sonnejw0 - Slashdot User

Submission + - Galaxy Survey Confounds Dark Matter Theory (newscientist.com)

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sonnejw0

on Wednesday September 30, 2009 @02:28PM

sonnejw0 writes: "Dark matter, a theoretical substance that lines the galaxies of outer-space, was postulated to account for the observed rotational energy in neighbouring galaxies which could not be accounted for in current theories of gravity. NewScientist is reporting on a new sky survey that has found constant ratios of dark matter deposited in these newly studied galaxies. This is a problem because galaxies should not have a constant ratio of dark to regular matter; this ratio should depend on the processes of their formation. These results point to a possible new theory of gravity:
"Now, the tale has taken a deeper turn into the unknown, thanks to an analysis of the normal matter at the centres of 28 galaxies of all shapes and sizes. The study shows that there is always five times more dark matter than normal matter where the dark matter density has dropped to one-quarter of its central value. The finding goes against expectations because the ratio of dark to normal matter should depend on the galaxy's history â" for example, whether it has merged with another galaxy or remained isolated during its entire existence. Mergers should skew the ratio of dark to normal matter on an individual basis."
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Submission + - Synthetic Sebum Makes Slippery Sailboats (newscientist.com)

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sonnejw0

on Monday September 28, 2009 @10:01AM

sonnejw0 writes: "Sea-faring vessels are a major contributor of greenhouse gas production due to a deficit in international laws and inherent inefficiencies at sea, such as barnacle build-up on hulls. Many marine animals avoid the build-up of drag-inducing barnacles through secreting oily residues from their pores or through the nano-molecular arrangement of their skin. Sailors regularly defoul their hulls, remove the barnacles, at dry-dock, which requires them to reduce the amount of time they have at sea. Some synthetic chemicals in paints have been used to prevent barnacle build-up but have been found to be toxic to marine animals and thus outlawed by several nations. Now, engineers are trying to replicate the skin of marine animals to produce a slippery hull to which marine bacteria cannot attach, saving fuel costs and improving speeds:
Designing ships to exude slime from their hulls could cut their fuel consumption by up to 20 per cent. The slime would form a gelatinous skin that continually sloughs off, taking with it the barnacles and other marine life forms that cause energy-sapping drag as they accumulate on the ships' underside.
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Submission + - NASA's plan to Harvest Moon Water (newscientist.com) 1

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sonnejw0

on Friday September 25, 2009 @03:22PM

sonnejw0 writes: "Now that we have identified water on the moon, how can we harvest it for lunar bases, for power and for drinking, and will it be a renewable lunar resource? NASA is already testing possible methods of harvesting this water in the vacuum of space ... using a regular microwave oven. Do you think they used the "Defrost" or "Popcorn" setting? From the article:
"But how do you extract water that is likely locked up as small concentrations of ice in the lunar soil? Microwaves could provide the key, according to work by Edwin Ethridge of NASA's Marshall Space Flight Center and William Kaukler of the University of Alabama, both in Huntsville, who first demonstrated the technique in 2006."
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Submission + - Alzheimer's Disease linked to Sleep Deprivation (newscientist.com) 3

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sonnejw0

on Friday September 25, 2009 @12:14PM

sonnejw0 writes: "NewScientist is reporting a link between sleep deprivation and increased amyloid-beta plaque load, the protein thought responsible for a large part of the symptoms of Alzheimer's Disease, in mice. Medication to abrogate insomnia reduced the plaque load. Also discussed is a recently discovered sleep cycle of amyloid-beta deposition in the brain, in which levels decrease while asleep. From the article:
"Holtzman also tried sending the mice to sleep with a drug that is being trialled for insomnia, called Almorexant. This reduced the amount of plaque-forming protein. He suggests that sleeping for longer could limit the formation of plaques, and perhaps block it altogether."
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