I'm studying special relativity and I'm having difficulty in understanding somethings. I have 2 questions I'm confused about. 1) If I am moving in relation to you, when you observe me, I should be in slow-motion. but you are moving in relation to me, so when I observe you, will you be in slow motion too? 2) Consider the following experiment. Pam and Jim are moving in a 1-dimensional space frame. Pam moves to the right with velocity v (in relation to me, I'm at rest at the origin), and Jim moves to the left with velocity v too. Both are hanging a 1 meter rule in the hands, pointing forward. They have always the same distance in relation to the origin. Consider the following events Event 1: the front of the Pam's rule touches Jim Event 2: the back of the Pam's rule passes Jim Event 3: the front of the Jim's rule touches Pam Event 4: the back of the Jim's rule passes Pam Δt(x,y) = time interval between event x and y measured by Pam Δt'(x,y) = time interval between event x and y measured by Jim Δt''(x,y) = time interval between event x and y measured by me For me, events 1 and 3, 2 and 4 should be simultaneous. But let's analyze Jim's frame of reference. For Jim, event 1 and 2 occur at the same place, so, Jim measures the proper time. Thereby Δt(1,2) > Δt'(1,2) Also, Δt'(3,4) > Δt(3,4) For symmetry, Δt(3,4)=Δt'(1,2), Δt(1,2)=Δt'(3,4) So Δt(1,2)>Δt(3,4) and the events should not be simultaneous to Jim, the same for Pam Is this right?