What happens at CERN? Roger Barlow Manchester University

The smaller the detail The bigger the apparatus Letters ~1/5 mm Details of print ~1/50 mm Individual paper fibres ~1/500 mm

The World’s biggest Microscope

CERN A co- operative European effort – sharing costs between many countries

Digging out a cavern

The final pillar

Tunnel – completed

LHC A machine for colliding protons at very high energies v= c

What happens? Protons collide with other protons Energies high enough to make new particles Particles stream out of the collision and analysed by detectors Results are recorded electronically and stored on disk for later analysis

The ATLAS detector

ATLAS in reality

Part of another detector (OPAL)

The DELPHI detector

What we see Proton hits proton and makes lots of stuff

Towards the New Periodic Table(?)

So finally Particle Physics is still a live subject. New discoveries are made. Textbooks go out of date. We understand things better. CERN is where it’s happening. For Europe and the world CERN is important for physicists and for taxpayers Visiting CERN is a great experience.