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.

[glatt]

Well, this may make it even more confusing. I drew a slanted line and attached the picture twice (under different names.) Do the lines look parallel, or is the one on the right tilted more?

[Slothboy]

Originally Posted by 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.

Hm. Actually I didn't believe this was unaltered either, because even if I covered one with my hand the other looked like it leaned more. But I opened up the Gimp, cut the image in half and moved one on top of the other with 50% transparency. I also increased the Flash Gordon noise and put some science stuff around. They are exactly the same.

[lookout123]

does the image change if you put the whole thing on a treadmill, though?

[Shawnee123]

Originally Posted by lookout123

does the image change if you put the whole thing on a treadmill, though?

I don't know, let me ask upper management. Is that a problem?