Thursday, March 19, 2009

Egyptian Fractions

The Egyptian were a clever lot. They discovered a lot of science/math out of necessity and availability of many strange phenomena. The flooding valley of the Nile left them with really fertile ground and gave them several opportunities. Having a large amount of the valley area flood every year fomented community organization and the establishment of a city authority to delegate zoning. Grain surpluses translated in hyperaccelerated development and trade.

The grain trade led to the creation of a set of measurements and instruments. One popular unit was the Heqat that measured volume. You would go to a bar in Men-nefer (Memphis) sit between the sun priest and the scribe and order 1/5 Heqat (1pint) of fine Egyptian beer which you would drink through a straw.

Out of the grain trade arose the necessity to create a system of fractional numbers. since grain could not be sold by the number a heqat was determined to be an important unit and any fraction of it would be represented as a sum of unit fractions. this was likely due to having to carry a different set of containers that could measure each fractional ammount.

so an egyptian merchant would have his heqat bag, a half heqat bag a third heqat bag a fourth heqat bag a fifth heqat bag....
so they decided to represent numbers as sums of unit fractions.

1/2=1/2
(2)
1/3=1/3
(3)
2/3=1/2+1/6
(4)
1/4=1/4
(5)
2/4=1/2
(6)
3/4=1/2+1/4
(7)
1/5=1/5
(8)
2/5=1/3+1/(15)
(9)
3/5=1/2+1/(10)
(10)
4/5=1/2+1/4+1/(20).
if you were an important egyptian mathematician and wanted to know the value of pi.you would make using a compass you draw a circle in the ground with one cubit of radius.
then the egyptian representation of pi would be
3 + 1/8 + 1/61 + 1/5020 +1/128541455 + 1/162924332716605980
this number system only has one advantage to reduce the number of bits necessary to express common units like 1/2 or 1/4 or 3/4 or 2/3.

Perhaps it was this awefull system that plateaued egyptian mathematical progress and let the summerians and other civs improve much more.

1 comments:

Anonymous said...

haha, u updated!