Event (relativity)

[1] Strictly speaking, the notion of an event is an idealization, in the sense that it specifies a definite time and place, whereas any actual event is bound to have a finite extent, both in time and in space.

This is done by means of the metric tensor, which allows for determining the causal structure of spacetime.

The difference (or interval) between two events can be classified into spacelike, lightlike and timelike separations.

The concept of an event in relativity as a point in spacetime with arbitrarily high precision size breaks down when considering the uncertainty principle, which stipulates that there is a minimum size or accuracy for measurements made in the universe, and you cannot have arbitrary precision in measurements.

unmeasurable) particle-antiparticle pairs which spontaneously appear and then disappear, due to the uncertainty principle.

Directly next to a black hole's event horizon, one of the elements of a virtual particle-antiparticle pair (either the particle or the antiparticle) gets sucked into the black hole, leaving the other to be emitted out into spacetime; this is the source of Hawking radiation.