The Mystery of 360 Degrees in a Circle

In summary, the reason 360 degrees is in a circle is because it is easier to calculate than 100 degrees. There are more divisors in 360 degrees than in 100 degrees, so it is a cleaner system.
  • #1
konartist
47
0
Does anyone know why there is 360 degrees in a circle? Why not 100 for simplicity sake?
 
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  • #2
3600 seconds in an hour.

EDIT: Maybe I should state that this is only an educated guess... Kind of...

EDIT2: Actually, it's a complete guess.
 
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  • #3
konartist said:
Does anyone know why there is 360 degrees in a circle? Why not 100 for simplicity sake?
It's a leftover from Babylonian maths, I think.

Note that 360 has a heck of a lot more divisors than 100; thus, one might argue that it is simpler to use 360 than 100 (there is, in however, a somewhat used system of measuring angles that uses 400 units in the full circle).
 
  • #4
The Sumerians watched the Sun, Moon, and the five visible planets (Mercury, Venus, Mars, Jupiter, and Saturn), primarily for omens. They did not try to understand the motions physically. They did, however, notice the circular track of the Sun's annual path across the sky and knew that it took about 360 days to complete one year's circuit. Consequently, they divided the circular path into 360 degrees to track each day's passage of the Sun's whole journey. This probably happened about 2400 BC.

From here:
http://www.wonderquest.com/circle.htm

However, this source states it a bit differently: http://mathforum.org/library/drmath/view/59075.html

the ratio of the perimeter of a regular hexagon
to the circumference of the circumscribed circle equals a number which in
modern notation is given by 57/60 + 36/(60^2) (the Babylonians used the
sexagesimal system, i.e., their base was 60 rather than 10).

The Babylonians knew, of course, that the perimeter of a hexagon is
exactly equal to six times the radius of the circumscribed circle, in fact
that was evidently the reason why they chose to divide the circle into 360 degrees
 
  • #5
didn't the Babylonians use a base 60 number system?
 
  • #6
Sexagesimal is base 60. Actually, the Babylonians used a dual base system. Base 60 was the primary base with 10 as the secondary base (another example of a dual base system would be the Roman numeral system which has 10 as a primary base and 5 as a secondary base).

With the number of degrees approximately equal to the number of days in a year, the position of the stars shifts about 1 degree per night - a handy thing to know if you navigate by the stars as the Babylonians did.

As constructed, angles in degrees are compatible with time. The only difference is that there are 15 degrees per hour (that's the Earth's approximate rotation rate).
 
  • #7
a similar question can be

"why are there are 32 bit operations most in computer.."
 
  • #8
heman said:
a similar question can be

"why are there are 32 bit operations most in computer.."
Everything in computers is based on the binary system. [tex]2^5 = 32[/tex]. You also see 64 bit and 128, etc...Currently 32 bit is the norm. Soon it will progress (if things keep going the way they are).
 
  • #9
And the answer is analogous:

Due to the regular rise&fall of the Nile, it was convenient for the ancient Egyptians to make 32 bit computers in order to estimate the optimal base angle in the construction of their pyramids.
 
  • #10
arildno said:
And the answer is analogous:

Due to the regular rise&fall of the Nile, it was convenient for the ancient Egyptians to make 32 bit computers in order to estimate the optimal base angle in the construction of their pyramids.

I did not know that!:bugeye:
 
  • #11
Another thing I heard was that Einstein failed math 3 times! I can't believe it.

So many interesting things about math!
 
  • #12
arildno said:
And the answer is analogous:

Due to the regular rise&fall of the Nile, it was convenient for the ancient Egyptians to make 32 bit computers in order to estimate the optimal base angle in the construction of their pyramids.
What's the connection between the Nile and 32 bit? High tide - low tide?
 
  • #13
FredGarvin said:
What's the connection between the Nile and 32 bit? High tide - low tide?
I think it had more to do with the mosquito population.
 
  • #14
I seem to recall hearing that there was some spiritual significance (Babylonian?) to the number 12 too (easily divides into 360).
 
  • #15
Phobos said:
I seem to recall hearing that there was some spiritual significance (Babylonian?) to the number 12 too (easily divides into 360).
More to do with the number base (Sexagesimal is base 60) BobG was talking about. Six of those fit the year fairly well.
And a base 60 divides in so many handy ways - 2 3 4 5 6 10 12 15 20 30
Gee - think it could compete with metric?
 
  • #16
Hey, using 360 degrees is FAR better than using [tex]2 \pi [/tex] radians!

-Dan
 
  • #17
arildno said:
Due to the regular rise&fall of the Nile, it was convenient for the ancient Egyptians to make 32 bit computers in order to estimate the optimal base angle in the construction of their pyramids.
I was totally unaware that the ancient Egyptians even had computers, never mind 32-bit ones. Did they look anything like this?















http://img82.imageshack.us/img82/188/cadbcpfcopy9la.jpg
 
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  • #18
Danger said:
I was totally unaware that the ancient Egyptians even had computers, never mind 32-bit ones. Did they look anything like this?
I was always under the impression that they only had 20 bit computers.
 

Related to The Mystery of 360 Degrees in a Circle

1. What is the significance of 360 degrees in a circle?

The use of 360 degrees in a circle is a convention that has been used for thousands of years. It is believed to have originated from the ancient Sumerian civilization, where the number 360 was considered sacred and was used as a base for their number system. It also has practical applications in navigation, astronomy, and geometry, making it a useful and widely accepted unit of measurement.

2. Why do we use degrees and not another unit of measurement for angles?

Degrees are commonly used because they are easily divisible into smaller units, such as minutes and seconds, which allows for more precise measurements. They also have a long history of use and are deeply ingrained in our mathematical systems. Other units of measurement, such as radians, are also used in certain fields, but degrees remain the most commonly used unit for measuring angles.

3. How did we come up with the concept of 360 degrees in a circle?

The concept of 360 degrees in a circle is believed to have originated from the Babylonian civilization, where they used a base-60 number system. This system was based on the number 60, which has many factors and is easily divisible, making it convenient for use in measurement. Over time, this was adapted and simplified to 360 degrees, which is still in use today.

4. Are there any cultures or civilizations that use a different unit for measuring angles?

Yes, there are several cultures and civilizations that use different units for measuring angles. For example, the ancient Egyptians used a unit called the seked, which was equivalent to the slope of a pyramid and was used for construction purposes. The ancient Greeks also used a unit called the gradian, which is equivalent to 1/400 of a circle. However, degrees remain the most widely used unit for measuring angles.

5. Can 360 degrees in a circle be explained by mathematical principles?

Yes, the concept of 360 degrees in a circle can be explained by mathematical principles. A circle is divided into 360 degrees because it is the sum of the interior angles of a regular polygon with 360 sides. This is based on the fact that the sum of the interior angles of any polygon is equal to (n-2) x 180 degrees, where n is the number of sides. This principle also applies to other shapes, such as triangles and quadrilaterals.

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