continued....
the delayed choice experiment in quantum mechanics opens the path for communication back in time.
the bars marked M are mirrors that reflect the photons.
the ones marked BSA and BSB are primary beam splitters
the one marked BS is the secondary beam splitter for both slit A and B photons, it causes them to be mixed so
that its impossible to tell if the photons originated from slit A or B with certainty.
the above experiment has four detection screens,
the four being
D1, D2 = we dont know which slit of the two the photon passed thru (generates an interference pattern consisten with wave like behaviour)
D3, D4 = we know which of the two slits the photon passed through, therefore we have the wich path information (result is two bands consistent with particle like behaviour)
D0 is neearest in space to the photon emitter. D0 receives the photon "twins" of the photons that go to D1-D4. That is their behaviour is linked.
the photons going to D1- D4 take a longer more complex path so, by the time they hit their final detection screen, their twin photon has allready been detected on Do
when the photons goto D3, or D4 and we know which path they took, hence they dont give interference pattern as predicted.
When they hit D1 and D2, we are not sure if they came from slit 1 or 2, hence they give interference pattern consistent with waves.
the surprising thing is that the experimenters found that the photons that hit D0 give interference patterns or not depending on if their corresponding photon hit detection screens where their path of travel was known (slit 1 or 2) or not
the implication being that the twin photons go back in time and change the outcome on D0 screen based on what happaned to them later in time
THIS OPENS UP A PATH FOR COMMUNICATING BACK IN TIME