Don’t know if anyone else ever comes back and reads here, but if so, I could use a bit of help.
I’m reading the quantum sequence, and I’m far enough in that the basics like this should be coming together. And mostly they are. But I have this nagging fact at the back of my mind that even though I can see why Figure 2 works, I can’t actually explain Figure 1.
I understand that the amplitude flows to both detectors. I understand that it follows the same rules each time. I understand why each end configuration gets the values it does. But why does each detector click 50% of the time?
Clearly I’m not supposed to glean that anything fundamental is happening with a 50% probability. Every path, every time, same rules. So why the apparently probabilistic result? Seems like both or neither should click every time.
The detector clicks 50% of the time because “detector makes a clicking noise” is so complex that it doesn’t ever end up in the same state as “detector doesn’t make a clicking noise” to interfere with it. There are multiple paths this photon can take to end up in the same configuration, because the photon moving around is simple enough that we can design an experiment to make some of the amplitude that’s flowed to different configurations flow back to the same configurations – but the detector is complex enough that it separates the amplitude flows far enough that next to none of the amplitude from “detector 1 goes off” and “detector 2 goes off” will flow to the same configuration; hence they won’t (noticeably) interfere with each other. And then the human either hears or doesn’t hear the detector; the human is also complex enough that “human hears a clicking noise from detector 1” and “human hears a clicking noise from detector 2″ aren’t going to interfere; there’s no way they’re ending up in the same configuration afterwards.
Anything that remembers where the photon went will not observe interference from the photon going the other way, because it needs to be able to reach the same configuration from both of those configurations for any amplitude flow to interfere.
Don’t know if anyone else ever comes back and reads here, but if so, I could use a bit of help.
I’m reading the quantum sequence, and I’m far enough in that the basics like this should be coming together. And mostly they are. But I have this nagging fact at the back of my mind that even though I can see why Figure 2 works, I can’t actually explain Figure 1.
I understand that the amplitude flows to both detectors. I understand that it follows the same rules each time. I understand why each end configuration gets the values it does. But why does each detector click 50% of the time?
Clearly I’m not supposed to glean that anything fundamental is happening with a 50% probability. Every path, every time, same rules. So why the apparently probabilistic result? Seems like both or neither should click every time.
The detector clicks 50% of the time because “detector makes a clicking noise” is so complex that it doesn’t ever end up in the same state as “detector doesn’t make a clicking noise” to interfere with it. There are multiple paths this photon can take to end up in the same configuration, because the photon moving around is simple enough that we can design an experiment to make some of the amplitude that’s flowed to different configurations flow back to the same configurations – but the detector is complex enough that it separates the amplitude flows far enough that next to none of the amplitude from “detector 1 goes off” and “detector 2 goes off” will flow to the same configuration; hence they won’t (noticeably) interfere with each other. And then the human either hears or doesn’t hear the detector; the human is also complex enough that “human hears a clicking noise from detector 1” and “human hears a clicking noise from detector 2″ aren’t going to interfere; there’s no way they’re ending up in the same configuration afterwards.
Anything that remembers where the photon went will not observe interference from the photon going the other way, because it needs to be able to reach the same configuration from both of those configurations for any amplitude flow to interfere.