Space is bad for astronauts' eyes
- 11:26 14 March 2012 by Andy Coghlan
- For similar stories, visit the Spaceflight Topic Guide
At http://www.newscientist.com/article/dn21585-space-is-bad-for-astronauts-eyes.html
Space flight may be bad for your eyesight. Changes found in astronauts' eye tissue may cause vision problems, and possibly even blindness. As well as threatening the health of astronauts, this could jeopardise long-haul missions into space.
Larry Kramer of Texas Medical School in Houston and colleagues carried out MRI scans on 27 NASA astronauts after they had spent an average of 108 days in space. Four had bulging of the optic nerve, three had kinks in the nerve sheath, and six had flattening of the eyeball.
The changes match those seen in people with idiopathic intracranial hypertension, a rare condition in which the pressure of blood and other fluids is abnormally high in the brain. People with the condition experience headaches, nausea, vomiting and visual problems including blindness.
In space, the alterations are probably caused by living in free-fall. "One potential mechanism is that blood which normally pools in the legs is shifted toward the skull, raising pressure," says Kramer.
The findings tally with the results of a survey of 300 astronauts carried out last year. Deteriorations in vision were reported by 29 per cent of astronauts on short-term missions, and 60 per cent on long-term missions.
Mission to Mars
"If astronauts are exhibiting these changes after only 100 days in space, what will happen on a three-year flight to Mars?" asks Jason Kring, who studies human performance in extreme conditions at the Embry-Riddle Aeronautical University in( more at http://www.newscientist.com/article/dn21585-space-is-bad-for-astronauts-eyes.html )Nanotrees mimic nature to harvest the sun's energy
Tiny forest uses sunlight to turn water in hydrogen fuel without greenhouse gas emissions
At http://www.msnbc.msn.com/id/46705416/ns/technology_and_science-science/#.T2CFtXmAq1e
If humans are going to mimic nature's unique way of converting sunlight into energy, we're going to need to build some very extraordinary trees.
Electrical engineers in California want to do just that. Their new "nanotree" device is made from cheap, abundant materials and uses sunlight to split water molecules into oxygen and hydrogen atoms that can be used in fuel cells to produce energy.
Hydrogen fuel cells could power everything from houses to cars. But hydrogen doesn't exist alone in nature. The atoms have to be separated from other molecules, like water.
Doing that requires energy and at present, about 90 present of hydrogen gas is created using fossil fuels, causing carbon dioxide emissions into the atmosphere, said Ke Sun, an electrical engineering Ph.D. student at U.C. San Diego who worked with Deli Wang, a professor of electrical and computer engineering, to produce the nanotree.
PHOTOS: Supercharged! Battery Power from the Future
Their nanotrees could potentially use sunlight to ultimately generate an electrical current for a controlled reaction without greenhouse gas emissions.
Basically it's just like a tree, said Wang, who along with Sun published an article about the nanotrees in the journal Nanoscale.
The nanotrees were several years in the making. Wang had worked on branched nanostructures before but they didn't resemble trees, and they weren't intended to ( more at http://www.msnbc.msn.com/id/46705416/ns/technology_and_science-science/#.T2CFtXmAq1e )
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