Event (relativity)

In physics, and in particular relativity, an event is a point in spacetime (that is, a specific place and time) and the physical situation or occurrence associated with it. For example, a glass breaking on the floor is an event; it occurs at a unique place and a unique time. 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.

Upon choosing a frame of reference, one can assign coordinates to the event: three spatial coordinates ${\displaystyle {\vec {x}}=(x,y,z)}$ to describe the location and one time coordinate ${\displaystyle t}$ to specify the moment at which the event occurs. These four coordinates ${\displaystyle ({\vec {x}},t)}$ together form a four-vector associated to the event.

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