Subscribe free to our newsletters via your
. 24/7 Space News .




TECH SPACE
Scientists create invisible objects without metamaterial cloaking
by Staff Writers
Moscow, Russia (SPX) Apr 15, 2015


This is the radio-frequency anechoic chamber used for the experiment. Image courtesy ITMO University. For a larger version of this image please go here.

Physicists from ITMO University, Ioffe Institute and Australian National University managed to make homogenous cylindrical objects completely invisible in the microwave range. Contrary to the now prevailing notion of invisibility that relies on metamaterial coatings, the scientists achieved the result using a homogenous object without any additional coating layers. The method is based on a new understanding of electromagnetic wave scattering. The results of the study were published in Scientific Reports.

The scientists studied light scattering from a glass cylinder filled with water. In essence, such an experiment represents a two-dimensional analog of a classical problem of scattering from a homogeneous sphere (Mie scattering), the solution to which is known for almost a century.

However, this classical problem contains unusual physics that manifests itself when materials with high values of refractive index are involved. In the study, the scientists used ordinary water whose refractive index can be regulated by changing temperature.

As it turned out, high refractive index is associated with two scattering mechanisms: resonant scattering, which is related to the localization of light inside the cylinder, and non-resonant, which is characterized by smooth dependence on the wave frequency.

The interaction between these mechanisms is referred to as Fano resonances. The researchers discovered that at certain frequencies waves scattered via resonant and non-resonant mechanisms have opposite phases and are mutually destroyed, thus making the object invisible.

The work led to the first experimental observation of an invisible homogeneous object by means of scattering cancellation. Importantly, the developed technique made it possible to switch from visibility to invisibility regimes at the same frequency of 1.9 GHz by simply changing the temperature of the water in the cylinder from 90 C to 50 C.

"Our theoretical calculations were successfully tested in microwave experiments. What matters is that the invisibility idea we implemented in our work can be applied to other electromagnetic wave ranges, including to the visible range. Materials with corresponding refractive index are either long known or can be developed at will," said Mikhail Rybin, first author of the paper and senior researcher at the Metamaterials Laboratory in ITMO University.

The discovery of invisibility phenomenon in a homogenous object and not an object covered with additional coating layers is also important from the engineering point of view. Because it is much easier to produce a homogeneous cylinder, the discovery could prompt further development of nanoantennas, wherein invisible structural elements could help reduce disturbances. For instance, invisible rods could be used as supports for a miniature antenna complex connecting two optical chips.

The subject of invisibility came into prominence with the development of metamaterials - artificially designed structures with optical properties that are not encountered elsewhere in nature.

Metamaterials are capable of changing the direction of light in exotic ways, including making light curve around the cloaked object. Nevertheless, coating layers based on metamaterials are extremely hard to fabricate and are not compatible with many other invisibility ideas. The method developed by the group is based on a new understanding of scattering processes and leaves behind the existing ones in simplicity and cost-effectiveness.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
ITMO University
Space Technology News - Applications and Research






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





TECH SPACE
Largest database of elastic properties accelerates material science
Berkeley CA (SPX) Apr 09, 2015
Scientists at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have published the world's largest set of data on the complete elastic properties of inorganic compounds, increasing by an order of magnitude the number of compounds for which such data exists. This new data set is expected to be a boon to materials scientists working on developing new materials w ... read more


TECH SPACE
Will the moon's first inhabitants live in giant lava tubes?

Soft Landing on the Moon an Extraordinary Challenge

Stop blaming the moon

Extent of Moon's giant volcanic eruption is revealed

TECH SPACE
Team Returning Orbiter to Duty After Computer Swap

More evidence for groundwater on Mars

Scars on Mars from 2012 Rover Landing Fade - Usually

Bill Nye and others discussing taking humans to Mars by 2033

TECH SPACE
How To Train Your Astronauts

Air Scrubber Plus Brings Space Age Technology Down To Earth

NASA Announces New Partnerships with Industry for Deep-Space Skills

A Year in Space

TECH SPACE
Chinese scientists mull power station in space

China completes second test on new carrier rocket's power system

China's Yutu rover reveals Moon's "complex" geological history

China's Space Laboratory Still Cloaked

TECH SPACE
Special 3-D delivery from space to Marshall Space Flight Center

NASA drives future discoveries with new ISS information system

Cosmonauts Take Tablet Computer Into Space

Russia announces plan to build new space station with NASA

TECH SPACE
Soyuz Installed at Baikonur, Expected to Launch Wednesday

THOR 7 encapsulation as next Ariane 5 campaigns proceeds

Soyuz ready March 27 flight to deploy two Galileo navsats

UAE Moves to Purchase Russian Spacecraft Launch Platform

TECH SPACE
Earthlike 'Star Wars' Tatooines may be common

Planets in the habitable zone around most stars, calculate researchers

Our Solar System May Have Once Harbored Super-Earths

SOFIA Finds Missing Link Between Supernovae and Planet Formation

TECH SPACE
Largest database of elastic properties accelerates material science

Raytheon expands radar production facility

Upgrade in works for Norway's counter-battery radar

Physicists create new molecule with record-setting dipole moment




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.