Feynman’s description of the two-slit situation exemplifies that there is no hope to find out from observations on the screen alone through which slit the electron actually came. This should not come as a surprise. By having not one but many histories playing out, quantum mechanics obviously limits what we can say about the past. The quantum past is inherently fuzzy. It isn’t the kind of sharp and definite history we usually think of when we consider the past.
