Dr Lyn Evans has spoken of his pride that Wales was involved in the discovery of what's believed to be the Higgs Boson particle.
Dr Evans from Aberdare was the project leader for research into Higgs Boson, which gives matter mass and and holds the physical fabric of the universe together.
Scientists have been looking for the Higgs since the 1960s, but the search began in earnest more than 20 years ago with early experiments at Cern in Europe and Fermilab in the US.
Scientists say they believe they have captured the elusive Higgs Boson particle that gives matter mass.
Professor John Womersley, chief executive of the Science and Technology Facilities Council, told reporters at a London briefing that they had discovered a particle consistent with the Higgs Boson.
– Professor John Womersley
Discovery is the important word. That is confirmed. It's a momentous day for science.
There is a strong Welsh connection to the groundbreaking scientific project as Dr Lyn Evans from Aberdare was the project leader.