Category Astronomy/Space

Engineers develop ‘meta-skin’ using Liquid-Metal technology to Trap Radar waves and Cloak objects

This flexible, stretchable and tunable "meta-skin" can trap radar waves and cloak objects from detection. Credit: Liang Dong/Iowa State University

This flexible, stretchable and tunable “meta-skin” can trap radar waves and cloak objects from detection. Credit: Liang Dong/Iowa State University

By stretching the flexible meta-skin, the device can be tuned to reduce the reflection of a wide range of radar frequencies. “It is believed that the present meta-skin technology will find many applications in electromagnetic frequency tuning, shielding and scattering suppression,” the engineers wrote in their paper.

Dong has a background in fabricating micro and nanoscale devices and working with liquids and polymers; Song has expertise in looking for new applications of electromagnetic waves...

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Death by Gamma-ray Bursts may place 1st Lower Bound on the Cosmological Constant

Artist's illustration of a gamma-ray burst.

Artist’s illustration of a gamma-ray burst. Energy from the explosion is beamed into two narrow, oppositely directed jets. Credit: NASA/Swift/Mary Pat Hrybyk-Keith and John Jones

Sometimes when a star collapses into a supernova, it releases gamma-ray bursts GRBs which last just a few seconds, but during that time they can release as much energy as the Sun will produce in its entire lifetime. They are so intense that, if pointed at the Earth from even the most distant edge of our galaxy, they could easily cause a mass extinction. It’s thought that a gamma-ray burst may have caused the Ordovician extinction around 440 million years ago, which wiped out 85% of all species at the time.

Clearly, the farther away a planet is from gamma-ray bursts, the better its chances of harboring advanced for...

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Team Simulates the Expansion of the Universe

The gravitational waves generated during the formation of structures in the universe are shown. The structures (distribution of masses) are shown as bright dots, gravitational waves by ellipses. The size of the ellipse is proportional to the amplitude of the wave and its orientation represents its polarization. CREDIT © Ruth Durrer, UNIGE

The gravitational waves generated during the formation of structures in the universe are shown. The structures (distribution of masses) are shown as bright dots, gravitational waves by ellipses. The size of the ellipse is proportional to the amplitude of the wave and its orientation represents its polarization. CREDIT © Ruth Durrer, UNIGE

The Universe is constantly expanding. It changes, creating new structures that merge. But how does our Universe evolve? Physicists at the University of Geneva (UNIGE), Switzerland, have developed a new code of numerical simulations that offers a glimpse of the complex process of the formation of structures in the Universe...

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Hubble and a Stellar Fingerprint

Hubble and a stellar fingerprint

Showcased at the center of this NASA/ESA Hubble Space Telescope image is an emission-line star known as IRAS 12196-6300.

Located just under 2,300 light-years from Earth, this star displays prominent emission lines, meaning that the star’s light, dispersed into a spectrum, shows up as a rainbow of colors marked with a characteristic pattern of dark and bright lines. The characteristics of these lines, when compared to the “fingerprints” left by particular atoms and molecules, can be used to reveal IRAS12196-6300’s chemical composition.

Under 10 million years old and not yet burning hydrogen at its core, unlike the sun, this star is still in its infancy. Further evidence of IRAS 12196-6300’s youth is provided by the presence of reflection nebulae...

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