My first post. I'm an interested layman. 1. There was a thread about this a few weeks ago but it didn't have an explanation that I could understand. Suppose my apparatus has a source that is not centered between the slits. Suppose I can measure the travel time for each particle from source to screen. With detectors at the slits I measure travel times of each clump on the screen and find that the travel times of each pile is different and agrees with what I expect. Now I shut off the slit detectors and start measuring travel time for each particle. Do I get interference? Can this experiment be done? Has it? Does being able to measure these times collapse the pattern because it gives me which way information? 2. Suppose I have a typical apparatus. I find that with detectors at the slits 1% of the particles get to the screen and 99% hit the barrier and are stopped. Now I shut off the slit detectors. Do I still see 1% getting to the screen? If so, does it mean that even though the particles are now ghosts, 99% of them are still banging their heads on the barrier? If they're spooky enough to go through both slits why does the barrier stop them? Does this mean that the "real" particle has to go through one of the slits and then it's ghost goes through the other one.