0 is not a number


I am zero and I love to hide. I am a real master at it and I find it really exciting. Especially when I am actually visible, but nobody can see me. Nobody discovered me for centuries. There were always moments when people could have seen me, yes, when they should have seen me - if they had only opened their eyes.

The philosophers and pseudo-philosophers gave me a special tickle. You made me a topic. Because they thought deeply about nothingness. But then they argued as sharp as they were stupid: You can't represent “nothing” by “something”. Totally wrong! The opposite is true: you have to represent nothing with a sign, otherwise you can neither talk about it nor count on it.

The Babylonians had a wonderful number system 4,000 years ago. Something like our decimal system, just not base 10, but base 60. That was perfect. At least almost perfect. You used only 59 digits. They had signs for 1 and 10 that they used to compose all the numbers - just not 60, as it would have been correct. Because I, the zero, was missing. And that had profound consequences.

Why? It's simple: imagine someone owed you 205 euros. If I, the zero, weren't there, you could just write this amount by first writing a 2, then leaving a space, and then writing the 5. Your counterpart would of course say: “I only owe you 25 euros, because there is no gap at all between the 2 and the 5, but the numbers are just not written very close to one another!” Apparently there would be no end to confusion. That would give the lawyers work, but they should rather deal with other problems!

And the Romans? The system of their numbers with its Is and Vs and Ms is completely useless for arithmetic. That's what the Romans had the abacus for. It already works with a kind of decimal system. Because the different rods on which the stones or pearls sit represent the units place, the tens place, the hundreds place and so on. A number is represented by sliding the corresponding stones into the center of the abacus. If all the stones are on the outside, that basically represents zero. But nobody noticed at the time!

The Romans only had to look at the other end of the world. The Maya in Central America had a number system with zero for a long time, namely a base 20 system. For this they needed 20 digits, from 1 to 19 - and the zero. The Maya used the most beautiful symbol for me, the zero: a beautiful shell. But nobody in Europe noticed: America was at least as inaccessible as zero at the time.

The Indians opened their eyes and saw me. We don't know when that was exactly. But when I was discovered, it suddenly became natural to use me. A little curl and everything was clear! My triumphal march began in the 7th century. The Arabs brought me to Spain, and from there I conquered Central Europe. Today I am taken for granted all over the world. Now that I have been known and I am omnipresent, nobody can imagine what it was like without me.

I was and am underestimated. When it comes to adding and subtracting, I'm actually harmless. I don't do anything to a number - nothing changes through me. That's why nobody takes me seriously. My true power only shows in the other types of arithmetic: When I multiply, I make everything null and void. And if you dared to divide by me, the number system would go awry. That is why it is also forbidden.

July 20, 2010

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