Well, it's the Thanksgiving Break from school and I have time to ponder some of those many ideas that have been rattling around in the back of my brain. Lately I've been thinking a lot about zero. We've been talking about how powerful this digit is in my math classes. This idea of a place-holder is so powerful. It allows us to create numbers of unimaginable magnitude.
"How can something be nothing?" asked the ancient Greeks. But those brave Indian mathematicians about 2200-2500 years ago started using a symbol to represent this idea of nothing. Not just nothing in terms of counting, but nothing of a particular place value in a numeral! This was a huge improvement over the Babylonian's empty space between digits. By the 9th Century AD, the Indian mathematicians were making use of zero in calculations, using it like any other number.
Of course the Maya had them all beat, using a symbol for zero as a placeholder in their base 20 system. However, this system was a parallel evolution and didn't seem to influence the systems we use today.