http://lesswrong.com/lw/r5/the_quantum_physics_sequence/
It's long and hard to understand, but easier to understand than other explanations of quantum physics.
You can skip right to the answer, though you may not accept it without having understood the background.
http://lesswrong.com/lw/qx/timeless_identity/
>If you can see the moments of now braided into time, the causal dependencies of future states on past states, the high-level pattern of synapses and the internal narrative as a computation within it - if you can viscerally dispel the classical hallucination of a little billiard ball that is you, and see your nows strung out in the river that never flows - then you can see that signing up for cryonics, being vitrified in liquid nitrogen when you die, and having your brain nanotechnologically reconstructed fifty years later, is actually less of a change than going to sleep, dreaming, and forgetting your dreams when you wake up.