ABSTRACT
Try to Imagine a situation in which you are not moving and nothing around you is moving. Such a static situation is a rarity. To minimize distractions, you may well have chosen to read this text in a place with minimal activity, such as a study carrel. Nonetheless, you are in motion as you breathe, scan and turn pages, take notes, glance at your watch, and so on. Your daily life is filled with constant activity. Your entertainment involves motion—television, movies, sports, games, dancing, and many other activities. In the classroom, the professor likely walks around the room, people wiggle, and your pen moves across your notebook. In social situations, speaking people approach you, move their mouths and bodies, and depart. On the road, you are in motion as you gauge the movement of vehicles around you, pulling over when you see and hear a fire truck or ambulance approaching you.
