Fossils from a family of the first known burrowing dinosaurs have been found by scientists in Montana. The fossils are from an adult and two juveniles. The bones are 95 million years old and were unearthed in a chamber at the end of a 2.1 meter long tunnel that was filled with sediment. The researchers say their discovery is the first definitive evidence that some dinosaurs dug dens and cared for their young in them.
"Burrowing also represents a mechanism by which small dinosaurs may have exploited the extreme environments of polar latitudes, deserts and high mountain areas," David Varricchio and colleagues write their paper.
The ability to burrow would have given it many advantages, said Anthony Martin, a co-author, such as surviving harsh climatic conditions or catastrophes such as volcanic eruptions -- rocks found in the sediment suggest there were active volcanos nearby. "Burrows have a nice way of evening out environmental conditions, like maintaining a stable temperature and humidity."
The researchers note that dinosaurs' snout, shoulder girdle and pelvis have structures that one would expect to see in an animal that dug into the ground. The burrow was a sloping twisting tunnel more than two metres (6.5 feet) long and about 70 centimetres (28 inches) wide. It is similar to burrows made today by striped hyenas and puffins.
"At first it seemed too big for the burrow," says Varricchio. However, modern mammals squeeze into tight places for protection, he reasons. "A tight fit precludes anyone meaner or bigger from getting in there," he said.
These burrowing dinosaurs represent a new species and has been given the scientific name Oryctodromeus cubicularis, which is a mix of Greek and Latin meaning "digging runner of the lair". They were hypsilophodonts, a group that includes the much larger duck-billed hadrosaurs. Based on the preserved vertebrae, the adult would have been about 2.1 meters (6.8 feet) from nose to tail, most of which was the tail itself. The whole animal probably weighed 22 to 32 kilograms, Varricchio estimates. So its body was approximately the size of a german shepard.
The tunnel ended in a chamber, where the skeletal remains of an adult and two juveniles were found. Unfortunately, the bones were disarticulated.
"It's not like they were sitting in the burrow and a flooding event filled the chamber with sediment and they were entombed. They must have died, undergone decay and then the burrow was filled."
The juveniles are more than half grown, suggesting that the parents cared for their young for a significant period.
This find is reported in the journal Proceedings of the Royal Society B, a journal of Britain's academy of sciences.
Saturday, March 31, 2007
Thursday, March 29, 2007
Is the Placebo Effect a Myth?
by Josie Glausiusz
Taking a swipe at conventional wisdom, medical philosophers Asbj#248;rn Hróbjartsson and Peter Gøtzsche of the University of Copenhagen recently proclaimed the placebo effect— one of the best-known but least understood curative processes— a myth.
After analyzing 114 placebo-controlled trials, they concluded that placebos are generally no more effective at relieving disease symptoms than no treatment at all. Now the attackers are under fire from placebo researchers who say the public is being misled.
"That article was a travesty," says neurobiologist Howard Fields of the University of California at San Francisco, who in the 1970s demonstrated that placebos appear to relieve pain by inducing the body to release opiates.
A new study coauthored by neuroscientist Fabrizio Benedetti of the University of Turin Medical School in Italy bolsters this notion. Benedetti found that patients who were informed they were receiving an intravenous analgesic experienced more pain relief than those who received it automatically via an infusion machine.
The painkiller's action was enhanced by the knowledge it was being given— a clear placebo effect. In a little-publicized portion of their paper, even Hróbjartsson and Gøtzsche concede that placebos can relieve pain.
Fields is especially irate that Hróbjartsson and Gøtzsche lumped together disparate trials, some of which found a placebo effect, some of which did not. In effect, the trials cancelled each other out. Why, then, have reporters rushed to embrace their results? Benedetti blames a reluctance to accept the power of the mind. "It is a sort of sigh of relief: 'Aah, we knew medicines were real and not the result of some psychological stuff.'
Taking a swipe at conventional wisdom, medical philosophers Asbj#248;rn Hróbjartsson and Peter Gøtzsche of the University of Copenhagen recently proclaimed the placebo effect— one of the best-known but least understood curative processes— a myth.
After analyzing 114 placebo-controlled trials, they concluded that placebos are generally no more effective at relieving disease symptoms than no treatment at all. Now the attackers are under fire from placebo researchers who say the public is being misled.
"That article was a travesty," says neurobiologist Howard Fields of the University of California at San Francisco, who in the 1970s demonstrated that placebos appear to relieve pain by inducing the body to release opiates.
A new study coauthored by neuroscientist Fabrizio Benedetti of the University of Turin Medical School in Italy bolsters this notion. Benedetti found that patients who were informed they were receiving an intravenous analgesic experienced more pain relief than those who received it automatically via an infusion machine.
The painkiller's action was enhanced by the knowledge it was being given— a clear placebo effect. In a little-publicized portion of their paper, even Hróbjartsson and Gøtzsche concede that placebos can relieve pain.
Fields is especially irate that Hróbjartsson and Gøtzsche lumped together disparate trials, some of which found a placebo effect, some of which did not. In effect, the trials cancelled each other out. Why, then, have reporters rushed to embrace their results? Benedetti blames a reluctance to accept the power of the mind. "It is a sort of sigh of relief: 'Aah, we knew medicines were real and not the result of some psychological stuff.'
Wednesday, March 28, 2007
Why We Sleep
Does sleep allow us to cull out and delete the throngs of ordinary, unimportant memories from each day?
by Anne Wootton
Our need for sleep is somehow tied to our ability to remember. Slumber is known to improve recall in creatures from fruit flies to humans, and the reigning theory among neuroscientists has been that the waves of brain activity during deep sleep reactivate neurons that were triggered during the day, strengthening neuronal connections and cementing them into solid memories. Now Giulio Tononi, a neuroscientist at the University of Wisconsin, says sleep scientists have it all wrong: We don't sleep to remember, we sleep to forget.
About 1,000 times a night, billions of neurons undergo a synchronous one-second burst of non-REM electrical activity. The longer a person has been sleep-deprived, the bigger the initial burst. Throughout the night the bursts become progressively smaller, until they finally disappear completely just before waking. Most researchers interpret this activity as the brain slowly reinforcing synaptic connections that already exist, but Tononi noticed that after each wave, the brain goes completely silent, which never happens when we're awake.
As we sleep, says Tononi, the brain isn't building but rather downscaling, and these silences between waves play a key role. "Going up and down, up and down, basically all the neurons fire and then all are silent—it's a wonderful way for the brain to tell the synapses to get weaker," Tononi explains. He suspects the progressive weakening allows only the strong connections to survive.
The theory is unorthodox, but it does make a certain amount of sense. Without the ability to pare away unneeded information as we sleep, our brains would face a serious energy shortage as well as a space crunch: Stronger synapses are typically bigger, and real estate in the brain is precious. By proportionally weakening synapses, the brain ensures that they retain the same strength relative to each other. So when we wake up each morning, all of our synapses are weaker, and some have vanished. With them, our smallest memories from each day may be lost forever.
by Anne Wootton
Our need for sleep is somehow tied to our ability to remember. Slumber is known to improve recall in creatures from fruit flies to humans, and the reigning theory among neuroscientists has been that the waves of brain activity during deep sleep reactivate neurons that were triggered during the day, strengthening neuronal connections and cementing them into solid memories. Now Giulio Tononi, a neuroscientist at the University of Wisconsin, says sleep scientists have it all wrong: We don't sleep to remember, we sleep to forget.
About 1,000 times a night, billions of neurons undergo a synchronous one-second burst of non-REM electrical activity. The longer a person has been sleep-deprived, the bigger the initial burst. Throughout the night the bursts become progressively smaller, until they finally disappear completely just before waking. Most researchers interpret this activity as the brain slowly reinforcing synaptic connections that already exist, but Tononi noticed that after each wave, the brain goes completely silent, which never happens when we're awake.
As we sleep, says Tononi, the brain isn't building but rather downscaling, and these silences between waves play a key role. "Going up and down, up and down, basically all the neurons fire and then all are silent—it's a wonderful way for the brain to tell the synapses to get weaker," Tononi explains. He suspects the progressive weakening allows only the strong connections to survive.
The theory is unorthodox, but it does make a certain amount of sense. Without the ability to pare away unneeded information as we sleep, our brains would face a serious energy shortage as well as a space crunch: Stronger synapses are typically bigger, and real estate in the brain is precious. By proportionally weakening synapses, the brain ensures that they retain the same strength relative to each other. So when we wake up each morning, all of our synapses are weaker, and some have vanished. With them, our smallest memories from each day may be lost forever.
Tuesday, March 27, 2007
Grace in Space
A pair of satellites map subtle variations in Earth’s gravitational field, revealing secret craters, undersea mountains, and the impact of climate change.
by Sam Flamsteed
If the Reverend Nevil Maskelyne came back to life, the 18th-century Astronomer Royal of Great Britain would probably have no trouble grasping the idea behind NASA’s remote sensing GRACE mission. Maskelyne proposed a remarkably similar experiment himself in a presentation to the Royal Society in 1772. “If the attraction of gravity be exerted, as Sir Isaac Newton supposes, not only between the large bodies of the universe, but between the minutest particles of which these bodies are composed . . . it will necessarily follow, that every hill must, by its attraction, alter the direction of gravitation in heavy bodies in its neighbourhood . . . .”
That’s exactly what GRACE, the Gravity Recovery and Climate Experiment, detects. Every 94 minutes or so, twin satellites whip once around Earth at an altitude of 310 miles, taking 30 days to cover the planet’s entire surface, then they do it again and again, sensing variations in local gravity. GRACE maps local variations in the force of gravity over Earth’s surface, revealing mountain ranges and ocean trenches as well as underground watersheds and other hidden concentrations of mass. A joint venture by NASA and the DLR (Deutsches Zentrum für Luft- und Raumfahrt, or German Aerospace Center), GRACE looks right past the familiar oceans, continents, and clouds, showing our planet in a fresh light—as a knobby, blobby globe of gravitational ups and downs.
Among other things, GRACE may have found a crater deep under the Antarctic ice that may mark an asteroid impact greater than the one that doomed the dinosaurs, measured the seafloor displacement that triggered the tsunami of 2004, and quantified changes in subsurface water in the Amazon and Congo river basins. “This is really an entirely new kind of remote sensing,” says project scientist Michael Watkins, of NASA’s Jet Propulsion Laboratory. “It’s like when radar or photography was first invented—you start realizing that it can be applied in all sorts of unanticipated ways. We’re still discovering them.”
The notion that Earth’s gravity field could be measured with satellites dates back to the dawn of the space age. In 1958 ground controllers tracking the first American satellite, Explorer 1, noted that its path faithfully traced the planet’s equatorial bulge (created by centrifugal forces generated by the planet’s rotation). By the 1960s rocket scientists realized that smaller, local variations in gravity could have further, unforeseen effects. Missiles carrying nuclear warheads, for example, could be thrown off course if no allowance was made for mountain ranges or valleys.
If Earth were a perfect sphere, perfectly uniform in density and covered to a uniform depth with ocean, the geoid—a word coined by geologists to refer to an imaginary plane located at the average level of the sea’s surface—would be a perfect sphere as well. Since the geoid would be evenly perpendicular to the pull of gravity in all places, that force would always pull you directly toward the precise center of the Earth. But Earth is nowhere near perfect or uniform, which means that gravity doesn’t always point straight down; a mountain range, for example, might divert it slightly to the left.
Understanding the subtleties of Earth’s gravitational field would be useful in many ways. Scientists could learn a lot about the structure of the planet, what it’s made of, and where the crust is thick or thin. A deposit of high-density underground rock, or an undersea mountain, is utterly invisible—yet they, too, skew the geoid away from perfect flatness. Even when the ocean is utterly calm, it isn’t flat. Measurements reveal that some parts of the ocean are a remarkable 390 feet lower than average, and others are 300 feet higher.
While scientists began to appreciate just how useful a map of the geoid could be, engineers were realizing that the most sensible way to measure the variations would be with a pair of satellites, instead of just one. A single orbiter would bob and weave with the gravity field just fine—but monitors would have to measure the ups and downs from the ground continuously by beaming radio waves back and forth. That would require an enormous network of ground stations. Yet two satellites flying far enough apart would experience different gravitational effects, so that only the distance between them must be measured. As the lead satellite approaches a place with more mass than average, it speeds up just a bit from the extra gravitational pull. Shortly thereafter, so does the second. Then, as the higher-mass region falls behind, each satellite is held back a little—again, first the leading, then the trailing satellite. By sending microwaves between the two, it would be possible to calculate that staggered acceleration, and thus infer the change in gravitational pull on Earth’s surface.
by Sam Flamsteed
If the Reverend Nevil Maskelyne came back to life, the 18th-century Astronomer Royal of Great Britain would probably have no trouble grasping the idea behind NASA’s remote sensing GRACE mission. Maskelyne proposed a remarkably similar experiment himself in a presentation to the Royal Society in 1772. “If the attraction of gravity be exerted, as Sir Isaac Newton supposes, not only between the large bodies of the universe, but between the minutest particles of which these bodies are composed . . . it will necessarily follow, that every hill must, by its attraction, alter the direction of gravitation in heavy bodies in its neighbourhood . . . .”
That’s exactly what GRACE, the Gravity Recovery and Climate Experiment, detects. Every 94 minutes or so, twin satellites whip once around Earth at an altitude of 310 miles, taking 30 days to cover the planet’s entire surface, then they do it again and again, sensing variations in local gravity. GRACE maps local variations in the force of gravity over Earth’s surface, revealing mountain ranges and ocean trenches as well as underground watersheds and other hidden concentrations of mass. A joint venture by NASA and the DLR (Deutsches Zentrum für Luft- und Raumfahrt, or German Aerospace Center), GRACE looks right past the familiar oceans, continents, and clouds, showing our planet in a fresh light—as a knobby, blobby globe of gravitational ups and downs.
Among other things, GRACE may have found a crater deep under the Antarctic ice that may mark an asteroid impact greater than the one that doomed the dinosaurs, measured the seafloor displacement that triggered the tsunami of 2004, and quantified changes in subsurface water in the Amazon and Congo river basins. “This is really an entirely new kind of remote sensing,” says project scientist Michael Watkins, of NASA’s Jet Propulsion Laboratory. “It’s like when radar or photography was first invented—you start realizing that it can be applied in all sorts of unanticipated ways. We’re still discovering them.”
The notion that Earth’s gravity field could be measured with satellites dates back to the dawn of the space age. In 1958 ground controllers tracking the first American satellite, Explorer 1, noted that its path faithfully traced the planet’s equatorial bulge (created by centrifugal forces generated by the planet’s rotation). By the 1960s rocket scientists realized that smaller, local variations in gravity could have further, unforeseen effects. Missiles carrying nuclear warheads, for example, could be thrown off course if no allowance was made for mountain ranges or valleys.
If Earth were a perfect sphere, perfectly uniform in density and covered to a uniform depth with ocean, the geoid—a word coined by geologists to refer to an imaginary plane located at the average level of the sea’s surface—would be a perfect sphere as well. Since the geoid would be evenly perpendicular to the pull of gravity in all places, that force would always pull you directly toward the precise center of the Earth. But Earth is nowhere near perfect or uniform, which means that gravity doesn’t always point straight down; a mountain range, for example, might divert it slightly to the left.
Understanding the subtleties of Earth’s gravitational field would be useful in many ways. Scientists could learn a lot about the structure of the planet, what it’s made of, and where the crust is thick or thin. A deposit of high-density underground rock, or an undersea mountain, is utterly invisible—yet they, too, skew the geoid away from perfect flatness. Even when the ocean is utterly calm, it isn’t flat. Measurements reveal that some parts of the ocean are a remarkable 390 feet lower than average, and others are 300 feet higher.
While scientists began to appreciate just how useful a map of the geoid could be, engineers were realizing that the most sensible way to measure the variations would be with a pair of satellites, instead of just one. A single orbiter would bob and weave with the gravity field just fine—but monitors would have to measure the ups and downs from the ground continuously by beaming radio waves back and forth. That would require an enormous network of ground stations. Yet two satellites flying far enough apart would experience different gravitational effects, so that only the distance between them must be measured. As the lead satellite approaches a place with more mass than average, it speeds up just a bit from the extra gravitational pull. Shortly thereafter, so does the second. Then, as the higher-mass region falls behind, each satellite is held back a little—again, first the leading, then the trailing satellite. By sending microwaves between the two, it would be possible to calculate that staggered acceleration, and thus infer the change in gravitational pull on Earth’s surface.
Sunday, March 25, 2007
New species found in bioblitz
An intense investigation of a small part of Wellington has uncovered hundreds of previously unknown species.
A 24-hour "bioblitz" in Otari-Wilton's Bush reserve has revealed 1345 new species of animals, plants, fungi and bacteria.
The bioblitz, which has previously been held in Auckland, involved 80 scientists.
Science director Phil Garnock-Jones says the biggest discovery is a new species of cave weta. Professor Garnock-Jones says once scientific tests prove the weta is of a new genus - family - those who discovered it will have to give it a name.
Garnock-Jones says if tests confirm it is a world first discovery it will be used for various research projects. He says it is likely to attract international attention from entomologists.
Source: Newstalk ZB
A 24-hour "bioblitz" in Otari-Wilton's Bush reserve has revealed 1345 new species of animals, plants, fungi and bacteria.
The bioblitz, which has previously been held in Auckland, involved 80 scientists.
Science director Phil Garnock-Jones says the biggest discovery is a new species of cave weta. Professor Garnock-Jones says once scientific tests prove the weta is of a new genus - family - those who discovered it will have to give it a name.
Garnock-Jones says if tests confirm it is a world first discovery it will be used for various research projects. He says it is likely to attract international attention from entomologists.
Source: Newstalk ZB
Wednesday, March 21, 2007
Researchers hot on the trail of brain cell degeneration
March 20, 2007 - A research team headed by Academy Research Fellow Michael Courtney has identified a new molecular pathway in neurons. The pathway is a factor in the degeneration of brain cells, which in turn plays an important role in neurological conditions and diseases, such as Alzheimer’s disease, epilepsy and stroke. Courtney and his team, based at the A. I. Virtanen Institute of the University of Kuopio, joined forces with Docent Eleanor Coffey’s team at the Turku Centre for Biotechnology to carry out the study as part of a series of successful collaborations between the two teams. The results of their study are published in the latest issue of Nature Neuroscience.
In a number of neurodegenerative diseases, neurons in the brain are over-stimulated, which triggers programmed cell death, or apoptosis. The study shows that the Rho protein, which has long been recognised as an important player in cancer formation, also plays a key role in the destruction of neurons in disease.
“These surprising findings add an entire pathway to the map of neurodegenerative signalling processes,” says Courtney. “This area of investigation could therefore offer novel therapeutic strategies for neurodegenerative diseases”.
Targeting molecular signals
How neurons actually die has been unclear. It is likely that it is associated with a variety of different mechanisms. Research has shown that the destruction of cells be over-stimulation depends on excess entry of calcium into the cells. Researchers have long been trying to map how cells generate destruction signals in response to the calcium, in the hope of finding new targets for drug design.
The object of the study, the Rho protein, belongs to a family of proteins able to influence signals that had been linked to cell degeneration. The two teams’ analysis demonstrated that over-stimulation causes activation of Rho as well as cell destruction signals. Blocking Rho activity by genetic modification keeps the protein in an inactive state, and the nerve cells thus survive a previously toxic level of over-stimulation.
The study identifies a new factor provoking cell degeneration. It is more than likely that future research will uncover more such factors interacting with each other. Investigating these will benefit new forms of treatment and advance research that aims to alleviate symptoms. The researchers behind the study hope that the results can be used in planning new targets for drugs to reduce the cell destruction signals caused by calcium entry. Finding new targets for medicine development is also significant in terms of the economy, owing to the costly treatment of these diseases, both in Finland and globally.
Cooperation between biocentres gets research going
The teams’ study is a perfect example of the cooperation between biocentres in Finland (Biocenter Finland) and international networking. The research was funded mainly by the Academy of Finland and the European Union. The two research teams are part of a Europe-wide consortium, STRESSPROTECT, within the EU Sixth Framework Programme. The consortium aims at generating the basis for novel neuroprotective drugs for neurodegenerative conditions involving over-stimulation of neurons – http://www.neuroprotect.eu
Academy of Finland
In a number of neurodegenerative diseases, neurons in the brain are over-stimulated, which triggers programmed cell death, or apoptosis. The study shows that the Rho protein, which has long been recognised as an important player in cancer formation, also plays a key role in the destruction of neurons in disease.
“These surprising findings add an entire pathway to the map of neurodegenerative signalling processes,” says Courtney. “This area of investigation could therefore offer novel therapeutic strategies for neurodegenerative diseases”.
Targeting molecular signals
How neurons actually die has been unclear. It is likely that it is associated with a variety of different mechanisms. Research has shown that the destruction of cells be over-stimulation depends on excess entry of calcium into the cells. Researchers have long been trying to map how cells generate destruction signals in response to the calcium, in the hope of finding new targets for drug design.
The object of the study, the Rho protein, belongs to a family of proteins able to influence signals that had been linked to cell degeneration. The two teams’ analysis demonstrated that over-stimulation causes activation of Rho as well as cell destruction signals. Blocking Rho activity by genetic modification keeps the protein in an inactive state, and the nerve cells thus survive a previously toxic level of over-stimulation.
The study identifies a new factor provoking cell degeneration. It is more than likely that future research will uncover more such factors interacting with each other. Investigating these will benefit new forms of treatment and advance research that aims to alleviate symptoms. The researchers behind the study hope that the results can be used in planning new targets for drugs to reduce the cell destruction signals caused by calcium entry. Finding new targets for medicine development is also significant in terms of the economy, owing to the costly treatment of these diseases, both in Finland and globally.
Cooperation between biocentres gets research going
The teams’ study is a perfect example of the cooperation between biocentres in Finland (Biocenter Finland) and international networking. The research was funded mainly by the Academy of Finland and the European Union. The two research teams are part of a Europe-wide consortium, STRESSPROTECT, within the EU Sixth Framework Programme. The consortium aims at generating the basis for novel neuroprotective drugs for neurodegenerative conditions involving over-stimulation of neurons – http://www.neuroprotect.eu
Academy of Finland
Tuesday, March 20, 2007
Researchers Hot On The Trail Of Brain Cell Degeneration
Science Daily — A research team headed by Academy Research Fellow Michael Courtney has identified a new molecular pathway in neurons. The pathway is a factor in the degeneration of brain cells, which in turn plays an important role in neurological conditions and diseases, such as Alzheimer's disease, epilepsy and stroke. Courtney and his team, based at the A. I. Virtanen Institute of the University of Kuopio, joined forces with Docent Eleanor Coffey's team at the Turku Centre for Biotechnology to carry out the study as part of a series of successful collaborations between the two teams. The results of their study are published in the latest issue of Nature Neuroscience.
In a number of neurodegenerative diseases, neurons in the brain are over-stimulated, which triggers programmed cell death, or apoptosis. The study shows that the Rho protein, which has long been recognised as an important player in cancer formation, also plays a key role in the destruction of neurons in disease.
"These surprising findings add an entire pathway to the map of neurodegenerative signalling processes," says Courtney. "This area of investigation could therefore offer novel therapeutic strategies for neurodegenerative diseases".
Targeting molecular signals
How neurons actually die has been unclear. It is likely that it is associated with a variety of different mechanisms. Research has shown that the destruction of cells be over-stimulation depends on excess entry of calcium into the cells. Researchers have long been trying to map how cells generate destruction signals in response to the calcium, in the hope of finding new targets for drug design.
The object of the study, the Rho protein, belongs to a family of proteins able to influence signals that had been linked to cell degeneration. The two teams' analysis demonstrated that over-stimulation causes activation of Rho as well as cell destruction signals. Blocking Rho activity by genetic modification keeps the protein in an inactive state, and the nerve cells thus survive a previously toxic level of over-stimulation.
The study identifies a new factor provoking cell degeneration. It is more than likely that future research will uncover more such factors interacting with each other. Investigating these will benefit new forms of treatment and advance research that aims to alleviate symptoms. The researchers behind the study hope that the results can be used in planning new targets for drugs to reduce the cell destruction signals caused by calcium entry. Finding new targets for medicine development is also significant in terms of the economy, owing to the costly treatment of these diseases, both in Finland and globally.
Cooperation between biocentres gets research going
The teams' study is a perfect example of the cooperation between biocentres in Finland (Biocenter Finland) and international networking. The research was funded mainly by the Academy of Finland and the European Union. The two research teams are part of a Europe-wide consortium, STRESSPROTECT, within the EU Sixth Framework Programme. The consortium aims at generating the basis for novel neuroprotective drugs for neurodegenerative conditions involving over-stimulation of neurons
(http://www.neuroprotect.eu).
Note: This story has been adapted from a news release issued by Academy of Finland.
In a number of neurodegenerative diseases, neurons in the brain are over-stimulated, which triggers programmed cell death, or apoptosis. The study shows that the Rho protein, which has long been recognised as an important player in cancer formation, also plays a key role in the destruction of neurons in disease.
"These surprising findings add an entire pathway to the map of neurodegenerative signalling processes," says Courtney. "This area of investigation could therefore offer novel therapeutic strategies for neurodegenerative diseases".
Targeting molecular signals
How neurons actually die has been unclear. It is likely that it is associated with a variety of different mechanisms. Research has shown that the destruction of cells be over-stimulation depends on excess entry of calcium into the cells. Researchers have long been trying to map how cells generate destruction signals in response to the calcium, in the hope of finding new targets for drug design.
The object of the study, the Rho protein, belongs to a family of proteins able to influence signals that had been linked to cell degeneration. The two teams' analysis demonstrated that over-stimulation causes activation of Rho as well as cell destruction signals. Blocking Rho activity by genetic modification keeps the protein in an inactive state, and the nerve cells thus survive a previously toxic level of over-stimulation.
The study identifies a new factor provoking cell degeneration. It is more than likely that future research will uncover more such factors interacting with each other. Investigating these will benefit new forms of treatment and advance research that aims to alleviate symptoms. The researchers behind the study hope that the results can be used in planning new targets for drugs to reduce the cell destruction signals caused by calcium entry. Finding new targets for medicine development is also significant in terms of the economy, owing to the costly treatment of these diseases, both in Finland and globally.
Cooperation between biocentres gets research going
The teams' study is a perfect example of the cooperation between biocentres in Finland (Biocenter Finland) and international networking. The research was funded mainly by the Academy of Finland and the European Union. The two research teams are part of a Europe-wide consortium, STRESSPROTECT, within the EU Sixth Framework Programme. The consortium aims at generating the basis for novel neuroprotective drugs for neurodegenerative conditions involving over-stimulation of neurons
(http://www.neuroprotect.eu).
Note: This story has been adapted from a news release issued by Academy of Finland.
Sunday, March 18, 2007
Could crazy technology save the planet?
By SETH BORENSTEIN,
AP Science Writer
WASHINGTON - Crazy-sounding ideas for saving the planet are getting a serious look from top scientists, a sign of their fears about global warming and the desire for an insurance policy in case things get worse.
How crazy?
There's the man-made "volcano" that shoots gigatons of sulfur high into the air. The space "sun shade" made of trillions of little reflectors between Earth and sun, slightly lowering the planet's temperature. The forest of ugly artificial "trees" that suck carbon dioxide out of the air. And the "Geritol solution" in which iron dust is dumped into the ocean.
"Of course it's desperation," said Stanford University professor Stephen Schneider. "It's planetary methadone for our planetary heroin addiction. It does come out of the pessimism of any realist that says this planet can't be trusted to do the right thing."
NASA is putting the finishing touches on a report summing up some of these ideas and has spent $75,000 to map out rough details of the sun shade concept. One of the premier climate modeling centers in the United States, the National Center for Atmospheric Research, has spent the last six weeks running computer simulations of the man-made volcano scenario and will soon turn its attention to the space umbrella idea.
And last month, billionaire Richard Branson offered a $25 million prize to the first feasible technology to reduce carbon dioxide levels in the air.
Simon "Pete" Worden, who heads NASA's Ames Research Center in Moffett Field, Calif., says some of these proposals, which represent a field called geoengineering, have been characterized as anywhere from "great" to "idiotic." As if to distance NASA from the issue a bit, Worden said the agency's report won't do much more than explain the range of possibilities.
Scientists in the recent past have been reluctant to consider such concepts. Many fear there will be unintended side effects; others worry such schemes might prevent the type of reduction in greenhouse gas emissions that scientists say are the only real way to fight global warming. These approaches are not an alternative to cutting pollution, said University of Calgary professor David Keith, a top geoengineering researcher.
Last month, Ralph Cicerone, president of the
National Academy of Sciences' name=c1> SEARCHNews News Photos Images Web' name=c3> National Academy of Sciences, told the nation's largest science conference that more research must be done in this field, but no action should be taken yet.
Here is a look at some of the ideas:
The Geritol solution
A private company is already carrying out this plan. Some scientists call it promising while others worry about the ecological fallout.
Planktos Inc. of Foster City, Calif., last week launched its ship, the Weatherbird II, on a trip to the Pacific Ocean to dump 50 tons of iron dust. The iron should grow plankton, part of an algae bloom that will drink up carbon dioxide from the atmosphere.
The idea of seeding the ocean with iron to beef up a natural plankton and algae system has been tried on a small scale several times since 1990. It has both succeeded and failed.
Planktos chief executive officer Russ George said his ship will try it on a larger scale, dumping a slurry of water and red iron dust from a hose into the sea.
"It makes a 25-foot swath of bright red for a very short period of time," George said.
The concept gained some credibility when it was mentioned in the 2001 report by the authoritative Intergovernmental Panel on Climate Change, which cited it as a possible way to attack carbon emissions.
Small experiments "showed unequivocally that there was a biological response to the addition of the iron," the climate report said. Plankton used the iron to photosynthesize, extract greenhouse gases from the air, and grow rapidly. It forms a thick green soup of all sorts of carbon dioxide-sucking algae, which sea life feast on, and the carbon drops into the ocean.
However, the international climate report also cautioned about "the ecological consequences of large-scale fertilization of the ocean."
Tim Barnett, a marine physicist at the Scripps Institution of Oceanography, said large-scale ocean seeding could change the crucial temperature difference between the sea surface and deeper waters and have a dramatic effect on marine life.
Cicerone, a climate scientist who is president of the National Academy of Sciences and advocate for more geoengineering research, called the Geritol solution promising. However, he noted that such actions by a company, or country, can have worldwide effects.
George, Planktos' CEO, said his company consulted with governments around the world and is only following previous scientific research. He said his firm will be dropping the iron in open international seas so he needs no permits. Most important, he said, is that it's such a small amount of iron compared to the ocean volume that it poses no threat.
He said it's unfair to lump his plan in with geoengineering, saying his company is just trying to restore the ocean to "a more ecologically normal and balanced state."
"We're a green solution," George said.
Planktos officials say that for every ton of iron used, 100,000 tons of carbon will be pulled into the ocean. Eventually, if this first large-scale test works, George hopes to remove 3 billion tons of carbon from the Earth's atmosphere, half of what's needed. Some scientists say that's overstated.
Planktos' efforts are financed by companies and individuals who buy carbon credits to offset their use of fossil fuels.
Man-made volcano
When Mount Pinatubo erupted 16 years ago in the Philippines it cooled the Earth for about a year because the sulfate particles in the upper atmosphere reflected some sunlight.
Several leading scientists, from Nobel Laureate Paul Crutzen to the late nuclear cold warrior Edward Teller, have proposed doing the same artificially to offset global warming.
Using jet engines, cannons or balloons to get sulfates in the air, humans could reduce the solar heat, and only increase current sulfur pollution by a small percentage, said Tom Wigley of the National Center for Atmospheric Research.
"It's an issue of the lesser of two evils," he said.
Scientists at the Center for Atmospheric Research put the idea into a computer climate model. The results aren't particularly cheap or promising, said NCAR scientist Caspar Ammann. It would take tens of thousands of tons of sulfate to be injected into the air each month, he said.
"From a practical point of view, it's completely ridiculous," Amman said. "Instead of investing so much into this, it would be much easier to cut down on the initial problem."
Both this technique and the solar umbrella while reducing heating, wouldn't reduce carbon dioxide. So they wouldn't counter a dramatic increase in the acidity of the world's oceans, which happens with global warming, scientists said. It harms sea life, especially coral reefs.
Despite that, Calgary's David Keith is working on tweaking the concept. He wants to find a more efficient chemical to inject into the atmosphere in case of emergency.
Solar umbrella
For far-out concepts, it's hard to beat Roger Angel's. Last fall, the University of Arizona astronomer proposed what he called a "sun shade." It would be a cloud of small Frisbee-like spaceships that go between Earth and the sun and act as an umbrella, reducing heat from the sun.
It really is just like turning down the knob by 2 percent of what's coming from the sun," he said.
The science for the ships, the rocketry to launch them, and the materials to make the shade are all doable, Angel said.
These nearly flat discs would each weigh less than an ounce and measure about a yard wide with three tab-like "ears" that are controllers sticking out just a few inches.
About 800,000 of these would be stacked into each rocket launch. It would take 16 trillion of them — that's million million — so there would be 20 million launches of rockets. All told, Angel figures 20 million tons of material to make the discs that together form the solar umbrella.
And then there's the cost: at least $4 trillion over 30 years, probably more.
"I compare it with sending men to Mars.I think they're both projects on the same scale," Angel said. "Given the danger to Earth, I think this project might warrant some fraction of the consideration of sending people to Mars."
Artificial trees
Scientifically, it's known as "air capture." But the instruments being used have been dubbed "artificial trees" — even though these devices are about as treelike as a radiator on a stick. They are designed to mimic the role of trees in using carbon dioxide, but early renderings show them looking more like the creation of a tinkering engineer with lots of steel.
Nearly a decade ago, Columbia University professor Klaus Lackner, hit on an idea for his then-middle school daughter's science fair project: Create air filters that grab carbon dioxide from the air using chemical absorbers and then compress the carbon dioxide into a liquid or compressed gas that can be shipped elsewhere. When his daughter was able to do it on a tiny scale, Lackner decided to look at doing it globally.
Newly inspired by the $25 million prize offered by Richard Branson, Lackner has fine-tuned the idea. He wants to develop a large filter that would absorb carbon dioxide from the air. Another chemical reaction would take the carbon from the absorbent material, and then a third process would change that greenhouse gas into a form that could be disposed of.
It would take wind and a lot of energy to power the air capture devices. They would stand tall like cell phone towers on steroids, reaching about 200 feet high with various-sized square filters at the top. Lackner envisions perhaps placing 100,000 of them near wind energy turbines.
Even if each filter was only the size of a television, it could remove about 25 tons of carbon dioxide a year, which is about how much one American produces annually, Lackner said. The captured carbon dioxide would be changed into a liquid or gas that can be piped away from the air capture devices.
Disposal might be the biggest cost, Lackner said.
Disposal of carbon dioxide, including that from fossil fuel plant emissions, is a major issue of scientific and technological research called sequestration. The idea is to bury it underground, often in old oil wells or deep below the sea floor. The Bush Administration, which doesn't like many geoengineering ideas is spending hundreds of millions of dollars on carbon sequestration, but mostly for power plant emissions
On the Net:
The Earth Engineering Center of Columbia University: http://www.seas.columbia.edu/earth/
The National Center for Atmospheric Research: http://www.ncar.ucar.edu/
Planktos Inc.: http://www.planktos.com/
AP Science Writer
WASHINGTON - Crazy-sounding ideas for saving the planet are getting a serious look from top scientists, a sign of their fears about global warming and the desire for an insurance policy in case things get worse.
How crazy?
There's the man-made "volcano" that shoots gigatons of sulfur high into the air. The space "sun shade" made of trillions of little reflectors between Earth and sun, slightly lowering the planet's temperature. The forest of ugly artificial "trees" that suck carbon dioxide out of the air. And the "Geritol solution" in which iron dust is dumped into the ocean.
"Of course it's desperation," said Stanford University professor Stephen Schneider. "It's planetary methadone for our planetary heroin addiction. It does come out of the pessimism of any realist that says this planet can't be trusted to do the right thing."
NASA is putting the finishing touches on a report summing up some of these ideas and has spent $75,000 to map out rough details of the sun shade concept. One of the premier climate modeling centers in the United States, the National Center for Atmospheric Research, has spent the last six weeks running computer simulations of the man-made volcano scenario and will soon turn its attention to the space umbrella idea.
And last month, billionaire Richard Branson offered a $25 million prize to the first feasible technology to reduce carbon dioxide levels in the air.
Simon "Pete" Worden, who heads NASA's Ames Research Center in Moffett Field, Calif., says some of these proposals, which represent a field called geoengineering, have been characterized as anywhere from "great" to "idiotic." As if to distance NASA from the issue a bit, Worden said the agency's report won't do much more than explain the range of possibilities.
Scientists in the recent past have been reluctant to consider such concepts. Many fear there will be unintended side effects; others worry such schemes might prevent the type of reduction in greenhouse gas emissions that scientists say are the only real way to fight global warming. These approaches are not an alternative to cutting pollution, said University of Calgary professor David Keith, a top geoengineering researcher.
Last month, Ralph Cicerone, president of the
National Academy of Sciences' name=c1> SEARCHNews News Photos Images Web' name=c3> National Academy of Sciences, told the nation's largest science conference that more research must be done in this field, but no action should be taken yet.
Here is a look at some of the ideas:
The Geritol solution
A private company is already carrying out this plan. Some scientists call it promising while others worry about the ecological fallout.
Planktos Inc. of Foster City, Calif., last week launched its ship, the Weatherbird II, on a trip to the Pacific Ocean to dump 50 tons of iron dust. The iron should grow plankton, part of an algae bloom that will drink up carbon dioxide from the atmosphere.
The idea of seeding the ocean with iron to beef up a natural plankton and algae system has been tried on a small scale several times since 1990. It has both succeeded and failed.
Planktos chief executive officer Russ George said his ship will try it on a larger scale, dumping a slurry of water and red iron dust from a hose into the sea.
"It makes a 25-foot swath of bright red for a very short period of time," George said.
The concept gained some credibility when it was mentioned in the 2001 report by the authoritative Intergovernmental Panel on Climate Change, which cited it as a possible way to attack carbon emissions.
Small experiments "showed unequivocally that there was a biological response to the addition of the iron," the climate report said. Plankton used the iron to photosynthesize, extract greenhouse gases from the air, and grow rapidly. It forms a thick green soup of all sorts of carbon dioxide-sucking algae, which sea life feast on, and the carbon drops into the ocean.
However, the international climate report also cautioned about "the ecological consequences of large-scale fertilization of the ocean."
Tim Barnett, a marine physicist at the Scripps Institution of Oceanography, said large-scale ocean seeding could change the crucial temperature difference between the sea surface and deeper waters and have a dramatic effect on marine life.
Cicerone, a climate scientist who is president of the National Academy of Sciences and advocate for more geoengineering research, called the Geritol solution promising. However, he noted that such actions by a company, or country, can have worldwide effects.
George, Planktos' CEO, said his company consulted with governments around the world and is only following previous scientific research. He said his firm will be dropping the iron in open international seas so he needs no permits. Most important, he said, is that it's such a small amount of iron compared to the ocean volume that it poses no threat.
He said it's unfair to lump his plan in with geoengineering, saying his company is just trying to restore the ocean to "a more ecologically normal and balanced state."
"We're a green solution," George said.
Planktos officials say that for every ton of iron used, 100,000 tons of carbon will be pulled into the ocean. Eventually, if this first large-scale test works, George hopes to remove 3 billion tons of carbon from the Earth's atmosphere, half of what's needed. Some scientists say that's overstated.
Planktos' efforts are financed by companies and individuals who buy carbon credits to offset their use of fossil fuels.
Man-made volcano
When Mount Pinatubo erupted 16 years ago in the Philippines it cooled the Earth for about a year because the sulfate particles in the upper atmosphere reflected some sunlight.
Several leading scientists, from Nobel Laureate Paul Crutzen to the late nuclear cold warrior Edward Teller, have proposed doing the same artificially to offset global warming.
Using jet engines, cannons or balloons to get sulfates in the air, humans could reduce the solar heat, and only increase current sulfur pollution by a small percentage, said Tom Wigley of the National Center for Atmospheric Research.
"It's an issue of the lesser of two evils," he said.
Scientists at the Center for Atmospheric Research put the idea into a computer climate model. The results aren't particularly cheap or promising, said NCAR scientist Caspar Ammann. It would take tens of thousands of tons of sulfate to be injected into the air each month, he said.
"From a practical point of view, it's completely ridiculous," Amman said. "Instead of investing so much into this, it would be much easier to cut down on the initial problem."
Both this technique and the solar umbrella while reducing heating, wouldn't reduce carbon dioxide. So they wouldn't counter a dramatic increase in the acidity of the world's oceans, which happens with global warming, scientists said. It harms sea life, especially coral reefs.
Despite that, Calgary's David Keith is working on tweaking the concept. He wants to find a more efficient chemical to inject into the atmosphere in case of emergency.
Solar umbrella
For far-out concepts, it's hard to beat Roger Angel's. Last fall, the University of Arizona astronomer proposed what he called a "sun shade." It would be a cloud of small Frisbee-like spaceships that go between Earth and the sun and act as an umbrella, reducing heat from the sun.
It really is just like turning down the knob by 2 percent of what's coming from the sun," he said.
The science for the ships, the rocketry to launch them, and the materials to make the shade are all doable, Angel said.
These nearly flat discs would each weigh less than an ounce and measure about a yard wide with three tab-like "ears" that are controllers sticking out just a few inches.
About 800,000 of these would be stacked into each rocket launch. It would take 16 trillion of them — that's million million — so there would be 20 million launches of rockets. All told, Angel figures 20 million tons of material to make the discs that together form the solar umbrella.
And then there's the cost: at least $4 trillion over 30 years, probably more.
"I compare it with sending men to Mars.I think they're both projects on the same scale," Angel said. "Given the danger to Earth, I think this project might warrant some fraction of the consideration of sending people to Mars."
Artificial trees
Scientifically, it's known as "air capture." But the instruments being used have been dubbed "artificial trees" — even though these devices are about as treelike as a radiator on a stick. They are designed to mimic the role of trees in using carbon dioxide, but early renderings show them looking more like the creation of a tinkering engineer with lots of steel.
Nearly a decade ago, Columbia University professor Klaus Lackner, hit on an idea for his then-middle school daughter's science fair project: Create air filters that grab carbon dioxide from the air using chemical absorbers and then compress the carbon dioxide into a liquid or compressed gas that can be shipped elsewhere. When his daughter was able to do it on a tiny scale, Lackner decided to look at doing it globally.
Newly inspired by the $25 million prize offered by Richard Branson, Lackner has fine-tuned the idea. He wants to develop a large filter that would absorb carbon dioxide from the air. Another chemical reaction would take the carbon from the absorbent material, and then a third process would change that greenhouse gas into a form that could be disposed of.
It would take wind and a lot of energy to power the air capture devices. They would stand tall like cell phone towers on steroids, reaching about 200 feet high with various-sized square filters at the top. Lackner envisions perhaps placing 100,000 of them near wind energy turbines.
Even if each filter was only the size of a television, it could remove about 25 tons of carbon dioxide a year, which is about how much one American produces annually, Lackner said. The captured carbon dioxide would be changed into a liquid or gas that can be piped away from the air capture devices.
Disposal might be the biggest cost, Lackner said.
Disposal of carbon dioxide, including that from fossil fuel plant emissions, is a major issue of scientific and technological research called sequestration. The idea is to bury it underground, often in old oil wells or deep below the sea floor. The Bush Administration, which doesn't like many geoengineering ideas is spending hundreds of millions of dollars on carbon sequestration, but mostly for power plant emissions
On the Net:
The Earth Engineering Center of Columbia University: http://www.seas.columbia.edu/earth/
The National Center for Atmospheric Research: http://www.ncar.ucar.edu/
Planktos Inc.: http://www.planktos.com/
Evolution and Extension revealed!
Study Challenges Theories on Species
Washington Post, DC - RANDOLPH E. SCHMID. AP. WASHINGTON -- More species develop in warm, tropical climates or cooler, temperate areas? It turns out the longtime answer _ the ...
More species develop in cooler climates
Baltimore Sun, MD - Mar 16, 2007
By Randolp E. Schmid. AP. Do more species develop in warm, tropical climates or cooler, temperate areas? It turns out the longtime answer - the tropics ...
Study Challenges Theories on Species
Forbes, NY - Mar 15, 2007
By RANDOLPH E. SCHMID . More species develop in warm, tropical climates or cooler, temperate areas? It turns out the longtime answer ...
Study challenges theories on species
Houston Chronicle, TX - Mar 15, 2007
By RANDOLPH E. SCHMID AP Science Writer. © 2007 AP. WASHINGTON — More species develop in warm, tropical climates or cooler, temperate areas? ...
Study challenges theories on species
USA Today - Mar 15, 2007
WASHINGTON (AP) — More species develop in warm, tropical climates or cooler, temperate areas? It turns out the longtime answer — the tropics — may be wrong. ...
Study Challenges Theories on Species
Wyoming News, WY - RANDOLPH E. SCHMID Saturday, March 17, 2007.
WASHINGTON - More species develop in warm, tropical climates or cooler, temperate areas? ...
Researchers debunk theory that species evolve faster in tropics
DailyIndia.com, FL - Mar 16, 2007
Washington, Mar 16: University of British Columbia researchers have found that contrary to common belief, species do not evolve faster in warmer tropical ...
A different take on the diversity of species
Philadelphia Inquirer, PA - Mar 16, 2007
Tropical areas may only seem to have more types because of longer life spans, a study suggests. By Randolph E. Schmid. Associated Press ...
Chill Out To Evolve
Science a Gogo - Mar 15, 2007
Species don't evolve faster in warmer climes as had been thought; rather, it appears to be cooler, more temperate, regions that crank-up speciation rates ...
Study Challenges Theories on Species
AND, South Africa - Mar 15, 2007
By (AND) - www.andnetwork.com. WASHINGTON (AP) -- More species develop in warm, tropical climates or cooler, temperate areas? It turns out the longtime ...
Study challenges theories on species
The Westfall Weekly News, Canada - Mar 15, 2007
By RANDOLPH E. SCHMID, AP Science Writer
. WASHINGTON - More species develop in warm, tropical climates or cooler, temperate areas? ...
Species do not evolve faster in warmer climates
HULIQ, NC - Mar 15, 2007
University of British Columbia researchers have discovered that contrary to common belief, species do not evolve faster in warmer climates. ...
The cooler, the better
News24, South Africa -
True, there are more different types of animals in the tropics than in places farther from the equator. But new research suggests that is because tropical ...
Researchers dispute more species in tropics theory
Xinhua, China - Mar 15, 2007
BEIJING, March 16 (Xinhuanet) -- Two researchers in the zoology department at the University of British Columbia are challenging the commonly held theory ...
Life is faster in the temperate zone
Nature.com (subscription), UK - Mar 15, 2007
Most people tend to think of the tropics as the hottest scene on the planet when it comes to spawning new life. But Canadian zoologists have found that it ...
Species evolve faster in cooler climes
New Scientist (subscription), UK - Mar 15, 2007
A male masked tityra (Tityra semifasciata), one of the tropical species included in the study, at a nesting hole in a snag. It diverged from its sister ...
High on Speciation
Science Now, DC - Mar 15, 2007
By John Simpson.
It seems like a no-brainer: To find out where most new species arise, see where most of them live. Take the tropics, home of more than half ...
The Why Files -- whyfiles.org
Why Files - Mar 15, 2007
Ask any conservation biologist, and you'll get the same message: The tropics have at outsize number of species. And you'll probably hear the same ...
Cold climates a hotbed for species turnover, UBC researchers say
CBC Saskatchewan, Canada - Mar 15, 2007
Long-term climate changes have led to a higher turnover of species in northern regions like Canada than in more diverse regions like the Amazon, ...
Evolution is faster in temperate zones
Mongabay.com - Mar 15, 2007
A new study argues that temperate zones are hotbeds of evolution, not tropical areas as conventionally held. The research, published in the March 16 issue ...
Surprising Pace of Evolution and Extinction Revealed
LiveScience.com, NY - Mar 15, 2007
By Ker Than.
New species of birds and mammals evolve faster at high latitudes than in the tropics, but they also go extinct faster, a new study suggests. ...
Washington Post, DC - RANDOLPH E. SCHMID. AP. WASHINGTON -- More species develop in warm, tropical climates or cooler, temperate areas? It turns out the longtime answer _ the ...
More species develop in cooler climates
Baltimore Sun, MD - Mar 16, 2007
By Randolp E. Schmid. AP. Do more species develop in warm, tropical climates or cooler, temperate areas? It turns out the longtime answer - the tropics ...
Study Challenges Theories on Species
Forbes, NY - Mar 15, 2007
By RANDOLPH E. SCHMID . More species develop in warm, tropical climates or cooler, temperate areas? It turns out the longtime answer ...
Study challenges theories on species
Houston Chronicle, TX - Mar 15, 2007
By RANDOLPH E. SCHMID AP Science Writer. © 2007 AP. WASHINGTON — More species develop in warm, tropical climates or cooler, temperate areas? ...
Study challenges theories on species
USA Today - Mar 15, 2007
WASHINGTON (AP) — More species develop in warm, tropical climates or cooler, temperate areas? It turns out the longtime answer — the tropics — may be wrong. ...
Study Challenges Theories on Species
Wyoming News, WY - RANDOLPH E. SCHMID Saturday, March 17, 2007.
WASHINGTON - More species develop in warm, tropical climates or cooler, temperate areas? ...
Researchers debunk theory that species evolve faster in tropics
DailyIndia.com, FL - Mar 16, 2007
Washington, Mar 16: University of British Columbia researchers have found that contrary to common belief, species do not evolve faster in warmer tropical ...
A different take on the diversity of species
Philadelphia Inquirer, PA - Mar 16, 2007
Tropical areas may only seem to have more types because of longer life spans, a study suggests. By Randolph E. Schmid. Associated Press ...
Chill Out To Evolve
Science a Gogo - Mar 15, 2007
Species don't evolve faster in warmer climes as had been thought; rather, it appears to be cooler, more temperate, regions that crank-up speciation rates ...
Study Challenges Theories on Species
AND, South Africa - Mar 15, 2007
By (AND) - www.andnetwork.com. WASHINGTON (AP) -- More species develop in warm, tropical climates or cooler, temperate areas? It turns out the longtime ...
Study challenges theories on species
The Westfall Weekly News, Canada - Mar 15, 2007
By RANDOLPH E. SCHMID, AP Science Writer
. WASHINGTON - More species develop in warm, tropical climates or cooler, temperate areas? ...
Species do not evolve faster in warmer climates
HULIQ, NC - Mar 15, 2007
University of British Columbia researchers have discovered that contrary to common belief, species do not evolve faster in warmer climates. ...
The cooler, the better
News24, South Africa -
True, there are more different types of animals in the tropics than in places farther from the equator. But new research suggests that is because tropical ...
Researchers dispute more species in tropics theory
Xinhua, China - Mar 15, 2007
BEIJING, March 16 (Xinhuanet) -- Two researchers in the zoology department at the University of British Columbia are challenging the commonly held theory ...
Life is faster in the temperate zone
Nature.com (subscription), UK - Mar 15, 2007
Most people tend to think of the tropics as the hottest scene on the planet when it comes to spawning new life. But Canadian zoologists have found that it ...
Species evolve faster in cooler climes
New Scientist (subscription), UK - Mar 15, 2007
A male masked tityra (Tityra semifasciata), one of the tropical species included in the study, at a nesting hole in a snag. It diverged from its sister ...
High on Speciation
Science Now, DC - Mar 15, 2007
By John Simpson.
It seems like a no-brainer: To find out where most new species arise, see where most of them live. Take the tropics, home of more than half ...
The Why Files -- whyfiles.org
Why Files - Mar 15, 2007
Ask any conservation biologist, and you'll get the same message: The tropics have at outsize number of species. And you'll probably hear the same ...
Cold climates a hotbed for species turnover, UBC researchers say
CBC Saskatchewan, Canada - Mar 15, 2007
Long-term climate changes have led to a higher turnover of species in northern regions like Canada than in more diverse regions like the Amazon, ...
Evolution is faster in temperate zones
Mongabay.com - Mar 15, 2007
A new study argues that temperate zones are hotbeds of evolution, not tropical areas as conventionally held. The research, published in the March 16 issue ...
Surprising Pace of Evolution and Extinction Revealed
LiveScience.com, NY - Mar 15, 2007
By Ker Than.
New species of birds and mammals evolve faster at high latitudes than in the tropics, but they also go extinct faster, a new study suggests. ...
Wednesday, March 14, 2007
Pig DNA Sheds Light on Human Migration
Anna Salleh, ABC Science Online
Ancient pig remains from the hobbit cave on Flores are helping researchers piece together how humans moved from Southeast Asia to the Pacific thousands of years ago.
Most scientists think humans spread east from Taiwan to the Pacific. But an international team, including Professor Alan Cooper of Australia's University of Adelaide, argues the pattern of humans moving out of Southeast Asia with their animals is more complex.
The researchers report their DNA study of domesticated pigs in this week's Proceedings of the National Academy of Sciences.
Humans have been domesticating pigs as a source of meat for so long that tracking their movement is a good way to trace human migration routes.Cooper, an expert in ancient DNA, and colleagues analyzed mitochondrial DNA from pigs in a number of Southeast Asian countries. They then compared it with the DNA of pigs that historically populated the Pacific.
Cooper said the oldest pig DNA they studied came from the tooth of a pig found in the hobbit cave on the Indonesian island of Flores, dated to 6000-7000 years old.
Route Pinpointed
Previous studies have found genetic similarities between Southeast Asian pigs and Pacific ones, suggesting the pigs moved from one to the other.
But Cooper said this latest research has identified the exact route they took.
"Pigs which go out across the Pacific and become the Polynesian pig, appear to originate around Laos, Cambodia and southeast China," he said. "We can actually see them coming down the Malaysian peninsula and across the Sunda island chain [Indonesia and New Guinea]."
Cooper said while most scientists think humans spread to the Pacific from Taiwan, this pig DNA evidence suggests they have a more complex origin.
"The trouble is we don't find any pigs from Taiwan going east," he said. "So we've got quite a different route."
Ancient pig remains from the hobbit cave on Flores are helping researchers piece together how humans moved from Southeast Asia to the Pacific thousands of years ago.
Most scientists think humans spread east from Taiwan to the Pacific. But an international team, including Professor Alan Cooper of Australia's University of Adelaide, argues the pattern of humans moving out of Southeast Asia with their animals is more complex.
The researchers report their DNA study of domesticated pigs in this week's Proceedings of the National Academy of Sciences.
Humans have been domesticating pigs as a source of meat for so long that tracking their movement is a good way to trace human migration routes.Cooper, an expert in ancient DNA, and colleagues analyzed mitochondrial DNA from pigs in a number of Southeast Asian countries. They then compared it with the DNA of pigs that historically populated the Pacific.
Cooper said the oldest pig DNA they studied came from the tooth of a pig found in the hobbit cave on the Indonesian island of Flores, dated to 6000-7000 years old.
Route Pinpointed
Previous studies have found genetic similarities between Southeast Asian pigs and Pacific ones, suggesting the pigs moved from one to the other.
But Cooper said this latest research has identified the exact route they took.
"Pigs which go out across the Pacific and become the Polynesian pig, appear to originate around Laos, Cambodia and southeast China," he said. "We can actually see them coming down the Malaysian peninsula and across the Sunda island chain [Indonesia and New Guinea]."
Cooper said while most scientists think humans spread to the Pacific from Taiwan, this pig DNA evidence suggests they have a more complex origin.
"The trouble is we don't find any pigs from Taiwan going east," he said. "So we've got quite a different route."
Tuesday, March 13, 2007
Houses of the Holy
Nine Neolithic houses excavated near Stonehenge are astounding archaeologists and opening up a radical new interpretation of the purpose of the 4,600-year-old circular stone monument. The houses were excavated nearby a “timber henge” of enormous postholes at Durrington Walls, a 1,500-foot-wide site that lies two miles northeast of Stonehenge along the river Avon. Recent excavations led by University of Sheffield archaeologist Mike Parker Pearson have led him to suggest the two sites were built as a single complex of complementary stone and wood circles linked by a river route.
Parker Pearson has found that, like Stonehenge, Durrington Walls had a wide, well-worn avenue to the river. But so far, houses have been found only at Durrington Walls. The structures contain central hearths, appear to have been inhabited, and may even have been part of a larger, town-size community, but it’s not clear whether they were occupied year-round or only at key seasonal times. Because the two sites have complementary alignments—Stonehenge faces the midsummer sunrise, Durrington Walls faces the midwinter sunrise—Parker Pearson and his colleagues have suggested that a voyage on the river route between the circles represented a journey between the realms of the living and the dead. Chunks of flint found at the site in shapes resembling male and female genitalia suggest that the voyage may have been undertaken to obtain help with fertility from ancestors.
Tim Darvill, an archaeologist at England’s Bournemouth University, thinks Stonehenge was a sort of Stone Age healing center. As evidence, he points out that many of the monument’s stones were brought from an area 160 miles away that was associated with healing properties. Past studies of skeletal remains from the many prehistoric burials in the Stonehenge area have also shown higher than normal rates of disease. The presence of dwellings would also be consistent with the possibility that ailing pilgrims from distant reaches once flocked to the monuments.
Parker Pearson has found that, like Stonehenge, Durrington Walls had a wide, well-worn avenue to the river. But so far, houses have been found only at Durrington Walls. The structures contain central hearths, appear to have been inhabited, and may even have been part of a larger, town-size community, but it’s not clear whether they were occupied year-round or only at key seasonal times. Because the two sites have complementary alignments—Stonehenge faces the midsummer sunrise, Durrington Walls faces the midwinter sunrise—Parker Pearson and his colleagues have suggested that a voyage on the river route between the circles represented a journey between the realms of the living and the dead. Chunks of flint found at the site in shapes resembling male and female genitalia suggest that the voyage may have been undertaken to obtain help with fertility from ancestors.
Tim Darvill, an archaeologist at England’s Bournemouth University, thinks Stonehenge was a sort of Stone Age healing center. As evidence, he points out that many of the monument’s stones were brought from an area 160 miles away that was associated with healing properties. Past studies of skeletal remains from the many prehistoric burials in the Stonehenge area have also shown higher than normal rates of disease. The presence of dwellings would also be consistent with the possibility that ailing pilgrims from distant reaches once flocked to the monuments.
Shield of Dreams
The handful of people who would be the first to detect a nuclear missile attack against the United States work just outside the town of Colorado Springs. Their daily commute takes them down a sloping mile-long tunnel, past baffled steel blast doors that are 20 feet high, three feet thick, and weigh 25 tons each, into the heart of Cheyenne Mountain. There, surrounded on all sides by at least 2,000 feet of granite, they spend eight-hour shifts in the missile-warning center, one of 15 subterranean buildings arrayed along a three-dimensional tic-tac-toe grid of intersecting tunnels. This is the central coordination facility for the NORAD (North American Aerospace Defense) command.
Data from satellites and a global network of radar stations flow into computers at the missile-warning center, where eight or nine people during a typical shift sit in front of 17-inch monitors. Hardly a day passes without the detection of a launch somewhere around the world, such as the Russians firing SCUD missiles at Chechens or the French lofting a satellite into orbit. But in the 36-year history of Cheyenne Mountain, there is one type of launch the staff has never seen and doesn't want to see: an intercontinental ballistic missile (ICBM) on its way to the United States. From training sessions, they know exactly what to expect.
First, on the center of their monitors, a grid map would appear showing the part of the world from which the missile was launched. A small red circle represents the launch point of the missile. Next, a computerized voice says "Quick alert! Quick alert!" Then an alarm sounds and a light flashes, signaling everyone in the missile-warning center that a desperate race against the clock has begun. A missile launched from a site halfway around the world can reach the United States in less than 25 minutes.
Within a few seconds, computers plot the missile's trajectory. If it is headed for North America, an officer at NORAD alerts a Pentagon task force and the White House. Major Barry Venable, an Army spokesman for the Cheyenne Mountain operations center, says the President has exactly two options at that point. He can order a massive nuclear counterattack against the aggressor nation. Or he can wait as the incoming missile, or many missiles, vaporizes a city, or many cities, which will happen whether he retaliates or not. Given the current state of technology, no other option exists. The United States cannot shoot down one ICBM, let alone hundreds of them. There are no weapons that can hit a slender projectile traveling at nearly 15,000 miles per hour, about 10 times faster than a bullet. So the obvious question has long been: Can such a defensive weapon be built?
President Bush is betting it can. In a speech at the National Defense University in Washington this past May, the President announced his intention to deploy a system that "could provide limited, but effective, defenses" against ballistic missiles armed with nuclear, biological, or chemical weapons. The defense system, advocates say, is not really intended to thwart an all-out attack by a major nuclear power, which might involve advanced weaponry such as multiple independently targetable reentry vehicles (MIRVs), missiles that bear many warheads. At best they say it could shoot down a few missiles launched by a rogue nation such as North Korea, Iran, or Iraq, as well as missiles accidentally fired from Russia.
The President hopes to make such a missile shield a central accomplishment of his administration. He envisions a complex, multilayered defense that counterattacks with ground-based and sea-based interceptor missiles and aircraft equipped with lasers powerful enough to destroy a rocket in flight. The administration has declared it wants to begin building an interceptor missile base in Alaska that could be operational as early as 2004.
As desirable as even a limited shield might be in an uncertain world, physicists and independent defense analysts who have carefully studied the problem of missile defense argue that the President's plan is deeply flawed, more a product of wishful thinking than sound scientific analysis. "The proponents of missile defense are for the most part totally nontechnical. Or they are defense contractors," says Richard Garwin, a physicist who, with Edward Teller, helped create the world's first hydrogen bomb 50 years ago. "The top levels of the Defense Department are political and managerial, not technical."
And the scientific and technical challenges are far greater than those of any offensive or defensive weapons system ever built. For a missile shield to be effective, every component--radar systems, satellites, missiles, communication networks--would have to perform flawlessly in the heat of combat, says Philip Coyle, who directed the Defense Department's office of testing and evaluation during the Clinton administration. "All the pieces of the system--which are major systems in themselves--have to achieve reliabilities that military equipment rarely ever has."
The flight of an ICBM is a tragic drama that unfolds in three relentless acts: boost phase, midcourse, and reentry.
The boost phase is by far the best chance to shoot down an enemy ICBM, but it lasts at most 300 seconds, the time a missile takes to clear the atmosphere. A rocket rising into the air presents a clear target, and satellites can easily spot its hot exhaust plume. Two very different sorts of weapons are being considered for this stage of defense, and neither will be ready for at least several years: ship-launched interceptor missiles and an exotic airborne laser.
Of these two weapons, only the airborne laser is in active development. Boeing, Lockheed-Martin, and TRW are trying to equip a modified 747 jumbo jet with up to 17 lasers. In theory, several of these aircraft would fly constant patrol above pariahs like Iraq and North Korea, ready to shoot down a missile within a minute or two of its launch.
Unlike the colored, flashing death rays of science-fiction movies, the airborne laser consists of infrared light, invisible to human eyes. A reaction between rather ordinary chemicals--hydrogen peroxide and potassium hydroxide, the ingredients in hair bleach and Drano--generates the laser. But to produce the megawatt beam that would be needed to bring down a rocket requires linking many such lasers together in a series and sparking them with tons of the chemicals. Plans call for a 747 equipped with 14 laser modules, each weighing about 6,000 pounds when full. The aircraft would also carry three more lasers: one to track the missile, a second to measure atmospheric turbulence, and a third to illuminate the exact target. To compensate for atmospheric effects, a flexible, mechanically controlled mirror that can change its shape every few thousandths of a second will focus and aim the killer beam.
The beam would not immediately explode its target. Instead, after several seconds, heat from the laser would crack the outer surface of one of the three stages of the booster rocket that propels the warhead into space, weakening it. Pressure from the liquid fuel within the stage would then rupture the rocket, causing a catastrophic explosion. No one knows if the idea can be made to work. The first test is not scheduled until 2003, and the project is not expected to be operational for at least seven years.
In the meantime, the sheer bulk of the laser equipment that must be installed on the 747 poses daunting problems. Since the atmosphere would partially absorb and scatter the laser beam, the 747 would have to fly quite high to make sure the beam remained powerful enough to destroy the missile. "A 747 that is heavily loaded doesn't like to fly high," says Philip Coyle. "And you've also got to get close to the forward edge of battle, because your laser power isn't going to be such that it can propagate through many miles of atmosphere. If you're close to the enemy, you make a pretty inviting target yourself."The chemicals that fuel the laser present other problems, says Coyle: "The laser puts out caustic gases in the chemical process. The compatibility of all these materials with an aircraft has yet to be worked out."
If the airborne laser can be built and made to work, it's reasonable to assume an enemy will build defenses to protect its missile from just such an attack. "We're an open society, and we tell people what we're doing," Coyle says. "If the enemy saw that we were doing tests of such a system, and it looked as if it might work, they could foil us pretty easily by just putting a reflective surface of paint on the missile." The reflective surface would need to withstand the laser's heat for just a minute or so, providing enough time for the missile to move into space, well beyond the laser's range.
"One of the dilemmas involved in creating a missile-defense system is that the offense always has the advantage," says Coyle. "They can always figure out how to beat it."
Ted Postol, a nuclear physicist at MIT and a former advisor to the Pentagon on ballistic missile technology, says there is little chance the airborne laser will be ready in 2008 as its developers say. "There are lots and lots of technical questions that are unresolved," he says. "My guess is that it is decades away--if it can be built at all." Still more dubious are plans for space-based lasers mounted on remote-controlled satellites designed to attack ICBMs during the boost phase. Even the most die-hard supporters of that research say space-based lasers won't be defending the United States in the foreseeable future.
The one means of defense that stands the best chance of actually destroying an ICBM in flight--interceptor missiles launched from Navy warships--is still on the drawing board. An interceptor is designed to destroy an ICBM simply by crashing into it. But the deployment of ship-based interceptors is rife with practical problems. For a ship's missiles to have a chance to catch up with and hit an enemy missile, the ship would have to be stationed within a few hundred miles of enemy territory, making it vulnerable to attack. And the interceptors themselves would have to be much faster than any missile in existence, which means they would also be much larger in order to carry the fuel needed to power their five-mile-per-second flight. "It would take whole new rockets that are fatter, longer, and faster than anything the Navy has now," says Coyle. "In addition, this stuff won't fit in the launch tubes on existing Navy ships."
Like airborne lasers, a ship-launched interceptor would have less than 300 seconds to destroy a missile before it went completely out of range. That leaves little time--perhaps no time--for the President to be consulted about a decision to fire. Coyle says: "You might have to shoot it down within as little as two minutes, certainly within three or four. Otherwise the enemy rocket has cleared the atmosphere. So the decision to fire has got to be computerized, because there just isn't enough time to contemplate what you're doing. The President isn't going to be in the loop; the secretary of defense or the national security advisor wouldn't be in the loop."
The lack of civilian or even human control over such a decision would be unprecedented. The destruction of an enemy warhead could cause debris--including chemical and biological weapons, if aboard--to rain down on neighboring countries. And there is a far greater danger: The interceptor could hit and destroy the enemy rocket without destroying the warhead. In that case the warhead would career off course and land who knows where.
Furthermore, there is little guarantee that an interceptor could hit the target. Coyle emphasizes how hard it is to shoot down combat aircraft that travel at a fraction of an ICBM's speed. "With air defenses--shooting down planes--you're doing really good if you can hit 25 percent of your targets," he says.
When the targets are missiles instead of planes, the statistics are sobering. After the Gulf War against Iraq, Postol analyzed the Army's claims about the Patriot missile's performance against Iraqi missiles launched at Israel. Although the exact number of SCUD- Patriot encounters during the war is classified, there are thought to have been about 80. The Army initially claimed that Patriots hit 96 percent of their targets. Postol found, as did the Government Accounting Office in a separate study, that the Patriots hit at most 6 percent--fewer than five out of 80. In fact, Postol could not confirm that any Patriot missile ever actually hit any SCUD missile.
When an ICBM's booster rocket burns out and falls back to Earth, the warhead travels through the vacuum of space solely under the influence of gravity. This midcourse phase, which lasts about 15 minutes, is the longest of the three phases of an ICBM's flight. To shoot down an ICBM in midcourse, President Bush would field as many as 250 missiles in Alaska and North Dakota, possibly complemented by sea-launched interceptors. Ground-based radar and space-based infrared satellites would guide each interceptor part of the way toward its target. Onboard tracking systems would take over during the final seconds as the interceptor homed in on the enemy warhead. As with the sea-based interceptors proposed for the boost phase of defense, 51-inch-long missiles would destroy the warhead simply by colliding with it.
What if an interceptor misses? Lieutenant General Ronald Kadish, head of the Ballistic Missile Defense Organization, argued in testimony before the Senate Armed Services Committee recently that there should be sufficient time during the midcourse phase to fire additional interceptors at a warhead. "Multiple shots at the target give a higher probability of being able to hit it," he said.
But critics argue that Kadish underestimates enemy countermeasures. During the midcourse phase, the tracking systems guiding an interceptor would probably have to cope not with a single target but with hundreds. The warhead is housed during its ascent in a protective shell called a bus. Once in space, the bus opens, releasing not only the warhead but also numerous decoys to fool satellites and radar networks. Without air to slow them down, all the objects, regardless of size, shape, or weight, travel at about 15,000 miles per hour, clustered around the warhead. Instead of having to destroy an individual missile, as in the boost phase, the interceptor must pick out the real warhead.
Kadish insists that the critics are too pessimistic. "I do not share the assessment that what we are attempting to accomplish with our system is in any way impossible," he told Senate Armed Services Committee members. "Over the coming months and years, I believe program results can speak for themselves in responding to the criticism that the [missile shield] cannot operate as designed against the projected countermeasure threat that a state of concern might pose."
Coyle, Postol, and other experts do not share Kadish's faith. Both the United States and Russia have designed missiles that contain decoys. There is no reason, says Coyle, why North Korea, Iran, or Iraq could not equip missiles with decoys too. "If they're smart enough to make ICBMs with sophisticated guidance systems and all the rest, I think they can figure out how to make decoys," says Coyle.
The simplest decoys are Mylar balloons, just like those sold in supermarkets, except that each one is about the size of a house. They reflect radar and present tracking stations with hundreds of signals. Besides balloons, the bus might spew out millions of pieces of half-inch-long radar-reflecting wires. Clouds of this chaff, as it is called, would envelop the warhead, making its exact location very difficult to determine. An interceptor could sail through the cloud without touching the warhead. Other chaff clouds would be empty, creating more false targets.
The radar stations and satellites the United States uses can track the launch and flight of a missile very accurately, but they cannot distinguish decoys from targets. To do that, the missile-defense system must rely on a powerful new radar, called X-band, now being tested on Kwajalein Atoll in the western Pacific. Like all radar, it sends out electromagnetic pulses and detects pulses that reflect back off the targets. X-band radar has a much shorter wavelength than any existing radar--just over an inch long--which allows it to resolve details of range, size, and shape that remain invisible to standard radar. The prototype is reported to be able to detect objects as far away as 1,200 miles. When the radar is fully developed, that range is expected to increase to about 2,400 miles. Several X-band radar stations would have to be built around the world.
Coyle points out that the X-band radar's high resolution will create problems of its own. The wavelength is so short, he says that it will reflect off rain or hail in the line of sight between the radar and the objects it tracks. And the radar has been anything but foolproof in early tests (see "Anatomy of a Test,"
Plans call for X-band radar to work in concert with a fleet of two dozen or so new infrared satellites, which have yet to be built. The program is behind schedule and over budget. In theory, X-band radar would be able to tell a warhead from decoy balloons because the round balloons and cone-shaped warhead would all create unique radar reflections. The satellites would find the target by measuring the amount of infrared radiation--heat--emitted by the warhead and the decoys; a 1,000-pound warhead would remain warmer as it traveled through the cold vacuum of space than would the light balloon decoys, which would rapidly cool. All of this information would be sent to a command center, most likely Cheyenne Mountain, which would automatically relay it to the computers on board the interceptor missile.
But even the most advanced detectors could be foiled by the simplest of countermeasures. Instead of using round balloons, an enemy might make cheap, detailed balloon replicas of the warhead, so the radar reflections from the decoy and the warhead would look identical to the X-band receivers. Small, battery-powered heaters placed inside the decoys could trick infrared satellites into believing they had spotted a real, warm warhead. Alternatively, the warhead itself could be cooled by sheathing it with an insulating aluminum shell filled with liquid nitrogen, hiding it from the infrared satellites (see "How to Hide a Missile," below). An enemy could even enclose the real warhead in a balloon, which would inflate when released from the bus, making the warhead indistinguishable from the decoys. Even if the interceptor managed to hit the house-sized balloon containing the refrigerator-sized warhead, it might just puncture the balloon and sail right past the warhead.
Postol points out another potential obstacle. Should the X-band radar somehow manage to single out the warhead from a herd of decoys, that information might be useless for the interceptor. "If the radar correctly identifies an object as a warhead, it doesn't mean that the kill vehicle will know which object to home in on," he says. The problem is that once the radar has relayed its information to the interceptor, the targets, traveling at about five miles per second, will have moved. "By the time the kill vehicle encounters the targets, they will have been remixed up," says Postol.
Closing on the flock of balloons, chaff, and warhead at more than 15,000 miles per hour, the interceptor would have to rely on its own sensors and would likely miss the warhead. Moreover, an enemy would not have to arm its missiles with nuclear warheads and decoys to defeat a defense shield. Instead, it could opt to load one warhead with a hundred or more small "bomblets," each packed with a biological weapon like anthrax spores. Dropped on a city and dispersed by the wind, they might be more devastating than any nuclear weapon. One hundred bomblets could release 440 pounds of anthrax over a city, enough to kill more than 100,000 people. A nuclear weapon built with third-world technology might kill 60,000. A missile-defense shield would be utterly helpless against such a threat--the bomblets would be far too small and numerous for any interceptors to destroy or even see.
A brief but climactic third act--reentry--follows the midcourse phase of the ICBM's flight. This final phase lasts only 40 seconds, and the chance of a successful interception at this point is nil. Although the light decoys will have burned up in the atmosphere, leaving the enemy warhead alone at last, the interceptors probably would not see it. Below a height of 80 miles, the heat of friction with the atmosphere blinds heat-seeking sensors. In any case, interceptors might still face hundreds of germ-bearing bomblets, not a lone warhead.
In describing the technical challenge of destroying an ICBM hurtling through space, some scientists have likened the task to hitting a bullet with a bullet. "We know how to hit a bullet with a bullet," Coyle says. "So that's not really the analogy. It's like when you were a kid and somebody threw a ball at you. You could stop that. But if they threw a handful of rocks you couldn't stop them all. That's the problem. We won't have enough bullets."
When the Cheyenne Mountain complex was completed in 1965, it was designed to withstand the nearby explosion of a 30-megaton warhead. Today's weapons are many times more powerful, and the operations center is no longer impregnable. These days, as the staff at Cheyenne Mountain continues to watch for the unthinkable, just as they have since the height of the cold war, they don't bother to close the blast doors anymore. If the unthinkable missile is spotted, the doors can be shut within 30 seconds, locking 800 people inside with enough food, water, heat, electricity, and filtered air to enable them to survive for about 30 days.
"During the cold war we used to keep them closed all the time--except during shift changes," says Venable. Now he and his colleagues hope they will never be closed again.
What is the threat?
By far the greatest threat of an attack is still posed by Russia, which possesses about 5,200 warheads mounted on missiles, probably 2,000 fewer than the United States. An accidental launch--or an unauthorized one by a rebellious officer--would probably involve at least a few dozen warheads, and possibly thousands. The commander of a single Russian submarine, for example, could fire as many as 64 warheads at the United States, enough to kill tens of millions of people. Such an attack would completely overwhelm any missile-defense system being contemplated.
China is believed to have no more than 20 ICBMs that could reach the United States. For now, because China apparently stores its warheads and rocket fuel separately from its missiles, there is little chance of an accidental launch. China also has one submarine armed with nuclear weapons, but it usually remains close to the Chinese mainland, and its missiles don't have the range to reach American territory. But the construction of an American missile-defense system could make China adopt a more aggressive policy and place fully armed missiles on high-alert status.
Among third-world countries considered hostile to the United States, only North Korea has actually launched a multistage rocket--the Taepo Dong I, which flew over Japan in 1998 before crashing into the Pacific. Unclassified U.S. government intelligence reports speculate that within 10 years North Korea, Iran, and Iraq might be able to build missiles that could hit the United States, but no one knows whether those countries will actually pursue such a program. ICBMs are expensive to develop, so a hostile third-world country might choose instead to smuggle biological weapons into the United States and then release them. Or a rogue state could stow a nuclear weapon on a cargo ship and detonate the weapon in an American harbor. Any of these strategies could be anonymous as well as potentially more destructive than an ICBM.
— T. F.
How to hide a missile
To find and destroy an ICBM traveling 10 times faster than a bullet 140 miles above Earth's surface requires exquisite timing. With an interceptor and an ICBM approaching each other at closing speeds measured in miles per second, a half-second delay in spotting the target could make the interceptor miss by thousands of feet. For most of its flight, the interceptor will be guided toward the ICBM by radar stations on Earth and by satellites. Although the exact capability of the interceptor's infrared instruments is classified, in flight tests the interceptor apparently detected its target at a range of about 450 miles. Those targets, however, were warm and stood out against the cold background of space. But an enemy could enclose a warhead in a thin metallic shell filled with liquid nitrogen; physicist Richard Garwin says such technology is not challenging. The liquid nitrogen would cool the warhead to 77 Kelvin, or -321 degrees Fahrenheit. At that temperature, the interceptor's sensors wouldn't see the target until it was only about half a mile away. Could the interceptor use its small maneuvering rockets to correct its course at such a short distance and hit the ICBM? As the diagram above shows, assuming the interceptor needed to change course by just 60 feet, it would need to accelerate at a rate of more than 400 g's, far beyond its ability.
— T. F.
Anatomy of a test
At 10:40 p.m. eastern time on July 14, a Minuteman II ICBM carrying a dummy warhead took off from Vandenberg Air Force Base near Los Angeles. Exactly 21 minutes later an interceptor missile roared into the sky from Kwajalein Atoll in the western Pacific, some 4,800 miles away. When a flash of light indicating that the missiles had collided appeared on closed-circuit televisions in the Pentagon at 11:09 p.m., supporters of the missile-defense program were jubilant. What went largely unreported was that the dummy warhead had a target beacon on board. "That's not a bad thing to do for a first test, but it was not a demonstration of something you could deploy," says Philip Coyle, who headed the Pentagon's department of testing and evaluation during the Clinton administration. "Presumably a country that attacks us wouldn't put beacons on their missiles."
More problematic was the performance of the new X-band radar station on Kwajalein, which was supposed to track the last leg of the target's flight, up to and including the collision with the interceptor. Debris completely confused the radar. "Every time there's a stage separation, there are belts and straps and different objects that come loose," says Coyle. Reflections from that debris prompted the X-band radar to indicate that the interceptor had missed the target. This raises questions about how well X-band radar would deal with simple enemy countermeasures, such as dumping millions of pieces of radar-reflecting wire, or chaff, around the warhead. "A chaff cloud would be a great countermeasure," says Coyle. "Lord knows the North Koreans are smart enough to do that."
— T. F.
Targeting Rogue Missiles
If Iraq, Iran, or North Korea launched an ICBM toward the United States, the best time for an in-flight interception would be during the 300-second-long boost phase. And the best way to do that, says physicist Richard Garwin, would be for the United States to have ground-based interceptor missiles in Turkey ready to shoot down Iraqi ICBMs, have interceptors located near the Caspian Sea to destroy Iranian missiles, and place missiles in Russia to foil any launches from North Korea. That would of course entail a joint effort with Russia. But one clear advantage of the plan is that Russia is not likely to feel threatened by interceptors clearly targeted at rogue nations. Moreover, ground-based interceptors in Russia and Turkey would not involve exotic, unproven technologies like the airborne laser that is a key element of the Bush administration's proposed missile shield. The interceptors now being developed for the national missile-defense system are designed to have a top speed of 5.3 miles per second--compared with an ICBM's speed of 4.7 miles per second--so boost-phase interceptors would have to be modified to reach their top speed within 100 seconds of an ICBM's launch. Such a system is far more likely to be successful than an exotic infrared laser system. With such a system in place, the United States might have a chance of defending itself and other countries against a rogue-nation missile attack. And, as Garwin wrote in the Bulletin of the Atomic Scientists, "it would be far less costly than the proposed national missile-defense system."
— T. F.
Web sources
The Center for Defense Information has an informative site on some of the basics behind national missile defense: www.cdi.org/hotspots/issuebrief/default.asp.
The Union of Concerned Scientists reports on a number of possible countermeasures to a national missile defense, as well as the viability of the proposed program: www.ucsusa.org/arms/CM_toc.html.
Data from satellites and a global network of radar stations flow into computers at the missile-warning center, where eight or nine people during a typical shift sit in front of 17-inch monitors. Hardly a day passes without the detection of a launch somewhere around the world, such as the Russians firing SCUD missiles at Chechens or the French lofting a satellite into orbit. But in the 36-year history of Cheyenne Mountain, there is one type of launch the staff has never seen and doesn't want to see: an intercontinental ballistic missile (ICBM) on its way to the United States. From training sessions, they know exactly what to expect.
First, on the center of their monitors, a grid map would appear showing the part of the world from which the missile was launched. A small red circle represents the launch point of the missile. Next, a computerized voice says "Quick alert! Quick alert!" Then an alarm sounds and a light flashes, signaling everyone in the missile-warning center that a desperate race against the clock has begun. A missile launched from a site halfway around the world can reach the United States in less than 25 minutes.
Within a few seconds, computers plot the missile's trajectory. If it is headed for North America, an officer at NORAD alerts a Pentagon task force and the White House. Major Barry Venable, an Army spokesman for the Cheyenne Mountain operations center, says the President has exactly two options at that point. He can order a massive nuclear counterattack against the aggressor nation. Or he can wait as the incoming missile, or many missiles, vaporizes a city, or many cities, which will happen whether he retaliates or not. Given the current state of technology, no other option exists. The United States cannot shoot down one ICBM, let alone hundreds of them. There are no weapons that can hit a slender projectile traveling at nearly 15,000 miles per hour, about 10 times faster than a bullet. So the obvious question has long been: Can such a defensive weapon be built?
President Bush is betting it can. In a speech at the National Defense University in Washington this past May, the President announced his intention to deploy a system that "could provide limited, but effective, defenses" against ballistic missiles armed with nuclear, biological, or chemical weapons. The defense system, advocates say, is not really intended to thwart an all-out attack by a major nuclear power, which might involve advanced weaponry such as multiple independently targetable reentry vehicles (MIRVs), missiles that bear many warheads. At best they say it could shoot down a few missiles launched by a rogue nation such as North Korea, Iran, or Iraq, as well as missiles accidentally fired from Russia.
The President hopes to make such a missile shield a central accomplishment of his administration. He envisions a complex, multilayered defense that counterattacks with ground-based and sea-based interceptor missiles and aircraft equipped with lasers powerful enough to destroy a rocket in flight. The administration has declared it wants to begin building an interceptor missile base in Alaska that could be operational as early as 2004.
As desirable as even a limited shield might be in an uncertain world, physicists and independent defense analysts who have carefully studied the problem of missile defense argue that the President's plan is deeply flawed, more a product of wishful thinking than sound scientific analysis. "The proponents of missile defense are for the most part totally nontechnical. Or they are defense contractors," says Richard Garwin, a physicist who, with Edward Teller, helped create the world's first hydrogen bomb 50 years ago. "The top levels of the Defense Department are political and managerial, not technical."
And the scientific and technical challenges are far greater than those of any offensive or defensive weapons system ever built. For a missile shield to be effective, every component--radar systems, satellites, missiles, communication networks--would have to perform flawlessly in the heat of combat, says Philip Coyle, who directed the Defense Department's office of testing and evaluation during the Clinton administration. "All the pieces of the system--which are major systems in themselves--have to achieve reliabilities that military equipment rarely ever has."
The flight of an ICBM is a tragic drama that unfolds in three relentless acts: boost phase, midcourse, and reentry.
The boost phase is by far the best chance to shoot down an enemy ICBM, but it lasts at most 300 seconds, the time a missile takes to clear the atmosphere. A rocket rising into the air presents a clear target, and satellites can easily spot its hot exhaust plume. Two very different sorts of weapons are being considered for this stage of defense, and neither will be ready for at least several years: ship-launched interceptor missiles and an exotic airborne laser.
Of these two weapons, only the airborne laser is in active development. Boeing, Lockheed-Martin, and TRW are trying to equip a modified 747 jumbo jet with up to 17 lasers. In theory, several of these aircraft would fly constant patrol above pariahs like Iraq and North Korea, ready to shoot down a missile within a minute or two of its launch.
Unlike the colored, flashing death rays of science-fiction movies, the airborne laser consists of infrared light, invisible to human eyes. A reaction between rather ordinary chemicals--hydrogen peroxide and potassium hydroxide, the ingredients in hair bleach and Drano--generates the laser. But to produce the megawatt beam that would be needed to bring down a rocket requires linking many such lasers together in a series and sparking them with tons of the chemicals. Plans call for a 747 equipped with 14 laser modules, each weighing about 6,000 pounds when full. The aircraft would also carry three more lasers: one to track the missile, a second to measure atmospheric turbulence, and a third to illuminate the exact target. To compensate for atmospheric effects, a flexible, mechanically controlled mirror that can change its shape every few thousandths of a second will focus and aim the killer beam.
The beam would not immediately explode its target. Instead, after several seconds, heat from the laser would crack the outer surface of one of the three stages of the booster rocket that propels the warhead into space, weakening it. Pressure from the liquid fuel within the stage would then rupture the rocket, causing a catastrophic explosion. No one knows if the idea can be made to work. The first test is not scheduled until 2003, and the project is not expected to be operational for at least seven years.
In the meantime, the sheer bulk of the laser equipment that must be installed on the 747 poses daunting problems. Since the atmosphere would partially absorb and scatter the laser beam, the 747 would have to fly quite high to make sure the beam remained powerful enough to destroy the missile. "A 747 that is heavily loaded doesn't like to fly high," says Philip Coyle. "And you've also got to get close to the forward edge of battle, because your laser power isn't going to be such that it can propagate through many miles of atmosphere. If you're close to the enemy, you make a pretty inviting target yourself."The chemicals that fuel the laser present other problems, says Coyle: "The laser puts out caustic gases in the chemical process. The compatibility of all these materials with an aircraft has yet to be worked out."
If the airborne laser can be built and made to work, it's reasonable to assume an enemy will build defenses to protect its missile from just such an attack. "We're an open society, and we tell people what we're doing," Coyle says. "If the enemy saw that we were doing tests of such a system, and it looked as if it might work, they could foil us pretty easily by just putting a reflective surface of paint on the missile." The reflective surface would need to withstand the laser's heat for just a minute or so, providing enough time for the missile to move into space, well beyond the laser's range.
"One of the dilemmas involved in creating a missile-defense system is that the offense always has the advantage," says Coyle. "They can always figure out how to beat it."
Ted Postol, a nuclear physicist at MIT and a former advisor to the Pentagon on ballistic missile technology, says there is little chance the airborne laser will be ready in 2008 as its developers say. "There are lots and lots of technical questions that are unresolved," he says. "My guess is that it is decades away--if it can be built at all." Still more dubious are plans for space-based lasers mounted on remote-controlled satellites designed to attack ICBMs during the boost phase. Even the most die-hard supporters of that research say space-based lasers won't be defending the United States in the foreseeable future.
The one means of defense that stands the best chance of actually destroying an ICBM in flight--interceptor missiles launched from Navy warships--is still on the drawing board. An interceptor is designed to destroy an ICBM simply by crashing into it. But the deployment of ship-based interceptors is rife with practical problems. For a ship's missiles to have a chance to catch up with and hit an enemy missile, the ship would have to be stationed within a few hundred miles of enemy territory, making it vulnerable to attack. And the interceptors themselves would have to be much faster than any missile in existence, which means they would also be much larger in order to carry the fuel needed to power their five-mile-per-second flight. "It would take whole new rockets that are fatter, longer, and faster than anything the Navy has now," says Coyle. "In addition, this stuff won't fit in the launch tubes on existing Navy ships."
Like airborne lasers, a ship-launched interceptor would have less than 300 seconds to destroy a missile before it went completely out of range. That leaves little time--perhaps no time--for the President to be consulted about a decision to fire. Coyle says: "You might have to shoot it down within as little as two minutes, certainly within three or four. Otherwise the enemy rocket has cleared the atmosphere. So the decision to fire has got to be computerized, because there just isn't enough time to contemplate what you're doing. The President isn't going to be in the loop; the secretary of defense or the national security advisor wouldn't be in the loop."
The lack of civilian or even human control over such a decision would be unprecedented. The destruction of an enemy warhead could cause debris--including chemical and biological weapons, if aboard--to rain down on neighboring countries. And there is a far greater danger: The interceptor could hit and destroy the enemy rocket without destroying the warhead. In that case the warhead would career off course and land who knows where.
Furthermore, there is little guarantee that an interceptor could hit the target. Coyle emphasizes how hard it is to shoot down combat aircraft that travel at a fraction of an ICBM's speed. "With air defenses--shooting down planes--you're doing really good if you can hit 25 percent of your targets," he says.
When the targets are missiles instead of planes, the statistics are sobering. After the Gulf War against Iraq, Postol analyzed the Army's claims about the Patriot missile's performance against Iraqi missiles launched at Israel. Although the exact number of SCUD- Patriot encounters during the war is classified, there are thought to have been about 80. The Army initially claimed that Patriots hit 96 percent of their targets. Postol found, as did the Government Accounting Office in a separate study, that the Patriots hit at most 6 percent--fewer than five out of 80. In fact, Postol could not confirm that any Patriot missile ever actually hit any SCUD missile.
When an ICBM's booster rocket burns out and falls back to Earth, the warhead travels through the vacuum of space solely under the influence of gravity. This midcourse phase, which lasts about 15 minutes, is the longest of the three phases of an ICBM's flight. To shoot down an ICBM in midcourse, President Bush would field as many as 250 missiles in Alaska and North Dakota, possibly complemented by sea-launched interceptors. Ground-based radar and space-based infrared satellites would guide each interceptor part of the way toward its target. Onboard tracking systems would take over during the final seconds as the interceptor homed in on the enemy warhead. As with the sea-based interceptors proposed for the boost phase of defense, 51-inch-long missiles would destroy the warhead simply by colliding with it.
What if an interceptor misses? Lieutenant General Ronald Kadish, head of the Ballistic Missile Defense Organization, argued in testimony before the Senate Armed Services Committee recently that there should be sufficient time during the midcourse phase to fire additional interceptors at a warhead. "Multiple shots at the target give a higher probability of being able to hit it," he said.
But critics argue that Kadish underestimates enemy countermeasures. During the midcourse phase, the tracking systems guiding an interceptor would probably have to cope not with a single target but with hundreds. The warhead is housed during its ascent in a protective shell called a bus. Once in space, the bus opens, releasing not only the warhead but also numerous decoys to fool satellites and radar networks. Without air to slow them down, all the objects, regardless of size, shape, or weight, travel at about 15,000 miles per hour, clustered around the warhead. Instead of having to destroy an individual missile, as in the boost phase, the interceptor must pick out the real warhead.
Kadish insists that the critics are too pessimistic. "I do not share the assessment that what we are attempting to accomplish with our system is in any way impossible," he told Senate Armed Services Committee members. "Over the coming months and years, I believe program results can speak for themselves in responding to the criticism that the [missile shield] cannot operate as designed against the projected countermeasure threat that a state of concern might pose."
Coyle, Postol, and other experts do not share Kadish's faith. Both the United States and Russia have designed missiles that contain decoys. There is no reason, says Coyle, why North Korea, Iran, or Iraq could not equip missiles with decoys too. "If they're smart enough to make ICBMs with sophisticated guidance systems and all the rest, I think they can figure out how to make decoys," says Coyle.
The simplest decoys are Mylar balloons, just like those sold in supermarkets, except that each one is about the size of a house. They reflect radar and present tracking stations with hundreds of signals. Besides balloons, the bus might spew out millions of pieces of half-inch-long radar-reflecting wires. Clouds of this chaff, as it is called, would envelop the warhead, making its exact location very difficult to determine. An interceptor could sail through the cloud without touching the warhead. Other chaff clouds would be empty, creating more false targets.
The radar stations and satellites the United States uses can track the launch and flight of a missile very accurately, but they cannot distinguish decoys from targets. To do that, the missile-defense system must rely on a powerful new radar, called X-band, now being tested on Kwajalein Atoll in the western Pacific. Like all radar, it sends out electromagnetic pulses and detects pulses that reflect back off the targets. X-band radar has a much shorter wavelength than any existing radar--just over an inch long--which allows it to resolve details of range, size, and shape that remain invisible to standard radar. The prototype is reported to be able to detect objects as far away as 1,200 miles. When the radar is fully developed, that range is expected to increase to about 2,400 miles. Several X-band radar stations would have to be built around the world.
Coyle points out that the X-band radar's high resolution will create problems of its own. The wavelength is so short, he says that it will reflect off rain or hail in the line of sight between the radar and the objects it tracks. And the radar has been anything but foolproof in early tests (see "Anatomy of a Test,"
Plans call for X-band radar to work in concert with a fleet of two dozen or so new infrared satellites, which have yet to be built. The program is behind schedule and over budget. In theory, X-band radar would be able to tell a warhead from decoy balloons because the round balloons and cone-shaped warhead would all create unique radar reflections. The satellites would find the target by measuring the amount of infrared radiation--heat--emitted by the warhead and the decoys; a 1,000-pound warhead would remain warmer as it traveled through the cold vacuum of space than would the light balloon decoys, which would rapidly cool. All of this information would be sent to a command center, most likely Cheyenne Mountain, which would automatically relay it to the computers on board the interceptor missile.
But even the most advanced detectors could be foiled by the simplest of countermeasures. Instead of using round balloons, an enemy might make cheap, detailed balloon replicas of the warhead, so the radar reflections from the decoy and the warhead would look identical to the X-band receivers. Small, battery-powered heaters placed inside the decoys could trick infrared satellites into believing they had spotted a real, warm warhead. Alternatively, the warhead itself could be cooled by sheathing it with an insulating aluminum shell filled with liquid nitrogen, hiding it from the infrared satellites (see "How to Hide a Missile," below). An enemy could even enclose the real warhead in a balloon, which would inflate when released from the bus, making the warhead indistinguishable from the decoys. Even if the interceptor managed to hit the house-sized balloon containing the refrigerator-sized warhead, it might just puncture the balloon and sail right past the warhead.
Postol points out another potential obstacle. Should the X-band radar somehow manage to single out the warhead from a herd of decoys, that information might be useless for the interceptor. "If the radar correctly identifies an object as a warhead, it doesn't mean that the kill vehicle will know which object to home in on," he says. The problem is that once the radar has relayed its information to the interceptor, the targets, traveling at about five miles per second, will have moved. "By the time the kill vehicle encounters the targets, they will have been remixed up," says Postol.
Closing on the flock of balloons, chaff, and warhead at more than 15,000 miles per hour, the interceptor would have to rely on its own sensors and would likely miss the warhead. Moreover, an enemy would not have to arm its missiles with nuclear warheads and decoys to defeat a defense shield. Instead, it could opt to load one warhead with a hundred or more small "bomblets," each packed with a biological weapon like anthrax spores. Dropped on a city and dispersed by the wind, they might be more devastating than any nuclear weapon. One hundred bomblets could release 440 pounds of anthrax over a city, enough to kill more than 100,000 people. A nuclear weapon built with third-world technology might kill 60,000. A missile-defense shield would be utterly helpless against such a threat--the bomblets would be far too small and numerous for any interceptors to destroy or even see.
A brief but climactic third act--reentry--follows the midcourse phase of the ICBM's flight. This final phase lasts only 40 seconds, and the chance of a successful interception at this point is nil. Although the light decoys will have burned up in the atmosphere, leaving the enemy warhead alone at last, the interceptors probably would not see it. Below a height of 80 miles, the heat of friction with the atmosphere blinds heat-seeking sensors. In any case, interceptors might still face hundreds of germ-bearing bomblets, not a lone warhead.
In describing the technical challenge of destroying an ICBM hurtling through space, some scientists have likened the task to hitting a bullet with a bullet. "We know how to hit a bullet with a bullet," Coyle says. "So that's not really the analogy. It's like when you were a kid and somebody threw a ball at you. You could stop that. But if they threw a handful of rocks you couldn't stop them all. That's the problem. We won't have enough bullets."
When the Cheyenne Mountain complex was completed in 1965, it was designed to withstand the nearby explosion of a 30-megaton warhead. Today's weapons are many times more powerful, and the operations center is no longer impregnable. These days, as the staff at Cheyenne Mountain continues to watch for the unthinkable, just as they have since the height of the cold war, they don't bother to close the blast doors anymore. If the unthinkable missile is spotted, the doors can be shut within 30 seconds, locking 800 people inside with enough food, water, heat, electricity, and filtered air to enable them to survive for about 30 days.
"During the cold war we used to keep them closed all the time--except during shift changes," says Venable. Now he and his colleagues hope they will never be closed again.
What is the threat?
By far the greatest threat of an attack is still posed by Russia, which possesses about 5,200 warheads mounted on missiles, probably 2,000 fewer than the United States. An accidental launch--or an unauthorized one by a rebellious officer--would probably involve at least a few dozen warheads, and possibly thousands. The commander of a single Russian submarine, for example, could fire as many as 64 warheads at the United States, enough to kill tens of millions of people. Such an attack would completely overwhelm any missile-defense system being contemplated.
China is believed to have no more than 20 ICBMs that could reach the United States. For now, because China apparently stores its warheads and rocket fuel separately from its missiles, there is little chance of an accidental launch. China also has one submarine armed with nuclear weapons, but it usually remains close to the Chinese mainland, and its missiles don't have the range to reach American territory. But the construction of an American missile-defense system could make China adopt a more aggressive policy and place fully armed missiles on high-alert status.
Among third-world countries considered hostile to the United States, only North Korea has actually launched a multistage rocket--the Taepo Dong I, which flew over Japan in 1998 before crashing into the Pacific. Unclassified U.S. government intelligence reports speculate that within 10 years North Korea, Iran, and Iraq might be able to build missiles that could hit the United States, but no one knows whether those countries will actually pursue such a program. ICBMs are expensive to develop, so a hostile third-world country might choose instead to smuggle biological weapons into the United States and then release them. Or a rogue state could stow a nuclear weapon on a cargo ship and detonate the weapon in an American harbor. Any of these strategies could be anonymous as well as potentially more destructive than an ICBM.
— T. F.
How to hide a missile
To find and destroy an ICBM traveling 10 times faster than a bullet 140 miles above Earth's surface requires exquisite timing. With an interceptor and an ICBM approaching each other at closing speeds measured in miles per second, a half-second delay in spotting the target could make the interceptor miss by thousands of feet. For most of its flight, the interceptor will be guided toward the ICBM by radar stations on Earth and by satellites. Although the exact capability of the interceptor's infrared instruments is classified, in flight tests the interceptor apparently detected its target at a range of about 450 miles. Those targets, however, were warm and stood out against the cold background of space. But an enemy could enclose a warhead in a thin metallic shell filled with liquid nitrogen; physicist Richard Garwin says such technology is not challenging. The liquid nitrogen would cool the warhead to 77 Kelvin, or -321 degrees Fahrenheit. At that temperature, the interceptor's sensors wouldn't see the target until it was only about half a mile away. Could the interceptor use its small maneuvering rockets to correct its course at such a short distance and hit the ICBM? As the diagram above shows, assuming the interceptor needed to change course by just 60 feet, it would need to accelerate at a rate of more than 400 g's, far beyond its ability.
— T. F.
Anatomy of a test
At 10:40 p.m. eastern time on July 14, a Minuteman II ICBM carrying a dummy warhead took off from Vandenberg Air Force Base near Los Angeles. Exactly 21 minutes later an interceptor missile roared into the sky from Kwajalein Atoll in the western Pacific, some 4,800 miles away. When a flash of light indicating that the missiles had collided appeared on closed-circuit televisions in the Pentagon at 11:09 p.m., supporters of the missile-defense program were jubilant. What went largely unreported was that the dummy warhead had a target beacon on board. "That's not a bad thing to do for a first test, but it was not a demonstration of something you could deploy," says Philip Coyle, who headed the Pentagon's department of testing and evaluation during the Clinton administration. "Presumably a country that attacks us wouldn't put beacons on their missiles."
More problematic was the performance of the new X-band radar station on Kwajalein, which was supposed to track the last leg of the target's flight, up to and including the collision with the interceptor. Debris completely confused the radar. "Every time there's a stage separation, there are belts and straps and different objects that come loose," says Coyle. Reflections from that debris prompted the X-band radar to indicate that the interceptor had missed the target. This raises questions about how well X-band radar would deal with simple enemy countermeasures, such as dumping millions of pieces of radar-reflecting wire, or chaff, around the warhead. "A chaff cloud would be a great countermeasure," says Coyle. "Lord knows the North Koreans are smart enough to do that."
— T. F.
Targeting Rogue Missiles
If Iraq, Iran, or North Korea launched an ICBM toward the United States, the best time for an in-flight interception would be during the 300-second-long boost phase. And the best way to do that, says physicist Richard Garwin, would be for the United States to have ground-based interceptor missiles in Turkey ready to shoot down Iraqi ICBMs, have interceptors located near the Caspian Sea to destroy Iranian missiles, and place missiles in Russia to foil any launches from North Korea. That would of course entail a joint effort with Russia. But one clear advantage of the plan is that Russia is not likely to feel threatened by interceptors clearly targeted at rogue nations. Moreover, ground-based interceptors in Russia and Turkey would not involve exotic, unproven technologies like the airborne laser that is a key element of the Bush administration's proposed missile shield. The interceptors now being developed for the national missile-defense system are designed to have a top speed of 5.3 miles per second--compared with an ICBM's speed of 4.7 miles per second--so boost-phase interceptors would have to be modified to reach their top speed within 100 seconds of an ICBM's launch. Such a system is far more likely to be successful than an exotic infrared laser system. With such a system in place, the United States might have a chance of defending itself and other countries against a rogue-nation missile attack. And, as Garwin wrote in the Bulletin of the Atomic Scientists, "it would be far less costly than the proposed national missile-defense system."
— T. F.
Web sources
The Center for Defense Information has an informative site on some of the basics behind national missile defense: www.cdi.org/hotspots/issuebrief/default.asp.
The Union of Concerned Scientists reports on a number of possible countermeasures to a national missile defense, as well as the viability of the proposed program: www.ucsusa.org/arms/CM_toc.html.
Monday, March 12, 2007
Neural Implant Empowers Paralyzed Man
Neuroscientist John Donoghue of Brown University has brought us a big step closer to the day when people can interact with computers directly through the power of thought. In July he and his team published a paper in Nature outlining remarkable progress in picking up brain signals with implanted electrodes and using those signals to control a range of devices.
The experiments were conducted on a 25-year-old Massachusetts man paralyzed from the neck down. In 2004, surgeons placed a tiny 100-electrode array in his primary motor cortex, the brain region that controls voluntary movement, to collect electrical impulses from nerve cells and send them to a series of signal processors. Donoghue and his colleagues then supervised as the computer translated the man's thoughts of moving his arm and hand into the actual movement of external devices. On the first day the system was up and running, he was able to master the technique. He could move a computer cursor, play a video game, open e-mails, draw a crude circle, operate a television remote control, and even move a prosthetic hand and arm—using nothing other than his will.
The same basic brain-computer interface system had been tested earlier in monkeys, and a group in Georgia implanted electrodes in people as far back as the 1990s. But no other group has used implanted electrodes to monitor so many human neurons at once or had such impressive results.
The system was removed from the original subject after 14 months. It is now being tested on three other patients, including one with ALS. Neurologist Leigh Hochberg, the lead author on the paper with Donoghue, hopes that the current trials are the first step toward giving severely disabled people an unprecedented degree of independence. "The participants in these trials are pioneers," he says.
The experiments were conducted on a 25-year-old Massachusetts man paralyzed from the neck down. In 2004, surgeons placed a tiny 100-electrode array in his primary motor cortex, the brain region that controls voluntary movement, to collect electrical impulses from nerve cells and send them to a series of signal processors. Donoghue and his colleagues then supervised as the computer translated the man's thoughts of moving his arm and hand into the actual movement of external devices. On the first day the system was up and running, he was able to master the technique. He could move a computer cursor, play a video game, open e-mails, draw a crude circle, operate a television remote control, and even move a prosthetic hand and arm—using nothing other than his will.
The same basic brain-computer interface system had been tested earlier in monkeys, and a group in Georgia implanted electrodes in people as far back as the 1990s. But no other group has used implanted electrodes to monitor so many human neurons at once or had such impressive results.
The system was removed from the original subject after 14 months. It is now being tested on three other patients, including one with ALS. Neurologist Leigh Hochberg, the lead author on the paper with Donoghue, hopes that the current trials are the first step toward giving severely disabled people an unprecedented degree of independence. "The participants in these trials are pioneers," he says.
Sunday, March 11, 2007
Like Water for Mars
Evidence of water flowing on our most similar neighbor
by Alex Stone
Pictures taken by the camera on NASA's Mars Global Surveyor suggest that rivulets of liquid water were flowing on the Red Planet within the past few years and may still be flowing today, welling up from beneath the Martian surface and streaming down gullies along the sloping walls of impact craters.
Two craters in particular caught the attention of NASA scientists. Both are in the planet's southern hemisphere, and both looked unremarkable at first glance. That changed when the Surveyor team reimaged the craters over several years and spotted two brightly streaked gullies with branched endings—a hallmark of flowing water—that were not visible in earlier pictures. The researchers speculate that the streaks formed when water bubbled up from a subsurface reservoir and ran down the gullies, leaving behind a pale-toned trail of sedimentation that is seen in the Surveyor snapshots as a bright line against a darker background. "We reimaged it several times at different sun angles to be sure it wasn't just a trick of different illumination conditions," says Ken Edgett, a member of the research team that made the discovery. More than just a geologic curiosity, finding water on Mars has major implications for the search for life, because the presence of H2O greatly increases the odds that living organisms once thrived on the planet, and perhaps still inhabit it today. "We didn't expect this to happen in our lifetime, let alone our 10-year mission," Edgett says.
But is the liquid flowing down these gullies really water? Probably, say experts at NASA's Jet Propulsion Laboratory, but more evidence is needed to seal the case. "You can never be certain from orbit," Edgett says. "But this is the best evidence yet of liquid water being present on Mars right now."
by Alex Stone
Pictures taken by the camera on NASA's Mars Global Surveyor suggest that rivulets of liquid water were flowing on the Red Planet within the past few years and may still be flowing today, welling up from beneath the Martian surface and streaming down gullies along the sloping walls of impact craters.
Two craters in particular caught the attention of NASA scientists. Both are in the planet's southern hemisphere, and both looked unremarkable at first glance. That changed when the Surveyor team reimaged the craters over several years and spotted two brightly streaked gullies with branched endings—a hallmark of flowing water—that were not visible in earlier pictures. The researchers speculate that the streaks formed when water bubbled up from a subsurface reservoir and ran down the gullies, leaving behind a pale-toned trail of sedimentation that is seen in the Surveyor snapshots as a bright line against a darker background. "We reimaged it several times at different sun angles to be sure it wasn't just a trick of different illumination conditions," says Ken Edgett, a member of the research team that made the discovery. More than just a geologic curiosity, finding water on Mars has major implications for the search for life, because the presence of H2O greatly increases the odds that living organisms once thrived on the planet, and perhaps still inhabit it today. "We didn't expect this to happen in our lifetime, let alone our 10-year mission," Edgett says.
But is the liquid flowing down these gullies really water? Probably, say experts at NASA's Jet Propulsion Laboratory, but more evidence is needed to seal the case. "You can never be certain from orbit," Edgett says. "But this is the best evidence yet of liquid water being present on Mars right now."
Neutrinos of the Sea
Scientists hope to find rare high-energy particles in the sea.
by Kathy A. Svitil
Giorgio Gratta, a physicist at Stanford University, is going fishing for high-energy neutrinos, ghostly subatomic particles that bombard Earth from unknown objects in deep space. These particles can interact with water, emitting a shudder of light, albeit under such rare circumstances that just a few of them strike each square mile of ocean each year.
But neutrinos can also heat the water, generating acoustic waves. The Navy's Atlantic Undersea Test and Evaluation Center, a 100-square-mile hydrophone array used to track ships and weapons during undersea naval exercises, could pick up these tiny vibrations. "You can put hydrophones in the water and listen to the neutrinos," Gratta says.
During the past several months, Gratta and his students have begun collecting data from seven of the array's 52 hydrophones. He is using computer software to filter out noise from wind, surf, ship engines, snapping shrimp, and echolocating dolphins. "Things look good," he says.
Next he hopes to plug into the rest of the hydrophones, start tallying the neutrinos, and begin to zero in on the strange, energetic objects that emit them.
by Kathy A. Svitil
Giorgio Gratta, a physicist at Stanford University, is going fishing for high-energy neutrinos, ghostly subatomic particles that bombard Earth from unknown objects in deep space. These particles can interact with water, emitting a shudder of light, albeit under such rare circumstances that just a few of them strike each square mile of ocean each year.
But neutrinos can also heat the water, generating acoustic waves. The Navy's Atlantic Undersea Test and Evaluation Center, a 100-square-mile hydrophone array used to track ships and weapons during undersea naval exercises, could pick up these tiny vibrations. "You can put hydrophones in the water and listen to the neutrinos," Gratta says.
During the past several months, Gratta and his students have begun collecting data from seven of the array's 52 hydrophones. He is using computer software to filter out noise from wind, surf, ship engines, snapping shrimp, and echolocating dolphins. "Things look good," he says.
Next he hopes to plug into the rest of the hydrophones, start tallying the neutrinos, and begin to zero in on the strange, energetic objects that emit them.
The Titanic's Revenge
Butterfly effect breaks up the world's biggest icebergby
by Jeffrey Winters
The largest icebergs usually hug the Antarctic coast for decades before wandering into deep ocean water, where they melt and fall to pieces. To listen for clues about how such icebergs eventually break apart, geophysicists Douglas MacAyeal of the University of Chicago and Emile Okal of Northwestern University planted seismographs on the surface of iceberg B15A, a 71-mile-long block of ice with the distinction of being the world's largest free-floating object. Their recording turned up the sounds of the iceberg being battered to bits against the Antarctic shore over a couple days in October 2005. The big surprise came when the researchers tracked down the origin of that battering.
By measuring ocean swells of different wavelengths, the duo traced the destructive turbulence to a storm in the Gulf of Alaska that, a few days earlier, had kicked up 40-foot-high seas. Like the proverbial butterfly that flapped its wings in Beijing and caused a hurricane halfway around the world, the Alaskan storm's waves spread out across the Pacific Ocean and broke apart an iceberg more than 8,000 miles away. "It was jaw dropping," says MacAyeal.
If global warming leads to an increase in monster storms, MacAyeal adds, then the entire Antarctic ice skirt could be in jeopardy: Larger sea swells could pulverize its huge icebergs and floating ice shelves. The ice skirt plays a critical role in keeping the land-based Antarctic ice cap in place. Destroy the floating ice and the ice cap (which holds enough water to raise sea levels by 200 feet) would collapse unimpeded into the sea.
by Jeffrey Winters
The largest icebergs usually hug the Antarctic coast for decades before wandering into deep ocean water, where they melt and fall to pieces. To listen for clues about how such icebergs eventually break apart, geophysicists Douglas MacAyeal of the University of Chicago and Emile Okal of Northwestern University planted seismographs on the surface of iceberg B15A, a 71-mile-long block of ice with the distinction of being the world's largest free-floating object. Their recording turned up the sounds of the iceberg being battered to bits against the Antarctic shore over a couple days in October 2005. The big surprise came when the researchers tracked down the origin of that battering.
By measuring ocean swells of different wavelengths, the duo traced the destructive turbulence to a storm in the Gulf of Alaska that, a few days earlier, had kicked up 40-foot-high seas. Like the proverbial butterfly that flapped its wings in Beijing and caused a hurricane halfway around the world, the Alaskan storm's waves spread out across the Pacific Ocean and broke apart an iceberg more than 8,000 miles away. "It was jaw dropping," says MacAyeal.
If global warming leads to an increase in monster storms, MacAyeal adds, then the entire Antarctic ice skirt could be in jeopardy: Larger sea swells could pulverize its huge icebergs and floating ice shelves. The ice skirt plays a critical role in keeping the land-based Antarctic ice cap in place. Destroy the floating ice and the ice cap (which holds enough water to raise sea levels by 200 feet) would collapse unimpeded into the sea.
Whatever Happened to... Project Blue Book?
The government gave up on alien tall tales.
by Stephen Ornes
From 1948 until 1969, the U.S. government collected about 80,000 pages of first-hand reports—including descriptions, drawings, and diagrams—on more than 12,000 sightings of UFOs.
Begun as Project Sign, it was quickly renamed Project Grudge, then Project Blue Book in early 1952. The new moniker, inspired by the blue books college students use to take written exams, was supposed to indicate the seriousness with which the study was being undertaken.
With 1,500 reports, 1952 was also the year with the most sightings. All in all, 701 remain "unidentified" to this day. The rest were attributed to a variety of sources, including bright planets, auroras, aircraft, searchlights, and birds. Project Blue Book was shut down in 1969 after a rigorous study led by the physicist Edward Condon concluded that UFO sightings all had mundane, nonthreatening explanations.
Since that time, the U.S. government no longer investigates claims of "flying saucers"—a term that dates back to the first widely reported UFO sighting by an American businessman in 1947. Independent groups of civilians still maintain that the government intentionally withholds information about UFO sightings, both past and present.
by Stephen Ornes
From 1948 until 1969, the U.S. government collected about 80,000 pages of first-hand reports—including descriptions, drawings, and diagrams—on more than 12,000 sightings of UFOs.
Begun as Project Sign, it was quickly renamed Project Grudge, then Project Blue Book in early 1952. The new moniker, inspired by the blue books college students use to take written exams, was supposed to indicate the seriousness with which the study was being undertaken.
With 1,500 reports, 1952 was also the year with the most sightings. All in all, 701 remain "unidentified" to this day. The rest were attributed to a variety of sources, including bright planets, auroras, aircraft, searchlights, and birds. Project Blue Book was shut down in 1969 after a rigorous study led by the physicist Edward Condon concluded that UFO sightings all had mundane, nonthreatening explanations.
Since that time, the U.S. government no longer investigates claims of "flying saucers"—a term that dates back to the first widely reported UFO sighting by an American businessman in 1947. Independent groups of civilians still maintain that the government intentionally withholds information about UFO sightings, both past and present.
Friday, March 9, 2007
The Top 6 Archaeology Stories of 2006
A tattooed iceman, figs as first farming, the Temple of the Fox, and more...
New Tomb Found In Valley of the Kings
Archaeologists uncovered the first new tomb in Egypt's Valley of the Kings since 1922...
Oldest Writing In New World Found
Workers digging in Mexico unearthed the oldest script ever found in the Western Hemisphere...
Peruvian Dig Uncovers First Western Observatory
The Temple of the Fox, located in the Chillón Valley in Peru, probably served as a rough farmers' almanac...
Old Beads Hint at Dawn Of Culture
Grape-size shell beads dated between 100,000 and 135,000 years old are the world's oldest known jewelry...
Mongolian Ice Yields Scythian Mummy
Last summer researchers recovered a 2,200-year-old Scythian mummy from permafrost...
Did Figs Beget Agriculture?
New research has pegged the fig as the first crop...
New Tomb Found In Valley of the Kings
Archaeologists uncovered the first new tomb in Egypt's Valley of the Kings since 1922...
Oldest Writing In New World Found
Workers digging in Mexico unearthed the oldest script ever found in the Western Hemisphere...
Peruvian Dig Uncovers First Western Observatory
The Temple of the Fox, located in the Chillón Valley in Peru, probably served as a rough farmers' almanac...
Old Beads Hint at Dawn Of Culture
Grape-size shell beads dated between 100,000 and 135,000 years old are the world's oldest known jewelry...
Mongolian Ice Yields Scythian Mummy
Last summer researchers recovered a 2,200-year-old Scythian mummy from permafrost...
Did Figs Beget Agriculture?
New research has pegged the fig as the first crop...
Thursday, March 8, 2007
The First Computer
A mysterious device found in Greek waters was not brought by aliens, but it was used by ancient Greeks to track distant stars.
by Stephen Ornes
In 1901, divers recovered a shoebox-size, gear-filled box from a 2,000-year-old shipwreck on the floor of the Mediterranean Sea. Ever since, the enigmatic box—known as the Antikythera Mechanism—has spawned its share of bizarre theories. "Some people thought it came from outer space," scoffs Athens University physicist Yanis Bitsakis. "And since the mechanism has Greek writing on it, the other ridiculous story is that Greeks themselves came from outer space and brought the mechanism with them." More sober minds suggested the box was a clock or a navigational device, but even those interpretations rested on skimpy evidence.
Now an international team of researchers claim they have found the answer. Three-dimensional scans of the machine's innards, taken last year by an eight-ton "microfocus" X-ray machine built around the mystery object, revealed ancient inscriptions and complicated gear trains that gave away the machine's purpose. "It's an all-in-one astronomical device," says Bitsakis, who spends up to 15 hours daily deciphering the inscribed text. "In a single machine, the designer tried to put all the knowledge he had about astronomical phenomena."
The 30-odd bronze gears and 2,000 inscribed Greek characters in the Antikythera Mechanism helped ancient Greek scientists track the cycles of the solar system and calculate the motions of the sun, the moon, and the planets. According to Cardiff University astrophysicist Michael Edmunds, the box technically qualifies as a computer. "To build one of these is not trivial," he says. "It shows how technically advanced the Greeks were."
by Stephen Ornes
In 1901, divers recovered a shoebox-size, gear-filled box from a 2,000-year-old shipwreck on the floor of the Mediterranean Sea. Ever since, the enigmatic box—known as the Antikythera Mechanism—has spawned its share of bizarre theories. "Some people thought it came from outer space," scoffs Athens University physicist Yanis Bitsakis. "And since the mechanism has Greek writing on it, the other ridiculous story is that Greeks themselves came from outer space and brought the mechanism with them." More sober minds suggested the box was a clock or a navigational device, but even those interpretations rested on skimpy evidence.
Now an international team of researchers claim they have found the answer. Three-dimensional scans of the machine's innards, taken last year by an eight-ton "microfocus" X-ray machine built around the mystery object, revealed ancient inscriptions and complicated gear trains that gave away the machine's purpose. "It's an all-in-one astronomical device," says Bitsakis, who spends up to 15 hours daily deciphering the inscribed text. "In a single machine, the designer tried to put all the knowledge he had about astronomical phenomena."
The 30-odd bronze gears and 2,000 inscribed Greek characters in the Antikythera Mechanism helped ancient Greek scientists track the cycles of the solar system and calculate the motions of the sun, the moon, and the planets. According to Cardiff University astrophysicist Michael Edmunds, the box technically qualifies as a computer. "To build one of these is not trivial," he says. "It shows how technically advanced the Greeks were."
The Top 7 Technology Stories of 2006
Good News For Light Sleepers
Gravity-defying beds are no longer a figment of Stanley Kubrick's imagination. 12.8.2006
Peer Review: Fighting the Terrorist Virus
If terrorism is cultivated by modern media, how do we fight it? 12.4.2006
How to Build an Invisibility Cloak
Using strange new materials not found in nature, physicists can make an object disappear. 11.20.2006
Science in the Crosshairs
Iraq's legacy as a mecca of learning falls casualty to chaos. 11.8.2006
Faster, Sleeker, Smaller
A quarter century's worth of DISCOVER advertisements reveals a radically changing world. 11.2.2006
The Truth About Liquid Bombs
Promising new technologies could sniff out liquid bombs. But can their limitations be overcome? 11.1.2006
Map: What Does the Internet Look Like?
Why China has as many IP addresses as an American university, which ISP should be called "Spamalot," and more. 10.30.2006
The No-Touch Pat-Down
One of the latest—and most amusing—gizmos in airport security: the air puffer 10.23.2006
Peer Review: Too Clear for Comfort
The increased detail of HDTV may decrease our viewing pleasure. 10.9.2006
Faster, Sleeker, Smaller
Discover advertisements reveal a radically changing world. 10.1.2006
Peer Review: Invading Our Own Privacy
We grumble about prying eyes, yet we love to upload our identities onto the Web. 9.2.2006
Neighborhood Watch Goes High Tech
Monitor your neighbors—or the Texas-Mexico border—right from your computer. 9.1.2006
Seconds From Disaster
Japan installs the world's first nationwide earthquake-detector system. 9.1.2006
Going Atomic... Again
America plans its first new nuclear warhead in two decades 9.1.2006
Jaron's World: The Murder of Mystery
How Silicon Valley joined the superstitious fringe as the enemy of open inquiry. 9.1.2006
Gravity-defying beds are no longer a figment of Stanley Kubrick's imagination. 12.8.2006
Peer Review: Fighting the Terrorist Virus
If terrorism is cultivated by modern media, how do we fight it? 12.4.2006
How to Build an Invisibility Cloak
Using strange new materials not found in nature, physicists can make an object disappear. 11.20.2006
Science in the Crosshairs
Iraq's legacy as a mecca of learning falls casualty to chaos. 11.8.2006
Faster, Sleeker, Smaller
A quarter century's worth of DISCOVER advertisements reveals a radically changing world. 11.2.2006
The Truth About Liquid Bombs
Promising new technologies could sniff out liquid bombs. But can their limitations be overcome? 11.1.2006
Map: What Does the Internet Look Like?
Why China has as many IP addresses as an American university, which ISP should be called "Spamalot," and more. 10.30.2006
The No-Touch Pat-Down
One of the latest—and most amusing—gizmos in airport security: the air puffer 10.23.2006
Peer Review: Too Clear for Comfort
The increased detail of HDTV may decrease our viewing pleasure. 10.9.2006
Faster, Sleeker, Smaller
Discover advertisements reveal a radically changing world. 10.1.2006
Peer Review: Invading Our Own Privacy
We grumble about prying eyes, yet we love to upload our identities onto the Web. 9.2.2006
Neighborhood Watch Goes High Tech
Monitor your neighbors—or the Texas-Mexico border—right from your computer. 9.1.2006
Seconds From Disaster
Japan installs the world's first nationwide earthquake-detector system. 9.1.2006
Going Atomic... Again
America plans its first new nuclear warhead in two decades 9.1.2006
Jaron's World: The Murder of Mystery
How Silicon Valley joined the superstitious fringe as the enemy of open inquiry. 9.1.2006
Tuesday, March 6, 2007
Sunday, March 4, 2007
The Top 13 Space Stories of 2006
The Top 13 Space Stories of 2006
The makings of life in space, dark matter in the spotlight, the first inflatable space station, and more
3 Cosmic Collision Brings Dark Matter Into View A violent collision has turned up the most direct evidence yet of dark matter...
10 Pluto DemotedPluto now falls under the quaint designation "dwarf planet"...
13 Probe Snaps Baby Picture of the Cosmos
A detailed snapshot of what the universe was like as a trillionth-of-a-second-old newborn...
22 Methane Rain Falls Mainly on Titan's PlainThe Huygens probe made a splat. "It landed in mud"...
45 Alien Planets Get Smaller, Fatter, Faster, and Hotter
This year ushered some of the oddest extrasolar plaents ever found...
48 Nearby Universe MappedAstrophysicists have produced the most detailed full-sky map of the nearby universe...
51 Ice Volcanoes Seen On Saturnian Moon
NASA's Cassini probe showed a geyser shooting jets of water and fine icy particles hundreds of miles into space...
56 Comet Dust Records Solar System Chaos
One-third of a milligram of dust from comet Wild 2 landed on Earth last January...
67 Complex Organic Molecules Formed in Outer SpaceAstronomers have identified eight new complex molecules in space...
75 Astro-Hotel LaunchedBigelow Aerospace last July launched Genesis 1, the first inflatable space station...
93 Renegade Planet Pair Defy ExplanationA pair of celestial objects circling one another have fed a growing debate over the dividing line between planets and stars...
96 Strange Swirls Spotted at Venus's PoleVenus is Earth's near-twin in size and mass, yet bafflingly different in other particulars...
100 Saturn SunburstThe Cassini spacecraft captured an extraordinary backlit image of Saturn and its gossamer rings...
The makings of life in space, dark matter in the spotlight, the first inflatable space station, and more
3 Cosmic Collision Brings Dark Matter Into View A violent collision has turned up the most direct evidence yet of dark matter...
10 Pluto DemotedPluto now falls under the quaint designation "dwarf planet"...
13 Probe Snaps Baby Picture of the Cosmos
A detailed snapshot of what the universe was like as a trillionth-of-a-second-old newborn...
22 Methane Rain Falls Mainly on Titan's PlainThe Huygens probe made a splat. "It landed in mud"...
45 Alien Planets Get Smaller, Fatter, Faster, and Hotter
This year ushered some of the oddest extrasolar plaents ever found...
48 Nearby Universe MappedAstrophysicists have produced the most detailed full-sky map of the nearby universe...
51 Ice Volcanoes Seen On Saturnian Moon
NASA's Cassini probe showed a geyser shooting jets of water and fine icy particles hundreds of miles into space...
56 Comet Dust Records Solar System Chaos
One-third of a milligram of dust from comet Wild 2 landed on Earth last January...
67 Complex Organic Molecules Formed in Outer SpaceAstronomers have identified eight new complex molecules in space...
75 Astro-Hotel LaunchedBigelow Aerospace last July launched Genesis 1, the first inflatable space station...
93 Renegade Planet Pair Defy ExplanationA pair of celestial objects circling one another have fed a growing debate over the dividing line between planets and stars...
96 Strange Swirls Spotted at Venus's PoleVenus is Earth's near-twin in size and mass, yet bafflingly different in other particulars...
100 Saturn SunburstThe Cassini spacecraft captured an extraordinary backlit image of Saturn and its gossamer rings...
it is... science!
it is.... science!
World's Biggest Binoculars
Astronomers open a new window onto the universe. 12.11.2006
One Giant Step for a Small, Crowded Country
Are the Japanese moving to the moon? 11.28.2006
A Death in the Solar System
Say good-bye to the old nine planets. Say hello to a whole new celestial family. 11.27.2006
Map: Space Junk
Garbage zipping through space could shatter a spececraft or crash into Earth. 11.16.2006
Did Life Begin In Space?
Interstellar organic molecules suggest that Earth may have been seeded by the cosmos. 11.9.2006
Mars Exposed
With the new Mars Reconnaissance Orbiter zeroing in on its target, NASA scientists prepare for an unprecedented look at the Red Planet's ancient seas and modern ice fields—key sites in the ongoing search for life. 10.10.2006
Mars Exposed
An unprecedented look at the Red Planet's ancient seas and modern ice fields. 10.1.2006
The Buzz on NASA
The Apollo 11 pioneer charts a radical course back into space. 9.13.2006
The Future of NASA
Michael Griffin is gearing NASA up to build a moon base. Is he paving the way to Mars or jeopardizing the future of American space exploration? 9.1.2006
Map: X-Ray Vision Shows How a Galaxy Cluster Grows
New X-ray data unveils the dynamics of galaxy cluster Abell 3266. 9.1.2006
Fossils of the First Life
New fossil analysis puts the beginning of life more than 3.4 billion years ago. 9.1.2006
Sky Lights: Confused About Your Direction?
If you lack a sense of personal trajectory, astronomers can help. 9.1.2006
Blinded by Science: Hawking's Exit Strategy
Why is one of the thinking community's heavy hitters dabbling in doomsday prophecy? 9.1.2006
Map: Earth's Fourth Dimension
A gravitational rainbow points to our planet's invisible topography. 8.14.2006
20 Things You Didn't Know About... Meteors
The Perseids may be a washout this year, but that's no excuse to ignore valuable news about X-ray slaps, the Tears of St. Lawrence, and the fiddly meteor/meteoroid/asteroid/meteorite distinction.
World's Biggest Binoculars
Astronomers open a new window onto the universe. 12.11.2006
One Giant Step for a Small, Crowded Country
Are the Japanese moving to the moon? 11.28.2006
A Death in the Solar System
Say good-bye to the old nine planets. Say hello to a whole new celestial family. 11.27.2006
Map: Space Junk
Garbage zipping through space could shatter a spececraft or crash into Earth. 11.16.2006
Did Life Begin In Space?
Interstellar organic molecules suggest that Earth may have been seeded by the cosmos. 11.9.2006
Mars Exposed
With the new Mars Reconnaissance Orbiter zeroing in on its target, NASA scientists prepare for an unprecedented look at the Red Planet's ancient seas and modern ice fields—key sites in the ongoing search for life. 10.10.2006
Mars Exposed
An unprecedented look at the Red Planet's ancient seas and modern ice fields. 10.1.2006
The Buzz on NASA
The Apollo 11 pioneer charts a radical course back into space. 9.13.2006
The Future of NASA
Michael Griffin is gearing NASA up to build a moon base. Is he paving the way to Mars or jeopardizing the future of American space exploration? 9.1.2006
Map: X-Ray Vision Shows How a Galaxy Cluster Grows
New X-ray data unveils the dynamics of galaxy cluster Abell 3266. 9.1.2006
Fossils of the First Life
New fossil analysis puts the beginning of life more than 3.4 billion years ago. 9.1.2006
Sky Lights: Confused About Your Direction?
If you lack a sense of personal trajectory, astronomers can help. 9.1.2006
Blinded by Science: Hawking's Exit Strategy
Why is one of the thinking community's heavy hitters dabbling in doomsday prophecy? 9.1.2006
Map: Earth's Fourth Dimension
A gravitational rainbow points to our planet's invisible topography. 8.14.2006
20 Things You Didn't Know About... Meteors
The Perseids may be a washout this year, but that's no excuse to ignore valuable news about X-ray slaps, the Tears of St. Lawrence, and the fiddly meteor/meteoroid/asteroid/meteorite distinction.
The God Experiments
The God Experiments
Five researchers take science where it's never gone before.
by John Horgan -->
Three years ago, the British evolutionary biologist Richard Dawkins became a guinea pig in an experiment. Neuroscientist Michael Persinger claimed he had induced religious experiences in subjects by stimulating specific regions of their brains with electromagnetic pulses. Dawkins, renowned for his biological theories as well as for his criticism of religion, volunteered to test Persinger's electromagnetic device—the "God machine," as some journalists dubbed it. "I've always been curious to know what it would be like to have a mystical experience," Dawkins said shortly before the experiment. Afterward, he admitted on BBC that he was "very disappointed" that he did not experience "communion with the universe" or some other spiritual sensation.
Many researchers, like Persinger, view the brain as the key to understanding religion. Others focus on psychological, genetic, and biochemical origins. The science of religion has historical precedents, with Sigmund Freud and William James addressing the topic early in the last century. Now modern researchers are applying brain scans, genetic probes, and other potent instruments as they attempt to locate the physiological causes of religious experience, characterize its effects, perhaps replicate it, and perhaps even begin to explain its abiding influence.
The endeavor is controversial, stretching science to its limits. Religion is arguably the most complex manifestation of the most complex phenomenon known to science, the human mind. Religion's dimensions range from the intensely personal to the cultural and political. Additionally, researchers come to study religious experiences with very different motives and assumptions. Some of them hope that their studies will inform and enrich faith. Others see religion as an embarrassing relic of our past, and they want to explain it away.
"Even when the neural basis of religion has been identified, it remains a plausible interpretation of any conceivable neuropsychological facts that there is a genuine experience of God," notes Fraser Watts, a psychologist and theologian at the University of Cambridge and an Anglican vicar. A major funder of research on religion is the John Templeton Foundation, started in 1987 by the Christian financier John Templeton to promote "collaboration" between science and religion.
The theories described below illustrate the diversity of scientific approaches to understanding religion. All these theories are tentative at best, and some will almost certainly turn out to be wrong. The field suffers from vague terminology, disagreement about what exactly "religion" is, and which of its aspects are most important. Does religion consist primarily of behaviors, such as attending church or following certain moral precepts? Or does it consist of beliefs—in God or in an afterlife? Is religion best studied as a set of experiences, such as the inchoate feelings of connection to the rest of nature that can occur during prayer or meditation? Comparing studies is often an exercise in comparing apples and oranges. Nonetheless, the science merits close attention.
Inventing God
Stewart Guthrie, an anthropologist at Fordham University in New York, is in the explain-it-away camp of researchers. Noting the plethora of gods that populate the world's religions, many with minds and emotions similar to our own, Guthrie argues that the belief in supernatural beings is a result of an illusion that arises from our tendency to project human qualities onto the world. Religion "may be best understood as systematic anthropomorphism," he writes in his book, Faces in the Clouds.
Anthropomorphism is an adaptive trait that enhanced our ancestors' chances of survival, he adds. If a Neanderthal mistook a tree creaking outside his cave for a human assailant, he suffered no adverse consequences beyond a moment's panic. If the Neanderthal made the opposite error—mistaking an assailant for a tree—the consequences might have been dire. In other words, better safe than sorry. Over millennia, as natural selection bolstered our unconscious anthropomorphic tendencies, they reached beyond specific objects and events to encompass all of nature, goes Guthrie's theory, until we persuaded ourselves that "the entire world of our experience is merely a show staged by some master dramatist."
Humans are not alone in this trait. In The Descent of Man, Charles Darwin noted that many "higher mammals" share the human propensity "to imagine that natural objects and agencies are animated by spiritual or living essences." As an example, he recalled watching his dog growl at a parasol lifted off the ground by a gust of wind.
Andrew Newberg, a neuroscientist at the University of Pennsylvania, has focused on the tendency of people from different religious traditions to report similar mystical experiences, which typically involve sensations of self-transcendence and "oneness." These commonalities indicate that the visions stem from the same neural processes, Newberg hypothesizes. To test his theory, Newberg has scanned the brains of more than 20 adherents of spiritual practices, including Christian prayer and Tibetan Buddhist meditation. He uses a technique called single-photon-emission-computed tomography, or SPECT, a variant of the better-known positron-emission tomography, PET.
The chief advantage of SPECT is that it can capture the brains of meditators in a relatively natural setting. The subject meditates not in the SPECT chamber itself but in a separate room. When a subject—a Franciscan nun, in one case—feels her ordinary self "dissolving into Christ consciousness," as she describes it, a radioactive fluid is injected into her body through an intravenous tube; the fluid travels to her brain and becomes trapped in nerve cells there. The nun then goes to the SPECT chamber, where a computer-controlled camera scans her brain. The resulting image reveals levels of neural activity in the moment immediately after she received the radioactive fluid, when she presumably was still immersed in contemplation.
Next Page » [1] 2 3
Five researchers take science where it's never gone before.
by John Horgan -->
Three years ago, the British evolutionary biologist Richard Dawkins became a guinea pig in an experiment. Neuroscientist Michael Persinger claimed he had induced religious experiences in subjects by stimulating specific regions of their brains with electromagnetic pulses. Dawkins, renowned for his biological theories as well as for his criticism of religion, volunteered to test Persinger's electromagnetic device—the "God machine," as some journalists dubbed it. "I've always been curious to know what it would be like to have a mystical experience," Dawkins said shortly before the experiment. Afterward, he admitted on BBC that he was "very disappointed" that he did not experience "communion with the universe" or some other spiritual sensation.
Many researchers, like Persinger, view the brain as the key to understanding religion. Others focus on psychological, genetic, and biochemical origins. The science of religion has historical precedents, with Sigmund Freud and William James addressing the topic early in the last century. Now modern researchers are applying brain scans, genetic probes, and other potent instruments as they attempt to locate the physiological causes of religious experience, characterize its effects, perhaps replicate it, and perhaps even begin to explain its abiding influence.
The endeavor is controversial, stretching science to its limits. Religion is arguably the most complex manifestation of the most complex phenomenon known to science, the human mind. Religion's dimensions range from the intensely personal to the cultural and political. Additionally, researchers come to study religious experiences with very different motives and assumptions. Some of them hope that their studies will inform and enrich faith. Others see religion as an embarrassing relic of our past, and they want to explain it away.
"Even when the neural basis of religion has been identified, it remains a plausible interpretation of any conceivable neuropsychological facts that there is a genuine experience of God," notes Fraser Watts, a psychologist and theologian at the University of Cambridge and an Anglican vicar. A major funder of research on religion is the John Templeton Foundation, started in 1987 by the Christian financier John Templeton to promote "collaboration" between science and religion.
The theories described below illustrate the diversity of scientific approaches to understanding religion. All these theories are tentative at best, and some will almost certainly turn out to be wrong. The field suffers from vague terminology, disagreement about what exactly "religion" is, and which of its aspects are most important. Does religion consist primarily of behaviors, such as attending church or following certain moral precepts? Or does it consist of beliefs—in God or in an afterlife? Is religion best studied as a set of experiences, such as the inchoate feelings of connection to the rest of nature that can occur during prayer or meditation? Comparing studies is often an exercise in comparing apples and oranges. Nonetheless, the science merits close attention.
Inventing God
Stewart Guthrie, an anthropologist at Fordham University in New York, is in the explain-it-away camp of researchers. Noting the plethora of gods that populate the world's religions, many with minds and emotions similar to our own, Guthrie argues that the belief in supernatural beings is a result of an illusion that arises from our tendency to project human qualities onto the world. Religion "may be best understood as systematic anthropomorphism," he writes in his book, Faces in the Clouds.
Anthropomorphism is an adaptive trait that enhanced our ancestors' chances of survival, he adds. If a Neanderthal mistook a tree creaking outside his cave for a human assailant, he suffered no adverse consequences beyond a moment's panic. If the Neanderthal made the opposite error—mistaking an assailant for a tree—the consequences might have been dire. In other words, better safe than sorry. Over millennia, as natural selection bolstered our unconscious anthropomorphic tendencies, they reached beyond specific objects and events to encompass all of nature, goes Guthrie's theory, until we persuaded ourselves that "the entire world of our experience is merely a show staged by some master dramatist."
Humans are not alone in this trait. In The Descent of Man, Charles Darwin noted that many "higher mammals" share the human propensity "to imagine that natural objects and agencies are animated by spiritual or living essences." As an example, he recalled watching his dog growl at a parasol lifted off the ground by a gust of wind.
Andrew Newberg, a neuroscientist at the University of Pennsylvania, has focused on the tendency of people from different religious traditions to report similar mystical experiences, which typically involve sensations of self-transcendence and "oneness." These commonalities indicate that the visions stem from the same neural processes, Newberg hypothesizes. To test his theory, Newberg has scanned the brains of more than 20 adherents of spiritual practices, including Christian prayer and Tibetan Buddhist meditation. He uses a technique called single-photon-emission-computed tomography, or SPECT, a variant of the better-known positron-emission tomography, PET.
The chief advantage of SPECT is that it can capture the brains of meditators in a relatively natural setting. The subject meditates not in the SPECT chamber itself but in a separate room. When a subject—a Franciscan nun, in one case—feels her ordinary self "dissolving into Christ consciousness," as she describes it, a radioactive fluid is injected into her body through an intravenous tube; the fluid travels to her brain and becomes trapped in nerve cells there. The nun then goes to the SPECT chamber, where a computer-controlled camera scans her brain. The resulting image reveals levels of neural activity in the moment immediately after she received the radioactive fluid, when she presumably was still immersed in contemplation.
Next Page » [1] 2 3
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