  The biggest and most lasting among David Bohm's (1917-1992) many achievements
is to have proposed a picture of reality that explains the empirical rules of
quantum mechanics. This picture, known as pilot wave theory or Bohmian
mechanics among other names, is still the simplest and most convincing
explanation available. According to this theory, electrons are point particles
in the literal sense and move along trajectories governed by Bohm's equation of
motion. In this paper, I describe some more recent developments and extensions
of Bohmian mechanics, concerning in particular relativistic space-time and
particle creation and annihilation.
