> As [Martin] Gardner tells the tale, on visiting Earth, an inquisitive alien wishes to collect all of human knowledge. Having no room for the Encyclopedia Britannica aboard an already-cramped spaceship (and lacking a CD-ROM player), the alien proposes a clever method for compressing the Encyclopedia's volumes. Assuming there are fewer than 1000 unique letters, digits, and other symbols in the text, our resourceful visitor assigns each symbol a three-digit code from 000 to 999, including leading 0s. The word "Snow," for example, might be encoded as 083110111119. Translating the entire Encyclopedia this way produces a giant integer that, with an imaginary decimal point to the left, is equivalent to the decimal fraction, A/B. To complete the data compression, the visitor places a mark on a small rod of otherworldly material that divides the bar into two lengths, A and B.

> After returning to Zenon (or wherever), the alien precisely measures the marked rod, obtains lengths A and B, and divides A/B to yield the original integer, which a computer decodes to print out the Encyclopedia.

- Dr Dobb's