What are Palindromes?

by Fran Black

A palindrome is a sequence of characters which is the same forwards as backwards. A palindrome is a word or phrase which reads the same in both directions. A palindrome is a word or phrase that reads the same forwards or backwards, for example, "noon", wow", "bib". A palindrome is when a word or phrase spells the same thing backwards (all letters reversed) as it does forwards.

Numbers can be palindromes too. We can decide that single digit numbers are all palindromes. A numeric palindrome is a sequence of numbers that is the same if read forwards or backwards (e.g., 1441 or 12321). So all even digit palindrome numbers are divisible by 11, and except for 11, all are composite numbers. Some numbers take a long time to yield a palindrome. In fact, no one has ever proven that any number leads to an infinite sequence of palindrome-free numbers in the base 10.

The concept of palindromes can also be extended to sequences and strings. A palindrome is a word, phrase, verse, or sentence which reads the same backward or forward. All can constitute examples of palindromes. Single word palindromes include "madam" and "radar". Palindromes can be of any length, and there are many sentence- and even paragraph-length palindromes. There are many short palindromes, but the number decreases sharply with increase in word length.

The period from 1860 to 1915 witnessed a flowering of public interest in various forms of wordplay and letterplay, including palindromes. Palindromes became a bit of a hobby during that time frame as writing a long palindrome requires patience and a keen eye for hidden words.

About the Author:

Francesca Black works in marketing at the Puzzle Place http://www.puzzle-place.net and Chess Strategies http://www.chess-strategies.net leading puzzle and strategy portals.