Whether viewed dimly through the haze and lights of a city or in all their glory in a pristine wilderness, the stars that surround the Earth are magnificent, and one day Earthlings will travel to some of the new planets that astronomers are locating. However, the stars we see are not necessarily where we think they are, according to an international research team.
"We know that the light from distant stars takes a very long time to reach the Earth," says Dr. Akhlesh Lakhtakia, distinguished professor of engineering science and mechanics, Penn State. "But, taking into account the distance a star will have moved while that light travels, we still may not be able to accurately locate the star.
Negative phase velocity media or materials with negative refractive index may be responsible for this locational uncertainty. Recently, materials researchers at the University of California San Diego, working with micro and nano materials, developed a metamaterial that had a negative refractive index for microwaves, proving that negative phase materials could exist at least in the microwave part of the electromagnetic spectrum. Their requirements for this material were that both the relative permittivity, a measure of the charge separation in a material, and the relative permeability, a measure of how electrons loop in materials, of a substance must be less than zero.
Vicki Fong | EurekAlert!
Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz
New functional principle to generate the „third harmonic“
16.02.2017 | Laser Zentrum Hannover e.V.
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
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17.02.2017 | Medical Engineering
17.02.2017 | Medical Engineering
17.02.2017 | Health and Medicine