Time travel.

I was just reading Scott Adams' blog, where he mentioned an idea known as "Retrocausality", but I will call it retrocausation, instead, because I want to. In effect, it is the idea that the present changes the past, not just vice-versa. This is a very fun idea, but not really as useful as it seems.

Example: you point a gun at a target and pull the trigger. Try to change what happens to the bullet or the target after the trigger is pulled.

Similarly, with retrocausation, you can cause the past without really changing what happened. Why? It already happened! By the time you figure out a) the effect in the past, and b) the cause in the present, the present will have become the recent past, with all its own causes from throughout time. So the timing is all off. If you think affecting the bullet and the target would be hard, think about this: affecting the past requires, instead of very little time, zero time (or less!).

Now, if the scientists figure out a way to show that the past is affected by future causes, then we'll be talking. But we'll probably be talking about predestination, so none of it will matter anyway. But just in case, I'm going to try to change the wording of that news article:
Retrocausation retrocausation retrocausation retrocausation retrocausation. Ha!