CERN's main focus is particle physics – the study of the fundamental constituents of matter – but the physics programme at the laboratory is much broader, ranging from nuclear to high-energy physics, from studies of antimatter to the possible effects of cosmic rays on clouds.
Since the 1970s, particle physicists have described the fundamental structure of matter using an elegant series of equations called the Standard Model. The model describes how everything that they observe in the universe is made from a few basic blocks called fundamental particles, governed by four forces. Physicists at CERN use the world's most powerful particle accelerators and detectors to test the predictions and limits of the Standard Model. Over the years it has explained many experimental results and precisely predicted a range of phenomena, such that today it is considered a well-tested physics theory.
But the model only describes the 4% of the known universe, and questions remain. Will we see a unification of forces at the high energies of the Large Hadron Collider (LHC)? Why is gravity so weak? Why is there more matter than antimatter in the universe? Is there more exotic physics waiting to be discovered at higher energies? Will we discover evidence for a theory called supersymmetry at the LHC? Or understand the Higgs boson that gives particles mass?
Physicists at CERN are looking for answers to these questions and more – find out more below.
The unprecedented energy of proton collisions at the LHC could be what scientists need to find a possible substructure for subatomic particles
Earth is subject to a constant bombardment of subatomic particles that can reach energies far higher than the largest machines
Invisible dark matter makes up most of the universe – but we can only detect it from its gravitational effects
Extra dimensions may sound like science fiction, but they could explain why gravity is so weak
CERN physicists collide heavy ions to free quarks - recreating conditions that existed in the universe just after the Big Bang
CERN scientists are probing the fundamental structure of the universe to find out what the elementary particles are and how they interact
Supersymmetry predicts a partner particle for each particle in the Standard Model, to help explain why particles have mass
All matter in the universe was formed in one explosive event 13.7 billion years ago – the Big Bang
The big bang should have created equal amounts of matter and antimatter. So why is there far more matter than antimatter in the universe?
Elementary particles may have gained their mass from an elusive particle – the Higgs boson
The Standard Model explains how the basic building blocks of matter interact, governed by four fundamental forces
The Z boson is a neutral elementary particle which - along with its electrically charged cousin, the W - carries the weak force
Will we see a unification of forces at the high energies of the Large Hadron Collider?
The W boson carries the weak force. It changes the character of particles of matter—allowing the Sun to burn and new elements to form