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Flaring black holes may solve cosmic ray puzzle
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Tim Davis/CORBIS
CHIMPS have an unusual way of interacting with dominant males – they yawn back at them. No one is sure why yawning is contagious in chimps and other animals. “People claim that it is some sort of measure of empathy,” says Jorg Massen at Utrecht University in the Netherlands. To test the theory, Massen and his colleagues monitored a group of chimpanzees at Burgers’ Zoo in Arnhem, the Netherlands. They filmed each of the 15 chimpanzees yawning – something the animals tend to do before they set off after a period of rest. They then played back the clips to the chimps individually to see whether the animals would yawn in response. Clips of male chimps yawning were about twice as likely to induce yawns as clips of female yawns (PLoS One, DOI: 10.1371/journal. pone.0040697). The team says this may be linked to the fact that dominant chimps are always male. Contagious yawns may help the group act in step with its dominant male and get the group moving after a period of rest, Massen says. He hopes to explore whether a similar link between yawning and social status exists in humans. “I wouldn’t be surprised if the yawns of President Obama would be more contagious than those of the average American,” he says.
Cosmic-ray burp follows black hole’s celestial dinner WHERE do ultra high-energy cosmic rays come from? These charged particles zoom to Earth from outer space, but why is a mystery. Now a possible source – gamma-ray bursts, which seemed to have been ruled out – have received a new lease of life. Gamma-ray bursts are usually created by exploding stars, which produce neutrinos. So last April, when the IceCube neutrino detector in Antarctica saw no neutrinos accompanying highenergy cosmic rays, astronomers favoured galaxies with active
supermassive black holes at their cores as the source of the rays. But a more recent study found that only one galaxy was powerful enough to have produced cosmic rays with such high energies. The rest appear to come from galaxies that seem too weak. This posed a “perplexing problem”, says Glennys Farrar of New York University, one of the study authors. Then they found a clue: gamma-ray burst GRB110328A, which happened in March 2011. Its afterglow persisted for over a week, instead of a few
hours like normal ones. The culprit was most likely a star falling into a galaxy’s central black hole. This would make a weak black hole flare up, producing a burst of gamma rays that in turn spits out cosmic rays, suggests Farrar (arxiv.org/abs/1207.3186v1). The trouble is testing the hypothesis. Gamma rays travel at the speed of light, so would arrive millennia ahead of any cosmic rays. Farrar hopes to strengthen the idea by matching more cosmic ray emissions with weak active galaxies. Stocktrek Images/Getty
Lowly chimps yawn to the chief
Monkey do, researchers see WHETHER a tree branch or a beer is the target, reaching for objects is fundamental primate behaviour. Neurons in the brain prepare for such movements, and this neural activity can now be deciphered, allowing researchers to predict what movements will occur. The discovery could help us to develop mind-controlled prosthetic limbs. Daniel Moran and Thomas Pearce at Washington University in St Louis, Missouri, trained two rhesus macaques to participate in a series of reaching exercises. When the monkeys reached for items – which were sometimes blocked by obstacles – electrodes measured the activity of neurons in their dorsal premotor cortex, a region of the brain that is involved in the perception of movement. Moran and Pearce managed to identify the neural activity corresponding with several aspects of the planned movement, such as the angle of reach, hand position and final target location (Science, DOI: 10.1126/science.1220642). Being able to decipher such information could aid the development of prosthetic limbs that can be controlled by thought alone, says Moran.
A bond that can only form in space THERE’S a new bond in town, and this secret agent works best in extreme situations. The chemical bond occurs in the presence of strong magnetic fields, such as those found around white dwarfs, the remnant cores of dead, low-mass stars. Earth’s field is too puny for it to happen here. Because the electrons in atomic bonds follow the Pauli principle – two of them cannot occupy the same quantum state – they pair up in couples of opposing spin. If the spins of both become aligned, one is forced into a so-called anti-bonding orbital. “The atoms are no longer bound
together and the molecule breaks apart,” says Kai Lange at the University of Oslo in Norway. But when Lange and colleagues simulated bonding in hydrogen and helium atoms in the magnetic field of a white dwarf – 10 billion times greater than Earth’s – the atoms were drawn into strongly bonded pairs in both cases. Because the electrons occupied the anti-bonding orbitals yet bonded together, it’s a new type of chemical bond (Science, DOI: 10.1126/science.1219703). The space-only bond shows chemistry changing under extreme conditions.
28 July 2012 | NewScientist | 15
Tim Davis/CORBIS
CHIMPS have an unusual way of interacting with dominant males – they yawn back at them. No one is sure why yawning is contagious in chimps and other animals. “People claim that it is some sort of measure of empathy,” says Jorg Massen at Utrecht University in the Netherlands. To test the theory, Massen and his colleagues monitored a group of chimpanzees at Burgers’ Zoo in Arnhem, the Netherlands. They filmed each of the 15 chimpanzees yawning – something the animals tend to do before they set off after a period of rest. They then played back the clips to the chimps individually to see whether the animals would yawn in response. Clips of male chimps yawning were about twice as likely to induce yawns as clips of female yawns (PLoS One, DOI: 10.1371/journal. pone.0040697). The team says this may be linked to the fact that dominant chimps are always male. Contagious yawns may help the group act in step with its dominant male and get the group moving after a period of rest, Massen says. He hopes to explore whether a similar link between yawning and social status exists in humans. “I wouldn’t be surprised if the yawns of President Obama would be more contagious than those of the average American,” he says.
Cosmic-ray burp follows black hole’s celestial dinner WHERE do ultra high-energy cosmic rays come from? These charged particles zoom to Earth from outer space, but why is a mystery. Now a possible source – gamma-ray bursts, which seemed to have been ruled out – have received a new lease of life. Gamma-ray bursts are usually created by exploding stars, which produce neutrinos. So last April, when the IceCube neutrino detector in Antarctica saw no neutrinos accompanying highenergy cosmic rays, astronomers favoured galaxies with active
supermassive black holes at their cores as the source of the rays. But a more recent study found that only one galaxy was powerful enough to have produced cosmic rays with such high energies. The rest appear to come from galaxies that seem too weak. This posed a “perplexing problem”, says Glennys Farrar of New York University, one of the study authors. Then they found a clue: gamma-ray burst GRB110328A, which happened in March 2011. Its afterglow persisted for over a week, instead of a few
hours like normal ones. The culprit was most likely a star falling into a galaxy’s central black hole. This would make a weak black hole flare up, producing a burst of gamma rays that in turn spits out cosmic rays, suggests Farrar (arxiv.org/abs/1207.3186v1). The trouble is testing the hypothesis. Gamma rays travel at the speed of light, so would arrive millennia ahead of any cosmic rays. Farrar hopes to strengthen the idea by matching more cosmic ray emissions with weak active galaxies. Stocktrek Images/Getty
Lowly chimps yawn to the chief
Monkey do, researchers see WHETHER a tree branch or a beer is the target, reaching for objects is fundamental primate behaviour. Neurons in the brain prepare for such movements, and this neural activity can now be deciphered, allowing researchers to predict what movements will occur. The discovery could help us to develop mind-controlled prosthetic limbs. Daniel Moran and Thomas Pearce at Washington University in St Louis, Missouri, trained two rhesus macaques to participate in a series of reaching exercises. When the monkeys reached for items – which were sometimes blocked by obstacles – electrodes measured the activity of neurons in their dorsal premotor cortex, a region of the brain that is involved in the perception of movement. Moran and Pearce managed to identify the neural activity corresponding with several aspects of the planned movement, such as the angle of reach, hand position and final target location (Science, DOI: 10.1126/science.1220642). Being able to decipher such information could aid the development of prosthetic limbs that can be controlled by thought alone, says Moran.
A bond that can only form in space THERE’S a new bond in town, and this secret agent works best in extreme situations. The chemical bond occurs in the presence of strong magnetic fields, such as those found around white dwarfs, the remnant cores of dead, low-mass stars. Earth’s field is too puny for it to happen here. Because the electrons in atomic bonds follow the Pauli principle – two of them cannot occupy the same quantum state – they pair up in couples of opposing spin. If the spins of both become aligned, one is forced into a so-called anti-bonding orbital. “The atoms are no longer bound
together and the molecule breaks apart,” says Kai Lange at the University of Oslo in Norway. But when Lange and colleagues simulated bonding in hydrogen and helium atoms in the magnetic field of a white dwarf – 10 billion times greater than Earth’s – the atoms were drawn into strongly bonded pairs in both cases. Because the electrons occupied the anti-bonding orbitals yet bonded together, it’s a new type of chemical bond (Science, DOI: 10.1126/science.1219703). The space-only bond shows chemistry changing under extreme conditions.
28 July 2012 | NewScientist | 15