Movie 17 & 18 (:27)

Script : Moving light sources also cast unusual shadows ­ because they cast different parts of the shadows from different positions at different times. Note the shadow's curving shape on the ground. Why does this occur ?
And although of equal intensity, why does the headlight appear brighter than the tail light as seen from above?

 

Comments : The shadow farthest away from the tram was created seconds EARLIER, when the tram was much farther to the left. Since light in this simulation moves at about walking speed, it took a significant amount of time for the shadow to reach the sidewalk, so it's delayed.