Palindrome (; "again") and ' (; "way, direction"). Palindromes date back at least to 79 AD, as a palindrome was found as a graffito at Herculaneum, a city buried by ash in that year. This palindrome, called the Sator Square, consists of a sentence written in Latin: "Sator Arepo Tenet Opera Rotas" ("The sower Arepo holds with effort the wheels"). It is remarkable for the fact that the first letters of each word form the first word, the second letters form the second word, and so forth. Hence, it can be arranged into a word square that reads in four different
Principle of indifference Principle of indifference The principle of indifference (also called principle of insufficient reason) is a rule for assigning epistemic probabilities. Suppose that there are "n" > 1 mutually exclusive and collectively exhaustive possibilities. The principle of indifference states that if the "n" possibilities are indistinguishable except for their names, then each possibility should be assigned a probability equal to 1/"n". In Bayesian probability, this is the simplest non-informative prior. The principle of indifference is meaningless under the frequency interpretation of probability, in which probabilities are relative frequencies rather than degrees of belief in uncertain propositions, conditional upon state information. The