• Background
• Inside Car
• Looking Out
• Quiz

## Background

You may remember from physics class that all motion is relative. In the case of the airline passenger, everything around her is moving at the same speed. The comfortable chair, the champagne glass, the overhead television projector, the magazines, and the passenger are all moving together at the exact same speed. We may feel the rumbling of the engines and the rumbling in our stomachs when the plane encounters turbulence. But we feel this motion rather than seeing it. Unless you look out the window, you will not perceive motion visually under these circumstances. From physics that which we use to determine what is moving is called our frame of reference. The aiplane, when you look inside the airplane, is your frame of reference.

Instead of an airplane, we will visualize this phenomenon with a car. Two videos were made over the same track of ground. One video just views the inside of the car and the second is looking out of the car in about the same direction. First look at the inside car video and try to imaging how the car if moving over this period of time. Then view the looking out video to see if you were correct.

## Inside Car

 This video looks down into the dash and door of the car. You get some sense of motion from the jiggling of the video from bumps on the road and the shadows. Draw the path you think the car takes.

## Looking Out

 Now, the camera looks out in about the same direction as it was in the car. You can use motion to tell the path of the car. Does it match your expectations?