Physics & Astronomy News

<p>Artist rendering<br />
New radiation source could be less harmful alternative to x-rays
A new source of intense terahertz (THz) radiation, which could offer a less harmful alternative to x-rays and has strong potential for use in industry, is being developed.
<p>Though Mercury may look drab to the human eye, different minerals appear in a rainbow of colors in this image from NASA's MESSENGER spacecraft. (Image credit: NASA/Johns Hopkins University APL/Carnegie Institution of Washington)</p>
Mercury May Have a Thinner Crust Than We Thought
Scientists used careful mathematical calculations to determine the density of Mercury’s crust, which is thinner than anyone thought.

<p>An artistic view of frequency conversion from near-infrared to mid-infrared through a nonlinear crystal. (Photo: Alexander Gelin)</p>
Molecules Brilliantly Illuminated
A new high-power laser system generates ultrashort pulses of light covering a large share of the mid-infrared spectrum.
<p>A cloud of atoms is held above a chip by electromagnetic fields. The EPR paradox was observed between the spatially separated regions A and B (Illustration: University of Basel, Department of Physics)</p>
EPR paradox observed in many-particle system for the first time
Physicists have observed the quantum mechanical Einstein-Podolsky-Rosen paradox in a system of several hundred interacting atoms for the first time.

Einstein’s “spooky action” goes massive!
The elusive quantum mechanical phenomenon called entanglement has now been made a reality in objects almost macroscopic in size.
Organic solar cells reach record efficiency
In an advance that makes a more flexible, inexpensive type of solar cell commercially viable, researchers have demonstrated organic solar cells that can achieve 15% efficiency.
New exotic phenomena seen in photonic crystals
Researchers observe, for the first time, topological effects unique to an 'open' system.

Science Facts

Light Fantastic

by NASA Headquarters and

Series of images over time of the light echo from the star known as V838 Monocerotis or V 838 Mon. : Image Courtesy NASA On the next hot summer day, imagine what would happen if the Sun suddenly became one million times brighter. Ice cream would quickly melt, sunscreen lotion wouldn't work very well, and that's just the beginning. Thankfully, our Sun doesn't misbehave this way. Yet, in early 2002, we witnessed strange behavior by a star in the dim winter constellation Monoceros (Moh-NO-ser-os) the Unicorn. The star, named V838 Monocerotis (Moh-NO-ser-u-tis) or V 838 Mon for short, grew very bright then cooled and faded away. The glow was bright enough to light up layers of dust surrounding the star, like a flashlight shining through smoke in a dark room.

What caused this star to become the brightest star in our Milky Way Galaxy for a short time? Astronomers think V838 Mon suddenly grew hotter and swelled to nearly 1,000 times larger than our Sun. At that size, we could see much more of the star, which explains why V838 Mon appeared so much brighter. Just that size, our Sun would swallow Earth and stretch all the way to Jupiter's orbit!

NASA's Hubble Space Telescope watched the dust shell around V838 Mon over many months after the outburst. Every time Hubble astronomers take a picture, the dust ring looks larger than before. But, in the Hubble pictures, the dust really isn't growing. Instead, light from the flash is sweeping through the dust, lighting up different parts. This illusion is called a 'light echo.'

Sound is just a sensation created in the human brain in response to small pressure fluctuations in the air.
The Doppler Effect

As any object moves through the air, the air near the object is disturbed. The disturbances are transmitted through the air at a distinct speed called the speed of sound, because sound itself is just ...
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Nuclides & Isotopes

An atom that has an unbalanced ratio of neutrons to protons in the nucleus seeks to become more stable. The unbalanced or unstable atom tries to become more stable by changing the number of neutrons a ...
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The largest known volcano in the solar system, Olympus Mons.
Mount Olympus

Olympus Mons, the largest volcano in the solar system, towers a breathtaking 25 km above the surrounding plains on Mars. Until recently scientists thought that Olympus Mons and other volcanoes on the ...
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Science Quote

'We should take care not to make intellect our god; it has powerful muscles but no personality.'

Albert Einstein

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