Designed with unique properties that are tasked with a particular purpose, they have been made to suit different structural, acoustic, and optical needs.
Finding a metamaterial capable of time reflection provides engineers with a whole new tool for manipulating light.
"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."
This research was published in Nature Physics.
Time Ping!.......................
By the way the clock in my truck is correct again in 6 months or so it will be an hour off again
It’s about time.
Soon to be called racist.
There's a blast from the past.
Yes, at the extremely super super low energy level of quantum-level events, “time reflections” can be observed, but much of what happens at the quantum level remains at the quantum level.
Quit looking for a time machine. You are not a quantum level entity.
Just gotta get that ‘Flux Capacitor’ thingy working....................
“Our experiment shows that it is possible to add time interfaces into the mix, extending the degrees of freedom to manipulate waves.”
No worries, the government will soon put a stop to any
extended freedom. It’s probably some kind of
threat to Our Democracy.
A time machine will and can never be invented. I know this because no one from the future has ever come back here.
Why would they want to?.........................
This article leaves out WAY too much information to be useable. It mentions “reflections” in space, which take time to propagate, but doesn’t say anything about reflections in time. Much theoretical science is extremely complicated and unintuitive, but it’s even more useless to non scientists when “science writers” try to distill it. I get the concept, but this article does it no justice. That said, I also won’t understand the theoretical analysis of the original paper anyway, but I suspect it’s just an “observation” that seems to maybe lead to another related thing and helps the eggheads publish stuff. I’ll wait for the practical application.
Mere, overwhelming curiosity
I read the whole thing and have no idea of what I read.
“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.”
I guess it makes sense, because if an EM wave is moving through a vacuum, it essentially has no time component. Only when it travels through a medium does it slow down enough for that to happen.
Well, I read only half before I realized I had no idea of what I read.
I must be smarter than you.
“I must be smarter than you.”
LOL. You probably are. Or maybe just less of an optimist.
I kept thinking, maybe if I read a bit more I’ll find out what it’s all about. Given how awfully written most science article are nowdays, I should have known better.
On the plus side, there was no obligatory mention of the “climate emergency” or “social justice” or “pronouns”.
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