# Divine proportion?

1. May 22, 2006

### Quantum1332

So, i didn't know what this was classified as, so i settled for this genre. Can someone explain to me exactly how this works. How does everything come back to 1.618.

2. May 22, 2006

### HallsofIvy

It doesn't, any more than "everything comes back to" 1, or 2, or 3.14! $\pi$ (which can be approximated by 3.14) satisfies some very basic relationships that are found (again approximately) throughout nature because they are simple. The "divine proportion", $\frac{-1+\sqrt{5}}{2}$ which is approximately 1.618, satisfies the very simple relation $z=\frac{1-z}{z}$ which, just because it is simple occurs throughout nature.

3. May 26, 2006

### arildno

ACTUALLY, Halls, $\frac{-1+\sqrt{5}}{2}$ is less than 1, and thus only extremely approximate to 1.618..

Runs and hides within a golden rectangle..

4. May 26, 2006

### HallsofIvy

Oops, writing too fast again. I meant
$$\frac{1+\sqrt{5}}{2}$$
which is, more accurately but still not exact, 1.6180339887498948482045868343656.

5. May 27, 2006

### Miro

If u read "the Da Vinchi Code", u'll find in it all the proportions that are related to this magic number, I read it and I was some astonished but I don't have the book now to tell u more.
But I do advise u to read it, or see the film

6. May 27, 2006

### matt grime

No, no, no, no.

That 'novel' is an (atrociously badly written) piece of fiction containing Dan Brown's (or it turns out his wife's) half assed research that is completely rubbish. Do not read it for the mathematical insight. Do not read it for literary merit either (it has none).

7. May 27, 2006

### DaveC426913

Is the divine proportion not so because it is the simplest from of recursion? Recursion is a very common mechanism in nature.

8. May 27, 2006

### arildno

Hmm, I'd say that the recurrence relation $a_{n+1}=a_{n}$ is even simpler than the recurrence relation for the Fibonacci numbers.

9. May 27, 2006

### matt grime

10. May 28, 2006

### arildno

As I see it, the reason why the divine proportion occurs so often is closely related to the probable fact that most mechanisms work on a local level, and thus, any seemingly macro-scale mechanism is actually just a compound effect of local mechanisms.
That the resultant global picture should, at times, mimick the local picture isn't a too exotic possibility. But that's basically what the "divine" proportion is about.

From this perspective, it is seen that there is nothing "divine" about that proportion; rather, its prevalence indicates that there isn't any grand, intelligent design going on in nature, independent from simple, natural mechanisms.

Last edited: May 28, 2006
11. May 31, 2006