Does matter differ from vacuum?
  A structured collection of thought provoking conclusions about space and time is given. Using only the Compton wavelength lambda = hbar / m c and the Schwarzschild radius r_s = 2 G m / c^2, it is argued that neither the continuity of space-time nor the concepts of space-point, instant, or point particle have experimental backing at high energies. It is then deduced that Lorentz, gauge, and discrete symmetries are not precisely fulfilled in nature. In the same way, using a simple and new Gedankenexperiment, it is found that at Planck energies, vacuum is fundamentally indistinguishable from radiation and from matter. Some consequences for supersymmetry, duality, and unification are presented. 
Christoph Schiller