Post 2
Why base 60?
One thing pops out of my mind is that one minute
consists of 60 seconds and one hour consists of 60 minutes. I guess base 60 relates to the revolution of
the earth. When the earth rotates 360 degrees, sun rises and sun sets once
which makes one day. In addition, a
circle has 360 degrees and until today we still use base 60 to tell time. In Chinese zodiac, there are 12 animals and 5
elements (gold, wood, water, fire and earth). Each animal has to rotate through each of the
five elements to complete one zodiac cycle, which is 60 years.
Base 60 is also known as sexagesimal. This numeral system was an invention of ancient Sumerians and was inherited by ancient Babylonians. There are more factors of 60 than factors of 10. Therefore, the base 60 system certainly has provided more convenience than base 10 system. One thing interesting is that the Babylonians instead of using times tables, they did their multiplication by using a simple formula that depended on knowing just the squares and used it to compute the products of two integers (Gill,2019). However, the base 60 system wasn’t able to stand the test of time, but instead the base 10 system has dominated the numeral system. One important reason is because we have 10 fingers and much easier to count.
One interesting question
is why base 20 was also very popular in ancient time?
Reference
Gill, N.S. (2019). Babylonian Mathematics and the Base 60
System. ThoughtCo. Retrieved from https://www.thoughtco.com/why-we-still-use-babylonian-mathematics-116679
Thanks Ivy. Do be careful to think about the historical origins of things like our time and angle measurement systems though. Did these pre-date the Babylonians? It's easy to feel that they have always existed, but they did start somewhere, at some time!
ReplyDeleteI'm not familiar with that system of multiplication (and I wonder whether it is connected with Ancient Egyptian multiplication that just uses doubling and addition). We'll do more work with base 20 when we come to Mayan mathematics!