dual spirals

topic posted Wed, February 21, 2007 - 5:33 AM by  calaebus
Share/Save/Bookmark
Advertisement

I want to ask something. In the classical golden spiral, there is a second spiral implied. Each curve is 1/4 a circle.. the second spiral results when you draw the 3/4 of the remaining circle outside the square, and you do not draw the 1/4 in the square. This spiral wobbles and is not as pleasing to the eye. What is it called? You can do the same thing with golden traiangles. I think there's 2 golden traiangles.. and they each have two logarithmic spirals each.
posted by:
calaebus
Montana
Advertisement
Advertisement
  • Unsu...
     

    Re: dual spirals

    Thu, February 22, 2007 - 5:45 AM
    That is interesting. I will have to draw that and think about it.
    I havnt seen that in any literature about the golden ratio.

    Did you think ccome up with this on your own?

    Thanks,
    Dan
    • Re: dual spirals

      Mon, February 26, 2007 - 11:00 PM
      Well, in the "golden spiral," you have a large circle, with a circle phi times its size nestled within it, with a circle phi times its size nestled within that, with a circle phi times its size nestled within that, with a circle phi times its size nestled within that...

      And each circle is positioned 90 degrees along the edge of its parent circle.. 90 degrees measuring from where it's parent circle is positioned on the edge of its grandparent circle.

      Then the golden spiral is simply each of those 90 degree turns.. and the rest of the 270 degree portion of each circle is ignored.

      each 90 degree turn will be phi times the length of each succeeding 90 degree turn.

      But an infinite number of logarithmic spirals can be constructed in this way by varying the angle in which a circle rests within the parent circle, and by varying the proportion between the size of the circles

      In the golden spiral, the proportion between each circle is phi, but the rotational angle is 90 degrees, and the portion of the curve which is regarded in the spiral is also that samer 90 degree turn.

      I don't think the spiral I was talking about it a correct spiral... that's why it's not appealing to the eye. For instance, The rotational angle was 90 degrees, but then I regarded the 270 degree portion. I think they should be equal

      But why is the rotational angle in the golden spiral 90 degrees, and not the "golden angle" , about 222.5 degrees? or maybe 137.5 degrees? I think that spiral would be more golden .. but we could not inscribe it inside a geometrical figure like a trqaiangle or a rectangle.

      Also there are three golden spirals? the one inside the golden rectangle, the one in the triangle with angles 72, 72, 36 , and the one in the triangle with angles 108, 36, 36

      In some places on the internet it shows a spiral inside the first triangle I mentioned, and it says it is a golden traingle, but it is different from the spiral in the rectangle. (although the length of each turn is a length phi times the previous one.)

      The golden spiral in the rectangle has 90 degree thurns, and the other two golden spirals have turns of 108 degrees .. and umm 144 degrees

      But 144 degrees is closer to the golden angle, so why isn't that spiral considered more golden? The Nautillus shell is always mentioned, but what about all of the other sea shells? the 144 degree spiral looks more like most shell spirals to me

      By the way I think the golden ratio is used in in the cells of living things-- in the enzymes or something. I think that is how life is able to "circumvent" the second law of thermodynamics. I reseached this before, well it does not circumvent any law, but it "harnesses" the law, much like a sail harnesses the laws of aerodynamics, and can direct the boat even egainst the wind... or a plane...

      Since there is a sense of infinity in the proportion, or of 100 percent efficiency. You have heard about new types of propulsion which are said to be hoaxes, because they violate the second law,
      such as a hydrogen car that can reuse its exhaust as more fuel... well I think something like that might
      be build by
      using divine proportions, since there is a sence of 100 percent efficiency in the proportion

Recent topics in "Golden Ratio"

Topic Author Replies Last Post
Golden Ratio and Attractiveness Khrysso Heart 0 August 19, 2009
Trigonometry and the Golden Ratio Unsubscribed 6 April 20, 2008
Rock band Tool uses Fibonacci sequence Erik 4 November 14, 2007
This way to the rabbit hole! Unsubscribed 0 May 6, 2007
Geometry and Art: From Escher to Animation (event in NYC) Unsubscribed 0 April 25, 2007