Einstein's theory at work in star pair
PASADENA, Calif., April 5 (UPI) -- NASA says a space telescope witnessed a dead star bending the light of its companion star, a phenomenon predicted by Einstein's theory of general relativity.
The observation of data from the Kepler space telescope is among the first detections of this effect in double-star systems, NASA Jet Propulsion Laboratory in Pasadena, Calif., reported Thursday.
The dead star is a white dwarf, the burned-out core of a star like the sun, and is locked into an orbital dance with a small "red dwarf" star.
While the white dwarf is the smaller of the pair, it is more massive that its partner, astronomers said.
"This white dwarf is about the size of Earth but has the mass of the sun," Phil Muirhead of the California Institute of Technology in Pasadena said. "It's so hefty that the red dwarf, though larger in physical size, is circling around the white dwarf."
When the red dwarf passes behind the white dwarf, the gravity of the much more massive white dwarf causes the red star's light to bend and brighten by minute but measurable amounts, scientists said.
"Only Kepler could detect this tiny, tiny effect," Doug Hudgins, Kepler program scientist at NASA Headquarters in Washington, said. "But with this detection, we are witnessing Einstein's theory of general relativity at play in a far-flung star system."
One of the predicted effects of Einstein's theory of general relativity is that gravity bends light, a phenomenon called gravitational lensing astronomers have used to gather evidence of dark matter and dark energy, two mysterious ingredients in the universe, and also to discover new, distant planets, JPL said.
Tablet sales gain, PC sales sinking
STAMFORD, Conn., April 5 (UPI) -- A shift in computing preferences has helped tablet shipments grow rapidly while sales of traditional PCs are in decline, a U.S. technology research firm says.
Gartner Inc., says tablet computer shipments are expected to grow 70 percent while personal computers and laptop shipments are predicted to decline 7.3 percent by 2017, ZDNet reported Friday.
Sales of PCs, tablets and smartphones -- collectively known as combined worldwide devices -- will show increases but the market share of the devices will shift over time with a greater focus on portability and mobile devices, Gartner said.
"As consumers shift their time away from their PC to tablets and smartphones, they will no longer see their PC as a device that they need to replace on a regular basis," Gartner research Vice President Carolina Milanesi said.
This has long been expected based on changes in user preferences over the long term, Gartner said.
By 2017 1.46 million devices will be running the Android platform while Windows-based machines will reach around the half-million mark, the Gartner report said.
Ice cores preserve 1,800 years of climate
COLUMBUS, Ohio, April 5 (UPI) -- Two ice cores from the tropical Peruvian Andes reveal Earth's detailed tropical climate history year by year for nearly 1,800 years, researchers say.
Researchers at Ohio State University who retrieved the cores from a Peruvian ice cap in 2003 are calling them "Rosetta Stone" samples with which to compare other climate histories from Earth's tropical and subtropical regions over the last two millennia.
The scientists said they noticed startling similarities to other ice cores retrieved from Tibet and the Himalaya, with patterns in the chemical composition of certain layers matching up, even though the cores were taken from opposite sides of the planet.
"These ice cores provide the longest and highest-resolution tropical ice core record to date," earth sciences Professor Lonnie Thompson said.
"In fact, having drilled ice cores throughout the tropics for more than 30 years, we now know that this is the highest-resolution tropical ice core record that is likely to be retrieved."
The cores will provide a new tool for researchers to study Earth's past climate and better understand the climate changes that are happening today, the researchers said.
The new cores are special, the researchers say, because most of their 1,800-year history exists as clearly defined layers of light and dark: light from the accumulated snow of the wet season, and dark from the accumulated dust of the dry season.
The cores will provide a permanent record for future use by climate scientists, Thompson said.
"The frozen history from this tropical ice cap -- which is melting away as Earth continues to warm -- is archived in freezers at minus 30 degrees centigrade (minus 22 degrees Fahrenheit) so that creative people will have access to it 20 years from now, using instruments and techniques that don't even exist today," he said.
Chemistry of Jupiter moon could aid life
PASADENA, Calif., April 5 (UPI) -- A common chemical abundant on Jupiter's moon Europa could be an important energy supply for simple forms of life, U.S. researchers say.
If hydrogen peroxide, found across much of the surface of Europa, were to mix into the oceans below it could create the energy needed to sustain very simple biological processes, scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif., said.
"Life as we know it needs liquid water, elements like carbon, nitrogen, phosphorus and sulfur, and it needs some form of chemical or light energy to get the business of life done," JPL researcher Kevin Hand said. "Europa has the liquid water and elements, and we think that compounds like peroxide might be an important part of the energy requirement.
"The availability of oxidants like peroxide on Earth was a critical part of the rise of complex, multicellular life."
Hydrogen peroxide was first detected on Europa by NASA's Galileo mission, which explored the Jupiter system from 1995 to 2003.
"At Europa, abundant compounds like peroxide could help to satisfy the chemical energy requirement needed for life within the ocean, if the peroxide is mixed into the ocean," Hand said.