. Solar Energy News .




.
TIME AND SPACE
Light in slow motion
by Peter F. Gammelby for Aarhus University News
Aarhus, Denmark (SPX) Feb 29, 2012

Ulrik I. Uggerhoj, Department of Physics and Astronomy.

How long does it take an electron to form a photon? The answer would normally be: so short a time that it cannot be measured. However, the international CERN team responsible for experiment NA63 - mainly staffed by physicists from Aarhus University - has now succeeded in dragging out the process, thereby making it measurable.

They achieved this by utilising the phenomena of objects moving slower and shortening in length from Einstein's theory of relativity, along with two pieces of gold foil and a micrometre screw.

In Niels Bohr's atom model, electrons orbit around the nucleus in 'shells' - the so-called stationary states. Light is emitted by a quantum leap between a high-lying shell and one nearer the nucleus.

However, it is impossible to find the electron between the two shells, so it could be thought that the light emission process itself was instantaneous: the electron is in the outer shell and immediately after sending out light, it is in the inner one.

However, Associate Professor Ulrik I. Uggerhoj, PhD student Kristoffer K. Andersen, Aarhus University, and the other NA63 members actually found that it takes the electron a measurable amount of time to emit light.

By letting the electron pass two very flat gold foils stretched out at a distance that can be measured with a precision of a few micrometres, they can 'force' the electron to emit shortwave light in a well-defined area. The distance between the foils corresponds to the length taken to form the light.

The results have been published in the journal Physical Review Letters under highlights.

Related Links
Aarhus University
Understanding Time and Space




.
.
Get Our Free Newsletters Via Email
...
Buy Advertising Editorial Enquiries




.

. Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle



TIME AND SPACE
Scientists score victory over uncertainty in quantum physics measurements
Atlanta GA (SPX) Feb 29, 2012
Most people attempt to reduce the little uncertainties of life by carrying umbrellas on cloudy days, purchasing automobile insurance or hiring inspectors to evaluate homes they might consider purchasing. For scientists, reducing uncertainty is a no less important goal, though in the weird realm of quantum physics, the term has a more specific meaning. For scientists working in quantum phys ... read more


TIME AND SPACE
Biofuel goals could change U.S. farming

Green fuel versus black gold

Biofuel said a sustainable fuel source

Plant toughness: Key to cracking biofuels?

TIME AND SPACE
Humanoid Robot Exhibition Opens Drexel Engineers Week

In new mass-production technique, robotic insects spring to life

A robot sketches portraits

New 'soft' motor made from artificial muscles

TIME AND SPACE
Mongolia to tap wind power

Yorkshire officials OK Hull turbine plant

Wind farm on hold over bald eagle concerns

Golden eagles found dead at wind farm

TIME AND SPACE
Cheaper battery power heralds electric car

Mechanism Behind Capacitor's High-Speed Energy Storage Discovered

Daimler, Mercedes seal Aussie G-Wagen deal

Japanese carmakers boost production in January

TIME AND SPACE
Azerbaijan rejects Iran fears over Israel 'arms buy'

East Africa hits it big in oil, gas boom

Oil prices rebound on Iran concerns

Developing sustainable power

TIME AND SPACE
NGOs in anti-nuke probe 'diverted' foreign funds: India

India slap cases on aid groups over nuclear row: reports

India freezes aid group funds over nuclear protests

Study Confirms Low Levels of Fallout from Fukushima and Enhances Knowledge

TIME AND SPACE
EU urges quicker energy market reforms

Call for tough new targets on European Union energy reduction

Controller Announces Bill to Drive Private Sector Energy Retrofits

10 Advantages to Supporting Geothermal Energy

TIME AND SPACE
Penn researcher helps discover and characterize a 300-million-year-old forest

UN recognizes US Girl Scouts for palm oil effort


Memory Foam Mattress Review

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

.

The content herein, unless otherwise known to be public domain, are Copyright 1995-2012 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement