Every time there's an eclipse, as my neighbour very religiously bathes four times, chants his mantras and performs the various rituals associated with this, most inauspicious of occult events, I, equally religiously, am usually to be found on my terrace, with camera mounted on tripod, trying to catch the event on SD card. This time, rather than just put up a series of images, I thought I'd write a few words on the perception of eclipses and the hows and whys of them.

Earlier, I stopped with the creation of a true zero by Brahmagupta. Now, I have to close the circle and take us back into Europe (last seen dismissing the possibility of something being nothing), a journey that goes through Baghdad, and to an author most known for love poetry, not the poetry of numbers!

It's been a while since I wrote about anything here, so what I'm going to do now is to write about nothing. Not just any old nothing that might be lying around, but THE nothing that is at the bottom of everything! No, I haven't suddenly decided to switch to Zen Buddhism; this is a continuation of the whole numbers thing from last time. What I talked about last time was the evolution of numbers, and how we ended up with the place-value system with a zero representing the concept of “nothing” in a particular location. I had left out was the use of a zero by itself, to represent nothing, as a real value. Because it is the most celebrated of Indian contributions to mathematics in pop culture, I want to try and find out where it actually comes from.

Consider a bronze-age shepherd or herder; tending to his animals, sometimes a few animals get lost, a few get eaten by predators, and a few are stolen by others. A few are also legitimately subtracted from his flock, by being bartered away with other tribespeople, and by being slaughtered for food. At the end of the week, the flock looks thin, compared to what he started out with, and he needs to take stock of his stock. Keeping the count of animals in his head is getting more and more difficult as the number of animals in his care grows.

I'd like to begin with something that's not particularly difficult, or unfamiliar - it's just an interesting factoid, and something that makes for a good story.

Understanding the history of a concept, sometimes even the very name of something can really push you to understanding the concept itself, where a dry explanation of it would just confuse you.