[IAEP] [Sur] sugerencia para actividad clock

[K. K. Subramaniam]

On Monday 20 Jul 2009 10:44:23 pm Yoshiki Ohshima wrote:
> However, my point of making that clock was that each kid should make
> one to understand it.
An objective tick-tock is just one way to understand time. It is the kronos 
time. However, the round clock face stood for a different concept of time - 
time as an interval between events. This is a much more interesting story to 
play out in Etoys.

The 12 divisions of a day (and twelve of night) trace back to the need for 
farmers to predict onset of annual rainy season. Rain leads to floods in the 
river depositing rich silt along the banks (and ground water) to raise crops. 
There are approximately 12 full moons between one Rainy season to another and 
approximately 30 sun rises between two full moons. The same divisions were 
also applied to day and night. Some cultures (like India) divided day and 
night into 30 slots each (or 60 slots total) while others divided them into 12 
slots each (24 total) and further into 60 minute slices. Some (like 
Babylonians) divided both day and night into 12 slots. These divisions allowed 
one reckon and predict the onset of rains. The numbers 12, 24, 30, 60 and 360  
became important in math. We continue to divide a circle into 360 degrees 
(12x30) to this day.

The word time itself is from a root word meaning 'to slice, to cut'. The Greek 
word, kairos  means both weather and opportune time. The Sanskrit word for 
year (varsha) also means rain.  Many words in our daily use are tied to this 
concept of time (hour, minute, temporary, noon, meal, siesta, tide).

Of course, 12 moons per year is approximate so an 'extra moon' is added every 
few years to catch up. This year is one of them, so it is a good opportunity 
to learn about  'blue moon'.

Subbu