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Posts Tagged ‘light’

Alexander Gerst’s Earth Timelapses

December 28, 2014 Leave a comment

Watch Earth roll by through the perspective of ESA astronaut Alexander Gerst in this six-minute timelapse video from space. Combining 12 500 images taken by Alexander during his six-month Blue Dot mission on the International Space Station this Ultra High Definition video shows the best our beautiful planet has to offer.

Marvel at the auroras, sunrises, clouds, stars, oceans, the Milky Way, the International Space Station, lightning, cities at night, spacecraft and the thin band of atmosphere that protects us from space.


Link To Full Story And Video

The Laws That Determine How Dust Affects The Light That Reaches Us From The Stars Are Being Rewritten


Credit: NASA, N. Walborn, J. Maíz-Apellániz and R. Barbá

Credit: NASA, N. Walborn, J. Maíz-Apellániz and R. Barbá

If the space traversed by light to reach our eyes were empty, knowing the properties of a star could be as simple as taking a picture of it and measuring its glow (something known as photometry). But the interstellar environment is strewn with dust that absorbs and scatters light, making objects look less luminous and redder—or colder—than they actually are. A recently published paper makes it possible, at last, to correct this distorting effect adequately.

“In the range of wavelengths that our eyes perceive -the visible light- of every billion photons that a star in the centre of the Milky Way emits, only one reaches our eyes,” says Jesús Maíz Apellániz, researcher at the Institute of Astrophysics of Andalusia (IAA-CSIC) in charge of the publication. “This is an extreme example of how dust affects the light of stars, a phenomenon that takes place in every single environment, albeit with less intensity.”

The effect of dust, then, must be reckoned with in any astronomical observation before trying to extract the characteristics of an object. Maíz Apellániz, together with an international team of collaborators, showed that the laws used since 1989 to calculate the extinction of light produced by dust had serious limitations and yielded, among others, erroneous temperature estimates for stars. So they took it upon themselves to change those laws.

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Particles break light-speed limit

September 22, 2011 2 comments

An Italian experiment has unveiled evidence that fundamental particles known as neutrinos can travel faster than light. Other researchers are cautious about the result, but if it stands further scrutiny, the finding would overturn the most fundamental rule of modern physics — that nothing travels faster than 299,792,458 metres per second.

The experiment is called OPERA (Oscillation Project with Emulsion-tRacking Apparatus), and lies 1,400 metres underground in the Gran Sasso National Laboratory in Italy. It is designed to study a beam of neutrinos coming from CERN, Europe’s premier high-energy physics laboratory located 730 kilometres away near Geneva, Switzerland. Neutrinos are fundamental particles that are electrically neutral, rarely interact with other matter, and have a vanishingly small mass. But they are all around us — the Sun produces so many neutrinos as a by-product of nuclear reactions that many billions pass through your eye every second.

Full Story: http://www.nature.com/news/2011/110922/full/news.2011.554.html