Background

The Ames room is a neat illusion because it can be instantiated in real space, as has been done in numerous science museums, such as those in Melbourne, Australia; Keswick, England; and Jerusalem, Israel. In the Ames room, we put two people of normal size into a room that is anything but normal. When viewed through a peephole on the side of one of the walls, the perception is of a very large person in one corner and a very small person in the other corner. The room, however, looks normal. But the room is not normal. Indeed, it defies almost all conventional rules of rooms. Its walls (except the one people are looking through) are trapezoids, as are the windows in the room. In versions in which there are floor tiles in the room, these are also trapezoids (see Figure 7.343). However, when we look through the viewing hole, we cannot distinguish the trapezoids, and we use our cues of familiar sizes and shapes to infer a normal room. Our visual systems convert the trapezoids into squares, so that we can perceive the room itself as normal. Because we perceive a normal room, we must therefore infer that the people are abnormally short or tall.

On the video in the next tab you can see people move around in the Ames room.

3D Movie (Stereopsis)

The video shows the people moving through the Ames room to show how the same object can appear to be different sizes when in different positions in the room.