RAY SUAREZ: Now: an extraordinary new discovery that helps confirm our understanding of the universe.
We start with this report from Tom Clarke of Independent Television News.
TOM CLARKE: Particle physicians, or not, were getting carried today, for today, Professor Peter Higgs got a rock star's welcome.
The particle he first dreamt up more than 40 years ago appears to have been be discovered.
PETER HIGGS, University of Edinburgh: Well, I would like to add my congratulations to everybody involved in this tremendous achievement. For me, it's really an incredible thing that it has happened in my lifetime.
PETER HIGGS: It's taken...
TOM CLARKE: When it was first proposed, the idea of the Higgs boson was almost insane, yet, here today, something that looks very much like it has been proven to exist. And in that, it fundamentally changes our understanding of the universe, because it means scientists' theory about how the universe works are almost spot on. And that makes it one of the landmark scientific discoveries of our age.
Advances like this in the world of the very, very small will undoubtedly lead to applications we have not even imagined. They found the particle using the largest and most expensive piece of scientific kit ever built. The large hadron collider probes the subatomic world by smashing particles together very hard.
So what is the Higgs boson? In a pool hall across the road, one of the men who helped find it was beating me, by way of explanation.
JONATHAN BUTTERWORTH, University College London: There is nothing like the Higgs in nature. This is a completely new kind of object. There's no analogy to it. It's not like we found number three, when we already had one and two. This is kind of a lynchpin that makes everything work.
TOM CLARKE: Most of the things we're familiar with in the universe have mass. But without the Higgs boson, there is no mass. And what goes for a pool ball applies the same to a planet, in fact, the whole universe.
So take away the Higgs, and there's nothing left to hold the entire universe together.
The machine that found the new particle has yet to run at full power. When it does in the coming years, weirder and more wonderful things could appear, like elusive dark matter. In that sense, today has been a true breakthrough, carrying the most fundamental science forward into the unknown.