  The LHC will probe the nature of the vacuum that determines the properties of
particles and the forces between them. Of particular importance is the fact
that our current theories allow the Universe to be trapped in a metastable
vacuum, which may decay in the distant future, changing the nature of matter.
This could be the case in the Standard Model if the LHC finds the Higgs boson
to be light. Supersymmetry is one favoured extension of the Standard Model
which one might invoke to try to avoid such instability. However, many
supersymmetric models are also condemned to vacuum decay for different reasons.
The LHC will be able to distinguish between different supersymmetric models,
thereby testing the stability of the vacuum, and foretelling the fate of the
Universe.
