Monday, June 20, 2005

Shock - Back to the Future not so scientific!

New Scientist Breaking News - No paradox for time travellers

What an interesting snippet from New Scientist on time travel this is. Actually, I recommend you at least read the conclusion section of the paper too, here. Nah, it's too good, let's just quote it now:

"According to our model, if you travel into the past quantum mechanically, you would only see
those alternatives consistent with the world you left behind you. In other words, while you are
aware of the past, you cannot change it. No matter how unlikely the events are that could have led
to your present circumstances, once they have actually occurred, they cannot be changed. Your
trip would set up resonances that are consistent with the future that has already unfolded.

This also has enormous consequences on the paradoxes of free will. It shows that it is perfectly
logical to assume that one has many choices and that one is free to take any one of them. Until
a choice is taken, the future is not determined. However, once a choice is taken, and it leads to
a particular future, it was inevitable. It could not have been otherwise. The boundary conditions
that the future events happen as they already have, guarantees that they must have been prepared
for in the past. So, looking backwards, the world is deterministic. However, looking forwards, the
future is probabilistic.

This completely explains the classical paradox. In fact, it serves as a kind
of indirect evidence that such feedback must actually take place in nature, in the sense that without
it, a paradox exists, while with it, the paradox is resolved. (Of course, there is an equally likely
explanation, namely that going backward in time is impossible. This also solves the paradox by
avoiding it.)"


So I think that means Marty McFly never should have started fading from view when his Dad looked like missing out on meeting his mother.

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