Why there are 360 degress in a circle

  • Context: High School 
  • Thread starter Thread starter Harmony360
  • Start date Start date
  • Tags Tags
    Circle
Click For Summary
SUMMARY

The division of a circle into 360 degrees is an arbitrary historical choice, primarily influenced by the Babylonian base-60 number system. This system contributed to the use of 360 degrees, as it aligns closely with the number of days in a year and has numerous divisors. The concept of 360 degrees has persisted despite its lack of fundamental necessity, similar to the arbitrary measurement of 12 inches in a foot. The historical context includes early astronomical beliefs and the synchronization of lunar and solar cycles, which have shaped our understanding of time and geometry.

PREREQUISITES
  • Understanding of Babylonian base-60 number system
  • Familiarity with basic geometry concepts
  • Knowledge of historical astronomical practices
  • Awareness of calendrical systems and their corrections
NEXT STEPS
  • Research the Babylonian numeral system and its influence on modern mathematics
  • Explore the historical development of geometric concepts
  • Study the relationship between astronomy and timekeeping
  • Investigate the evolution of calendrical systems and their impact on modern society
USEFUL FOR

Students of mathematics, historians of science, educators in geometry, and anyone interested in the historical context of measurement systems.

Harmony360
Messages
2
Reaction score
0
Mentor comment: Harmony360 original post violated our rules. The new wording is mine. D H[/color]

So, why there are 360 degress in a circle?
 
Last edited by a moderator:
Mathematics news on Phys.org
It was arbitrarily chosen.

Well, of course, there was historic reasons as to why it was done, but there is no fundamental reason to use 360 degrees.
 
There are 360 degrees in a circle for historical reasons. It's entirely arbitrary. You could use any number at all. You could say there are 2pi radians in a circle and everything would work out the same. Perhaps 360 was chosen because it's more or less the number of days in the year, and 360 has a lot of divisors.

I didn't follow the details of your chart, but it looks like some kind of cranky mysticism. There is no fundamental reason for dividing a circle into 360 parts, any more than there's anything meaningful about there being 12 inches in a foot.
 
Last edited:
SteveL27 said:
There are 360 degrees in a circle for historical reasons. It's entirely arbitrary. You could use any number at all. You could say there are 2pi radians in a circle and everything would work out the same. Perhaps 360 was chosen because it's more or less the number of days in the year, and 360 has a lot of divisors.

I didn't follow the details of your chart, but it looks like some kind of cranky mysticism. There is no fundamental reason for dividing a circle into 360 parts, any more than there's anything meaningful than saying there are 12 inches in a foot.

Doesn't it have something to do with Base 60? Much like themetric system is based on decimals?
 
Hey Harmony360 and welcome to the forums.

You might get hints by studying the Babylonians. They used a base 60 number system by default and this might be a connection to the use of 360 degrees for use with time.

They certainly used it for time (this is where we get minutes and seconds from), so its possible that they used it in an extended way for geometry as well.
 
yes, blame the babylonians (i always do).

for a time, it was thought that the year had 360 days in it, which would make 12 months of 30 days each. note that 12 is 1/5 of 60, and 30 is 1/2 of 60, so these are "convenient" fractions in a base-60 number system.

alas, it took astronomers some time to realize that this estimation of a solar year was incorrect. we have been paying for it with various calendrical "corrections" ever since (with bizarre conventions of leap years, and mis-matched month lengths, not to mention the whole gregorian/julian snafu).

apparently, early philosophy literally thought that life was circles within circles, with everything lining up like some grand cosmic clock. the gods themselves created this order, and although such a notion may seem on the surface ludicrous, it persists in many of the common elements of language and thought (including, ironically, a great deal of relatively "modern" science).

early astronomers also thought that the lunar cycle and the solar cycle were synchronized (a quaint reminder of this is still evident on many old clock dials, and even some wrist-watches), which is how subdivisions of solar years came to be called "moons" (months).

which goes to show that an idea, even if totally wrong, may well outlive its usefulness, causing hair-pulling for young geometry students everywhere.
 

Similar threads

  • · Replies 23 ·
Replies
23
Views
15K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 13 ·
Replies
13
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 3 ·
Replies
3
Views
7K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 3 ·
Replies
3
Views
5K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 12 ·
Replies
12
Views
2K