Associated Topics || Dr. Math Home || Search Dr. Math

### Origin of the 360-Degree Circle

```
Date: 11/10/1999 at 07:31:54
From: Tommy Griffin
Subject: Babylonians

Did the Babylonians discover the 360-degree circle?
```

```
Date: 11/10/1999 at 08:01:39
From: Doctor Jerry
Subject: Re: Babylonians

Hi Tommy,

According to Otto Neugebauer (in his _The Exact Sciences in
Antiquity_), who is one of the world's leading experts in ancient
mathematics and astronomy, "A second Egyptian contribution to
astronomy is the division of the day into 24 hours, though these hours
were originally not of even length but were dependent upon the
seasons." A little further on he says, "Thus our present division of
the day into 24 hours of 60 minutes each is the result of a
Hellenistic (Greek) modification of an Egyptian practice combined with
Babylonian numerical procedures."

As you may know, the Babylonians/Mesopotamians used base 60 numbers in
their business, astronomy, and mathematics (they used base 10 numbers
as well). Probably connected to this was the division of the
circumference of a circle into 360 parts by Babylonian astronomers.
Geometric circles and the apparent movement of stars on the celestial
sphere go naturally together and time is a common feature of
astronomy. I think, then, that it was natural to use the division of a
circle on a clock face.

However, Otto Neugebauer (again in his _The Exact Sciences in
Antiquity_) also says that, "The division of the circumference of the
circle into 360 parts originated in Babylonian astronomy of the last
centuries BC. The [base 60] number system as such is many centuries
older and has nothing to do with astronomical concepts."

- Doctor Jerry, The Math Forum
http://mathforum.org/dr.math/
```
Associated Topics:
Middle School Conic Sections/Circles
Middle School Geometry
Middle School History/Biography

Search the Dr. Math Library:

 Find items containing (put spaces between keywords):   Click only once for faster results: [ Choose "whole words" when searching for a word like age.] all keywords, in any order at least one, that exact phrase parts of words whole words

Submit your own question to Dr. Math
Math Forum Home || Math Library || Quick Reference || Math Forum Search