They would go back to the past and listen to music on an mp3 player
The motorcyclist stands with his back to the motorcycle and walks away from him
Actor Taylor Lautner in the dark, with his back to the camera. Werewolf
Five students stand in pairs with their backs to the blackboard
The guy walks down the road with his back to the camera. The guy in the winter forest
The girl is sitting with her back to the teddy bear
Stunning delorean from the movie "Back to the Future"