Physics Today: The final launch of the space shuttle Endeavour, scheduled for today, has been delayed for at least 48 hours because of a problem with the heaters associated with the shuttle’s auxiliary power unit, according to Manuel Roig-Franzia writing for the Washington Post. Officials at first thought the weather would cause a delay, but forecasters predicted the skies would clear in time. Endeavor is scheduled to deliver the Alpha Mass Spectrometer (AMS-2), the “first fundamental science experiment to the International Space Station,” says Nobel Prize winner Samuel Ting, AMS-2′s principle investigator. The $2 billion experiment, a collaboration between more than 40 institutions and 600 physicists, has taken more than 17 years to reach this point and has suffered dramatic setbacks, including the loss of its ride to the space station following the space shuttle Columbia disaster in 2003 and the last-minute replacement last year of its superconducting magnet with a less powerful permanent magnet.
Monthly Archives: April 2011
Putin fires space chief
AFP: Anatoly Perminov will be replaced as head of the Russian space agency Roskosmos after a series of high-profile mishaps. Vladimir Popovkin, currently first deputy defense minister, will replace him. Although Perminov had reached the maximum age for state employees, there have been clear indications of government frustration with Roskosmos’s performance for some time. The latest manned launch for the International Space Station was delayed in March, less than a month before the 50th anniversary of Yuri Gagarin’s first spaceflight. In February, the Geo-IK-2 military satellite was rendered useless for defense when it was put into the wrong orbit. And in December, a fuel miscalculation caused three navigation satellites for the new Russian GLONASS system to crash into the ocean off Hawaii instead of reaching orbit. In February, Deputy Prime Minister Sergei Ivanov issued a scathing assessment of Roskosmos’s performance, saying that the GLONASS mishap was characteristic of its problems and that any repeat satellite failure would be unacceptable. Perminov has served as Roskosmos chief since March 2004.
Elusive million-year-old ice core could provide clues to climate change
New Scientist: Four science teams—from Europe, Australia, China, and the US—are racing to retrieve the first million-year-old sample from Antarctica’s ice. Ancient ice could hold clues to past changes in Earth’s climate. Using such ice samples, scientists could study the concentration of carbon dioxide in the ancient atmosphere by analyzing the air trapped in tiny bubbles within the ice. A decline in carbon dioxide concentration could explain the advent of an ice age, for example. One researcher, Robin Bell of the Lamont-Doherty Earth Observatory of Columbia University, and her colleagues have come across a potential problem with the hunt, however. They have found that ice sheets in Dome A, one of the drilling sites, is growing from the bottom up. This could mean that any ancient ice that was once there has melted and been replaced.
Monster Alabama tornado spawned by rare “perfect storm”
National Geographic: The tornado that devastated Tuscaloosa, Alabama, on Wednesday was the result of an unusual confluence of meteorological conditions. Current estimates put the twister’s wind speed at about 260 mph, and it may have remained in contact with the ground for more than 200 miles. An unusually strong jet stream over the region, with wind speeds of 150 mph, caused intense upward motion in the atmosphere. The colder, drier air within combined with the warm, moist air already in place to create rotating thunderstorms known as supercells—one of the few types of storms that spawn tornadoes. A 50 mph wind closer to the ground only increased the storms’ rotation. Wednesday’s tornado outbreak included more than 100 twisters across 6 states and killed at least 283 people, making it the worst outbreak since 3 April 1974, when 330 people were killed in an area that stretched from Alabama to Indiana.
First stars were spinning tops
Science: The first stars, formed about 300 million years after the Big Bang, are thought to have been hundreds of times bigger than the Sun. According to a new study, they also whirled at incredible speeds of about 500 km/s—250 times faster than the Sun does. While it is unlikely that those stars could be detected directly, the velocity of their rotation probably led to their ending their lives with a gamma-ray burst (GRB), which produces a huge flash of high-energy radiation. GRBs can be detected from much farther away than individual stars. NASA is considering a small explorer mission; its Joint Astrophysics Nascent Universe Satellite could give astronomers the means to observe GRBs created by primordial stars in their final moments.
African ocean current may help keep Europe warm
BBC: In 2007 the Intergovernmental Panel on Climate Change (IPCC) predicted that increased greenhouse gas concentrations would lead to a weakening of the Atlantic Meridional Overturning Circulation, which includes the Gulf Stream. The result would be cooler temperatures in Europe. A group of researchers who have just published a new study in Nature say, however, that changes to another ocean current, the Agulhas Current, could keep Europe warm even if the Gulf Stream switches off. The Agulhas Current flows southward down the eastern coast of Africa, and although most of the water heads east back into the Indian Ocean, some of it leaks around Africa’s southern tip—Cape Agulhas—and flows into the Atlantic. One of those researchers, Lisa Beal from the Rosen School of Marine and Atmospheric Science in Miami, Florida, said that research on the current to date has been sparse but that wind shifts farther south make it likely that the Agulhas Leakage is increasing. “This could mean that current IPCC model predictions for the next century are wrong and there will be no cooling in the North Atlantic to partially offset the effects of global climate change over North America and Europe,” said Beal.
Quantum effects brought to light, and sight
Nature: Quantum effects are usually detected indirectly via precision instruments. Now Nicolas Gisin, of the University of Geneva in Switzerland, and colleagues have created a new test to see if the human eye can pick up signs of entanglement, writes Zeeya Merali for Nature. The researchers entangled two photons, sent one to a standard photon detector, and amplified the other, creating a light field of thousands of photons with the same quantum state. The humans in the experiment observed the same effects of entanglement that the photon detectors recorded. However, Gisin set up the experiment so that the state of the second, amplified photon was measured before amplification, thus breaking the entanglement. Both the human observers and the photon detectors were deceived into giving false positives by the effect known as the detection loophole: Some photons will always be lost during the experiment. The more photons involved, the more the effect is magnified—and the more the results for both human and mechanical detectors are distorted.
Magnets used to reduce diagnosis time for infections
New Scientist: Two techniques involving magnets could significantly reduce the time it takes—from days to hours—to diagnose a fatal infection, writes Jessica Hamzelou for New Scientist. A team at MIT has created a device that uses magnetic resonance to detect a fungus called Candida, which has a 40% mortality rate. Because there are five species of Candida, the team engineered five types of molecular probe, each of which contains a magnetic particle. When the probes are put into blood samples and a magnetic pulse is applied, the water molecules begin to spin; the time it takes for the molecules to return to rest determines whether a species of Candida is present and how much of it there is. A second team at Harvard University has been working to diagnose sepsis. Team members coated magnetic particles with an immune-system protein that binds to the cell walls of pathogens in the blood. The entire cluster can be pulled out using a magnet, and the pathogen can then be identified. “In my opinion both techniques could significantly advance the field of diagnostics…. It’s pretty cool,” said Dirk Kuhlmeier at the Fraunhofer Institute for Cell Therapy and Immunology in Leipzig, Germany.
CERN says Higgs particle speculation is premature
UPI: CERN’s director of communications James Gillies has told the BBC that the leaked report of a possible Higgs detection originated from a small group within the large ATLAS collaboration. The report is genuine but premature in that it has yet to be endorsed by the ATLAS collaboration or subjected to rigorous testing and peer review. Publicized last Thursday, the leaked information set off an explosion of speculation, comment, and recriminations on physics blogs.
Getting the most out of an electric-car battery
New York Times: New York Times energy and environment blogger Jim Witkin predicts over the next five years car-battery technology will see big breakthroughs, which will increase the range and reduce the costs of electric cars. Nothing can change the fact that any rechargeable battery will gradually lose its energy storage capacity after repeated charging and discharging. However, although the battery may no longer power a car, it can still have enough energy capacity for other purposes. Hence, multiple ventures are under way to explore second-life applications, such as using the batteries in the electric utility grid to help manage power flow. And because reuse may be the most viable option for the many batteries that will be required to run the electric cars of the future, new automobile financial and ownership models are being proposed. One possibility is the automaker’s or finance company’s retaining ownership of the battery and leasing it to the car’s owner; then the owner would pay only for the portion of the battery used while it’s in the car.