[squeakland] [NaturalMath] KIds from around the world measuring the Circumference of the Earth

[K. K. Subramaniam]

On Thursday 29 Sep 2011 9:48:55 AM Alan Kay wrote:
> But consider a flat Earth and a low small sun directly over the well. This
> will yield exactly Eratosthenes' result. The key here, which I've never
> seen mentioned in any books for children, is that the Greeks had to have a
> very good set of reasons for thinking the Earth round and the sun large
> enough and far enough away (and they did).
I believe the motivation for celestial measurements goes much farther into 
history to the beginnings of agriculture in Asia. Rice was the staple diet in 
this region but it is a water-intensive crop. Farmers were dependent on 
Monsoon rains. A single harvest was sufficient to feed the population for an 
entire year. But sowing even a week earlier or later could spell doom. So 
people started tracking movements of celestial objects like Sun and Moon to 
forecast the arrival of rains. This history is carried in many words in Indian 
languages - Varsha (rains, year), Maasa (moon, month) and so on.

Tracing such connections over the millenia will be a lot more interesting than 
just using shadows to measure Earth's circumference. Without a framework, this 
exercise may just be performed, recorded and forgotten. It may not motivate 
students to ponder deeply on "why?".

Regards .. Subbu