Take the 2-minute tour ×
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free, no registration required.

Possible Duplicate:
Entanglement in time

I heard that there is an experiment that uses quantum entanglement to try to send messages back to the past. I am having a hard time understanding how such experiments would work theoretically.

Can anyone offer me some insights toward these types of experiment?

share|improve this question
    
Possible duplicate: physics.stackexchange.com/q/27641/2451 –  Qmechanic Oct 3 '12 at 13:03
    
Also see physics.stackexchange.com/questions/15282/… –  Hal Swyers Oct 3 '12 at 13:16
add comment

marked as duplicate by Qmechanic, dmckee Oct 4 '12 at 13:57

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

3 Answers

up vote 0 down vote accepted

Perfect state distinguishability and computational speedups with postselected closed timelike curves

http://rd.springer.com/article/10.1007/s10701-011-9601-0

http://arxiv.org/pdf/1008.0433.pdf

....Postselection of quantum teleportation in this fashion implies that an entangled state efectively creates a noiseless quantum channel into the past.....

share|improve this answer
add comment

I don't know what kind of experiment might work like that. The only thing that comes to mind is that it could somehow exploit the superluminal speed of wavefunction collapse to transmit information. But this is, of course, impossible.

Although the collapse itself is instantaneous, it is completely random so there is no information transferred in it. The moment of transfer comes when the two parties use classical communication to compare the measurement results on both parts of the system. But this can never happen faster than with the speed of light.

share|improve this answer
add comment

My theory is if one day we can send a message to the past, somebody will obviously sent message in the past to explain they are able to send message over the time.

Today, as we know, we never receive this kind of message. So we will never able to send message in the past.

share|improve this answer
    
+1 for an answer that made me smile –  Benjamin Hodgson Oct 12 '12 at 17:11
    
We just haven't invented the right receiving device yet :) –  jcayzac Dec 6 '13 at 5:44
add comment

Not the answer you're looking for? Browse other questions tagged or ask your own question.