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Astrophile: Mars coils hold with those who favour fire
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Fiery end to poetic Brain may not be hardwired to link numbers and space Martian debate END of the line for a number completely ignored the extent of hardwired into the healthy brain.
nasa
theory? Cognitive scientists have long thought that our ability to map numbers onto a physical space – such as along a line – is an innate ability. A study involving a remote tribe suggests otherwise. In 2002, researchers discovered that people with brain damage who were unable to fully perceive one side of their body had trouble interpreting the number line – they claimed, for example, that the number 5 lies halfway between 2 and 6. The finding was a boost to the idea that the number line is
Rafael Núñez of the University of California, San Diego, and colleagues question that idea. They asked 20 adult members of the Yupno tribe, native to Papua New Guinea, to place the numbers 1 to 10 along a 22-centimetre-long line printed on a card. Fourteen of the adults were unschooled. A further 10 controls in California performed the same task. The team found that both the controls and the schooled Yupno mapped the numbers onto the line. But the unschooled Yupno
the number line. They lumped numbers 1 and 2 at one end of the line, and all other numbers at the other end (PLoS One, DOI: 10.1371/ journal.pone.0035662). Núñez says the finding shows that the number line is a cultural metaphor for representing numbers, which has been used as the basis for more sophisticated mathematics. “The number line doesn’t seem to be something we have built into our brains,” he says. “But we teach it and it’s so natural that it’s all over the place.” Kevin Ebi / Alamy
SOME say a Martian valley formed in fire, some say in ice. Now curious spiral patterns have been glimpsed at one end of the valley floor – and hold with those who favour fire. The Athabasca Valles region, a channelled and scabbed valley just north of the Red Planet’s equator, was clearly carved by floods of fluid tens of millions of years ago. But, in a beautiful echo of the apocalyptic 1920s poem Fire and Ice by Robert Frost, no one knew whether that fluid was water or molten lava. Andrew Ryan of Arizona State University in Tempe and colleagues say they have settled the debate. In images from the sharp-eyed HiRISE camera on NASA’s Mars Reconnaissance Orbiter, Ryan noticed subtle spiral patterns, 5 to 30 metres wide, on Cerberus Palus, a plain at the south-west end of Athabasca (Science, DOI: 10.1126/ science.1219437). They could only be formed by volcanic processes, he says. “I was blown away,” he adds. The spirals, shown below, either formed on top of a cooling lava lake that pooled in the region, or when two flows of lava travelling in different directions or at different speeds moved past each other. The team found 296 spirals in a single HiRISE image that covered 90 square kilometres. Only two spirals were seen elsewhere, making it unclear if the spirals are unique to this region.
Atomic clock sets time travel record THE tick-tock of a super-accurate atomic clock has been sent over a longer distance than ever before. This paves the way for a global network of synchronised clocks for testing fundamental physics. Atomic clocks use precisely tuned electromagnetic waves to track the vibrations of atoms. Satellite transmissions can synchronise older atomic clocks, which track atoms that vibrate at microwave frequencies, but are not precise enough for optical clocks that use faster, optical frequencies. Instead, Katharina Predehl of the Max Planck Institute of Quantum Optics in Garching, Germany, and colleagues received a laser signal they had sent through 920 kilometres of optical fibre from an optical clock at Germany’s national metrology institute (PTB) in Braunschweig. The signal was about 1000 times more precise than signals transmitted by satellite (Science, DOI: 10.1126/science.1218442). The ability to synchronise two or more distant atomic clocks could be used to measure potential changes in fundamental physical constants or to test Einstein’s theory of gravity.
Biological GPS located in pigeons THE pigeon’s biological global positioning system has been recorded in action. David Dickman and Le-Qing Wu of Baylor College in Houston, Texas, collected seven homing pigeons (Columba livia) and inserted electrodes into their brains to record the activity of individual neurons. Dickman and Wu then placed the birds in an artificial magnetic field. As the researchers adjusted the intensity and angle of the magnets, they noticed that 53 neurons in one area of the brainstem were particularly active. These neurons
probably link to the brain’s internal map, and so act as a biological GPS (Science, DOI: 10.1126/ science.1216567). “It’s a stunning piece of work,” says David Keays of the Research Institute of Molecular Pathology in Vienna, Austria. “But what still remains unknown is how pigeons detect the magnetic field in the first place.” Dickman says the work means it may one day be possible to restore navigational ability to people who have lost it due to brain injury or neurodegenerative conditions such as Alzheimer’s disease.
5 May 2012 | NewScientist | 15
Fiery end to poetic Brain may not be hardwired to link numbers and space Martian debate END of the line for a number completely ignored the extent of hardwired into the healthy brain.
nasa
theory? Cognitive scientists have long thought that our ability to map numbers onto a physical space – such as along a line – is an innate ability. A study involving a remote tribe suggests otherwise. In 2002, researchers discovered that people with brain damage who were unable to fully perceive one side of their body had trouble interpreting the number line – they claimed, for example, that the number 5 lies halfway between 2 and 6. The finding was a boost to the idea that the number line is
Rafael Núñez of the University of California, San Diego, and colleagues question that idea. They asked 20 adult members of the Yupno tribe, native to Papua New Guinea, to place the numbers 1 to 10 along a 22-centimetre-long line printed on a card. Fourteen of the adults were unschooled. A further 10 controls in California performed the same task. The team found that both the controls and the schooled Yupno mapped the numbers onto the line. But the unschooled Yupno
the number line. They lumped numbers 1 and 2 at one end of the line, and all other numbers at the other end (PLoS One, DOI: 10.1371/ journal.pone.0035662). Núñez says the finding shows that the number line is a cultural metaphor for representing numbers, which has been used as the basis for more sophisticated mathematics. “The number line doesn’t seem to be something we have built into our brains,” he says. “But we teach it and it’s so natural that it’s all over the place.” Kevin Ebi / Alamy
SOME say a Martian valley formed in fire, some say in ice. Now curious spiral patterns have been glimpsed at one end of the valley floor – and hold with those who favour fire. The Athabasca Valles region, a channelled and scabbed valley just north of the Red Planet’s equator, was clearly carved by floods of fluid tens of millions of years ago. But, in a beautiful echo of the apocalyptic 1920s poem Fire and Ice by Robert Frost, no one knew whether that fluid was water or molten lava. Andrew Ryan of Arizona State University in Tempe and colleagues say they have settled the debate. In images from the sharp-eyed HiRISE camera on NASA’s Mars Reconnaissance Orbiter, Ryan noticed subtle spiral patterns, 5 to 30 metres wide, on Cerberus Palus, a plain at the south-west end of Athabasca (Science, DOI: 10.1126/ science.1219437). They could only be formed by volcanic processes, he says. “I was blown away,” he adds. The spirals, shown below, either formed on top of a cooling lava lake that pooled in the region, or when two flows of lava travelling in different directions or at different speeds moved past each other. The team found 296 spirals in a single HiRISE image that covered 90 square kilometres. Only two spirals were seen elsewhere, making it unclear if the spirals are unique to this region.
Atomic clock sets time travel record THE tick-tock of a super-accurate atomic clock has been sent over a longer distance than ever before. This paves the way for a global network of synchronised clocks for testing fundamental physics. Atomic clocks use precisely tuned electromagnetic waves to track the vibrations of atoms. Satellite transmissions can synchronise older atomic clocks, which track atoms that vibrate at microwave frequencies, but are not precise enough for optical clocks that use faster, optical frequencies. Instead, Katharina Predehl of the Max Planck Institute of Quantum Optics in Garching, Germany, and colleagues received a laser signal they had sent through 920 kilometres of optical fibre from an optical clock at Germany’s national metrology institute (PTB) in Braunschweig. The signal was about 1000 times more precise than signals transmitted by satellite (Science, DOI: 10.1126/science.1218442). The ability to synchronise two or more distant atomic clocks could be used to measure potential changes in fundamental physical constants or to test Einstein’s theory of gravity.
Biological GPS located in pigeons THE pigeon’s biological global positioning system has been recorded in action. David Dickman and Le-Qing Wu of Baylor College in Houston, Texas, collected seven homing pigeons (Columba livia) and inserted electrodes into their brains to record the activity of individual neurons. Dickman and Wu then placed the birds in an artificial magnetic field. As the researchers adjusted the intensity and angle of the magnets, they noticed that 53 neurons in one area of the brainstem were particularly active. These neurons
probably link to the brain’s internal map, and so act as a biological GPS (Science, DOI: 10.1126/ science.1216567). “It’s a stunning piece of work,” says David Keays of the Research Institute of Molecular Pathology in Vienna, Austria. “But what still remains unknown is how pigeons detect the magnetic field in the first place.” Dickman says the work means it may one day be possible to restore navigational ability to people who have lost it due to brain injury or neurodegenerative conditions such as Alzheimer’s disease.
5 May 2012 | NewScientist | 15