Palindrome

A palindrome is a word, number, phrase, or other sequence of characters which reads the same backward as forward, such as madam or racecar or the number 10801. Sentence-length palindromes may be written when allowances are made for adjustments to capital letters, punctuation, and word dividers, such as 'A man, a plan, a canal, Panama!', 'Was it a car or a cat I saw?' or 'No 'x' in Nixon'. A palindrome is a word, number, phrase, or other sequence of characters which reads the same backward as forward, such as madam or racecar or the number 10801. Sentence-length palindromes may be written when allowances are made for adjustments to capital letters, punctuation, and word dividers, such as 'A man, a plan, a canal, Panama!', 'Was it a car or a cat I saw?' or 'No 'x' in Nixon'. Composing literature in palindromes is an example of constrained writing. The word 'palindrome' was first published by Henry Peacham in his book, 'The Truth of Our Times' (1638). It is derived from the Greek roots palin (πάλιν; 'again') and dromos (δρóμος; 'way, direction'); however, the Greek language uses a different word, i.e. καρκινικός, to refer to letter-by-letter reversible writing. 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 ways: horizontally or vertically from either top left to bottom right or bottom right to top left. As such, they can be referred to as palindromatic. A palindrome with the same square property is the Hebrew palindrome, 'We explained the glutton who is in the honey was burned and incinerated', (פרשנו רעבתן שבדבש נתבער ונשרף; perashnu: ra`avtan shebad'vash nitba`er venisraf), credited to Abraham ibn Ezra in 1924, and referring to the halachic question as to whether a fly landing in honey makes the honey treif (non-kosher). The palindromic Latin riddle 'In girum imus nocte et consumimur igni' ('we go in a circle at night and are consumed by fire') describes the behavior of moths. It is likely that this palindrome is from medieval rather than ancient times. The second word, borrowed from Greek, should properly be spelled gyrum. Byzantine Greeks often inscribed the palindrome, 'Wash sins, not only face' ΝΙΨΟΝ ΑΝΟΜΗΜΑΤΑ ΜΗ ΜΟΝΑΝ ΟΨΙΝ ('Nipson anomēmata mē monan opsin', engraving 'ps' with the single Greek letter Ψ, psi), on baptismal fonts; most notably in the basilica of Hagia Sophia, i.e. of the Holy Wisdom of God, in Constantinople. A variant, also a palindrome, replaces the plural ΑΝΟΜΗΜΑΤΑ ('sins') by the singular ΑΝΟΜΗΜΑ ('sin'). This practice was continued in many churches in Western Europe, such as the font at St. Mary's Church, Nottingham and also the font of St. Stephen d'Egres, Paris; at St. Menin's Abbey, Orléans; at Dulwich College; and at the following churches in England: Worlingworth (Suffolk), Harlow (Essex), Knapton (Norfolk), St Martin, Ludgate (London), and Hadleigh (Suffolk). Some well-known English palindromes are, 'Able was I ere I saw Elba', 'A man, a plan, a canal – Panama', 'Madam, I'm Adam' and 'Never odd or even'. English palindromes of notable length include mathematician Peter Hilton's 'Doc, note: I dissent. A fast never prevents a fatness. I diet on cod' and Scottish poet Alastair Reid's 'T. Eliot, top bard, notes putrid tang emanating, is sad; I'd assign it a name: gnat dirt upset on drab pot toilet.'