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

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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Science

Submission + - Synthetic Sebum Makes Slippery Sailboats (newscientist.com)

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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