As I wandered the aisles of my local Whole Foods one afternoon not long ago I, noticed a bright yellow sign attached to the glass door of a showcase containing packages of frozen vegetables. At the top of the sign was the word SALE, but when I looked at the other information on the sign I saw that the “sale” price was $1.49, which also happened to be the regular price of one of those bags of frozen vegetables. Truth-teller that the sign was, its “You save ___” section read “You save 0¢.” Now, I don’t think I’d ever seen a sign making a big to-do of the fact that customers would save nothing by buying an item, so I called over the first person I could find who worked in the store and pointed out the sign to him. He was baffled by it too, so he ended up giving me a bag of vegetables for a price equal to the advertised amount of the “savings,” which is to say that I ended up paying zero for my bag of frozen vegetables.
If that sign was strange, so is the word cero/zero. If you’re wondering why I say cero/zero is peculiar, ask yourself whether zero is singular or plural. The number one is certainly a singular, and any attached noun shows that: un centavo, one cent. Two, three, four, and every higher number are plurals, and any modified noun takes a plural form: dos centavos, two cents. Now for the strangeness: zero isn’t even as big as one, zero is in fact nothing, but when zero comes before a count noun (a noun that can be pluralized because it refers to things that are countable), that count noun appears in the plural. For example, a review of the children’s book How Many Elephants included the sentence “We open the flap that is the closet door to find zero elephants in the closet.” Spanish treats cero the same way, and I even found an example with the same noun; a Spanish-language Wikipedia article on cero has this question and answer: “¿Cuánto tiempo tardaremos en llenar la caja [con elefantes]? Jamás la llenaremos si tenemos cero elefantes.” And if you let me use the word singular with its meaning ‘out of the ordinary, unusual, strange,’ then I can put the striking conclusion this way:
The singular number cero/zero behaves like a plural.
This strange behavior of the number 0 most likely comes from the fact that for most of human history, whenever people started to count things, they began with 1, and that’s still almost always true today. Indo-European reflected human history: it had a set of endings for the singular, and another set for the dual, which was used for things that come in natural pairs, like eyes. Beyond that, all other whole numbers were put into the plural category, for which there was a third set of endings. After thousands (probably tens of thousands) of years of human development, some very smart people—notably among the ancient Hindus and Mayans—conceived the idea of zero. Psychologically, we seem to think of the number 0 as just another late addition to our number system, and we lump it in with all the large numbers that we are free to add to the right end, which is the plural end, of the infinite chain of numbers.
But wait, you object: this is a language blog, not a blog devoted to grocery stores or mathematics, and you’ve told us zero about the origins of the word cero/zero itself. All right, let’s zero in on that bit of etymology. Spanish and English borrowed their words from Italian zero, which was simplified from Medieval Latin zephirum. That had come from the Arabic sifr that meant ’empty, nothing,’ which is a good description of zero. In a different line of development, Medieval Latin turned the Arabic word into cifra, which passed unchanged into Spanish; it also became Old French cifre and then English cipher, which originally meant the same as its doublet zero. A cifra/cipher came to be ‘a character in general, whether a letter or a digit.’ Then, because people have long used numbers and letters to encode messages that they wanted to keep hidden, cifra/cipher added the meaning ‘a secret system of writing.’ Corresponding to that sense of the word we have the verb descifrar/decipher, with its extended meaning ‘to figure out’ (and notice how English figure can be a synonym of cipher).
© 2011 Steven Schwartzman
Note: For another take on zero and cipher, see a recent post at The virtual linguist.