The seeds of a sunflower, the spines of a cactus, and the bracts of a pine cone all grow in whirling spiral patterns. Remarkable for their complexity and beauty, they also show consistent mathematical patterns that scientists have been striving to understand.
A surprising number of plants have spiral patterns in which each leaf, seed, or other structure follows the next at a particular angle called the golden angle. The golden angle is about 137.5º. Two radii of a circle C form the golden angle if they divide the circle into two areas A and B so that A/B = B/C.
Science & Technology
Chimpanzees and bonobos can communicate with greater flexibility using hand gestures than they can with facial expressions or vocalizations, new research shows. Their use of hand motions to convey different meanings in different circumstances suggests that gestures may have played an important part in the evolution of language.
Researchers speculate about how prehuman species developed the capacity for complex language. One theory suggests that humans' apelike ancestors first communicated through gestures. Once the neural circuits for gesture-based language had evolved, those same brain areas could have switched over to verbal communication. Indeed, research has shown that modern apes use the same area of the brain to interpret hand signals as humans use to process spoken language.
Working at the Yerkes National Primate Research Center in Atlanta, Frans B.M. de Waal and Amy S. Pollick observed communications among 34 captive chimpanzees and among 13 captive bonobos, also known as pygmy chimpanzees. The researchers logged every hand gesture, facial expression, and vocal cry that one animal directed at another. They also noted the social context - playing, grooming, fighting, having sex, eating, and so on - in which each signal occurred.
Researchers speculate about how prehuman species developed the capacity for complex language. One theory suggests that humans' apelike ancestors first communicated through gestures. Once the neural circuits for gesture-based language had evolved, those same brain areas could have switched over to verbal communication. Indeed, research has shown that modern apes use the same area of the brain to interpret hand signals as humans use to process spoken language.
Working at the Yerkes National Primate Research Center in Atlanta, Frans B.M. de Waal and Amy S. Pollick observed communications among 34 captive chimpanzees and among 13 captive bonobos, also known as pygmy chimpanzees. The researchers logged every hand gesture, facial expression, and vocal cry that one animal directed at another. They also noted the social context - playing, grooming, fighting, having sex, eating, and so on - in which each signal occurred.
With temperatures ranging from 1000 to 2000°C, gravity 15 times stronger than Earth's, and a year that lasts just 5.6 of our days, HAT-P-2b is not a planet you'd want to visit for vacation.
The unusual gas giant - located 440 light-years away in the constellation Hercules - turns out to be the most massive planet found outside our solar system so far.
Astronomers at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, spotted the superdense planet using the HATNet global network of automated telescopes, which scans a large fraction of the Northern Hemisphere sky every night to search for planets.
HAT-P-2b, the second planet the project has discovered, stunned scientists with far-out features unprecedented for an alien world.
The unusual gas giant - located 440 light-years away in the constellation Hercules - turns out to be the most massive planet found outside our solar system so far.
Astronomers at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, spotted the superdense planet using the HATNet global network of automated telescopes, which scans a large fraction of the Northern Hemisphere sky every night to search for planets.
HAT-P-2b, the second planet the project has discovered, stunned scientists with far-out features unprecedented for an alien world.
NASA has released stunning new images of Jupiter and its moons taken by the New Horizons spacecraft. Views include a movie of a volcanic eruption on Jupiter's moon Io; a nighttime shot of auroras and lava on Io; a color photo of the "Little Red Spot" churning in Jupiter's cloudtops; images of small moons herding dust and boulders through Jupiter's faint rings--and much more: gallery.
"We'll be analyzing these data for months to come," says Science Mission Directorate Associate Administrator and New Horizons Principal Investigator Alan Stern of NASA Headquarters. "We have collected spectacular scientific products as well as evocative images."
New Horizons came within 1.4 million miles of Jupiter on Feb. 28 in a gravity assist maneuver designed to trim three years off its travel time to Pluto. For several weeks before and after this closest approach, the piano-sized robotic probe trained its seven cameras and sensors on Jupiter and its four largest moons, storing data from nearly 700 observations on its digital recorders and gradually sending that information back to Earth. About 70 percent of the expected 34 gigabits of data has come back so far, radioed to NASA's largest antennas over more than 600 million miles.
"We'll be analyzing these data for months to come," says Science Mission Directorate Associate Administrator and New Horizons Principal Investigator Alan Stern of NASA Headquarters. "We have collected spectacular scientific products as well as evocative images."
New Horizons came within 1.4 million miles of Jupiter on Feb. 28 in a gravity assist maneuver designed to trim three years off its travel time to Pluto. For several weeks before and after this closest approach, the piano-sized robotic probe trained its seven cameras and sensors on Jupiter and its four largest moons, storing data from nearly 700 observations on its digital recorders and gradually sending that information back to Earth. About 70 percent of the expected 34 gigabits of data has come back so far, radioed to NASA's largest antennas over more than 600 million miles.
US researchers carrying out a sonar survey of Loch Ness have been amazed to find a common toad crawling in the mud 324ft (98m) down.
Researchers working with high-precision planetary radars, including the Goldstone Solar System Radar of NASA's Jet Propulsion Laboratory, Pasadena, Calif., have discovered strong evidence that the planet Mercury has a molten core. The finding explains a more than three-decade old planetary mystery that began with the flight of JPL's Mariner 10 spacecraft. The research appears in this week's issue of the journal Science.
MIAMI - Florida legislators voted on Thursday to replace touch-screen voting machines installed in 15 counties after the troubled 2000 presidential election here with a system of optical scan voting.
The new system is scheduled to be running in time for the 2008 presidential election.
The new system is scheduled to be running in time for the 2008 presidential election.
UNITED NATIONS -- The countdown begins next week for the United Nations to take on the task of saving the world -- not from the usual scourges of war, disease or poverty, but from an asteroid attack.
History is replete with examples of social organizations, whether a business or a nation, that failed to perceive the realities of a changing environment and didn't adapt in time to prevent calamity. Hubris and a self-reinforced dynamic of mass delusion characterize the waning phases of these once powerful groups. In hindsight we ask, "What were they thinking? Wasn't the situation obvious to everyone? The evidence is so clear!" Here's the question we should ask next: "Is history now repeating itself?"
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Being the closest planet to the Sun, you might think Mercury would be the most likely rocky planet in the Solar System to have a molten core, but for the past three decades physicists have not been quite so sure. By taking radar measurements of Mercury using ground-based radio telescopes, however, physicists in the US and Russia claim to have proved that the variation in the planet's spin rate is indeed characteristic of a molten core. Their work also lends weight to the idea that Mercury, like Earth, produces its magnetic field in the molten core through dynamo action (Science 316 710).
Despite its 400 °C surface temperatures, physicists originally predicted that Mercury's small mass - about 5% that of the Earth - would have allowed its core to cool down enough to solidify long ago. But their predictions became much less certain in the 1970s after NASA's Mariner 10 spacecraft flew by the planet and detected a small internal dipole magnetic field. Although some claimed that the field could have been a fossil of an earlier one "frozen" into the crust, others maintained that this was very unlikely, and that dipole magnetic fields in terrestrial planets are normally a result of the convection of molten iron producing a dynamo.
Despite its 400 °C surface temperatures, physicists originally predicted that Mercury's small mass - about 5% that of the Earth - would have allowed its core to cool down enough to solidify long ago. But their predictions became much less certain in the 1970s after NASA's Mariner 10 spacecraft flew by the planet and detected a small internal dipole magnetic field. Although some claimed that the field could have been a fossil of an earlier one "frozen" into the crust, others maintained that this was very unlikely, and that dipole magnetic fields in terrestrial planets are normally a result of the convection of molten iron producing a dynamo.
