MUNICH, Germany, April 18 (UPI) -- A study of stars in the Milky Way found no evidence for dark matter in a large volume around the sun, a blow to current cosmological theories, scientists say.
Current theory suggests the solar neighborhood should be filled with dark matter, a mysterious invisible substance that can only be detected indirectly by the gravitational force it exerts.
But a new study by a team of astronomers in Chile has found that these theories just do not fit the observational facts, suggesting attempts to directly detect dark matter particles on Earth are unlikely to be successful.
Using a telescope at the European Southern Observatory's La Silla facility in Chile, astronomers mapped the motions of more than 400 stars up to 13,000 light-years from the sun to calculate the mass of material in the vicinity of the sun.
"The amount of mass that we derive matches very well with what we see -- stars, dust and gas -- in the region around the sun," Christian Moni Bidin of the Universidad de Concepcion, Chile, said.
"But this leaves no room for the extra material -- dark matter -- that we were expecting. Our calculations show that it should have shown up very clearly in our measurements. But it was just not there!"
It is widely accepted that dark matter makes up about 80 percent of the mass in the universe, despite the fact that it has resisted all attempts to clarify its nature, a release from ESO headquarters in Munich, German, said Wednesday.
"Despite the new results, the Milky Way certainly rotates much faster than the visible matter alone can account for. So, if dark matter is not present where we expected it, a new solution for the missing mass problem must be found," Moni Bidin said.
"Our results contradict the currently accepted models. The mystery of dark matter has just become even more mysterious."
Cellphones may someday see through walls
DALLAS, April 18 (UPI) -- U.S. scientists say they've developed an imaging chip that could turn cellphones into devices to see through walls, wood, plastics, paper and other objects.
Researchers at the University of Texas at Dallas say their research builds on two scientific advances; the ability to tap into an unused range in the electromagnetic spectrum, and a new microchip technology.
The terahertz band of the electromagnetic spectrum, which falls between microwave and infrared, has not been accessible for most consumer devices, they said.
"We've created approaches that open a previously untapped portion of the electromagnetic spectrum for consumer use and life-saving medical applications," Kenneth O, professor of electrical engineering, said in a UT release Wednesday. "The terahertz range is full of unlimited potential that could benefit us all."
Researchers have combined this capability with CMOS (Complementary Metal-Oxide Semiconductor) technology that creates the microchips found in many consumer electronic devices used in daily life such as personal computers, smart phones, high definition TV and game consoles.
"CMOS is affordable and can be used to make lots of chips," O said. "The combination of CMOS and terahertz means you could put this chip and receiver on the back of a cellphone, turning it into a device carried in your pocket that can see through objects."
Out of concerns of privacy, O and his team say they are focused on uses in the distance range of less than 4 inches.
Applications could range from finding studs in walls to authentication of important documents or detecting counterfeit money, researchers said, and manufacturing companies could apply the technology to process control.
Terahertz can also be used for imaging to detect cancer tumors, diagnosing disease through breath analysis, and monitoring air toxicity, they said.
"There are all kinds of things you could be able to do that we just haven't yet thought about," O said.
Poll: Consumers would go for Apple TV
LONDON, April 18 (UPI) -- Twenty-five percent of U.S. consumers would be interested in buying an Apple-branded television set if the company introduced one, a poll indicates.
With rumors of an Apple TV rampant, British marketing and research company KAE conducted a survey that had a quarter of U.S. respondents saying they would be ready to buy one now, electrichouse.com reported Tuesday.
In Britain, the figure was 30 percent, and for those who already own at least one Apple device the figure jumped to 38 percent in the United States and 42 percent in Britain.
"Such a move would be an incredibly powerful extension of the iOS platform, accessed via a more compelling device option than Apple's current offering (the Apple TV streaming box), Lee Powney, KAE's chief commercial officer, said.
Market leaders such as Sony, Samsung and LG would most likely suffer if Apple comes to market with a competing TV, he said.
Endangered porpoises dying in China
YUEYANG, China, April 18 (UPI) -- Chinese wildlife officials say the corpses of 12 endangered finless porpoises, including a pregnant one, have been found around Dongting Lake in Hunan province.
The discoveries have raised concerns finless porpoises, which have lived in the Yangtze River and adjacent lakes for more than 20 million years, could become extinct within 15 years, scientists said.
"Apparently the prolonged drought and low water level due to climate change and increasing offshore human activities are reducing the living space for finless porpoises, accelerating its extinction," Wang Kexiong, an expert of the Institute of Hydrobiology under the Chinese Academy of Sciences, told China Daily.
Scientists estimate the number of Yangtze finless porpoises has decreased to around 1,000.
The porpoises may have died due to starvation, poisoning or infectious disease, Xie Yongjun, a professor of animal husbandry at Yueyang Vocational and Technical College, said.