B
bonepile
Guest
I have recently finished reading John Gribbin's book <i>In Search of Shroedinger's Cat</i>, and it left me with a big question concerning quantum entanglement and FTL communication. It seems to me that there is a simple experiment that could demonstrate instantaneous communication if my understanding is correct.<br /><br />Before I get into this hypothetical experiment, let me say that I have heard a lot that relativity forbids FTL communication. Does anyone know why this is? I understand that light and matter cannot travel faster than light, but information is a theoretical concept with no direct dependence on any underlying physical reality.<br /><br />Anyways, on to my little experiment:<br /><br />1) Create a stream of entangled photons moving in opposite directions. The receiver will receive photon stream <i>R</i>, and the transmitter will receive stream <i>T</i>. The receiver and the transmitter are nearly equidistant from the source of the photons, with the transmitter being slightly closer.<br /><br />2) On the receiver side (stream <i>R</i>), set up a version of the double-slit experiment. However, instead of having two parallel slits, use orthogonal slits.<br /><br />Here is the big IF in this experiment. When the photons reach this double slit plate, the polarization is unknown. Therefore, the light should be able to pass through both the vertical and horizontal slits. This should create an interference pattern on a second plate behind the slits.<br /><br />Is that correct? If it isn't, then my experiment will not work, but if it is...<br /><br />3) At the transmitter side (stream <i>T</i>), simply transmit a "1" by inserting a polarizer in front of the photon stream. It does not matter what the polarization of each photon actually is - once you insert the filter, the polarization of photons in stream <i>R</i> should become "known", and the interference pattern should go away.<br /><br />4) At the receiver side, interference = 0, no interference = 1.<br />