Basic Information
The Novikov self-consistency principle, also known as the Novikov self-consistency conjecture, is a principle developed by Dr. Igor Novikov in the mid-1980s to solve the problem of paradoxes in time travel, which is theoretically permitted in certain solutions of general relativity (solutions containing what are known as closed timelike curves). Stated simply, the Novikov consistency principle asserts that if an event exists that would give rise to a paradox, or to any "change" to the past whatsoever, then the probability of that event is zero.
Philosopher Paul Horwich, who has written a number of papers on time travel, made a similar argument prior to Novikov: that autoinfanticide did not present a problem for time travel - it merely showed that if you went back in time you would find you would not be able to kill yourself. Horwich also argued that it was possible to affect the past, but not to change it.
The Novikov self-consistency principle proposes that contradictory causal loops cannot form, but that consistent ones can.
Sources
The text above came from wikipedia, which has an excellent (though rather dense) article explaining the Novikov self-consistency principle in depth:
http://en.wikipedia.org/wiki/Novikov_self-consistency_principle
See Also:
- See also In Spite Of A Nail and Ontological Inertia.
- For a more whimsical explanation, see Hitlers Time Travel Exemption Act or Clock Roaches.
- For a competing view, see Temporal Paradox]
Game and Story Use
- If Novikov is right, you can't change the past. You can still go experience it, but probability itself will prevent you from altering anything that has already happened. No paradox can result, but certain actions may fail despite all efforts, almost as if the universe itself were out to stop you.