
#1
Jun405, 07:02 PM

P: 2,223

Why was the number '360' chosen to be the number of degrees in a complete revolution? How far back does the number go?




#2
Jun405, 07:07 PM

P: 42

I'd think it was something to do with the number of days in the year that they believed was correct at the time. Also it is easy to divide it up I guess...
I'm not too good on the history of science... 



#3
Jun405, 07:08 PM

P: 2,223

There are easier numbers to divide. I just dont see any logical sense as to why 360 was chosen.




#4
Jun405, 07:13 PM

P: 42

360 degrees
I still think its something to do with the number of days in the year...




#5
Jun405, 07:14 PM

P: 606

A site I checked out claimed this exerpt was from a book called 'The History of Pi' by Petr Beckman.




#6
Jun405, 07:17 PM

P: 42

cool :D  well at least I learned something new staying up this late revising....




#7
Jun405, 07:35 PM

P: 2,223

So the 360 is somewhat arbitrary, and could be replaced by any figure, or does it truly represent something about a circle (or an angle)?




#8
Jun405, 08:00 PM

P: 606

It seems to be arbitrary. The Babylonians chose 60 as their numeric base rather than 10. 60 can be divided without remainder by 1,2,3,4,5 and 6. 60x6=360. Seems that avoiding decimals is the main reason it was put into use.




#9
Jun405, 08:13 PM

P: 2,223

Interesting stuff, thanks alot.




#10
Jun405, 08:42 PM

P: 26

Whoa. The babylonians used...base 60? That means they'd need 60 individual symbols for the numbers 0 through 59, right? O_o




#11
Jun405, 09:04 PM

P: 606

59 actually. no zeros at that time I think.
http://wwwgroups.dcs.stand.ac.uk/~..._numerals.html Looking at this it appears they almost did use a base 10. For some reason they decided not to stop at 10 and went all the way to 60, repeating the series all the way. Hmm, would this also be because more numbers are divisible into 60 than 10? 



#12
Jun405, 10:27 PM

P: 2,223

That sounds okay, but then there are numbers that have a more factors than 60. why was it just sixty? For example, setting it at 120 would give them 1,2,3,4,5,6,8,10.




#13
Jun405, 10:59 PM

P: 606

Looking at their system of numerals it looks like using a base of 120 would give them one more numeral that would not result in decimals and would create much more difficulty in expressing those numbers. The example in the text states that 424000 would be written in Sumerian by using the numbers 1,57,46,40. They would have to calculate 1 x 60^3 + 57 x 60^2 + 46 x 60 + 40 = 424000. With a base of 120 they would need over twice as many numerals and would need to calculate by hand much larger numbers. That is my guess. 



#14
Jun505, 01:01 AM

P: 2,223

But then one could argue that a number smaller than 60, perhaps 30, would make that calculation even easier. I wonder what their real reason was.




#15
Jun505, 01:09 AM

P: 606

Very true. Your guess is as good as mine, probably better. My understanding of math sucks.




#16
Jun505, 02:12 AM

P: 2,223

Thanks for the help man.




#17
Jun505, 10:19 AM

Sci Advisor
P: 2,751




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