I have always been fascinated by the idea of time travel. It's been an obsession of mine ever since I was a little kid. I have some thoughts on the subject that I plan to post eventually, but in the meantime I have a thought experiment for you all to think about. Consider it a kind of prologue; something to stir the water and stimulate speculation. It's just something to bear in mind and something that will serve as a frame of reference when I finally get around to delving deeper into the matter.
Alright, the experiment begins with a large vault. The vault has a combination lock on the door, and you are the only one that has the combination. Inside the vault there is a time machine and a table. On the table there is only a single coin. Now, on Friday evening you set this coin so that it is facing heads up on the table. You seal and lock the vault and leave for the weekend. No one else can enter the vault while your gone, since no one else has the combination, and no one else is able to disturb the coin. On Monday morning you return and open the vault. Then, depending on what you find, you plan on doing one of two things:
- If you find that the coin is still on heads, you plan to get into the time machine, travel back to Saturday afternoon and flip the coin to tails. That being the case, the coin should have been on tails when you opened the vault on Monday morning, having already been flipped by yourself on Saturday. However...
- If you find that the coin has been flipped to tails, you plan to destroy the time machine, rendering it impossible to have ever traveled back to flip the coin. But if that's the case, then how did the coin ever come to be on tails?
