  LECTURE GIVEN AT TH2002.
  Given a set of Boolean variables, and some constraints between them, is it
possible to find a configuration of the variables which satisfies all
constraints? This problem, which is at the heart of combinatorial optimization
and computational complexity theory, is used as a guide to show the convergence
between these fields and the statistical physics of disordered systems. New
results on satisfiability, both on the theoretical and practical side, can be
obtained thanks to the use of physics concepts and methods.
