dawn stover

Have you ever printed out an e-mail message or meeting agenda, only to throw it out a few hours later? If Xerox researchers are to be believed, promiscuous printing happens all the time. Based on studies at their own office and elsewhere, the researchers claim that up to 40 percent of all documents printed in offices are discarded within a day.

The company has a solution: erasable paper. Hailed by Time magazine as one of the best inventions of 2007, the paper is coated with a chemical that changes color when exposed to a certain wavelength of light but fades back to its original shade in 16 to 24 hours, making the paper reusable. Of course it doesn't last forever. Dirt happens. But a Xerox
spokesman says the paper can survive about 50 passes through a
printer.

Erasable paper may save trees but not printers: Xerox research suggests you'll want to have a separate printer for disappearing documents. Send your document to the wrong printer, and you could turn your company's annual report into a daily report.—Dawn Stover

Seeing is believing, check out Xerox's video here.

This'll give you an idea of how much coal Americans are burning: Peabody Energy, the world's largest private-sector coal company, has a ticker showing its estimated 2007 coal sales. The ticker goes up by seven or eight tons every second.

Peabody says its coal products fuel approximately 10 percent of all U.S. electricity generation and more than 2 percent worldwide. Which means we're burning roughly 70 to 80 tons per second in this country alone. A large power plant operating in peak season may burn as many as 500 train cars' worth of coal in a single day.

Coal is relatively cheap, and we have lots of it. But despite constant references within the industry to "clean coal," nobody has yet come up with a cost-effective way to burn large amounts of coal without releasing heat-trapping carbon dioxide gas into the atmosphere.—Dawn Stover

Image: Peabody Energy

AquaBuOY is sunk. The $2 million buoy, deployed off the Oregon coast by the Canadian energy company Finavera Renewables, disappeared beneath the waves a day before its test run was to be completed. The 74-foot-tall device, a floating buoy meant to convert wave motion into electricity, had been in place for less than a month.

Finavera plans to retrieve the buoy from its resting place 150 feet below the ocean surface, but that will have to wait until calmer weather next spring. Despite the sinking, a company spokesman said the test was successful because data collected from the system's computer will be used to build a better buoy next time around.—Dawn Stover

Image: Finavera Renewables

It's the world's smallest radio. Made from a single carbon nanotube, "the real nanopod" is 10,000 times thinner than a human hair but can receive and play tunes broadcast by AM and FM radio stations.

The first song played on the nanotube radio was Eric Clapton's Layla. The technology isn't perfect yet (you'll hear some static), but the song is clearly recognizable.

In the image at left, taken by a transmission electron microscope, a slender nanotube protrudes from an electrode that provides power for the tiny radio (the radio waves were added to the image for effect). When the frequency of the incoming radio waves matches the resonant frequency of the nanotube, it vibrates. The nanotube's tip, which is electrically charged, detects the mechanical vibrations and translates them into sound signals.

Researchers at the U.S. Department of Energys Lawrence Berkeley National Laboratory and the University of California at Berkeley who teamed up to invent the radio say that its extremely small size opens the door to some exciting applications. For example, they envision radios that could be implanted in the inner ear as hearing aids or as discrete devices for receiving information.—Dawn Stover

Image: Courtesy Zettl Research Group, Lawrence Berkeley National Laboratory and the University of
    California at Berkeley

It's a vicious cycle: Global warming is increasing the chances of wildfires, and now we know the reverse is also true. Scientists have confirmed that wildfires release large amounts of heat-trapping carbon dioxide into the atmosphere. That's no surprise, but the amounts are jaw-dropping: Big fires like the recent ones in California can belch out as much carbon dioxide in a few weeks as all of the state's motor vehicle traffic does in a year.

Christine Wiedinmyer of the National Center for Atmospheric Research and Jason Neff of the
University of Colorado used satellite observations of fires and a new
computer model to estimate carbon dioxide emissions based on the amount of vegetation burned. The California fires broke out after their paper, published online yesterday in
the journal Carbon Balance and Management, was already written. However, a preliminary calculation by Wiedinmyer suggests that the fires emitted
7.9 million metric tons of carbon dioxide in just the one-week period
of October 19-26. That's about 25 percent of the average
monthly emissions from all fossil fuel burning throughout California.—Dawn StoverImage: Jeff Turner, Wildfire in Santa Clarita

In Britain, redheads are known as gingers and are often treated as second-class citizens. The news that some Neanderthals may have been redheads probably wont help.

When a team of European research scientists looked at DNA samples from two Neanderthal specimens, they found a gene that affects the body's production of melanin, resulting in red hair and pale skin. The finding is reported in the forthcoming issue of the journal Science. The scientists say that the Neanderthal gene sequence is different from the sequence in modern humans that produces red hair, so they probably arose separately.

Although some people have theorized that modern redheads are descended from Neanderthals, scientists disagree about whether there was any interbreeding between Neanderthals and the ancestors of modern man. They coexisted for many years, but Neanderthals disappeared from Europe more than 24,000 years ago.—Dawn Stover

Image: Michael Hofreiter and Kurt Fiusterweier/MPG EVA

You don't need a rocket to send scientific instruments into space. A really big balloon works just as well, according to an international research team that plans to take a closer-than-ever look at the sun.

Today, the deep-space asteroid-studying spaceprobe Dawn was successfully launched on schedule, satisfying the requirements of DAWNOK. After a few false starts, NASA's mission to study the origins of the solar system is now officially under way, headed forthe main asteroid belt between Mars and Jupiter. The unmanned
spacecraft will begin its exploration of Vesta in 2011, and Ceres in
2015. By comparing the two asteroids, scientists hope to learn more
about how the solar system formed and why Vesta and Ceres failed to become full-size planets.

Back on this planet, our stock was halted at a price of POP$78.75, and will pay out at POP$100 immediately. Onward and upward! —John Mahoney and Dawn Stover

NASA says its Mars Odyssey spacecraft has spotted seven possible cave entrances on Mars. These dark features, several hundred feet across, have a more constant temperature from day to night than the ground surrounding them (as shown in the infrared images at center and right). If the "Seven Sisters" holes turn out to be caves, it's possible they could provide a protected niche for past or present life on Mars—or serve as underground shelters for future human colonization.—Dawn Stover

Image: NASA/JPL-Caltech/ASU/USGS

First there was Google Earth, now there's Google Moon, a lunar mapping platform anyone can use. The website has maps embedded with panoramic images and links to audio and video clips from moon missions.—Dawn Stover

Image: NASA 

Want to see what would happen to your car in a crash? Enter your vehicle's make, model and year to watch a Consumer Reports crash test.—Dawn Stover

Image: National Highway Traffic Safety Administration

When six men got trapped in a Utah coal mine on August 6, the mine's chief executive declared that the cave-in was caused by a natural earthquake. The University of Utah Seismograph Stations did record a magnitude-3.9 earthquake, but the quake was probably caused by the mine collapse—rather than the other way around.

Seismograph stations recorded a smaller seismic event on Thursday, when a second implosion killed three men who were participating in the rescue effort, including an inspector from the U.S. Labor Department's Mine Safety and Health Administration. Called a "bump" by mining officials, it is the seismic event recorded in blue on the lower right section of this chart.

Seismologists at the University of Utah, the U.S. Geological Survey and the University of California, Berkeley, say that the downward motion of seismic waves from both events is strong evidence of collapse. The second event happened less than a mile underground, which would be quite shallow for a natural earthquake.

The "bumps" are likely to continue. The roof of the Crandall Canyon mine is held up by pillars of coal. When some pillars fail, that can increase the stress on nearby pillars that are still standing.—Dawn Stover

Yes, according to scientists at Louisiana State Universitys Pennington Biomedical Research Center in Baton Rouge.

At an American Chemical Society symposium this morning, they reported that human adenovirus-36, a common virus that causes respiratory and eye infections, can transform adult stem cells into fat cells. In controlled studies, stem cells that were not exposed to the virus did not develop into fat cells.

An earlier study at Louisiana State showed that 30 percent of obese people were infected with the virus, while only 11 percent of lean people were infected. But until the new study was done, there was no proof that the virus can actually cause fat levels to increase.

Not everyone infected with adenovirus-36 will put on pounds, the scientists say, but it is one potential cause of the nationwide obesity epidemic. And its a cause that might eventually be treatable with antiviral medications or vaccines.—Dawn Stover