• Lev Vaidman replied to the topic Counterfactual communication protocol in the forum Bohm's theory 6 years, 4 months ago

    Dear Aurelian,

    Thank You for the Comment. But why you say that Bob cannot superpose the message in a coherent way? He should put in the location 1 of the mirror, a 50:50 beam splitter instead, and a permanent mirror at location 2. This provides a coherent superposition of messages 1 and 2. Alice can arrange interference between them and measure the phase which Bob fixes. This modification is “Bohmian counterfactual” as well.

    • Yes if you include a BS you can exploit entanglement but then ,and this my point, the delay can modify the dynamic of alice in a non local way. If the system of Bob is acting fast or slow you will get a situationvery similar to your example with bubbles. Hardy in several papers showed that in bohmian mechanics the time of of the operations is very important. I am more or less sure that this will be same here.