Eliminating the Paradoxes

Time travellers are usually warned not to make significant changes to the past and to avoid meeting their past selves to avoid creating a paradox. Examples of this may be found in many time travel movies, such as the Back to the Future trilogy.

But in physics, a paradox is not an event that can actually happen — it is a purely theoretical concept that points towards an inconsistency in the theory itself. In other words, consistency paradoxes don’t merely imply time travel is a dangerous endeavour, they imply it simply cannot be possible.