A palindrome is a word or a number or a sequence of units that is able to be read the same way from either direction, be it forwards or backwards. Punctuation and spaces between the words or lettering is allowed. Composing literature that is categorized as a palindrome is known as ‘constrained writing.’
The longest single word palindrome in the English language contains nine letters and is “stratagem" meaning mega tarts. Other fun palindromes exist such as:
The word palindrome is derived from the Greek ‘palin,’ or “back” and ‘dromos’ or "direction." The actual Greek phrase alluded to the backward movement of the crab. Palindromes date back to about 70AD, when they were first found as a graffito buried in ash at Herculaneum.
This first known palindrome was in Latin and read “sator arepo tent opera rotas” which means either:
The sower Arepo holds the wheels with effort.
or
The sower Arepo leads with his hand the plough.
Not exactly a grammatically correct sentence, but still pretty fun.
Palindromes were also found in the ancient Greek language and in ancient Sanskrit, so obviously people have been having quite a lot of fun with these unique words for quite a long time.
Another aspect of the palindrome is that it is able to reproduce itself. If a word is formed from the first letters and then from the second, the third and the forth it can then be arranged into a word square. A word square can be read in four different ways either horizontally, vertically from and from left to bottom right or visa versa.
The most common of English palindromes are those that are read character by character, for instance level, rotor and race-car. Character by character means that each character of the word matches, and the word can be spelled the same forwards or backwards.
“Madam I’m Adam” is a famous character by character palindrome. Palindrome examples also exist in phrases or sentences where punctuation, capitals and spacing are ignored. For instance “Sit on a potato pan, Otis”. One of perhaps the most famous palindromes that exit in this form is “Able was I ere I saw Elba.”
Palindromes exist in names too; a past Prime Minister of Cambodia was named Lon Nol.
Some palindromes use words rather than letters, for example “First ladies rule the State and state the rule: ladies first.” There, instead of each character matching, the whole sentence can be read backwards and forwards. The individual letters don’t match, but the whole words do.
Palindromes aren’t just a word game. They are also found in numbers and are studied in recreational mathematic. In fact, a palindromic prime is known as a palindromic number that is a prime number.
Palindromes are even seen in molecular biology. Many molecular lengths between 4 and 8 nucleotides are palindromic as they correspond to nitrogenous sequences that read the same forwards as they do backwards.
Palindromes are seen in dates, and even in acoustics when a phrase once recorded and played backwards sounds the same. Palindromes are also found in modern and classical music pieces.
The longest known palindrome in the Oxford Dictionary is “tattarrattat”. The longest palindrome in use today is said to the Finnish word “saippuakivikauppias” which means soap stone vendor. A derivative of this is the palindrome “saippuakalasalakauppias” meaning soapfish bootlegger.