Comment Re:Limits of Measurement (Score 1) 144
Electrons interfere with themselves, because the fluctuation (which is the electron) exists in the full region between the source and screen. The interference pattern is the same no matter how slowly (in terms of electron rate) you fire the electrons, so build up is not a concern.
And this is an important point. I'm not a physicist, but one thing that helped me understand this better is to consider firing a single electron (for example) at the two slits one at the time. It could be at the rate of one per minute, one hour or whatever.
Every electron that makes it through to the screen behind the two slits will hit it at a single point. Nothing unusual there. However, if you make a histogram on the screen based on how frequently each spot gets hit by an electron you'll see the interference pattern you'd expect from a wave being split in two from the two slits. So each electron is a wave that travels through both slits, not one or the other.