What is a paradoxical situation?

A paradox is a situation that ends in a conclusion that does not justify the cause, and therefore self contradictory. A paradoxical situation would be, for example, if a british man came upon the shoresof America, and stated 'all Englishmen are liars'. This would mean that he, as an Englishman, is telling the truth, so it means that he is lying, so he is telling the truth, and so the loop repeats. this lack of resole has sparked many ideas of time paradoxes, and what the resolve would be. Like, if a man went back in time and killed his grandfather before he was conceived, then he would never hae benn born and couldn't have killed his grandfather, thus, scientifically speaking, not making sense.

as no-one has a time machine, we don't know what may happen, but here are a few theories:

The affected time and area would become non-existant,

The Universe would explode, implode or become non-existent (Back to the Future)

Time would justify the anomally, so the man himself may become his own grandfather (Futurama),

The man may just find himself unable.

Another though is, when suns are compressed, the become nonexistent, and because this too doesnt make a whole heap of sense, a black hole appears. Maybe that is the universes way of justifying thing that make no sense at all...?