1.618

It isn't used in any of the things you asked about.

 

You people are weird !

 

Fanie, how technical do you want to get? It can get fairly complicated, depending on how comfortable you are with mathematics. Even at that, it's use in it's various forms, is less then common in current trends and applications, again, because we've devised better algorithms to sort out some of these issues.

 

PAR , I would be interested. I am sure I could learn something.

 

That's not SoF, it's Skin on Blubber.

 

That's not a SOF or a SOB, it's a George Buehler design, possibly an African theme . . .

 

Do you figure her Height to Beam ratio is 1.6?

 

I thought this would be a nice artsy discourse the value of the golden theorem in design. Not to sure about her being Buehleresk.

 

Hey, that a sharpie beam to length ratio. I wonder if it could be used to design a boat?

 

To bad this thread is not getting much attention. I like the idea of finding constructs to interpret the real world. Math being one of the constructs of the human mind. It does not not exist in the real world. But is useful in the attempt to divine the true nature of thing.

 

Sorry, I forgot the ":1" part of that woman's HBR.

Now, a 48' x 8' cruising sharpie with a freeboard at the bow of 5' (5/8) might look nice. If applying the proportions being discussed in this thread to the sheer the lowest point might be roughly in the neighborhood of 38%-40% LOA (1:1.6 to 1:1.5); but, from what I've read many a nice looking sheer will have freeboard midships and stern at just about the same height (a 1:1 ratio is also in the Fibonacci series but that may just be a coincidence), so that would put the lowest point not much below that and reserve most of the rise in sheer to the forward of midships ... which both seems like it might agree with some of classic sheer lines of old and also might help combat powderhorn in such a relatively long hull (of course you could just adopt reverse sheer in a powerboat and use powderhorn rather than try to downplay it).

Rolling on, freeboard at the stern and midships could be set at 3' (3/5) and let the lowest point be set by the curve of sheer that looks best given these four reference points. An imaginary line, to set the cabin-roof juncture to, at midships could be set at 3/2 above the sheer, and would gently curve upwards towards the bow peak or a point agreeably above it (aft, it might just run with the sheer, any designer who wants to suggest a better coordination of these lines please do so).

Does that seem like it might be a nice start for an attractive, if entirely conventional and not "Italian design", looking boat?

 

Okay, in as simple terms as I can (minimum hieroglyphics):

If you divide a line into two parts so that: the longer part divided by the smaller part, is also equal to the whole length, divided by the longer part, then you will have the golden ratio. (the "A+B is to A as A is to B" thingie I mentioned previously).



If used as a basis for a rectangle, it's considered ideal by some, mostly long dead artist types. You be the judge, but 1.7, 1.5, who knows, but I'll bet it would look just as good. Now saying this I did just get some new windows for our rental house, which where 34" by 54", clearly within the range of this "ideal ratio".

There is a unique (intentional or not) relationship between the Golden Ratio and the Fibonacci Sequence; the next number is found by adding up the two numbers before it. If you take any two successive Fibonacci Numbers, their ratio is very close to the Golden Ratio. I believe someone, with not much better to do ages ago, noticed this quirk and ran with it.

It gets more interesting when you start to play with geometry:



a/b is 1.6, b/c is 1.6, c/d is 1.6 . . . okay, this is clever, but not as unusual as you might think, as mechanical relationships do occur, even in the seemingly randomness of natural selection (which isn't all that random actually).

 

Par mentioned window opening height.

Something I have been trying to find out is this.

If you have a rectangular component sliding inside a frame, and the rectangular component is too wide in relationship to its length it twists sideways and jams.

What is the ratio between width and depth before the sliding component slides and doesn't jam??

Poida

 

Where is it written that there is a relationship between the width and depth, that affects jamming ? I'd say it might be more a relationship between the depth of the window, and the side clearances, but a little candle wax will help, whatever the reasoning.

 

It should be related to the coefficient of friction between the sash (sliding part) and the frame, and the amount of space between the sash and frame. It will also depend on where the sash is pushed.