  From the interaction of physics and astrophysics we are witnessing in these
years a splendid synthesis of theoretical, experimental and observational
results originating from three fundametal physical processes. They were
originally proposed by Dirac, by Breit and Wheeler and by Sauter, Heisenberg,
Euler and Schwinger. The vacuum polarization process in strong electromagnetic
field, pioneered by Sauter, Heisenberg, Euler and Schwinger, introduced the
concept of critical electric field. It has been searched without success for
more than forty years by heavy-ion collisions in many of the leading particle
accelerators worldwide. The novel situation today is that these same processes
can be studied on a much more grandiose scale during the gravitational collapse
leading to the formation of a black hole being observed in Gamma Ray Bursts.
This report is dedicated to the scientific race in act. The theoretical and
experimental work developed in Earth-based laboratories is confronted with the
theoretical interpretation of space-based observations of phenomena originating
on cosmological scales. What has become clear in the last ten years is that all
the three above mentioned processes, duly extended in the general relativistic
framework, are necessary for the understanding of the physics of the
gravitational collapse to a black hole. Vice versa, the natural arena where
these processes can be observed in mutual interaction and on an unprecedented
scale, is indeed the realm of relativistic astrophysics.
