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[aprssig] Metric [[furlongs ... Appology

Glenn Little WB4UIV glennmaillist at bellsouth.net
Sat Sep 8 04:26:08 UTC 2007

Somewhere in this thread, someone mentioned time and why we did not use 10 
hours vs 12 hours.

A circle has 360 degrees, why I do not know. A day is defined as 24 hours 
(sort of). As the earth really rotates at 15.04 degrees per hour (plus or 
minus, due to drag of the wind on mountains and waves at sea), the day is 
really 360 divided by 15.04 or  23.936 hours. To correct for the difference 
between 24 hours per day and 23.936 hours per day, we have a leap year 
every four years unless it is a century year (ending in 00) where we forget 
the leap year (there are some other conditions to delete the leap year).

If we changed to a metric hour day of 10 hours, we would have to change a 
lot of navigation calculations (15.04 is a defined navigational constant 
known as earth rate). We would have to redefine the calendar to eliminate 
leap year. WE would have to reeducate a lot of people (it was really hard 
to educate a lot of them the first time around).

Probably easier to leave it the way it is, rather than confuse a lot of 
people, spend a lot of money redefining navigation, filling the landfill 
with all the old clocks and probably some other consequences.

On the other hand it would create some more jobs getting all these changes 



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