Motion Parallax and Perspective Convergence

The book says, "Motion parallax occurs when, as we move, near by objects appear to glide rapidly past us, but more distant objects appear to move more slowly." (page 233) It also says perspective convergence is when parallel lines are being extended out and the observer is perceiving them as converging the farther away they are (page 231).

I recently rode up to philly as a passenger in a car and I saw examples of both of these occurances. I noticed when I looked out the passenger side window, the trees and the lines on the road seem to go by really fast. However, when I looked out the windsheild, the trees and lines appear to be coming at me in slow motion. Then as we kept on driving, I noticed ahead what I assumed to be one flashing light on a sign. As we got closer it looked like two flashing lights on the sign. When we were even closer I realized it was four flashing lights on a sign that was behind the original sign I thought they were on. I also did notice the road converging, but it occurred to me that the road was not the only thing that could converge.

I found a video taped at an air show and I did realize that when you look at a plane in the sky, it appears to be moving slowly because it is at a distance. The same when you see videos of a Tsunami. The wave appears to be in slow motion at a distance until it is right ontop of the camera.


-Jen Thomas