Novikov self-consistency principle

The Novikov self-consistency principle, also known as the Novikov self-consistency conjecture and Larry Niven's law of conservation of history is an idea made up by Russian physicist Igor Dmitriyevich Novikov in the 1980's. Novikov made it to solve the problem of paradoxes in time travel. The idea says that if something happens that could cause a paradox or change the past, the chance of that thing happening is zero. Then, it would be impossible to make paradoxes.