In terms of a background on this related experiment the University of Oregon had this to report when they conducted a test:

The formation of the interference pattern requires the existence of two slits, but how can a single photon passing through one slit `know’ about the existence of the other slit? We are stuck going back to thinking of each photon as a wave that hits both slits. Or we have to think of the photon as splitting and going through each slit separately (but how does the photon know a pair of slits is coming?). The only solution is to give up the idea of a photon or an electron having location. The location of a subatomic particle is not defined until it is observed (such as striking a screen).

This is definitely mind bending that watching a photon can change the trajectory.  How does this effect time travel?

You can read more about it on this link.

thanks to the university of oregon for the great info