Séminaire général de Physique avec :
Paulo A. Maia Neto
Instituto de Física UFRJ
I review the physics of dispersive interactions, from the van der Waals to the Casimir (or Casimir-Polder for atoms) long-distance asymptotic regime. Recent experimental results gave rise to a debate on the role of dissipation in real metals. From a theoretical point-of-view, the development of the scattering approach now allows us to consider realistic models with various non-trivial geometries, for both atom-surface and surface-surface interactions.