December 18, 2007: Illusion

[Phage0070]

There actually is a slight trimming; while the top portions of the image are the same the bottom portion has been altered. About where the first series of pillars meets that floor two or three pixels have been removed in a line across the second image. The images are the same size though, so on the second image you can actually see more of the structure at the bottom. The images are also slightly out of line; the second image is several pixels higher than the first image.

Imagine a two parallel slanted lines, then remove a portion from one line and mate the ends vertically, extending the bottom of the line by the same amount. What you end up with is two lines that are still parallel, but the top portion of one is farther over in the direction of the tilt. It is amazing our brains can detect such subtle manipulations, but it is not completely brain-based.