The particles will generate the interference pattern only if each particle could have traveled through either of the two slits, and there is no way of ascertaining which slit each one passed through.

• 只有在每个粒子都可由两道狭缝中的任一道通过，并且无法确知是通过了哪道狭缝，这些粒子才会产生干涉图样。