8 October 2013Last updated at 11:48

Two scientists have won the Nobel prize in physics for their work on the theory of the Higgs boson.
Peter Higgs, from the UK, and Francois Englert from Belgium, shared the prize.

In the 1960s they were among several physicists who proposed a mechanism to explain why the most basic building blocks of the Universe have mass.

The mechanism predicts a particle - the Higgs boson - which was finally discovered in 2012 at the Large Hadron Collider at Cern, in Switzerland.

"This year's prize is about something small that makes all the difference," said Staffan Normark, Permanent Secretary of the Royal Swedish Academy of Sciences.

The official citation read: "For the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN's Large Hadron Collider"

http://m.bbc.co.uk/news/science-environment-24436781