SimReal SimReal - Physics - Quantum Physics - Max Zhender Interferometer Mach-Zhender Interferometer A particle is starting at A and ending at either F or G. At both F and G we have a counter showing how many times the particle is arriving there. At B we have a mirror (selector) with 50% probability that the particle will continue further on the way to C and 50% probability that the particle will continue further on the way to D. At E we have a mirror (selector) of the same type as at B with 50% probability that the particle will continue further on the way to F and 50% probability that the particle will continue further on the way to G. At C and D we have a total-reflector. At the path BC and BE we have placed two measure instrument to register which way the particle is going. Such a measurement will not have any effect on a classical particle, but it will have an effect on a quantum particle. With a classical particle we easily see that the particle will arrive at F and G with the same probability (50%). If the particle is a quantum particle, the particle will at the same time go both the way BCE and the way BDE. From E will always go to F, never to G. On the other hand, if we try to measure (either at M1 or at M2) which way the particle will go, the particle will go only one of the ways, and this is independent of which measurement we are doing. And now the particle will behave as a classical particle from the moment we are measuring.