  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.
