Oh yes, and then there are the time paradoxes.

He cannot be removed from his immediate area because of the vast energy loss and time paradoxes that would result.

Now that this time paradox had intervened, would that future still take place?

However, time paradoxes have begun to form, apparently as a consequence of his return.

In short, it says that it is impossible to create time paradoxes.

Peter learns of Walter's plan to sacrifice himself to take the child into the future, necessary to prevent a time paradox.

"But that can't be right," Chekov said slowly, as if the time paradox had just occurred to him.

"And this would not set up a time paradox," Tuvok said.

He tries to rewrite the notes, but fails due to a time paradox.

The old time paradox again, only I won't buy it.