- Supreme Court Takes Climate Pollution Case
- Computer Geeks: Compete to Help NASA Explain Dark Energy
- Huge Magnetic Filament Erupts on the Sun
- Laser Light Can Lift Tiny Objects
Posted: 06 Dec 2010 03:08 PM PST
The United States Supreme Court has agreed to hear a landmark case on greenhouse gases, potentially affirming or denying the public's right to limit corporate pollution.
At issue is American Electric Power Co. v. Connecticut, a case filed by environmental groups and eight states against midwestern utility companies. Connecticut, New York, California, Iowa, New Jersey, Rhode Island, Vermont and Wisconsin claimed the power companies' contributions to climate change made them a public nuisance, and asked courts to cap their emissions.
The case was filed before the Environmental Protection Agency's right to regulate greenhouse gases was established, and represents an attempt by citizens to control greenhouse gases in the absence of federal mandates. As described in a previous Climate Desk story on American Electric Power Co. v. Connecticut, the case is grounded in a century-long tradition of communities holding big polluters responsible for damaging public health.
Further lawsuits have been inspired by the case, including one by Gulf Coast residents against oil refineries they say contributed to Hurricane Katrina, and another by residents of an Alaskan island village about to be swamped by rising seas.
A New York court ruled against the states in 2005, saying the suit raised a "political question" beyond judicial scope. An appeals court reversed that decision last year, noting that the link between greenhouse gas pollution and climate change is not a political question. As justification, they even cited Georgia v. Tennessee Copper Co., an obscure Supreme Court decision in which the high court supported Georgia's right to sue two copper companies responsible for crop-destroying pollution.
It's this appeal that the Supreme Court will review.
Somewhat surprisingly, the Obama administration asked the Supreme Court not to take the case, arguing that greenhouse gas controls should be decided executively or legislatively, not by states or judges. Though climate change legislation has been a failure, the Supreme Court ruled in 2007 that the EPA could regulate greenhouse gases, a process scheduled to begin early next year.
More predictably, the U.S. Chamber of Commerce and a variety of energy industry groups filed petitions in favor of the companies. They say that court-ordered caps could raise energy costs. According to the energy companies, "the potential compensation for climate change impacts would make the tobacco payouts look like peanuts."
The case will be heard in the early spring and decided by July.
Posted: 06 Dec 2010 11:05 AM PST
If you can teach computers to learn, NASA needs your help.
Cosmologists hope gamers, programmers, computer scientists and geeks-of-all-trades can help them identify evidence of dark matter. An international group of astronomers are hosting a competition, called GREAT10 (for GRavitational lEnsing Accuracy Testing), to come up with better ways to analyze distorted images of galaxies — the signatures of invisible dark matter lurking in the universe.
Massive clumps of matter can act as a giant cosmic magnifying glass, distorting space-time in their immediate vicinity. Light traveling through the matter clump is warped and distorted, a phenomenon called gravitational lensing.
Sometimes the distortions are obvious, like in the Hubble image of a distant galaxy cluster above. But sometimes they're too subtle to be picked out by human eyes, and can even be confused with noise from the telescope used to take the galaxies' picture.
So cosmologists have turned to machine learning algorithms that teach computers to recognize patterns.
"We're trying to teach computers to pick out the correct shape given all sorts of other noise around the galaxy's shape," said NASA cosmologist Jason Rhodes, who is helping to organize the challenge. "We have our ideas as a community about how to do this, but we realized a few years ago that it was quite possible there were ideas we weren't familiar with."
The competition is designed to bring fresh ideas from machine learning and computer science experts. But the challenge is open to anyone.
"The image manipulation software and techniques used in gaming and some digital cameras are very similar," said astrophysicist Thomas Kitching of the University of Edinburgh, which is helping to sponsor the event. "Anyone with experience in image manipulation and software development would be in a good position to enter the competition."
Rhodes compares GREAT to other citizen science and engineering challenges, like the X-Prize private spaceflight competitions or the Netflix Prize to improve the movie rental website's recommendation algorithms. Those challenges promised million-dollar prizes, which is beyond the cosmology community's budget. But the GREAT10 winner will probably get an iPad or a Mac laptop.
And the real grand prize is helping to solve one of the trickiest and most fundamental puzzles in astronomy: What is the universe made of?
Ultimately, the computer programs developed for the GREAT challenge will be used to help unmask dark matter and dark energy, the mysterious stuff that makes up 95 percent of the universe.
By studying slightly distorted galaxies, scientists can make detailed maps of dark matter, the stubbornly invisible stuff that makes up 24 percent of the universe and makes itself known through gravitational tugs on regular visible matter. Knowing where the dark matter is and how it changes over time will help astronomers decipher dark energy, an even more mysterious substance that makes up 72 percent of the universe.
"The most exciting thing about this is that we are taking an interdisciplinary approach to one of the most pressing problems in all of science," Rhodes said. "The ultimate goal here is really to develop methods for studying the composition of the universe and the ultimate fate of the universe. People who haven't spent their lives studying cosmology can make a real contribution via the GREAT10 challenge."
Image: Light bends around the massive galaxy cluster Abell 2218 in this image from the Hubble Space Telescope. Credit: Andrew Fruchter (STScI) et al., WFPC2, HST, NASA
Posted: 06 Dec 2010 11:03 AM PST
A magnetic filament more than 50 times the Earth's width is erupting off the surface of the sun.
Update 4:25 p.m. EST: The mega-filament collapsed in a gorgeous cascade of hot plasma between noon and 2 p.m. EST. NASA's Solar Dynamics Observatory captured a beautiful movie of the eruption (above). The explosion does not appear to be aimed at Earth, so we shouldn't expect any magnetic storms or satellite troubles.
The loop of hot plasma has been snaking around the sun's southeast limb since Dec. 4, and appears to be growing by the hour. When SDO saw it on Dec. 4, the filament was more than 250,000 miles long, about 30 times the diameter of the Earth. In the image below, taken at about 12:30 p.m. EST on Dec. 6, the loop of charged plasma stretches more than 435,000 miles, the full radius of the sun.
So far the gigantic prominence has hung suspended peacefully above the sun's surface, but this morning it started showing signs of instability. Long filaments like this one can break apart as coronal mass ejections, releasing tons of hot, charged material into the inner solar system and potentially causing magnetic storms on Earth — although this one seems to be safe.
The image you see is in ultraviolet channels, not visible light. This prominence is an excellent target for backyard telescopes. If you capture any great sun photos in the next few days, let us know.
Posted: 06 Dec 2010 08:24 AM PST
Light has been put to work generating the same force that makes airplanes fly, a study appearing online December 5 in Nature Photonics shows. With the right design, a uniform stream of light has pushed tiny objects in much the same way that an airplane wing hoists a 747 off the ground.
Researchers have known for a long time that blasting an object with light can push the object away. That's the idea behind solar sails, which harness radiation for propulsion in space, for instance. "The ability of light to push on something is known," says study coauthor Grover Swartzlander of the Rochester Institute of Technology in New York.
Light's new trick is fancier than a boring push: It created the more complicated force called lift, evident when a flow in one direction moves an object perpendicularly. Airfoils generate lift; as an engine propels a plane forward, its cambered wings cause it to rise.
Lightfoils aren't about to keep an Airbus aloft for the time it takes to fly from JFK to LAX. But arrays of the tiny devices might be used to power micromachines, transport tiny particles or even enable better steering methods on solar sails.
Optical lift is "a really neat idea," says physicist Miles Padgett of the University of Glasgow in Scotland, but it's too early to say how the effect might be harnessed. "Maybe it's useful, maybe it's not. Time will tell."
That light can have this unexpected lift effect started with a very simple question, Swartzlander says: "If we have something in the shape of a wing and we shine light through it, what happens?" Modeling experiments told the researchers that an asymmetrical deflection of light would create a surprisingly stable lift force. "So we thought we'd better do an experiment," Swartzlander says. "Because this just looks too pretty."
The researchers created tiny rods shaped kind of like airplane wings — flat on one side and rounded on the other. When these micron-sized lightfoils were immersed in water and hit with 130 milliwatts of light from the bottom of the chamber, they started to move up, as expected. But the rods also began moving to the side, a direction perpendicular to the incoming light. Tiny symmetrical spheres didn't exhibit this lift effect, the team found.
Optical lift is different from the aerodynamic lift created by an airfoil. A plane flies because air flowing more slowly under its wing exerts more pressure than the faster-moving air flowing above. But in a lightfoil, the lift is created inside the object as the beam shines through. The shape of the transparent lightfoil causes light to be refracted differently depending on where it goes through, which causes a corresponding bending of the beam's momentum that creates lift.
These lightfoils' lift angles were about 60 degrees, the team found. "Most aerodynamic things take off at very gradual angles, but this has a very striking, very powerful lift angle," Swartzlander says. "You can imagine what would happen if your airplane took off at 60 degrees — your stomach would be in your feet."
As the rods lift, they shouldn't stall out, the paper predicts. "The subtlety is that it actually self-stabilizes," Padgett says. "It twists a little bit one way, and you think, 'Oh dear, it'll stop working,' then the light rotates it back again."
Swartzlander says he hopes to ultimately test the lightfoils in air, too, and try different shapes and materials with various refractive properties. In the study, the researchers used ultraviolet light to generate the lift, but other kinds of light would work just as well, Swartzlander says. "The beautiful thing about this is that it would work as long as you have light."
Video: Riding a beam of light, a tiny particle thousandths of millimeters in size is pushed sideways by the same force that keeps airplanes aloft. Credit: Swartzlander et al.
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