"The Big Bang Machine"
Farid.Ould-Saada@fys.uio.no

Experimental elementary particle physics is the activity which - going hand-in-hand with theoretical particle physics - seeks to discover and understand the basic constituents of matter and the interactions among them. The present state of our knoweledge is contained in the Standard Model. 

The Large Hadron Collider LHC at the CERN laboratory in Geneva will be the first particle accelerator to explore directly a new energy frontier, the TeV scale. By colliding beams of protons or lead nuclei, the LHC will probe deeper into matter than ever before, reproducing conditions in the first nanoseconds in the life of the Universe. Starting in 2007, four experiments, among them ATLAS, will collect data that might reveal new physics phenomena.

Among the open questions, LHC may reveal the origin of particle masses, explain dark matter, investigate extra space dimensions, and help understand the origin of matter in the Universe. Several aspects of LHC physics touch on the interface between particle physics and cosmology, such that one already talks about Astro-Cosmo-(Geo?)-Particle physics. In a sense, particle physics is the science of matter, energy, space and time.