Where has all the antimatter gone?
24 April 2013 Last updated at 10:16 BST
Where has all the antimatter gone? The Universe today is made of matter, but scientists believe that in the beginning, the Big Bang created equal amounts of matter and antimatter.
A new discovery at the Large Hadron Collider at Cern means scientists are furthering our understanding of the differences in behaviour between matter and antimatter.
Chris Parkes, professor of physics at the University of Manchester and a spokesman for the UK's involvement at Cern, explains why the antimatter has disappeared.
First broadcast on BBC Radio 4's Today programme on Wednesday 24 April 2013.