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Can A Solar Cell Help The Blind To See?


More than 10 million Americans are thought to have macular degeneration and retinitis pigmentosa, diseases of the retina that often result in blindness. Help may come in the form of an artificial retina made from photovoltaic chips -- the same kind that turn sunlight into electricity. Surgeons at three hospitals began inserting the slivers of silicon, made by Optobionics Corp., into the eyes of legally blind volunteers in late January. Smaller than an "o" in this text, the chips are placed behind the retina, where doctors hope they will convert light into electrical pulses, effectively replacing the eye's light-sensing cells destroyed by disease.

In earlier tests, patients reported limited improvement in sight within a few months, says Dr. John Pollack of Rush University Medical Center in Chicago, which is involved in the clinical trial. Patients in the latest test will be monitored for two years.

The race to privatize space travel has already produced a few starstruck entrepreneurs. One is Virgin Atlantic Airways chief Richard Branson. He plans to launch a suborbital space tourism business in three years, with five "spaceliners" modeled on aerospace pioneer Burt Rutan's now-famous SpaceShipOne. Some 13,500 people have asked for a reservation.

To heighten competition, Las Vegas hotelier Robert Bigelow and friends are funding a $50 million contest called America's Space Prize. His own startup, Bigelow Aerospace, aims to put a small hotel into orbit in 2010, but it'll need space taxis to ferry people there. So the new space prize will go to the first private company that sends a five-person spaceship around the earth twice at an altitude of 250 miles -- four times higher than SpaceShipOne's record-breaking flight last year.

In mid-January, Space Exploration Technologies got off to an early start by test-firing a powerful rocket engine for almost three minutes -- long enough to boost 1,500 pounds into orbit. Five engines could be lashed together for the purpose of lofting space taxis. Better known as SpaceX, the El Segundo (Calif.) company was founded in 2002 by Elon Musk, who made his fortune as a dot-com entrepreneur.

Imagine using your cell phone or MP3 player for a week or two without recharging it. Researchers at Georgia Institute of Technology say it may soon be possible, thanks to a new concept in silicon chips that does more with less energy.

Today, processors use lots of energy to be absolutely certain that each data bit is either a 0 or 1 at every step of a calculation. But if an application doesn't need such certainty -- and many don't -- then energy consumption could be greatly reduced, and speed would get a boost. After testing one of his prototype chips, researcher Krishna Palem concludes that a hundredfold improvement could be an easy target.

Processing voices is one task that could tolerate less certainty, as minor errors are unlikely to make an audible difference. But even sophisticated tasks such as financial analyses, risk assessment, and cryptography are candidates.

-- Peelings from oranges and other citrus fruits may be a new source of plastics. Cornell University researchers led by chemist Geoffrey Coates have developed a catalyst that triggers limonene oxide, the main constituent of orange-peel oil, to combine with carbon dioxide and form a novel polymer. Called polylimonene carbonate, it has properties similar to polystyrene, a widely used plastic. The process offers not only a renewable substitute for oil, the source of most of today's polymers, but also a way to "lock up" CO2 that otherwise could escape into the air and contribute to global warming.

-- Global warming, meanwhile, could be a self-catalyzing process. In the Jan. 20 issue of Nature, an international team of scientists report that rising temperatures may cause more carbon dioxide to be released by the soil. This is part of a natural process in which microbes eat carbon compounds and discharge CO2. Normally, 90% of such compounds in the soil are indigestible to the bugs. But as temperatures rise, more types could be on the menu, thus unleashing more CO2.


Toyota's Hydrogen Man
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