Epr

[Elmo]

Hi all,

 

I must admit I'm a newbie in quantum physics. But I would like to know a little bit more about the EPR paradox. I mean, I've found quite surprising the possibility of transmitting information without transferring mass and energy, just considering quantum entanglement.

 

Thanks you all,

[swansont]

You can't send information faster than light using entangled particles.

 

What is it you want to know?

[Elmo]

Sorry if I dind't explain myself very well, I didn't mean sending information faster than the speed of light.

I mean, entangled particles allow to send information without the necessity of moving those particles, and that would be of great advantage in some fields.

But, that advantage wouldn't be lost by the fact of having to measure the state of the particles and apply correlation methods to the measurements in order to ensure what information are we retrieving?

Maybe my only problem is a lack of useful concepts. I still have to work in some bibliography ;-)

 

Thanks for the reply!

[swansont]

What's the point of information transfer if the particles are in the same place?

 

The advantage of using entanglement is in the fidelity. If you tried to use spin entanglement and measure classically, you have a 50% chance of getting the wrong answer. Using quantum teleportation, the fidelity can reach 100%

 

http://www.its.caltech.edu/~qoptics/teleport.html

[Elmo]

Thanks for the link swansont, I promise I'll keep on studying this

[kleinwolf]

There is no information transfer, this you can understand classically via Bertelmann's socks argument :

-imagine 2 socks a blue and a yellow

-EPR paradox is not a paradox, it's really easy to understand that if you choose one sock, the remaining sock has the other color...this 100% sure..even before you know or see (i.e. "measure with your eyes") the color of yours...

 

however, in quantum mechanics, the possibilities remain after you measure once, by changing the angles of measurement, like you measure at A +/- and B -/+...then you remeasure a second time after B by changing the angle , you can again find + or -..whereas classically if the color of your sock is yellow...it remains yellow, even if you look at it again