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Planning a trip to Mars? Take plenty of shielding to protect from cosmic rays

September 30th, 2009

Planning a trip to Mars? Take plenty of shielding. According to sensors on NASA’s ACE (Advanced Composition Explorer) spacecraft, galactic cosmic rays have just hit a Space Age high.

Cosmic Rays

“In 2009, cosmic ray intensities have increased 19% beyond anything we’ve seen in the past 50 years,” says Richard Mewaldt of Caltech. “The increase is significant, and it could mean we need to re-think how much radiation shielding astronauts take with them on deep-space missions.”

Galactic cosmic rays are speeding charged particles that include protons and heavier atomic nuclei. They come from outside the solar system, though their exact sources are still being debated.

Earth dwellers are protected from cosmic rays by the planet’s magnetic field and atmosphere. But outside Earth’s protective influence, cosmic rays can play havoc with spacecraft electronics – they may be responsible for some recent computer glitches on NASA’s Kepler spacecraft, which temporarily halted its planet-hunting observations. They can also damage astronaut DNA, which can lead to cancer.
“At times of low solar activity, this natural shielding is weakened, and more cosmic rays are able to reach the inner solar system,” explains Pesnell.

Cosmic Rays

Cosmic Rays

Mewaldt lists three aspects of the current solar minimum that are combining to create the perfect storm:

1. The sun’s magnetic field is weak. “There has been a sharp decline in the sun’s interplanetary magnetic field down to 4 nT (nanoTesla) from typical values of 6 to 8 nT,” he says. “This record-low interplanetary magnetic field undoubtedly contributes to the record-high cosmic ray fluxes.” [data]

2. The solar wind is flagging. “Measurements by the Ulysses spacecraft show that solar wind pressure is at a 50-year low,” he continues, “so the magnetic bubble that protects the solar system is not being inflated as much as usual.” A smaller bubble gives cosmic rays a shorter-shot into the solar system. Once a cosmic ray enters the solar system, it must “swim upstream” against the solar wind. Solar wind speeds have dropped to very low levels in 2008 and 2009, making it easier than usual for a cosmic ray to proceed. [data]

3. The current sheet is flattening. Imagine the sun wearing a ballerina’s skirt as wide as the entire solar system with an electrical current flowing along its wavy folds. It’s real, and it’s called the “heliospheric current sheet,” a vast transition zone where the polarity of the sun’s magnetic field changes from plus to minus. The current sheet is important because cosmic rays are guided by its folds. Lately, the current sheet has been flattening itself out, allowing cosmic rays more direct access to the inner solar system.

Complete Article @ NASA

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'Green' cluster bombs to seed areas with risk of desertification

May 11th, 2009

Arican pilot Gale Halvorson airdropped candies in the name of hope, for the Berlin children. War equals devastation, so dropping candies instead of bombs was probably personal retribution. Inspired by this incident, designer Hwang Jin wook and pals have come up with a plan to combat deforestation and desertification of land in a similar fashion. Their mission is called “Seedbomb.”

Mission Seedbomb involves a bomber aircraft and charges full of the Seed Capsules. Essentially the project involves artificial dispersal of seeds over arid areas where natural vegetation has lapsed due to man-made follies like deforestation leading to desertification. Each capsule contains artificial soil and seeds, and are air-dropped over the selected regions.

Housed in biodegradable plastic, the artificial soil provides nourishment and moisture to the seed; till it grows out to be a strong enough plant to sustain itself. As the sapling matures, the plastic capsule melts away, leaving behind a brand new generation.

Sounds like Mission (im)Possible to me, however the logistics of desert environment and the kind of seeds to be dispersed will require a lot research and expertise from the botanists. Because once the capsule melts away and the artificial soil’s nourishment and moisture used up, it’ll take a lot of effort on the plant’s part to survive the harsh environment.

Designers: Hwang Jin wook, Jeon You ho, Han Kuk il & Kim Ji myung

Seed Bomb

SeedBomb

Seedbomb

Seed Bomb

Seed bomb

SeedBomb

VIA: YANKODESIGN

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Scientists decode mysterious green glow of the sea

April 2nd, 2009
Green glow

Credit: Scripps Institution of Oceanography, UC San Diego

Many longtime sailors have been mesmerized by the dazzling displays of green light often seen below the ocean surface in tropical seas. Now researchers at Scripps Institution of Oceanography at UC San Diego have uncovered key clues about the bioluminescent worms that produce the green glow and the biological mechanisms behind their light production. 

Marine fireworms use bioluminescence to attract suitors in an undersea mating ritual. Research conducted by Scripps marine biologists Dimitri Deheyn and Michael Latz reveals that the worms also may use the light as a defensive measure. The report, published as the cover story of the current issue of the journal Invertebrate Biology, provides insights into the function of fireworm bioluminescence and moves scientists closer to identifying the molecular basis of the light. 

“This is another step toward understanding the biology of the bioluminescence in fireworms, and it also brings us closer to isolating the protein that produces the light,” said Deheyn, a scientist in the Marine Biology Research Division at Scripps. “If we understand how it is possible to keep light so stable for such a long time, it would provide opportunities to use that protein or reaction in biomedical, bioengineering and other fields—the same way other proteins have been used.”

 

Read the rest of the article at LAB SPACES

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Exceptional Australian Heat Wave

February 28th, 2009
Heat wave in Australia 2009

Heat wave in Australia, february 2009

Australia heat wave february 2009

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Carbon nanotubes could replace platinum and lead to affordable hydrogen cars

February 9th, 2009

The joke about hydrogen-powered cars is that they’re about 10 years away–and always will be. The technology has been held up largely by the high cost of hydrogen fuel cells, but now researchers say they’ve found a way to bring down the cost dramatically by making a key component out of carbon nanotubes instead of platinum. More than half the cost of fuel-cell stacks comes from platinum, according to the Department of Energy. “Fuel cells haven’t been commercialized for larger-scale applications because platinum is too expensive,” says Liming Dai [Technology Review], the lead author of the new study.

Carbon Nanotubes

Carbon nanotubes

 


Researcher found that tightly packed, vertically aligned carbon nanotubes doped with nitrogen were more effective as catalysts than platinum, which is usually used to help oxygen react within the fuel cell. That is a vital stage of the fuel cell cycle. Rather than burning fuel to create heat to power a turbine, fuel cells turn chemical energy directly into a flow of electricity. Hydrogen gas, for example, is pumped past one electrode (the anode), where it is split into its constituent electrons and protons. The electrons then flow out of the anode, providing electrical power, while the protons diffuse through the cell. Electrons and protons both end up at a second electrode (the cathode), where they combine with oxygen to form water [New Scientist].

That second reaction is very slow, so engineers have developed cathodes made out of materials that act as chemical catalysts and speed up the reaction. Until now, platinum was considered the best catalyst, but now carbon nanotubes with a trace of nitrogen (the critical ingredient) have left the precious metal in the dust.

 

 

 

READ THE REST OF THE ARTICLE IN DISCOVER MAGAZINE

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Nasa wants its rubber ducks back

December 23rd, 2008

The US space agency (Nasa) would like its rubber ducks back, please.

Ninety bathtub toys were hurled into a drainage hole on the Greenland ice in September – an experiment to see how melt waters find their way to the base of the ice sheet.

NASA rubber ducks

It was hoped the ducks would flow along subglacial channels and eventually pop out into the sea. They may still, but nothing has been seen of them so far.

“We haven’t heard anything from them yet,” said Nasa’s Alberto Behar. “If somebody does find one, it will be a great breakthrough for us.”

Dr Behar is a robotics expert with the agency at its Jet Propulsion Laboratory in Pasadena. He has been studying the tubular crevasses that appear on the surface of the Greenland ice known as moulins.

These “plug holes” can drain vast lakes of melt water that settle on the top of the ice during summer months. Scientists would like to know how and to what extent this water can help lubricate the base of the ice sheet, moving it faster towards the ocean.

Source: BBC NEWS

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