A palindrome is a word, number, phrase, or other sequences of characters that reads the same backward as forward. Palindromes can be found in a wide range of fields including music, computational theory, and genomes.
The word palindrome was introduced by Henry Peacham in 1638 and means “a running back.” Today, palindromes are one focus in the recreational linguistics community that includes such luminaries as J.A. Lindon, Dimitri Borgmann, and A. Ross Eckler, Jr.
The video below is a trailer for The Palindromists, a documentary that follows the world’s greatest palindromists as they prepare for the 2017 World Palindrome Championship.
Simple, character-unit palindromes are many and include civic, kayak, level, madam, racecar, radar, refer, and rotor. Some names are palindromes as well, such as Anna, Ava, Bob, Eve, Hannah, and Otto.
There are also word-unit palindromes in which the units of reversal are the words:
- I did, did I?
- She was, was she?
- Fall leaves after leaves fall.
- You know, I did little for you, for little did I know you.
- You can cage a swallow, can’t you, but you can’t swallow a cage, can you?
- Is it crazy how saying sentences backward creates backward sentences saying how crazy it is?
Well-known whole-phrase palindromes that ignore punctuation, capitalization, and spaces include:
- Nurses run.
- Borrow or rob?
- Dammit, I’m mad.
- Do geese see God?
- Never odd or even.
- Was it a car or a cat I saw?
- Murder for a jar of red rum.
- A man, a plan, a canal – Panama.
Examples of whole-phrase palindromes that include the spaces are:
- Step on no pets.
- Able was I ere I saw Elba.
- Live on time, emit no evil.
The Sator Square is the earliest datable 2D palindrome. It was found in the ruins of Pompeii at Herculaneum, a city buried in volcanic ash in 79 AD. It consists of the Latin sentence, “Sator Arepo Tenet Opera Rotas” (Arepo, the sower, carefully guides the wheels). It’s remarkable in that it can be read four different ways: horizontally or vertically from either top left to bottom right or bottom right to top left. The meaning of the acrostic is debated but believed by some scholars to mean, “God controls the universe.” Throughout the medieval period, the Sator Square was commonly carved into amulets and worn to ward off disease and ill-fortune.