[randomguy1254]

I think the distinction is that observation can affect a system. In order to look at a particle, you need to bounce a photon off of it, which affects it. The particle/wave still exists and is still "doing calculation", its just that measuring the system literally and obviously affects it. Some people attach far too much significance to this.

[EGreg]

No, I heard this is a common misunderstanding. You can bounce light off particles going through ONE SLIT and still destroy the interference patten. Partivles going through the other slit shouldn't have been deflected - yet the interference pattern is totally broken!

What you are suggesting is there is a hidden variable theory.

[randomguy1254]

Hmm, I'm maybe missing something in this example. In the two slit experiment, a single photon can appear to go through two slits simultaneously. You appear to be suggesting that there are multiple particles going throw the slits which creates the interference, but I understand it that one particle interferes with itself, when you do not detect which slit it goes through.