I don't know if this is "fascinating," but (IMHO) it does fall under the category of "ya learn something new every day!"

My carpet cleaner showed me this trick when I asked him why the rug in front of my kitchen sink always had to be drug back into place. It only travels one direction, even though we walk both ways on it.

He asked for a pencil and paper. Then he put the paper on the floor and vigorously rolled the pencil forward and backward on it with the palm of his hand (picture yourself playing with PlayDoh and making a snake).

The paper only traveled in the direction that the throw rug does!!!

He said carpet installers use this trick to make sure they are laying the carpet all the same direction.