Bob is moving to the right (positive x direction) in his spaceship at a velocity v, and Alice is observing him. Each has their own lattice of clocks and measuring systems, which can be represented in two spacetime diagrams, one for Bob’s frame of reference and one for Alice’s. True or false: Bob’s world line is the line of same location given by xB = 0, whether it’s drawn on Alice’s spacetime diagram or Bob’s spacetime diagram.