Temporal paradox

A temporal paradox, is a time paradox, or time travel paradox. It is a paradox,               or logical contradiction, of time and time travel. 

Temporal paradoxes fall into two broad groups. Consistency paradoxes (example: the grandfather paradox) and causal loops. 

A causal loop is a paradox of time travel. It occurs when a future event is the cause of a past event, which in turn is the cause of the future event. Both events then exist in spacetime, but their origin cannot be known.

 References 

Category:Logical paradoxes