 So, we just stick these values into the Lorentz transformations and we find the difference in time in Bob's reference frame is v over c squared gamma L a. Or, using what we know about length contraction, L a equals L d on gamma, v over c squared L b. So now we have a quantitative result for the time difference that Bob measures between two events that are simultaneous in Alice's frame. So what does this depend on? Well, the first term is v over c squared. So in other words, in our everyday life, when velocity is much smaller than the speed of light, we don't notice this. But as the velocity gets larger, so does this effect. The other thing it depends on is the spacing between these two events. So if the events happen further and further apart, they are less and less simultaneous in Bob's frame. In other words, a separation in space in Alice's frame corresponds to a separation in time in Bob's. This is related to what we said earlier about how the Lorentz transformations being symmetric implies that space and time are related.