Question: How do you learn from your work about how the universe was created?

Clara Nellist answered on 13 Mar 2014:

Unfortunately, there isn’t any data available that can tell us how the universe was created. But, we can use particle physics to learn a lot about what we think happened in the moments very soon after it happened.

There are experiments at the Large Hadron Collider at CERN that are looking into what the Universe might have been like very early on. One of these is the ALICE experiment. By colliding clumps of protons and neutrons stuck together like in an Iron atom (but without any electrons) with single protons they can create a soup of hot and tightly packed particles called a quark-gluon plasma. This is thought to be what the Universe was like when it was very young and we can look at how it behaves.

There’s also another theory that says that at the beginning of the Universe there were equal numbers of matter particles and antimatter particles. But now, almost everything around us is made of matter, so where did all the antimatter go? And why? The LHCb experiment at CERN is trying to work this out by looking at if some heavy particle prefer to change to matter particle *slightly* more than to antimatter particles.

And then to my experiment ATLAS (and to be fair, our rival experiment CMS 😉 ), we’ve been studying the Higgs boson (among other things) and this is a really important part of our theory of how particles work and interact. If we hadn’t found it, then we would have had to question a lot of what we though we know about how the Universe works. But we did find it, so now we want to understand as much as we can about it!

Cool, right! 🙂