  Experiment plays a decisive role in physics. It is the single source of our
understanding of nature. But, during the last century the main accent in
theoretical physics has moved toward metaphysics. Some
mathematicians/theoreticians try to develop new approaches, ignoring
experiments. Three examples of such treatment are discussed here: the
Gutzwiller approach, the classical description of the tunneling phenomenon and
the role of irregular motion in classical mechanics. The foundations of special
relativity are also discussed.
