The state of motion of a given historian changes the intimate relationship between the historian and the process being investigated, and it is this relationship that constitutes the history. This effect conspicuously manifests itself in regions in which space-time is strongly curved; for instance, around a ­massive star that has consumed its nuclear fuel and contracts under its own gravitational field.

When this process is viewed by an observer collapsing together with the star, its history is finite and it abruptly ends up in the black hole singularity. When the same process is viewed by an external observer, the history of the collapsing star lasts to infinity.

Relativity theory is a macroscopic theory, but if we want to penetrate the very roots of Chronos’s power we must reach the most fundamental layer of the world’s structure, the layer on which all physical forces are unified and universal gravity exhibits its quantum nature.

So far we have no such theory; we are only trying to tame this hypothetical layer with the help of various more or less speculative conceptions. The main obstacle is by no means the lack of clever ideas, but rather the painful deficiency of empirical indications. However, even our partial results show that, on our road to the final theory, old Chronos keeps for us a host of surprises.