Science: For more than 50 years, astrophysicists have speculated that inside a superdense neutron star, nuclear matter might flow without any resistance whatsoever—much like electricity does in earthy materials known as superconductors, writes Adrian Cho for Science. Now, two teams say they have direct evidence of such bizarre “superfluidity” in a neutron star, and other researchers seem convinced. Dany Page, a theoretical astrophysicist at the National Autonomous University of Mexico in Mexico City, and colleagues published their results in Physical Review Letters, while Wynn Ho of the University of Southampton in the UK and Craig Heinke of the University of Alberta in Edmonton, Canada, and colleagues report a similar analysis in a paper in press at the Monthly Notices of the Royal Astronomical Society.
Monthly Archives: February 2011
World water shortage may result due to climate change and population growth
Daily Mail: Water demand in many countries will exceed supply by 40% within 20 years due to the combined threat of climate change and population growth, scientists have warned. About 300 scientists, policymakers, and economists are attending the Connecting Water Resources 2011 conference in Ottawa 28 February–3 March; it is hosted by the Canadian Water Network. The event is a precursor for World Water Day to be held 20–22 March in Cape Town, South Africa. “What people don’t often realise is how much water there is in everything we make and buy, from T-shirts to wine,” said Nicholas Parker, chairman of Cleantech Group, an international environmental technology consulting company. A variety of water conservation measures are being proposed.
New theory challenges existence of dark matter
BBC: A controversial theory that challenges the existence of dark matter has been buoyed by studies of gas-rich galaxies, writes Jason Palmer for the BBC. Instead of invoking dark matter, the modified Newtonian dynamics theory says that the effects of gravity change in places where its pull is very low. The new paper suggests that this theory better predicts the relationship between rotation speeds and masses in gassy galaxies. However, critics maintain that dark-matter theory is a better general description of the universe we see. The study, available online, will be published in Physical Review Letters.
Israeli scholar analyzes blue dye in ancient cloth
New York Times: An Israeli scholar says he has identified the first known physical sample of tekhelet—the shade of blue used for ritual prayer tassels and for ceremonial robes worn by high priests. Zvi Koren, a professor specializing in the analytical chemistry of ancient colorants, analyzed a 2000-year-old piece of dyed fabric recovered from Masada, King Herod’s Judean Desert fortress. The exact shade of blue used has been a mystery for centuries. The dye was produced from the secretion of the sea snail, still found on Israeli beaches, but the technique of producing the dye was lost some time after the Jews were exiled from Israel in AD 70.
Space shuttle Discovery takes off for the last time
Physics Today: Discovery, the busiest space shuttle in NASA’s fleet, was successfully launched on its final mission yesterday, at 4:50 pm, from Kennedy Space Center in Florida. Pete Spotts, writing for the Christian Science Monitor, gives an overview of Discovery and its last trip. The ship is carrying an Italian-built cargo carrier reengineered to provide extra storage space on the International Space Station. In addition, the orbiter is lofting some five tons of supplies and Robonaut 2, which designers envision as an eventual humanoid helpmate for future space station crews. Space.com provides a photo album of the building of Discovery in the early 1980s.
Is technology immortal?
NPR: NPR’s Robert Krulwich recently made a bet with Kevin Kelly, founding editor of Wired magazine, who claimed that “there is no species of technology that’s gone globally extinct on this planet”—in other words, there is no tool, no invention ever manufactured by humans that isn’t still being made new today. Krulwich appealed to his readers to come up with suggestions to prove Kelly wrong, which he narrowed to what he thought were three definitely dead technologies: radium suppositories, a Roman corvus (a plank used to board enemy ships), and the memory device inside a 1950s jukebox. Kelly proves him wrong, in this entertaining NPR blog.
Two exoplanets share the same orbit
New Scientist: In the four-planet system KOI-730, two of the planets share the same orbit around their star. They circle their Sun-like parent star every 9.8 days at exactly the same orbital distance, one about 120 degrees ahead of the other—called the gravitational “sweet spot.” The discovery bolsters the theory that our Moon was formed about 50 million years after the birth of the solar system, from the debris of a collision between a Mars-sized body and Earth.
Citizen scientists take up the slack
Science: In 2007 astronomer Chris Lintott, who works at the Adler Planetarium in Chicago, and colleagues were drowning under a data deluge—1 million images of galaxies to characterize and only one graduate student to do it. So they set up a website, called Galaxy Zoo, to recruit volunteer citizen scientists to help. The project was so successful—it attracted about 375 000 people working from the comfort of their own homes—that it was expanded to other projects, including studies of the Moon and an analysis of old ship logs for climate data. In Eli Kintisch’s article for Science, Lintott offers some suggestions to scientists for successful partnerships with armchair researchers.
Ground liquefaction a factor in New Zealand earthquake
Guardian: The damage caused by Tuesday’s earthquake in Christchurch, New Zealand, caught many experts by surprise. The severity of the damage appears to be due to a combination of the earthquake coming from a previously unknown fault that runs beneath the city, building weakening caused by the 2010 earthquake, and the violence of the shaking because the city rests on damp sediments. “Liquefaction is a huge problem in Christchurch because the city is built on an alluvial plain, on sediments that are vulnerable to liquefaction,” said John Clague, an expert in natural hazards at Simon Fraser University in British Columbia. “When shaken, these sediments transform into a liquid, causing irregular settlement of the ground, which is extremely damaging to buildings and buried structures, like water lines.”
South Dakota underground lab site remains viable
Science: Despite funding cuts by the National Science Board last December, the Deep Underground Science and Engineering Laboratory (DUSEL), expected to be built in the former Homestake gold mine near Lead, South Dakota, will retain its viability as a future facility a while longer. The National Science Foundation and the Department of Energy have agreed to pay for pumping water out of the mine so that it does not flood, which should preserve the site while the two agencies wrangle over how to transfer primary responsibility for DUSEL from NSF to DOE.