Brian Greene, the John Cusack of String Theory, got me interested in quantum after I read his latest book, Fabric of the Cosmos. He talks about how entanglement can't be used for faster than light communication, but after seeing the delayed choice experiment I have to wonder why. So, unless you're interested in quantum, this will probably seem a little fucked.
Here's the basic setup: (see this diagram for a better idea) we have A and C seperated by a given distance and B at their midpoint. B contains a special laser which spits out individual photons at a fixed rate. This laser is run through a beam splitter (BS), both outputs of which are fed into down converters (DC) which generate entangled photons. It's basically two copies of Aspect's experiment to prove ESR-like "spooky" action being fed by a beam splitter, so it's being combined with a modified form of the double slit experiment to elicit the "delayed choice" effect through entanglement.
The pair of entangled photons emerging from the DCs travel through space, arriving at A and C simultaneously. C has two mirrors/prisms which direct the beams across each other onto a viewing screen. A has a "which path detector" (WPD) which can be selectively toggled.
When A's WPD is off, the probability waves emerging from both paths of the beam splitter are uncollapsed. Consequently, they will interfere with each other when their paths cross as they are projected onto C's screen. However, by switching on the WPD, A can collapse the probability waves at C through the "delayed choice" effect, eliciting particle-like behavior from the entangled photons and destroying the interference pattern on C's side.
So while you have to wait for the photon stream to reach A and C initially, A should, in theory, be able to communicate a message of "wave" or "particle" to C instantaneously, which should be exhibited by either the presence or absense of an interference pattern on C's screen respectively.
My first question is did anyone actually read that? If you answered yes, then my second question is does anyone care? Finally, if you answered yes to that question, my third question would be... does this actually work? My guess is... no
Here's the basic setup: (see this diagram for a better idea) we have A and C seperated by a given distance and B at their midpoint. B contains a special laser which spits out individual photons at a fixed rate. This laser is run through a beam splitter (BS), both outputs of which are fed into down converters (DC) which generate entangled photons. It's basically two copies of Aspect's experiment to prove ESR-like "spooky" action being fed by a beam splitter, so it's being combined with a modified form of the double slit experiment to elicit the "delayed choice" effect through entanglement.
The pair of entangled photons emerging from the DCs travel through space, arriving at A and C simultaneously. C has two mirrors/prisms which direct the beams across each other onto a viewing screen. A has a "which path detector" (WPD) which can be selectively toggled.
When A's WPD is off, the probability waves emerging from both paths of the beam splitter are uncollapsed. Consequently, they will interfere with each other when their paths cross as they are projected onto C's screen. However, by switching on the WPD, A can collapse the probability waves at C through the "delayed choice" effect, eliciting particle-like behavior from the entangled photons and destroying the interference pattern on C's side.
So while you have to wait for the photon stream to reach A and C initially, A should, in theory, be able to communicate a message of "wave" or "particle" to C instantaneously, which should be exhibited by either the presence or absense of an interference pattern on C's screen respectively.
My first question is did anyone actually read that? If you answered yes, then my second question is does anyone care? Finally, if you answered yes to that question, my third question would be... does this actually work? My guess is... no
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