qqp question1: Interstellar (2014 movie): Cooper got coordinates from the message in Murph's bedroom. Where did those coordinates come from originally? question2: In the movie Interstellar, Cooper sees Murph sitting in her room after he reaches the 5D world. Does it mean that the light reflected off of Murph crosses the spacetime barrier of 3D world & enters Cooper's 5D world? If Cooper can see Murph, why can't she see him? Principle of reversibility right?