(Phys.org)—Researchers have created a dc invisibility cloak made of a metamaterial that not only shields an object almost perfectly, but at 1-cm thick is also the thinnest cloak ever constructed, reaching the ultimate limit ...
New research shows that the speed of light may not be fixed after all, but rather fluctuates.
General Physics
Mar 25, 2013
83
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(PhysOrg.com) -- Materials researchers at Penn State University have reported the highest known breakdown strength for a bulk glass ever measured. Breakdown strength, along with dielectric constant, determines how much energy ...
Condensed Matter
May 5, 2009
7
0
In 1897, H.G. Wells created a fictional scientist who became invisible by changing his refractive index to that of air, so that his body could not absorb or reflect light. More recently, Harry Potter disappeared from sight ...
General Physics
Mar 4, 2011
58
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While the researchers can't promise delivery to a parallel universe or a school for wizards, books like Pullman's Dark Materials and JK Rowling's Harry Potter are steps closer to reality now that researchers in China have ...
General Physics
Aug 13, 2009
6
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Scientists from the National Physical Laboratory (NPL) have developed a new lead-free, high temperature ceramic capacitor that could improve the efficiency and reliability of electric and hybrid vehicles.
Electronics & Semiconductors
Aug 2, 2013
2
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Metamaterials, precisely designed composite materials that have properties not found in natural ones, could be used to make light-bending invisibility cloaks, flat lenses and other otherwise impossible devices.
Condensed Matter
Dec 1, 2014
2
2
(Phys.org) —Researchers from the NIST Center for Nanoscale Science and Technology (CNST) have established guidelines for using surface plasmon polaritons (SPPs) to improve absorption in both photovoltaic or photoelectrochemical ...
General Physics
Aug 18, 2014
0
0
Tailoring and manipulating electromagnetic wave propagation has been of great interest within the scientific community for many decades. In this context, wave propagation has been engineered by properly introducing spatial ...
Optics & Photonics
Jul 21, 2020
0
93
An earlier discovery of liquid water lakes beneath Mars' south pole may not be as wet as believed, a new paper says.
Space Exploration
Jun 29, 2021
1
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In electromagnetism, absolute permittivity is the measure of the resistance that is encountered when forming an electric field in a medium. In other words, permittivity is a measure of how an electric field affects, and is affected by, a dielectric medium. The permittivity of a medium describes how much electric field (more correctly, flux) is 'generated' per unit charge. Less electric flux exists in a medium with a high permittivity (per unit charge) due to polarization effects. Permittivity is directly related to electric susceptibility, which is a measure of how easily a dielectric polarizes in response to an electric field. Thus, permittivity relates to a material's ability to transmit (or "permit") an electric field.
In SI units, permittivity ε is measured in farads per meter (F/m); electric susceptibility χ is dimensionless. They are related to each other through
where εr is the relative permittivity of the material, and = 8.85… × 10−12 F/m is the vacuum permittivity.
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