From John Spivey, Thorverton, Devon, UK
You write about complex electric circuits used to represent a fourth physical dimension (17 October, p 40). For a lighter take on a fourth dimension, read “–And He Built a Crooked House–” by Robert A. Heinlein. It is a story about a house built in the shape of a 4D cube, or a tesseract.
This gives an entertaining – but not necessarily scientific – view of problems when interacting with a physical fourth dimension. There are many video representations of the tesseract online, which show how a cube can turn itself inside out by moving within the fourth dimension.
