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Black holes in laboratory

Imagine being able to peek inside a black hole and even perform experiments there. It may not be as far-fetched as it sounds, thanks to a team which claims to have simulated a black hole’s event horizon in the lab.

Ulf Leonhardt at the University of St Andrews, UK, and his colleagues accomplished the feat by firing lasers down an optical fibre, exploiting the fact that different wavelengths of light move at different speeds within an optical fibre. They first shot a relatively slowmoving laser pulse through the fibre, and then sent a faster “probe wave” chasing after it. The first pulse distorts the optical properties of the fibre simply by travelling through it. This distortion forces the speedy probe wave to slow down dramatically when it catches up with the slower pulse and tries to move through it. In fact, the probe wave becomes trapped and can never overtake the pulse’s leading edge, which effectively becomes a black hole event horizon, beyond which light cannot escape.

This “laser black hole” could allow physicists to examine what happens to light on both sides of a event horizon – “a feat that is utterly impossible in astrophysics”, the authors note in their paper. Cosmologists have already worked out exactly how light should change frequency as it approaches an event horizon – from the outside or the inside of a black hole – and sure enough, the team observed exactly these shifts in their experiment. It should also be possible to use the artificial event horizon to help test whether anything can escape from a black hole. In the 1970s, Stephen Hawking predicted that hot black holes could radiate particles, dubbed Hawking radiation, but it’s tough to check this using telescopes, because they’d be swamped by noise. The team calculates that their laser black hole shares this property, and that it will “radiate” photons if it heats up to about 1000 °C. Ray Rivers at Imperial College London is impressed by the work’s potential to test astrophysical phenomena: “They’ve done some clever stuff to give us a chance of seeing Hawking radiation for the first time.” Leonhardt presented the results at the Cosmology Meets Condensed Matter meeting in London last month.

Author: Zeeya Merali

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Microsoft offers to acquire Yahoo for $44.6 billion

Microsoft Corp. Friday offered to acquire Yahoo Inc. for approximately 44.6 billion U.S. dollars. In a statement posted on its website, Microsoft said it has made a proposal to Yahoo’s Board of Directors to acquire all the outstanding shares of the search company’s common stock for 31 dollars a share.The offer represents a 62 percent premium above the closing price of Yahoo common stock on Thursday.

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Mediterranean cable break disrupts communications with Asia

Internet service is disrupted more than 50 percent across the entire Middle East. The outages are caused by two submarine cable systems in the Mediterranean Sea which were cut, apparently by accident by ship anchors. India suffered up to 60 percent disruption, while 70 percent of the nationwide network in Egypt is down, news agencies reported.

Similar shortages occurred in the United Arab Emirates (UAE), Kuwait, Bahrain, Qatar and Saudi Arabia. “It’s a national disaster,” said Joseph Metry, network supervisor at Orascom Telecom Holding SAE, the biggest mobile- phone company in the Middle East and North Africa, as quoted by Bloomberg News.

The cable system which was cut somewhere 5.2 miles from Alexandria beach in northern Egypt was co-owned by several companies, among which AT&T Inc., the biggest U.S. phone company, and Verizon Communications Inc., the second-biggest U.S. phone company. Customers of both companies were affected.

Currently, telecommunications companies are rerouting traffic through other connections which will lead to congestions at peak hours.

“There has been a 50 to 60 per cent cut in bandwidth,” Rajesh Chharia, the President of Internet Service Providers Association of India confirmed to India Today.

Repairs may take up to two weeks. It is still unknown what actually happened, because undersea cables are very strong, shielded with several layers of steel.

“Despite this being an international cable affecting many Gulf and Arab countries, we are closest to it and so we have a lot of responsibility,” said Egyptian telecommunications expert Rafaat Hindy to AP. “We are working as fast as we can.”

A modern undersea or submarine communications cable is made up of a core of optical fibers, shielded with multiple layers of copper, aluminum, polycarbonate, stranded steel wires, Mylar and polyethylene. The first undersea cables were used for telegraph and were laid in the second half of the nineteenth century. As of 2003, submarine cables link all the world’s populated continents.

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Garmin First handset nuviphone announced

Last night at a secret event, Garmin, best known for its GPS receivers, announced its first foray into the mobile phone arena. The Garmin Nuviphone is a full touch based device with a large 3.5″ touchscreen and integrated GPS. Other features include a camera with video recording and support for HSDPA high-speed 3G networks. This UMTS/GSM handset is planned to be available in the third quarter of 2008, but pricing has not been announced.

Garmin has not released technical specifications, but they have announced some innovative software features that are sure to impress. The Nuviphone, when placed in its vehicle mount, will automatically turn on the GPS receiver and switch to navigation mode, transferring any active calls to handsfree mode. The GPS navigation will include Garmin Online, which provides easy access to local traffic information, gas prices, and hotel rate information.

Photos taken with the built-in camera will automatically be geo-tagged with location data, so that users can visually browse through their landmarks. Google is also a big partner, adding its integrated local search capabilities, as well as access to Google’s Panoramio library, with snapshots of landmarks tagged with location information.

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