# Quantum Entanglement FTL Thought Experiment

1. Oct 22, 2011

### AustinLee

I am not sure if I understand quantum entanglement so I will propose a thought experiment which you can tell me if it is correct

Say I entangle two quanta of matter, such that by observing one I collapse the wave function of the other immediately. Then I give one of the particles still in superposition to a receiver on earth. I will take the other other particle to the moon Europa with me. If I find water beneath Europa, I will observe my particle, collapsing the wave function, at a precise predetermined time. If I don't find water I don't observe my particle and leave it in wave function at the predetermined time. My receiver will know, if there is water beneath Europa by seeing if his Particle has collapsed or not(double slit can determine if it as wave or particle). He will record the time and bit of info. I will then return to earth and see that my receiver got my information at the instance of that time, therefore allowing faster than light communication.

Now if I was the receiver I could never know what information was transmitted, because the transmitter exist in superposition to me. I can never know what happened during the predetermined time.

Therefore, my reality is completely different if I am the transmitter or the receiver. In other words the transmitter and receiver have different Timelines. FTL communications can only be viewed and useful for those in the role of transmitters.

2. Oct 22, 2011

### jfy4

There is no such thing as passive observation... If your receiver wants to know the state of his entangled particle, he has to interact with it... That's going to cause a problem.

3. Oct 23, 2011

### xts

Try to design such detector - propose the experiment giving different outcome if performed with "collapsed" particle and different if with "uncollapsed".
I am afraid - even double slit won't help you with that...