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Why are degrees based on 360?

  1. Jun 23, 2005 #1
    My guess is that 360 has no mathematical advantage, but it has something to do with 360 (and something) days in a year, or it was derived from some other number of importance. :confused:
  2. jcsd
  3. Jun 23, 2005 #2
  4. Jun 23, 2005 #3

    matt grime

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    i think you should google for this. i've seen this question asked a lot and ltos of answers given. look em up.
  5. Jun 23, 2005 #4
    wow, base 60 sounds like too much. I like out base 10, and 26 char alphebet lol.

    Thread dismissed
  6. Jun 23, 2005 #5
    it is interesting though that base 10 could not be a more terrible choice for doing arithmetic. base 60 (babylonian) and base 20 (mayan) are easier to work with, and more numbers divide evenly.

    we have 10 fingers though, which is probably why 10 became used..
  7. Jun 23, 2005 #6


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    The babylonians knew perfectly well that the year had 365 days. They observed that each day the Sun would rise in a slightly different position against the horizon. They called this displacement one degree. So the circumference of the horizon had 365 degrees.
    Since 365 was an awkward number, they decided later to change the division to 360, a number which have many more divisors then 365.
    The error committed was very small, so we continue to say that the Sun rises each day one degree ahead of the previous day.
  8. Jun 23, 2005 #7


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    That is a very interesting idea, could you elaborate? Consider that the rising sun does not move around the entire horizon over the year, but only a small segment of it. Consider that it moves much slower in the summer and and winter and faster spring in fall.

    Humm..., perhaps it was not the sun they were observing but the motion of the more distant stars?
  9. Jun 23, 2005 #8
    one way that the ancients did this was to build a really high pillar that was balanced. there is one day a year (based upon where you are on the earth) when the sun will pass directly through zenith and the pole won't cast a shadow.

    if you time the amount of time from that point until the next one a year later, you have a "tropical year". the interesting thing is that if you do the same thing, but by measuring the position of a distant star, you get the "sidereal year" which is slightly different.

    the difference has been theorized to be due to lunar-precession, that the moon causes the earth to "wobble" on it's axis. this theory has been challenged though, given recent data of the venus transits.
  10. Jun 24, 2005 #9


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    I stand corrected. In reality Babylonians saw that each day the Sun rose one degree ahead against the background of fixed stars. This is also the origin of the signs of the Zodiac.
  11. Jun 24, 2005 #10


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    This only happens between the Tropic of Cancer and the Tropic of Capricorn. Elsewhere the Sun never reaches the zenith. People used the SHORTEST shadow, and counted the days. They actually found 365+ days between shortest shadows of course, but the Babylonians had a place arithmetic based on 20 and they wanted an even multiple of 20, so they picked 360.
  12. Jun 24, 2005 #11
    selfAdjoint, you are correct.

    My interest has always been in the Mesamerican civilizations, I had forgotten that this wouldn't be exactly true for everyone.
  13. Jun 24, 2005 #12
    As a previous poster noted, the number 360 came to us from the ancient Sumerians (via the ancient Greeks, via the Babylonians, via the Sumerians, who supposedly received it from the gods/extraterrestrials who taught mankind all the basics of civilization).

    The number 12 was also significant to them.

    If you are interested, Zecharia Sitchin has written several books that examine early history and has provided one of the best and most thoroughly documented examinations of very early history. Here is the URL to his website:


    Of course, you should not accept one person's opinion as truth but, if nothing else, his books make very fascinating reading. Among the several topics he examines include:
    (i) pyramid building (which seemed to become the fashion at several locations on Earth--all at about the same time);
    (ii) the Great Deluge (civilizations at several locations around Earth had oral history about a Great Flood--and all of them put the Flood at about the same time);
    (iii) the astrology of civilizations at several locations (including China) around Earth seemed very similar, making use of the same constellations and the number 12;
    (iv) circumcision of males (the "Celestial Sign" was to copied by being cut into human flesh);
    and much more.

    In fact, the Imperial system of measure (miles, feet, pounds, etc.) includes much "sacred geometry" that comes to us from the "gods".

    His books are to be highly recommended.


  14. Jun 24, 2005 #13
    This is a good one (just after the last picture):

  15. Jun 24, 2005 #14


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    As you said, you should not accept Sitchin's opinion as truth. For agood critic of his writings see this site wich contains links to several others.
  16. Jun 24, 2005 #15
    Haha those look nothing alike.
  17. Jun 25, 2005 #16


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