Recognition of art

One bizarre possibility is that forms like those from rule 30 could have been created as art long ago but not be recognized now. For while it is easy to tell that a cave painting of an animal is a piece of purposeful art, dots carved into a rock in an approximate rule 30 pattern might not even be noticed as something of human origin. But although there are many seemingly random painted patterns in caves from perhaps 30,000 BC, I would be amazed if any of them were actually produced by definite simple rules. (See page 839.)