phase transition tagged posts

Physicists set Limits on Size of Neutron Stars

Range of the size for a typical neutron star compared to the city of Frankfurt. Credit: Lukas Weih, Goethe University, satellite image: GeoBasis-DE/BKG (2009) Google

Range of the size for a typical neutron star compared to the city of Frankfurt. Credit: Lukas Weih, Goethe University, satellite image: GeoBasis-DE/BKG (2009) Google

Comparison of billions of theoretical models with gravitational waves results in the answer to an old riddle. How large is a neutron star? Previous estimates varied from eight to sixteen kilometres. Astrophysicists at the Goethe University Frankfurt and the FIAS have now succeeded in determining the size of neutron stars to within 1.5 kilometres by using an elaborate statistical approach supported by data from the measurement of gravitational waves. The researchers’ report appears in the current issue of Physical Review Letters.

Neutron stars are the densest objects in our universe, with a mass larger than that of our sun comp...

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Metamaterial Device allows Chameleon-like Behavior in the Infrared

This is an infrared image of metadevice composed of vanadium dioxide with gold patterned mesh. (Top) Device without any electric current showing the PSU cut from the pattern and reflective. (Middle) Device with 2.03 amps

This is an infrared image of metadevice composed of vanadium dioxide with gold patterned mesh. (Top) Device without any electric current showing the PSU cut from the pattern and reflective. (Middle) Device with 2.03 amps

An electric current will not only heat a hybrid metamaterial, but will also trigger it to change state and fade into the background like a chameleon in what may be the proof-of-concept of the first controllable metamaterial device, or metadevice. “Previous metamaterials work focused mainly on cloaking objects so they were invisible in the radio frequency or other specific frequencies,” said Douglas H. Werner, John L. and Genevieve H. McCain Chair Professor of electrical engineering, Penn State...

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