  Electrons in graphene, behaving as massless relativistic Dirac particles,
provide a new perspective on the relation between condensed matter and
high-energy physics. We discuss atomic collapse, a novel state of superheavy
atoms stripped of their discrete energy levels, which are transformed into
resonant states. Charge impurities in graphene provide a convenient condensed
matter system in which this effect can be explored. Relativistic dynamics also
manifests itself in another system, graphene p-n junctions. We show how the
transport problem in the presence of magnetic field can be solved with the help
of a Lorentz transformation, and use it to investigate magnetotransport in p-n
junctions. Finally, we review recent proposal to use Fabry-Perot resonances in
p-n-p structures as a vehicle to investigate Klein scattering, another hallmark
phenomenon of relativistic dynamics.
