Please see attached image below.
The DEVICE is beaming two streams of entangled particle pairs (B1 and B2) in opposite directions (e.g.: Particle no. 1 (p1) goes left, Particle no. 2 (p2) goes right, where p1 and p2 are making up an entangled particle pair). Let us follow the left particle beam (B1) for now. When B1 encounters the Double Slit Apparatus (A1) in its way, an interference pattern will form on the Detector Screen (S1) behind. There is a switchable Which-way Detector (D1) that can monitor Double Slit Apparatus (A1). If D1 is switched off, the interference pattern prevails; however, if D1 is active, the wave function collapses and draws a ballistic pattern over time.
My questions are:
- what pattern is detected by S2 if D1 is active?
- and what pattern emerges on S2 when it is turned off?