Physicists demonstrate a time cloaking device

Jul 18, 2011 by Bob Yirka report

Physicists Moti Fridman and colleagues at Cornell University have successfully demonstrated a so-called time cloaking device that is able to “hide” time for 15 trillionths of a second. In a paper published on arXiv, the researchers describe how they were able to cause light passing through a fiber optic cable to compress, than decompress, causing a hole or void to exist, long enough for there to be a lag between the two.

Unlike other proven cloaking devices that work by bending light around objects, this works by compressing the light passing through the optical cable by means of a special silicon lens that causes some of the light passing through it to speed up and some to slow down, which causes the waves to divide. Another lens, a little farther up the cable then causes the light to be put back together. The result is light emerging from the end of the cable that appears to be unaltered, which means, for the little bit of space between the lenses, things have or could have gone on, with no record of it occurring.

While it appears the new technology might be used for signal processing application, it appears equally likely it might be used for both good and bad purpose as well. For example, if coded messages could be hidden in a series of these cloaks, it would be mighty difficult to intercept them, making for very secure communications. On the other hand, it also seems logical to conclude that such a hidden time lag, if it could be made to pulse on and off, over and over as a data is passing through, could be used to intercept data without there being a record of it.

In the demonstration, the reason that creating a temporary gap in the light in a fiber optic cable is considered to be cloaking time is because of the type of duality that exists between space and time in electromagnetic theory, which says in short, that diffraction and dispersion are symmetric in spacetime.

If only the technology could be expanded to real world size, you could step between two lenses, and do anything you wish, and it would never be recorded in time; for the rest of the world, it would never have happened. Alas, it’s not to be however, the researchers point out that they don’t expect the technique could ever produce a gap that lasts any longer than 120 microseconds, not nearly enough time to do anything worth hiding.

Explore further: Using antineutrinos to monitor nuclear reactors

More information: Demonstration of temporal cloaking, arXiv:1107.2062v1
Abstract
Recent research has uncovered a remarkable ability to manipulate and control electromagnetic fields to produce effects such as perfect imaging and spatial cloaking. To achieve spatial cloaking, the index of refraction is manipulated to flow light from a probe around an object in such a way that a "hole" in space is created, and it remains hidden. Alternatively, it may be desirable to cloak the occurrence of an event over a finite time period, and the idea of temporal cloaking was proposed in which the dispersion of the material is manipulated in time to produce a "time hole" in the probe beam to hide the occurrence of the event from the observer. This approach is based on accelerating and slowing down the front and rear parts, respectively, of the probe beam to create a well controlled temporal gap in which the event occurs so the probe beam is not modified in any way by the event. The probe beam is then restored to its original form by the reverse manipulation of the dispersion. Here we present an experimental demonstration of temporal cloaking by applying concepts from the time-space duality between diffraction and dispersive broadening. We characterize the performance of our temporal cloak by detecting the spectral modification of a probe beam due to an optical interaction while the cloak is turned off and on and show that the event is observed when the cloak is turned off but becomes undetectable when the cloak is turned on. These results are a significant step toward the development of full spatio-temporal cloaking.

Related Stories

A 'cloaking device' -- it's all done with mirrors

May 13, 2009

(PhysOrg.com) -- Somewhat the way Harry Potter can cover himself with a cloak and become invisible, Cornell researchers have developed a device that can make it seem that a bump in a carpet -- or, indeed, ...

Next generation cloaking device demonstrated

Jan 15, 2009

A device that can bestow invisibility to an object by "cloaking" it from visual light is closer to reality. After being the first to demonstrate the feasibility of such a device by constructing a prototype ...

Scientists closer to making invisibility cloak a reality

Mar 05, 2009

J.K. Rowling may not have realized just how close Harry Potter's invisibility cloak was to becoming a reality when she introduced it in the first book of her best-selling fictional series in 1998. Scientists, however, have ...

Time Lens Speeds Up Optical Data Transmission

Sep 28, 2009

(PhysOrg.com) -- Researchers at Cornell University have developed a device called a "time lens" which is a silicon device for speeding up optical data. The basic components of this device are an optical-fiber ...

Recommended for you

Using antineutrinos to monitor nuclear reactors

5 hours ago

When monitoring nuclear reactors, the International Atomic Energy Agency has to rely on input given by the operators. In the future, antineutrino detectors may provide an additional option for monitoring. ...

Imaging turns a corner

9 hours ago

(Phys.org) —Scientists have developed a new microscope which enables a dramatically improved view of biological cells.

Mapping the road to quantum gravity

22 hours ago

The road uniting quantum field theory and general relativity – the two great theories of modern physics – has been impassable for 80 years. Could a tool from condensed matter physics finally help map ...

User comments : 7

Adjust slider to filter visible comments by rank

Display comments: newest first

epicurious
5 / 5 (3) Jul 18, 2011
a poorly written summary that is both uninformative and subjective
xvi
5 / 5 (7) Jul 18, 2011
you could step between two lenses, and do anything you wish, and it would never be recorded in time; for the rest of the world, it would never have happened

Yeah right! It should read: "for the rest of the world, it wouldn't be visible". That's quite different from "never happened"...
Raygunner
1.5 / 5 (2) Jul 18, 2011
This is a pure illusion and has ZERO to do with "time". I think the entire concept of time is an illusion - it is just a unit of measurement - nothing more.
Darkboy
not rated yet Jul 19, 2011
This is a pure illusion and has ZERO to do with "time". I think the entire concept of time is an illusion - it is just a unit of measurement - nothing more.

Please refrain from crackpot speech, nobody appreciates that. It has been proven, both mathematically (General relativity) and experimentally that time IS something all right; it exists as a dimension of the 4-dimensional spacetime. Although I remember an article here on physorg that talked about time being something else entirely different form how we thought about it, they didn't suddenly disapprove of it for no apparent reason. And I'll say, while it has been proven and described mathematically, it is also true that there are many researchers that want to understand it fundamentally. Time is a "hot topic" in modern theoretical physics, so to say, but not because of that you get to say it doesn't exist.
Pyle
not rated yet Jul 19, 2011
I'd think that an outside observer would notice the difference between light around the cloaking lens and the light going through the cloaking lens. The lens isn't going to "speed" the light, but just "mask" some period of time. Within a cable I'd think this would work to "hide" something, but as a cloaking method it seems pretty limited from the get go.

Anyone else?
ScienceLust
not rated yet Jul 19, 2011
I can do the same thing with a cardboard tube.Should i get a nobel prize?
The title was way to good for the article.
poof
not rated yet Jul 21, 2011
this article is a time cloaking device.

More news stories

A 'quantum leap' in encryption technology

Toshiba Research Europe, BT, ADVA Optical Networking and the National Physical Laboratory (NPL), the UK's National Measurement Institute, today announced the first successful trial of Quantum Key Distribution ...

Phase transiting to a new quantum universe

(Phys.org) —Recent insight and discovery of a new class of quantum transition opens the way for a whole new subfield of materials physics and quantum technologies.

When things get glassy, molecules go fractal

Colorful church windows, beads on a necklace and many of our favorite plastics share something in common—they all belong to a state of matter known as glasses. School children learn the difference between ...

Autism Genome Project delivers genetic discovery

A new study from investigators with the Autism Genome Project, the world's largest research project on identifying genes associated with risk for autism, has found that the comprehensive use of copy number variant (CNV) genetic ...

Study links California drought to global warming

While researchers have sometimes connected weather extremes to man-made global warming, usually it is not done in real time. Now a study is asserting a link between climate change and both the intensifying California drought ...