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Communications

'Optical Fiber' Made Out of Thin Air 115

Posted by Soulskill
from the sufficiently-advanced-technology dept.
Dave Knott writes: Scientists from the University of Maryland say they have turned thin air into an "optical fiber" that can transmit and amplify light signals without the need for any cables. As described in the research, this was accomplished by generating a laser with its light split into a ring of multiple beams forming a pipe. Very short and powerful pulses from the laser are used to heat the air molecules along the beam extremely quickly. Such rapid heating produces sound waves that take about a microsecond to converge to the center of the pipe, creating a high-density area surrounded by a low-density area left behind in the wake of the laser beams. The lower density region of air surrounding the center of the air waveguide has a lower refractive index, keeping the light focused, and allowing the higher-density region (with its correspondingly higher index of refraction) to act like an optical fiber. The findings, reported in the journal Optica, have applications in long range laser communications, high-resolution topographic mapping, air pollution and climate change research, and could also be used by the military to make laser weapons.
Government

WikiLeaks: NSA Recording All Telephone Calls In Afghanistan 241

Posted by Soulskill
from the stirring-the-pot dept.
On Monday, The Intercept reported that the NSA is recording the content of every cell phone call in the Bahamas. At the time of publication, The Intercept said there was another country in which the NSA was doing this, but declined to name it because of "specific, credible concerns that doing so could lead to increased violence." Now, reader Advocatus Diaboli points out that WikiLeaks has spilled the beans: the country being fully monitored by the NSA is Afghanistan. Julian Assange wrote, "Such censorship strips a nation of its right to self-determination on a matter which affects its whole population. An ongoing crime of mass espionage is being committed against the victim state and its population. By denying an entire population the knowledge of its own victimization, this act of censorship denies each individual in that country the opportunity to seek an effective remedy, whether in international courts, or elsewhere. Pre-notification to the perpetrating authorities also permits the erasure of evidence which could be used in a successful criminal prosecution, civil claim, or other investigations. ... We do not believe it is the place of media to 'aid and abet' a state in escaping detection and prosecution for a serious crime against a population. Consequently WikiLeaks cannot be complicit in the censorship of victim state X. The country in question is Afghanistan."

"It ain't so much the things we don't know that get us in trouble. It's the things we know that ain't so." -- Artemus Ward aka Charles Farrar Brown

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