Tuesday, May 13, 2008
A laser-generated optical comb might sound like something Flash Gordon would use to straighten his hair. It's actually a super precise measuring device, able to find the frequency of radiation more accurately than any other method. That might sound less exciting than a new kind of paint-dryer, but has applications in little things like the measurement of time, probing the fundamental constants of the universe, and finding other planets. You know, small stuff.
Every light source, radio signal or cosmic ray we encounter has a frequency - find the frequency and you have information about the radiation. Electronics can accurately measure these up to about a hundred gigahertz, (100,000,000,000 cycles per second!) which sounds like a lot - but some critical sources go up into the hundreds of Terahertz, a thousand times higher and more. There's a quick trick to simplify the problem: instead of measuring the absolute frequency of a source you can measure the frequency difference with a known reference - combining the two creates "beats", a musically-monickered phenomenon with a frequency equal to the difference of the two component parts. So if we had a source of known frequencies close to what we want to measure, this "beat frequency" can be small enough to be measured by regular electronics.
This is where the optical frequency comb comes in. By setting up a laser cavity very carefully, mode-locking conditions mean that only certain regular frequencies can circulate - the fundamental, and the harmonics which are twice that, three times that, and onwards up. This is where the idea of the comb as a "ruler" comes from - a series of regular markings in frequency, just like your ruler has little ink markings at known intervals of distance. It's also where the "comb" comes from - a plot of frequencies output is a series of spikes separated by narrow gaps, looking just like the classic Fonz-favored hair-straightener. Combine your comb with a photodiode and the right electronic gadgetry and you can measure high frequencies with unprecedented precision.
This is nothing particularly new - optical combs have been a very active field since Halls and Hänsch won a little thing called the Nobel Prize for work on the technique in 2005. More recently, researchers at the University of Konstanz and the National Institute of Science and Technology have developed an ultra-small, ultra-accurate comb which could even be used in space. This would help satellite telescopes in the search for exoplanets.
If you tell somebody a planet is a hard thing to spot, they might look at you funny - unless they're an astronomer. Planets (small, rock, don't emit light) tend to hang out near stars (gigantic, fusion reactors, emit light pretty much by definition) and can be hard to make out, especially since the only light they emit is reflected from the parent star (the gigantic mega-bright source of the exact same radiation). We do have one chance - as the planet orbits, the frequencies reflected get shifted up and down around the original value by the Doppler shift (just as ambulance sirens get higher then lower as they shoot past you in the street). The problem so far has been that these frequency shifts are orders of magnitude below what we can resolve - until the new super-miniature comb, built by Albrecht Bartels at the Konstanz Center for Applied Photonics, gets in on the action.
So, when you think combs are just for picking the imperfections out of your coiffure (or making truly terrible noise with a sheet of wax paper), remember that high-tech hardware is combing the universe for alien worlds.
Posted by Luke McKinney.
Optical comb smaller than a real comb http://www.physorg.com/news129217511.html2005 Nobel Prize http://nobelprize.org/nobel_prizes/physics/laureates/200
Compton Gamma Ray Observatory equipment helps to sniff out radioactive sources.
The 9-year mission of NASA’s Compton Gamma Ray Observatory ended in 2000 with a plunge into the Pacific Ocean. But its spare parts are living on — as a detector of dirty bombs.
James Ryan, an astrophysicist at the University of New Hampshire in Durham, has recycled parts from one of the space telescope’s old instruments, realizing that they can work just as well pointing horizontally as they did vertically up into the heavens.
The telescope once spotted gamma rays streaming from radioactive elements in the sky. Now its technology is being used to detect gamma rays emitted by radioactive substances, such as plutonium, uranium and caesium, which could be used in dirty bombs combining conventional explosives with radioactive material.
“If we can detect aluminum 26 on the other side of the galaxy, we can detect this stuff on the other side of the street,” says Ryan, who will present results from a prototype detector on Monday in Boston at a conference sponsored by the Institute of Electrical and Electronics Engineers and the US Department of Homeland Security.
There are many techniques for spotting radioactive materials. Some sensors pick up neutrons spat out by radioactive atoms. This technique is very sensitive — neutrons cannot be shielded by lead or concrete walls — but somewhat non-discriminatory.
Gamma rays, although they can be shielded, are emitted with specific energies depending on their parent nuclei, thus providing a potential fingerprint of the radioactive material (although it can still be difficult to tell one thing from another, including, bizarrely, cat litter and uranium; see 'The quest for a finer gamma ray detector').
Many commercial gamma-ray detectors, however, can’t detect the direction of a source. Directionality is particularly useful, for example, if scanning rows of shipping containers rather than single trucks at border crossings, or when tracking a dirty bomb. Ryan recalls watching a US National Guard field exercise in Cape Cod, Massachusetts, as the soldiers struggled to track down a radioactive source in a building, as if they were playing a game of Hot and Cold. “I said, ‘Good grief, that’s a piece of cake. I can spot that a block away’,” Ryan says.
He went back to his lab and dusted off the spare instruments from the Compton Observatory that he had kept since its launch.
Pinpointing the source
The Compton device detects light emitted by electron scattering, caused by gamma rays hitting two layers in the instrument. These two detections allow a user to track the direction of the incoming rays. Ryan says that, from a distance of 10 metres, he can pinpoint a source like caesium to within a third of a metre from side-to-side.
“It’ll work, but it’s not optimal, given the fact it’s so dated,” says Nick Mascarenhas, a physicist at Sandia National Laboratory in Livermore, California, who is building his own directional radiation detector. “It’s probably going to have limitations.”
Even if the nearly 20-year-old Compton telescope technology isn’t the best available kit to turn into a commercial bomb-sniffing tool, homeland security is certainly benefiting by learning from, or borrowing, astrophysical tools that can 'image' the location of radioactive sources, rather than just detecting their presence. “We’re showing that imaging has very powerful advantages,” says Mascarenhas.
Mascarenhas is building a neutron detector that also relies on an astrophysical device — a detector that was first flown in high-altitude balloons to look for neutrons coming from the Sun. It also has directional capabilities, which makes it easier to filter out background radiation - whether from trace uranium and thorium in rock in the ground, or background radiation in the sky. The signal of interest can thus be isolated in a shorter amount of time, he says.
Steve Ahlen, an astrophysicist a Boston University in Massachusetts, says that it is natural that approaches in high-energy physics and astrophysics trickle down into security applications.
Ahlen himself is working on a 30-centimetre cube full of carbon tetrafluoride gas, originally designed to seek elusive dark-matter particles. He realized that by adding helium, his cube could also hunt for neutrons. Now he’s getting funding from the Department of Homeland Security, for a device with two applications: “I really believe it’s the world’s best neutron detector,” he says.
The possible victim is a young woman who seems to have been buried alive, said Ana Maria Groot, one of the lead anthropologists from the National University of Colombia working at the site.
"Her mouth is open as if in terror, and her hands seem contracted as if she had tried grabbing hold of something," Groot said.
Another tomb contains the remains of a man with a curved tibia, or shinbone, possible evidence that the man was a shaman, she added.
Spanish observers in the 1500s wrote of indigenous shamans spending long periods in caves with no exposure to sunlight. A lack of sunlight would produce a shortage of vitamin D, causing curving of the bones, explained Groot's colleague, Virgilio Becerra.
Two Mysterious Cultures
Aside from such unusual finds, the site is unique for its age and length of occupation, the anthropologists say.
The tombs range in date from around the first century to the 16th century A.D., based on analysis of pottery found with the remains.
The first 500 years of the site's use date to the so-called Herrera period, when several small, obscure groups thrived in this region of the Andean highlands during the development of agriculture.
"The agriculture became more intensive, more systematic at this time," Groot said.
"We have high expectations about finding what kinds of plants they cultivated."
From around A.D. 500 to 1500, the site seems to have been occupied by the Muisca, another culture that is one of Colombia's most important but least understood civilizations, Groot said. Rife with artifacts from both periods, the Usme site is a potential treasure trove of information, she added.
"A settlement like Usme offers the chance to research the settlement's development through different moments in a prolonged occupation," she said.
"We can identify those changes as expressed in their cultural practices."
Ongoing analysis should reveal more about life expectancy, diet, disease, and other aspects of daily life and social organization in the settlement, Groot added.
Temple Site and Other Discoveries
Anthropologists also found ruins of a human settlement next to the burial site, including what may be evidence of a temple. Holes for posts suggest a large circular structure, Groot said.
Pottery found with the remains mostly includes fragments of decorative and simple pitchers, cooking pots, and cups.
The decorative pitchers combine geometric designs with images of animals such as frogs, birds, and snakes.
Researchers also found stones for grating or cutting vegetables and for grinding grain, though no evidence of the settlers' diet has yet been determined.
Local authorities are considering making the site into a museum.
Excavation began in January and will continue while anthropologists await results from radiocarbon sampling of human bones and other objects to determine their ages.
Guillermo Cock is an archaeologist and Andean expert whose work has been partly funded by the National Geographic Society, which operates National Geographic News.
He cautioned that apparent evidence of human sacrifice seen at Usme likely has other origins.
In the case of the young woman who looks to have been buried alive, her contracted hands may be explained by early arthritis, he said.
Likewise, her opened jaw may be the result of the body having been moved before or after burial, he said.
Nonetheless, the Usme site should prove "invaluable" to science, said Cock, whose work has helped unearth burial sites with thousands of tombs in Peru.
(Read related story; "Dozens of Inca Mummies Discovered Buried in Peru" [March 11, 2004].)
"Conservation [of graves and other archaeological material] in Colombia and Venezuela tends to be poor because of the soil's humidity, which quickly destroys organic remains," Cock said.
"If the period that each tomb belongs to can be identified, even if they are in a poor state, it would be an invaluable amount of information about this Muisca population."
Captive cheetahs are being besieged by amyloid deposits and fibrils (bottom panels, respectively) in their livers.
Credit: Yumi Une/National Academy of Sciences, PNAS (2008)
Although famously speedy, cheetahs can't seem to outrun a deadly disease called amyloid A (AA) amyloidosis. The illness kills up to 70% of the cats in captivity and has frustrated breeding efforts. In a new study, researchers provide the first compelling evidence that may explain how the disease is transmitted.
AA amyloidosis resembles mad cow disease. Like mad cow disease, a misfolded version of a protein--in this case amyloid A--converts normal proteins into abnormal ones, a process that snowballs into large deposits of damaging protein in tissues such as the spleen and liver. (The mad cow protein does most of its damage in the brain and central nervous system.) Animals often die of kidney failure, and the incidence of AA amyloidosis has spiked from 20% to 70% of captive cheetahs since the 1980s.
AA amyloidosis is not caused by a bacteria or virus, yet there's reason to suspect that it can spread from animal to animal like an infectious disease. Both mad cow disease and scrapie--a related disease in sheep--appear to be contagious. And when captive cheetahs are kept in small enclosures close together, AA amyloidosis strikes younger animals and with more severity, a finding that supports the contagion hypothesis. Yet biologists have been hard-pressed to figure out how the disease moves from cat to cat.
To examine potential routes of transmission, Keiichi Higuchi, a biologist at Shinshu University in Matsumoto, Japan, and colleagues isolated the AA protein from diseased animals' livers. From the protein, the researchers were able to develop a fluorescent tag that, in further experiments, picked up the AA protein in feces of diseased cheetahs. The find supports previous studies that had flagged feces as a possible infection route for similar diseases in deer and mice. What's more, the AA protein in the feces was more transmissible and more effective in inducing the disease in mice than the protein isolated from the liver, possibly due to its smaller size and greater instability, the researchers report online today in the Proceedings of the National Academy of Sciences.
It's still unclear how captive cheetahs come into contact with each other's feces. Higuchi's team suspects that this may happen when the cats lick their fur while grooming or when they eat food that has touched contaminated soil. Based on their finding, the researchers suggest that zoos or captive-breeding colonies can limit the spread of AA amyloidosis by removing feces as soon as possible or by keeping the animals' food separated from areas that have come into contact with feces. "These results provide possible measures for rescuing cheetahs from extinction," says Higuchi. There are only about 12,500 cheetahs alive on the planet today, he notes, so any cheetah death is a blow to the species' chance of survival.
Sarah Durant, a conservation biologist at the Zoological Society of London and the U.S.–based Wildlife Conservation Society, says limiting the spread of AA amyloidosis among captive animals is a good strategy. Although the disease is unlikely to affect free-roaming cheetahs, she says that conquering it in captivity could raise awareness of the plight of wild cheetahs.
A robotic system designed to care for millions of biological samples in sub-zero temperatures has been chosen as a finalist for a top engineering award.
The Polar system is already used at the UK Biobank, a facility that aims to shed light on debilitating diseases.
The robot system will guard 10 million human blood and fluid samples at -80C for 25 years, whilst also allowing scientists to access them at any time.
It is one of four finalists which will compete for the annual MacRobert award.
The prize is given out by the UK's Royal Academy of Engineering for technological and engineering innovation.
The other finalists are the first commercially available bionic hand, an advanced filter to remove soot from diesel engines and a tiny silicon sensor which can detect explosives or toxic chemicals.
The Polar system, designed by the Automation Partnership, consists of a series of ultra-low temperature compartments designed to hold blood and urine samples, which can be accessed automatically by robotic arms.
A US defence agency has recently placed an order for the sensors
The liquid-nitrogen cooled store has been designed so that researchers do not have to enter a refrigerated area to retrieve or load samples.
It has been used by pharmaceutical companies as well as the UK Biobank, a medical research facility which intends to collect samples and data from more than 500,000 volunteers.
This will be used as tool by researchers investigating a range of life-threatening illnesses including cancer, heart disease and diabetes.
It already contains data from more than 100,000 volunteers.
It is one of three technologies with potential medical benefits that have been picked as finalists for this year's awards.
A novel kind of chemical sensor, designed by Owlstone, a spin-out of Cambridge University, also has therapeutic uses.
The chemical chips are able to detect trace amounts of a wide variety of chemicals using a patented technique called Field Asymmetric Ion Mass Spectroscopy (FAIMS).
It fingerprints compounds by analysing how their charged forms move through a gas when subjected to electric fields. Each substance has its own characteristic signature.
The sensor can be reprogrammed to look for different chemical fingerprints, such as those found in pre combustion fumes during the initial stages of a fire.
However, one potential use is as a "breathalyser" to detect and diagnose illness by analysing chemicals on a patient's breath.
It is known that asthma sufferers, those with cystic fibrosis and some forms of cancer breathe out chemical markers of their condition.
The third medical technology selected by a panel of judges was the i-LIMB hand, a prosthetic device with five individually powered digits.
The firm has previously won a MacRobert Award for its filters
The design started life in 1963 when researchers at Edinburgh's Princess Margaret Rose Hospital proposed a design to help children affected by Thalidomide.
It has taken more than 40 years to build a commercial product.
"Since we launched it in July 2007 over 200 patients have been fitted with it all over the world," said Stuart Mead, chief executive of the firm.
One of the first patients to be fitted with a device was Donald McKillop who had to have his right hand amputated after complications following an accident.
"The most important thing is the movement of the fingers, that's what really makes the difference," he said. "It's truly incredible to see the fingers moving and gripping around objects that I haven't been able to pick up before."
The final contender for the prize is a compact, soot filter for diesel cars, designed by engineers at Johnson Matthey.
The design uses heat from the engine to control hydrocarbon, carbon monoxide as well as soot emissions. It improves the efficiency of filters fitted inside the lower temperature exhaust.
"We have already exported over 1.5 million of these filters for use in European cars ahead of new emissions control legislation which comes into force from 2009", Dr Martyn Twigg of the firm. "These alone will stop millions kilograms of soot entering the atmosphere over the life of these vehicles."
The firm has previously won a MacRobert award for technology used to control soot emissions from trucks and buses.The team will find out if it is a winner again - along with the other finalists - at a ceremony in London on 9 June.
Imagine my delight at discovering an absolutely epic experiment to turn your household vacuum cleaner into a bazooka. Word. Yay kids, this is where science helps you to shoot your friends in the gonads.
What You Will Need
Vacuum cleaner, Cardboard tubes (of similar size to vacuum tube), some duct tape, bubble wrap and play-dough or dowel.mages compiled from 1, 2, 3 and own photo
Also see first Image for the following steps.
1. First you will need to create the T, which is the attachment to the vacuum tube and the horizontal pipe, essential for firing your projectile. To do this, cut about ten centimeters off your cardboard tube and shape the short tube nicely so that it will hug the horizontal one.
2. Cut a hole or a series of holes 5cm away from the end and place the smaller piece of tube directly over them. You will then need to seal the T using duct tape. Make sure no air escapes – otherwise - epic fail.
3. Then attach the vacuum hose to the short tube, again using duct tape and ensuring that no air escapes.
4. Now onto the projectile. Depending on how much of a psycho you are, you can either make it out of a dowel or bubble wrap. There are two different methods here:
If you are using a dowel, make sure that it fits in snuggly: too small and it won’t fly out and too large will result in friction. If it is too large you may have to sand it, but then you’re really trying too hard.
With the bubble wrap size isn’t too much of a problem, as you can basically create it as large as you like. To do so, roll a sausage of play-dough and then carefully wrap the bubble wrap cylindrically around it. To keep it in place, tape together.
5. Now for the fun part:
i. Turn on the vacuum cleaner
ii. Hold a piece of paper over the front end.
iii. Release a projectile from the back
iv. The projectile flies out at mega speed in a very satisfying way. It can reach between 30-40 feet.
You can see a video here of the bazoka in action, or below is a video of a much more powerful vacuum-powered bazooka being tested in Japan:
So, what’s the science behind this?
The bazooka works very much like a straw. Depending on how powerful your vacuum cleaner is, it can suck out between 10-20% of the air inside the tube, which although doesn’t sound like much, creates a huge difference between the high pressure of the air outside and the low air pressure inside. The force is strong enough for the projectile to move rapidly down the tube and knock the card off.
Ok, but how is this related to the environment?
The experiment illustrates low pressure incredibly well, which can be a deadly element in weather systems. Low pressure systems generally bring rain, cyclones or hurricanes. Perhaps the best analogy would be that like the vacuum powered bazooka, tornadoes suck up debris in much the same way that the vacuum bazooka fires projectiles.
The government seeks to reverse a lower court ruling that allowed Kansas-based Creekstone Farms Premium Beef to conduct more comprehensive testing to satisfy demand from overseas customers in Japan and elsewhere.
Less than 1% of slaughtered cows are tested for the disease under Agriculture Department guidelines. The agency argues that widespread testing does not guarantee food safety and could result in a false positive that scares consumers.
"They want to create false assurances," Justice Department attorney Eric Flesig-Greene told a three-judge panel of the U.S. Court of Appeals for the D.C. Circuit.
But Creekstone attorney Russell Frye contended that the Agriculture Department's regulations covering the treatment of domestic animals contain no prohibition against an individual company testing for mad cow disease, because the test is conducted only after a cow is slaughtered. He said the agency has no authority to prevent companies from using the test to reassure customers.
"This is the government telling the consumers, 'You're not entitled to this information,"' Frye said.
Chief Judge David Sentelle seemed to agree with Creekstone's contention that the additional testing would not interfere with agency regulations governing the treatment of animals.
"All they want to do is create information," Sentelle said, noting that it's up to consumers to decide how to interpret the information.
Larger meatpackers have opposed Creekstone's push to allow wider testing out of fear that consumer pressure would force them to begin testing all animals too. Increased testing would raise the price of meat by a few cents per pound.
Mad cow disease, or bovine spongiform encephalopathy, can be fatal to humans who eat tainted beef. Three cases of mad cow disease have been discovered in the U.S. since 2003.
The district court's ruling last year in favor of Creekstone was supposed to take effect June 1, 2007, but the Agriculture Department's appeal has delayed the testing so far.
It was an embarrassing admission for Brazil's president, Luiz Inacio Lula da Silva, who had said his government's efforts to control illegal logging and introduce better certification of land ownership were working.
The figures also focussed attention on the fate of the Amazon rainforest, raising the question of whether the region can be economically developed without being destroyed.
"Deforestation is linked to economic factors," says Paulo Barreto, senior researcher at Imazon, a non-governmental organisation, in his offices in Belem, the capital of the Amazonian state of Para.
"Seventy-five per cent of the deforestation in the Amazon is to create cattle pasture," says Mr Barreto.
"Brazil has become over the last five years the world's leading beef exporter. All the expansion of the cattle industry in the last few years has been in the Amazon."
This report is part of a BBC World Service special on the Amazon rainforest.
There will be a series of live and recorded broadcasts starting at 0500GMT on Thursday 15 May.
Highlights will include a double edition of Newshour, presented live from three locations in Brazil at 1200 and a one hour special at 1600.
As demand for beef and soybeans grow in the rapidly growing economies of Asia, in particular China, many observers fear the pressure on the rainforest will continue.
The Brazilian federal government was sufficiently worried about the recorded 2007 rise in deforestation to launch a large police operation in February. Thousands of officers were sent to some of the worst-hit areas to tackle illegal logging, closing down sawmills and issuing fines.
But some say such operations fail to address endemic problems of the region.
"Fraud in the land registry system is a big problem." says Paulo Barretto.
"Collecting fines for deforestation are at very low levels. The environment ministry thinks the psychological impact of receiving a fine will be enough, but they are never collected. "
But with Brazil's increasingly important role on the world stage as a major agricultural power, a new pragmatism is emerging.
Some projections suggest that 40% of the forest could be lost by 2050
"We will have to discuss environmental sustainability in the Amazon in a new way, " said Brazilian environmentalist and former congressman Fabio Feldman in a debate in early April on Globo TV.
"The Amazon is providing environmental services for the world and we must find a mechanism which can compensate agribusiness so that they do not deforest."
In the state of Amazonas, which has suffered much less deforestation than some other parts of the region, the authorities are launching a scheme which could hold the key to solving the paradox of how you marry economic development and environmentalism.
Under the scheme, in return for around $30 a month, families are asked to protect the environment and endangered animals and fish, and not to sell wood.
The scheme is initially for families in local conservation areas but could be rolled out further afield. The plan is also being looked at with interest by other Amazonian countries in the region.
The Amazon rainforest
Largest continuous tropical forest
Shared by nine countries
65% Brazilian territory
Covers 6.6m sq km in total
Pop: 30m - 23.5m are in Brazil
Elsewhere in the Amazon region international concerns are pushing farmers and producers to take into account the environment in a new way as they seek international lines of credit to modernise and become more efficient.
"Brazil has plenty of abandoned land that could be put to good use instead of cutting down the rainforest, " says Erai Maggi, one of the world's biggest soya farmers with lands in the south of Mato Grosso state.
"We need better infrastructure here, then we could become even more efficient and help improve world food stocks which are at a 30-year low. Currently to export we have to take our soya 3,000km down a bad highway to the ports in the south of the country."
Far to the south in, the capital Brasilia, the federal government has come up with more ambitious proposals, including the controversial creation of an economic zoning plan.
Brazil may divide the Amazon into regions of different economic activities
This would divide the Amazon is divided into regions of different economic activities.
All this would take time. Meanwhile, the Brazilian government's space research institute, INPE, has been developing satellite surveillance systems that show month by month pictures of deforestation which in theory should make it easier to catch the perpetrators of environmental crimes and help slow deforestation rates.
Nevertheless, future scenarios for the Amazon still look dire.
Pessimistic projections suggest that if the current rate of deforestation continues, with little policing or punishment for deforesters, 40% of the forest will be gone by the year 2050.
If the government makes its conservation areas work and punishes deforestation, as well as investing in reforestation and the re-use of areas already stripped of their forest this figure could be reduced to a loss of only 27%.
At the very best with good projects to reduce deforestation and paying people not to cut forest, Brazil might be able to keep the loss down to 20%.
Study: With locked crust, Earth could become another Venus
HOUSTON, May 12, 2008 -- A new study of possible links between climate and geophysics on Earth and similar planets finds that prolonged heating of the atmosphere can shut down plate tectonics and cause a planet's crust to become locked in place.
"The heat required goes far beyond anything we expect from human-induced climate change, but things like volcanic activity and changes in the sun's luminosity could lead to this level of heating," said lead author Adrian Lenardic, associate professor of Earth science at Rice University. "Our goal was to establish an upper limit of naturally generated climate variation beyond which the entire solid planet would respond."
Lenardic said the research team wanted to better understand the differences between the Earth and Venus and establish the potential range of conditions that could exist on Earth-like planets beyond the solar system. The team includes Lenardic and co-authors Mark Jellinek of the University of British Columbia in Vancouver and Louis Moresi of Monash University in Clayton, Australia. The research is available online from the journal Earth and Planetary Science Letters.
The findings may explain why Venus evolved differently from Earth. The two planets are close in size and geological makeup, but Venus' carbon dioxide-rich atmosphere is almost 100 times more dense than the Earth's and acts like a blanket. As a result, Venus' surface temperature is hotter than that of even Mercury, which is twice as close to the sun.
The Earth's crust -- along with carbon trapped on the oceans' floors -- gets returned to the interior of the Earth when free-floating sections of crust called tectonic plates slide beneath one another and return to the Earth's mantle. The mantle is a flowing layer of rock that extends from the planet's outer core, about 1,800 miles below the surface, to within about 30 miles of the surface, just below the crust.
"We found the Earth's plate tectonics could become unstable if the surface temperature rose by 100 degrees Fahrenheit or more for a few million years," Lenardic said. "The time period and the rise in temperatures, while drastic for humans, are not unreasonable on a geologic scale, particularly compared to what scientists previously thought would be required to affect a planet's geodynamics."
Conventional wisdom holds that plate tectonics is both stable and self-correcting, but that view relies on the assumption that excess heat from the Earth's mantle can efficiently escape through the crust. The stress generated by flowing mantle helps keep tectonic plates in motion, and the mantle can become less viscous if it heats up. The new findings show that prolonged heating of a planet's crust via rising atmospheric temperatures can heat the deep inside of the planet and shut down tectonic plate movement.
"We found a corresponding spike in volcanic activity could accompany the initial locking of the tectonic plates," Lenardic said. "This may explain the large percentage of volcanic plains that we find on Venus."
Venus' surface, which shows no outward signs of tectonic activity, is bone dry and heavily scarred with volcanoes. Scientists have long believed that Venus' crust, lacking water to help lubricate tectonic plate boundaries, is too rigid for active plate tectonics.
Lenardic said one of the most significant findings in the new study is that the atmospheric heating needed to shut down plate tectonics is considerably less than the critical temperature beyond which free water could exist on the Earth's surface.
"The water doesn't have to boil away for irrevocable heating to occur," Lenardic said. "The cycle of heating can be kicked off long before that happens. All that's required is enough prolonged surface heating to cause a feedback loop in the planet's mantle convection cycle."
The suit challenged the Environmental Protection Agency's 2006 decision to reauthorize the four pesticides used on fruit and vegetable fields in California.
A 1996 federal law required the EPA to reassess the safety of all pesticides used on foods. Based on this reassessment, the EPA was to decide whether to approve their use. The EPA found that four substances posed substantial risks to human health but they concluded that the cost savings to growers outweighed the dangers to humans.
These four pesticides reportedly put thousands of farm workers and their families at risk of serious illness.
EPA spokesman Tim Lyons stated that the agency would review the lawsuit and respond in court. However, they did say: "Our mission is to protect the environment and human health."
California officials have officially classified one of the pesticides (ethoprop) as a carcinogen. The state requires manufacturers to disclose this risk on any product label but cannot outright ban the pesticide because it has the EPA's approval. The suit said the pesticide, which is mainly used on potatoes, sugarcane, and tobacco, has been linked to fish deaths and has also begun to drift from fields into nearby rural communities.
Another pesticide (methidathion) has been listed as an air contaminant by the California Department of Pesticide Regulation due to the potential health hazards associated with it. This chemical is used on artichokes, oranges, almonds, peaches and olives in California.
The other two pesticides are methamidophos (used mostly on potatoes and cotton) and oxydemeton-methyl (used on broccoli, lettuce, cauliflower, corn, cabbage and Brussels sprouts). The suit stated that both have been associated with bird deaths. Methamidophos has been banned or severely restricted in several countries in recent years. Oxydemeton-methyl is now linked to birth defects.
The basis for the lawsuit is the EPA's own findings about the risks associated with these four pesticides.
Federal law allows the agency latitude to approve the continued use of risky pesticides such as these based on offsetting benefits. The main benefit preventing the EPA ban of these chemicals is, not surprisingly, cost savings. However, the EPA has failed to address the specific dangers each pesticide poses to children. It has also not taken into adequate account the potential adverse effects on farm workers or to wildlife.
The suit is seeking a court order requiring the agency to re-evaluate once again the use of these pesticides. Plaintiffs in the suit include the United Farm Workers, the Teamsters, Pesticide Action Network North America, Beyond Pesticides and the Natural Resources Defense Council.
Editor’s note: We’re pleased to welcome Max Gladwell, of MaxGladwell.com, as a regular guest writer on sustainablog. Max Gladwell covers the nexus of social media and green living. We feel that these two trends and technological developments hold tremendous promise for improving quality of life for everyone on the planet.
If you’re reading this blog, then you’re on board with social media. There’s a good chance you belong to social networks like Facebook or MySpace. It’s likely that you Digg stories and even possible that you Twitter. These technologies and services, together with a growing number of others, make up the social web. It’s much like the regular web, but more interactive. More…social. It invites and even demands active participation from everyone. It has a global reach with viral capacity, and yet it’s bringing local communities closer together. It enables people to connect, organize, and make a difference as never before. Indeed, social media is a powerful force, one that the world’s CEOs are starting to acknowledge and take seriously.
Many entrepreneurs, activists, and marketers are leveraging the social web for positive change. In the process and by its very nature, they are giving each of us the tools to change the world and make it a better place. There are thousands of examples, which is precisely why Max Gladwell exists. Here are 10 worth exploring.
1. Do-Good Widgets: If you’re Facebook page was a car, these would be your bumper stickers. Only these do more than spread the message. Widgets are standalone web applications that can run inside any web page. They take many forms, ranging from the absurd to the truly useful and socially valuable. The best ones engage us in ways that lead to action, awareness, and even fund-raising. Facebook was the first to offer them, and MySpace recently followed. Other social networks offer widgets, but these two have a scale that gives them unrivaled potential. Causes is the 800-pound gorilla in the do-good widget space with millions of daily active users on Facebook alone. If you support a cause, chances are you can find it in Causes. We support 14 ranging from “Recycle not Waste” to “Ride Bikes” and “GREEN“. Each Cause enables you to recruit others and make donations.
A new suite of widgets from Dank Apps called Social Change offers widgets for three main initiatives: Stop Climate Change Now, which raises funds for The Nature Conservancy; Earn For AIDS, which raises funds for the Clinton HIV/AIDS Initiative; and Earn for Breast Cancer, which raises funds for the Breast Cancer Research Foundation. Each of these allows you to send karma points to friends and play games, all of which generate donations from sponsors.
I’m sure I’d get hate comments if I didn’t also mention Lil Green Patch, which has helped to save over 20 million square feet of rainforest.
2. Get a Green Job: The business networking space is currently dominated by LinkedIn, but JustMeans has a new social media platform that “rallies both companies and individuals around social responsibility.” As you make your way through the registration and profile-building gauntlet, you are posed with two unique questions: What kind of change do you want to create in the world over the next 12 months? How do you plan on creating this positive change? The site encourages networking between members by recommending matches based on shared interests. Plus, you can network with companies themselves as “stakeholders”. Companies as well as nonprofits set up their own profiles, similar to Facebook Pages, where they can post content about initiatives and CSR efforts. An entire section of the site is dedicated to job listings. This is business networking with a purpose.
3. Greenstream: Twitter is a way to stay in touch with friends and keep up with breaking news. It is a source of both cutting-edge news and unchecked banality. It all depends on how you want to use it. You can follow CNN, BBC, GreenOptions, and MaxGladwell as “micro-blogs”, where you receive bits of news and links in 140 characters or less. Or you can track the musings of iJustine and Aubs for pure entertainment value. Recently, we started a new Twitter channel called the “greenstream.” Whereas Twitter asks, “What are you doing”, this adds “that is green?” So if you’re shopping at a farmer’s market, drinking fair trade coffee, or carpooling to work, these qualify as Tweets for the greenstream. Just tag your Tweet with “#greenstream”, and it will be indexed for viewing by all. Alternately, if you want to Twitter a green tip, just enter “#greentip” and check the index page for those.
4. Hugg a Story: Hugg.com is the green counterpart to the wildly popular Digg.com. These are social news sites that enable users to vote and comment on what’s important (and what’s not). This process places the power in the hands of real people who, collectively, determine which issues get attention, rather than leaving it up to the major news organizations to tell us what’s important. The great thing about them, though, is that they get better and more accurate as more people participate. So it’s your civic and social duty to Hugg and Digg stories that matter to you.
5. Join the “Make The Difference Network“: Actress Jessica Biel, in a collaboration with her father and brother, just launched a social network that connects people and businesses with charitable organizations. Make The Difference Network already has a number of prominent celebrities signed up as members, complete with their favorite causes. Each of the site’s constituencies has a profile platform, and it’s free for all to participate. The “Find Your Wish” section gives people some direction in matching their personal interests or passions with charities ranging from addiction and animals to labor and literacy.
6. Go Shopping: Your purchasing decisions matter. Though presidential elections come once every four years, you vote with your wallet every day. Combined with the tools of social media, you get social shopping. Alonovo describes this as “the power of millions of informed, aware and caring people acting in concert. For a better world.” The company provides a platform in which to interact with fellow conscious consumers, to research products based on a range of social and environmental criteria, and ultimately make informed purchases through Amazon.com. You choose a charitable benefactor, and 50-100% of the commission paid to Alonovo is donated on your behalf.
OsoEco, which is currently in private beta, takes a different tact. Using a bookmark feature for the Firefox browser, you can pull products from any retail site and import them into OsoEco with one click. It’s much like a wiki in this way (more below). Then you review the product for others to see and rate. According to the company, they “created OsoEco to answer our own questions about what’s green, what’s sustainable, and what kinds of things we should buy and do that are good for our communities and, not to sound completely cheesy and cliche, our world.”
7. Contribute to a Wiki: Most are familiar with Wikipedia. It’s a fantastic resource for information and an even more incredible phenomenon of collaborative creation on a global scale. What’s incredible to consider, though, is that it’s just the beginning. As author Clay Shirky points out, it’s a drop in the well compared to the untapped potential of our cognitive surplus. PlayGreen.org is one example of how wikis are being built for specific topic areas. Anyone can contribute or edit articles such as How to build a green PC and RecycleBank. Imagine an entire Wikipedia of knowledge and human experience dedicated to specific issues like global warming, cancer, autism, and renewable energy. That’s where we’re headed.
8. Start Your Own Social Network: Ning has made starting a social network as easy as signing up for an email address. For an example, see the Max Gladwell network or any one of more than 100 networks tagged with “green”. The platform guides you through the customization process, where you can add features like a blog, news feed, videos, calendar, and assorted gadgets (widgets) to give it more utility. This is perfect for organizations on a tight budget that want a place to aggregate information, organize, and keep its members connected. With a bit of coding skill and a premium account, you can customize however you’d like and integrate your own sponsors or advertising.
9. Get Sponsored: SocialVibe is leveraging the traffic we generate from our social networking pages to fund various causes. It works quite simply. You sign up and select from a list of sponsors to endorse, ranging from PowerBar and Cherry Coke to Adobe and Apple. Next, you select a cause to support. We picked an environmental index of sorts that includes “water quality, global warming research and preventative measures, wildlife, agriculture, rainforest preservation and sustainable production of food and building materials.” SocialVibe places your ad on your social networking pages and can also generate code that you can embed most anywhere. When it’s viewed, you generate donations for your cause and also earn points and other perks for yourself.
10. Broadcast Your Message: The cost of web broadcasting (webcasting) has effectively dropped to zero. A number of new technologies are making it possible for anyone to have their own live online TV channel. Indeed, signing up for Ustream.tv is like renting your own production studio. While you’re broadcasting live, viewers can communicate with you and other viewers through a chat interface, and you can even add a co-host. Your “shows” can be archived for later playback, and you can post them to YouTube or your personal pages for further distribution. Ustream also provides a social networking platform and a number of ways to promote your shows, such as through Twitter alerts.
Seesmic has a much different approach with “video conversations”. It’s similar to Twitter in many ways, only instead of posting text entries you record video clips. Other users respond, which forms a thread of video clips that become a video conversation. These clips can be embeded anywhere you want, such as your MySpace page or blog. In fact, Seesmic offers a plugin feature for blogs where you can leave video comments. While there’s nothing particularly green about these video technologies, they represent a next step in communications and an efficient means for producing and distributing green messages.
Solar System Powers Donggwang Green Village on Semi-Tropical Jeju Island
Donggwang is on the western half of Jeju-do, the largest of South Korea’s semi-tropical southern islands. Near the village, Halla Mountain, a volcano and the tallest mountain in South Korea, rises from the island’s center amidst a patchwork of small farms.
Donggwang has achieved what even the most powerful countries in the world are still struggling to accomplish: total energy independence with clean technology.
On the roof of each of the 40 houses in Donggwang lies a large beds of solar panels. Even the small, local elementary school runs on free electric energy from the sun. The photovoltaic panels produce enough energy to power the entire area. Amidst cattle and fields, Donggwang is a state-of-the-art renewable energy village.
I spoke with Choo Chan Lee, who lives in Donggwang. Mr. Lee, a Seoul native, retired to Donggwang green village after operating a successful grocery store in New York for many years. He and his wife invited my in for tea to talk about the solar system and their life in Donggwang.
“Dongwang is a solar town,” Mr. Lee says. “[The solar systems] are a lot of help for us. Mine is 2.1 kW.”
In 2004, the government helped to install solar systems in Donggwang, paying 70% of the installation fees.
“They told us this is your town,” recalls Mr. Lee. “Do you wand them or not? We said that we would like them.”
When asked whether he is concerned about environmental issues, Mr. Lee replies casually, “Yeah, the environment is a very important issue. In Jeju we don’t have many factories, so the air is very nice. Very nice environment. The motto is a clean city - clean island. They’re trying to do this solar and then the windmills. My favorite part of living in Jeju is the fresh air. The clean air.”