Quote:
Originally Posted by nyrath
No, because the "information" is not being transmitted.
You are talking about Bell's Inequality.
A superficial reading of the situation would fool one into thinking this could be used to transmit information faster than light, or from inside a black hole's event horizon to the exterior. Sorry, that turns out not to be the case.
Say you have a source of quantum entangled particles. One particle goes off to your friend at Alpha Centauri. You measure the polarization of the particles pair you have, which instantly changes the polarization of the particle pair at Alpha Centauri. FTL communication, right?
Nope.
What you get at your end is a stream of random numbers. No information there. Your friend at Alpha Centauri has a stream of random numbers. No information there. However, if your friend sends you his stream of random numbers (either at the speed of light via radio, or slower than light by traveling by rocket), then you can compare the two sets of random numbers.
Which will tell you that, yes, sometime in the past, FTL information was transmitted. But the only way to get the information out of this is to compare the two lists, and the only way to compare the lists is to re-send the information slower or at the speed of light. Which sort of defeats the purpose of FTL.
It is even worse with the black hole situation, since it is impossible to transmit the second list out of the event horizon by slower or at the speed of light rates.
So no, you cannot use Bell's Inequality to send information out of an event horizon. |
Actually, you can get equivalent result from a desktop experiment. It's easy to do, if you have the correct parts. You need a laser, a two slit device, two small pieces of polarizing film, two Large pieces of polarizing film, and a non-polarizing beamsplitter. (Finding a commercial source for two slits can be tough, the rest you can buy at an optical supply store for less that $20. excluding the laser.)
Take and attach the two small pieces of polarizing film to the two slit such that each side of the two slit goes through only one one of the polarizing films, while setting each polarizing file at a 90 degree polarization to each other. (A three o'clock position on an analogue clock)
Now shoot the laser through the two slit at a target. You'll get two dots, because the polarization contains the Welcher Weg information (Welcher Weg is German for which way. If you can tell which slit the photon went through, you don't get an entanglement interference pattern.)
Here's the fun part. Take one of the big pieces of polarizing film and set it in line with two dot, at the same polarized angle as one of the two dots. You'll get one dot. The other gets polarized out of existence. Now rotate the large polarizing film slowly, At 45 degrees you no longer get a dot you get an interference pattern. Hooray! You have just built a quantum eraser. If you keep twisting it you'll get one dot again (the other side) at 90 degrees rotation. You can make the localization information go away!
Now for the
piece de resistance'. Throw the beamsplitter (remember that part?) in between the two slit and the target (and large) film. You'll get another copy of the two dots going to another spot. Put up another target and film and make another quantum eraser. In playing with them, you'll quickly find out the one does not affect the other.
The implication is that "localization" is strictly a local (at one spot) affair...