Science Actualit�s : - Picture of the day

The Theory of General Relativity confirmed on a vast scale

Fri, 12 Mar 2010 00:00:00 +0100

This partial chart shows the distribution of some 70,000 galaxies at a distance of up to 7 billion light years. The distribution and speed of the galaxies observed today provide evidence that the Theory of General Relativity genuinely works on a very large scale. This has been demonstrated by American and Swiss astrophysicists.
Source: Nature, 11th March 2010

Chile: after the earthquake, a tsunami hits the south of the country

Wed, 3 Mar 2010 00:00:00 +0100

On the 27th February, Chile suffered an earthquake measuring 8.8 on the Richter scale, followed by twenty or so aftershocks of over 5 and four of over 6. The epicentre was out at sea, off the coast of the city of Concepci�n. Along 200 km of coastline in Maule province, a tidal wave submerged towns such as Dichato (photo) and villages up to 2 km inland. On the 9th March, the toll stood at 497 dead.

Does the positioning of the eyes affect agility when running?

Thu, 25 Feb 2010 00:00:00 +0100

No, say researchers from Liverpool University after studying 51 species of mammal (left, a rabbit; right, a cat), notably using MRI. According to their results, the brains of mammals can handle all the demands of running wherever their eyes are placed: ahead, to the side or even behind.
Source: Journal of Anatomy, February 2010, DOI 10.1111/j.1469-7580.2010.01211.x

Fossil spiders 165 million years old

Fri, 19 Feb 2010 00:00:00 +0100

Spiders trapped in volcanic ash and covered with a fine layer of clay during the Jurassic period have been found on the Daohugou site in China. Their size (barely a centimetre) and perfect state of preservation (leg hairs and genitals clearly visible) have enabled researchers to identify the family to which they belong: Plectreuridae, only found in the Southern United States, Mexico and Cuba today.
Source: Naturwissenschaften, DOI 10.1007/s00114-010-0649-z

Giant fossils with major inferences...

Fri, 12 Feb 2010 00:00:00 +0100

Large gastropods (up to 7 cm) found* in marine sediments in Utah (USA) and dating from 1 million years after the great Permian-Triassic mass extinction event** challenge the theory that living creatures grew smaller (called the "Lilliput Effect") for several million years after each event.
* By an international team of French, German, American and Swiss palaeontologists.
** The Permian-Triassic event (-252 million years) resulted in the disappearance of more than 90% of marine species.
Source: Geology, February 2010

An asteroid collision seen by Hubble?

Fri, 5 Feb 2010 00:00:00 +0100

This intriguing, comet-shaped object photographed by space telescope Hubble on the 29th January and named P/2010 A2 is not a comet at all. While its filamentary structure made up of dust trails gives that impression, the strange X-shape of its nucleus suggest to astronomers that it is likelier to have been produced by a collision between two asteroids travelling five times faster than a rifle bullet (5 km/sec). For a long time now, astronomers have thought that the asteroid belt was formed by collisions, but they have never seen one until now.

Neuronal connections in 3D

Fri, 29 Jan 2010 00:00:00 +0100

Using an electronic microscopy method that freeze cells almost instantly - so capturing biological structures in mid-operation - a team of researchers from the Marx-Planck Institute of Biochemistry (Germany) has succeeded in determining the three-dimensional structure of a synapse between two neurones for the first time. In yellow, the synaptic vesicles interlinked by "connectors" (in red). Thanks to this 3D visualisation, the researchers can monitor the effects of a pharmacological treatment on the connections between neurones.
J. Cell Biol. Doi:10.1083/jcb.200908082

Water and a little clay to make plastic

Fri, 22 Jan 2010 00:00:00 +0100

Researchers from the University of Tokyo have succeeded in making plastic from water, clay and a thickening agent (sodium polyacrylate). Although the mixture is 98% water, it produces a transparent, elastic hydrogel sufficiently strong to form a 3.5 cm bridge that can stand alone between two supports.
Nature, DOI: 10.1038/nature08693

The first solar eclipse of the year

Fri, 15 Jan 2010 00:00:00 +0100

An annular eclipse of the Sun (taking the form of a thin ring of light around the shadow cast by the Moon) occurred on Friday 15th January. At first visible from Central Africa, it crossed the Indian Ocean and Asia to reach China (here, over Zhengzhou, capital of Henan Province), plunging the world into semi-darkness along a path 12,900 kilometres long and 300 kilometres across.

The most complex of mathematical structures has been found "in real life"

Tue, 12 Jan 2010 00:00:00 +0100

During an experiment on cobalt and niobium crystals conducted in the laboratory at a temperature of 0.04� C above absolute zero, physicists have observed a complex form of mathematical symmetry for the first time. It is the E8 structure, discovered in 1887 by Norwegian mathematician Sophus Lie. It took 18 mathematicians 4 years of work and 77 hours of calculation on a supercomputer to describe the structure in 2007 (see photo). The mathematicians themselves are amazed to have encountered it in the real world!
New Scientist, 07 January 2010