  The physical origin of the Casimir force is connected with the existence of
zero-point and thermal fluctuations. The Casimir effect is very general and
finds applications in various fields of physics. This review is limited to the
rapid progress at the intersection of experiment and theory that has been
achieved in the last few years. It includes a critical assessment of the
proposed approaches to the resolution of the puzzles arising in the
applications of the Lifshitz theory of the van der Waals and Casimir forces to
real materials. All the primary experiments on the measurement of the Casimir
force between macroscopic bodies and the Casimir-Polder force between an atom
and a wall that have been performed in the last decade are reviewed, including
the theory needed for their interpretation. The methodology for the comparison
between experiment and theory in the force-distance measurements is presented.
The experimental and theoretical results described here provide a deeper
understanding of the phenomenon of dispersion forces in real materials and
offer guidance for the application of Lifshitz theory for the interpretation of
the measurement results.
