Het Universum

De Independent bericht:

'The universe gives up its deepest secret.
It is the invisible material that makes up most of the cosmos. Now, scientists have created the first image of dark matter
By Steve Connor, Science Editor

One of the greatest mysteries of the universe is about to be unravelled with the first detailed, three-dimensional map of dark matter - the invisible material that makes up most of the cosmos.
Astronomers announced yesterday that they have achieved the apparently impossible task of creating a picture of something that has defied every attempt to detect it since its existence was first postulated in 1933.
Scientists have known for many years that there is more to the universe than can be seen or detected through their telescopes but it is only now that they have been able to capture the first significant 3D-image of this otherwise invisible material.
Unlike the ordinary matter of the planets, stars and galaxies, which can be seen through telescopes or detected by scientific instruments, nobody has seen dark matter or knows what it is made of, though calculations suggest that it is at least six times bigger than the rest of the visible universe combined.
A team of 70 astronomers from Europe, America and Japan used the Hubble space telescope to build up a picture of dark matter in a vast region of space where some of the galaxies date back to half the age of the universe - nearly 7 billion years.
They used a phenomenon known as gravitational lensing, first predicted by Albert Einstein, to investigate an area of the sky nine times the size of a full moon. Gravitational lensing occurs when light from distant galaxies is bent by the gravitational influence of any matter that it passes on its journey through space.
The scientists were able to exploit the technique by collecting the distorted light from half a million faraway galaxies to reconstruct some of the missing mass of the universe which is otherwise invisible to conventional telescopes.
"We have, for the first time, mapped the large-scale distribution of dark matter in the universe," said Richard Massey of the California Institute of Technology in Pasadena, one of the lead scientists in the team. "Dark matter is a mysterious and invisible form of matter, about which we know very little, yet it dominates the mass of the universe."
One of the most important discoveries to emerge from the study is that dark matter appears to form an invisible scaffold or skeleton around which the visible universe has formed.
Although cosmologists have theorised that this would be the case, the findings are dramatic proof that their calculations are correct and that, without dark matter, the known universe that we can see would not be able to exist.'

Lees verder: http://news.independent.co.uk/world/science_technology/article2134891.ece