Wgat would a "light clock" measure in free fall? I've read in a couple of different books that the similarities between acceleration from gravity and rockets or whatever is only local. Both books said one of the reasons is because with acceleration from gravity two objects in free fall starting from the same place and a distance between them will slowly converge as they free fall towards the gravitational body. (oddly one of the books said the objects would meet at the centre of the body?) Are the objects in free fall following "straight lines" (geodesic)? With a light clock in free fall horizontally what happens to the time measurement if the mirrors are attached (distance between mirrors maintained)? (from the perspective of an observer from where the light clock was released) An easy guess is the clock ticks more slowly. What happens to the time measurement if the mirrors are not attached and slowly coverage with the higher gravitational potential? (from the perspective of an observer from where the light clock was released) I guess the observer sees the clock tick at the same rate. Said differently that the reduced distance between the mirrors makes up for the time dilation. Not the point of my question, but my guesses to my questions tells me the book that says the objects meet at the centre of the body is wrong. And also that no matter how close the objects were at the start of their free fall they never meet. Seems like that would define a singularity if they did.