05 April 2001
05 April 2001
Experiments on a newly created composite material have shown that it bends microwaves passing through it in a direction that seems to defy the laws of physics, scientists said on Thursday, in a discovery that could help in making more advanced lenses and antennas.
The composite, made of fiberglass and copper, caused microwaves shot through it to bend in an opposite direction than the laws of physics predict, making it the first material to have a ``negative index of refraction,'' physicists said in a study appearing in the journal Science.
Electromagnetic radiation -- such as light and microwaves -- passing through ordinary materials is deflected in the same direction, giving those materials a ``positive index of refraction,'' they said. An example is the way light bends when it passes from air to water.
The composite could be useful in developing better antennas and other technology for the cellular communications industry, said physicist Sheldon Schultz, who created the material along with colleagues David Smith and Richard Shelby at the University of California at San Diego.
Although the composite cannot focus visible light, Schultz said he hopes that obstacle can be overcome in the future.
Physicist John Pendry of London's Imperial College has said that a material with a ``negative refraction'' would make possible the construction of a lens capable of focusing light to limits not currently achievable.
Applications for composites in the sports and leisure sector will be showcased by various exhibitors at Composites Europe in Stuttgart, Germany, on 6-8 November.
The programme has been announced for the second Composites in Sport Conference and Exhibition, being held at Loughborough University, UK, on 3-4 October 2018.