 So to get some practice using these Lorentz transformations, let's use them to revisit the fundamental effects, beginning with the relativity of simultaneity. So here we have Bob's reference frame and Alice moving with some speed V relative to it. So Alice is on a train, which she measures in her reference frame to have length LA. Now in Alice's frame, two events happen simultaneously at either end of the train. So in Alice's frame, the separation in space between these two events is LA and the separation in time is zero. Using the Lorentz transformations, what is the separation in time between the two events in Bob's reference frame?