ClipArt ETC
Print this figure on a sheet of paper and then give it a slight twirling motion as if you were swirling water around in a dish. The cog-wheels will appear to revolve slowly, while the other wheels turn rapidly in the opposite direction.

Visual Illusion

Print this figure on a sheet of paper and then give it a slight twirling motion as if you were swirling…

Which line is longer? The black line on the right appears longer than the line beside it, but both lines are exactly the same length.

Visual Illusion: Line Length

Which line is longer? The black line on the right appears longer than the line beside it, but both lines…

Who is the biggest? The policeman, most people would say. But the policeman is really the smallest, and the little girl is the biggest.

Visual Illusion: Perspective

Who is the biggest? The policeman, most people would say. But the policeman is really the smallest,…

If you fix your eyes on the two white spaces between the lines it will appear as if the top space becomes wider at the ends, and as if the bottom space becomes wider in the middle. But both lines are perfectly straight.

Visual Illusion: Sloping Lines

If you fix your eyes on the two white spaces between the lines it will appear as if the top space becomes…