Double slit experiment

[mitarbre]

I have a simple question about the double slit experiment for which I couldn't find an answer elsewhere.

Lets say that I shoot one million photons from the source while keeping only the first slit open and that I detect N1 photons on the screen behind the slits. If I now shoot one million photons while keeping only the second slit open I detect N2 photons (N1 and N2 should be pretty close). If I now open both slits and I shoot one million photons how many photons should I detect? N1+N2 or considerably less?

Thanks!

[mitarbre]

Anyone? Is my question stupid or no one knows the answer?

[prajor]

It should be n1 + n2. Why do you think it should be less.

[mitarbre]

I wanted to confirm what I thought and if such is the case than it looks to me that the interference pattern is a property of space between slits and the detector and not a property of the particle. In other words, making slits alters the space in such a way that the detected position of the particle is biased. Somewhat like a wavy bowling lane. Does it make any sense?

[chafelix]

No, in both cases you detect N1+N2, but that is if you have one HUGE detector that will grab anything past the slits, or alternatively a large number of detectors that cover all space past the slits. The interference pattern has to do with the distribution of photons caught by each such detector, depending on its position, not the total number of photons caught by all detectors