wu :: forums
« wu :: forums - Golden Ratio or Phi »

Welcome, Guest. Please Login or Register.
Dec 12th, 2024, 6:56am

RIDDLES SITE WRITE MATH! Home Home Help Help Search Search Members Members Login Login Register Register
   wu :: forums
   general
   truth
(Moderators: ThudnBlunder, towr, Grimbal, Icarus, SMQ, Eigenray, william wu)
   Golden Ratio or Phi
« Previous topic | Next topic »
Pages: 1 2  Reply Reply Notify of replies Notify of replies Send Topic Send Topic Print Print
   Author  Topic: Golden Ratio or Phi  (Read 7831 times)
Mugwump101
Junior Member
**





    KidNovelist
WWW Email

Gender: female
Posts: 61
Golden Ratio or Phi  
« on: Dec 6th, 2006, 1:20am »
Quote Quote Modify Modify

I'm looking for more information of where Phi or the Golden Ratio is found (I.e. exotic or creative places not like the vitruvian man or obvious) and how it was found.
 
Any ideas?
IP Logged

"When I examine myself and my methods of thought, I come to the conclusion that the gift of fantasy has meant more to me than my talent for absorbing positive knowledge. "~ Albert Einstein
towr
wu::riddles Moderator
Uberpuzzler
*****



Some people are average, some are just mean.

   


Gender: male
Posts: 13730
Re: Golden Ratio or Phi  
« Reply #1 on: Dec 6th, 2006, 1:48am »
Quote Quote Modify Modify

You can find it in a lot of ancient greek architecture. Various places in math (like geometry, e.g. pentagrams); if you look hard enough you can find it in pretty faces. If you really look hard enough, everywhere (But that's just the aneristic principle at work, really)
 
I'm not sure what exactly you want to know though. Of course wikipedia is a good start.
IP Logged

Wikipedia, Google, Mathworld, Integer sequence DB
rmsgrey
Uberpuzzler
*****





134688278 134688278   rmsgrey   rmsgrey


Gender: male
Posts: 2874
Re: Golden Ratio or Phi  
« Reply #2 on: Dec 6th, 2006, 7:05am »
Quote Quote Modify Modify

It turns up (as an angle) in plants because it's very irrational - spacing shoots the golden angle apart means they overlap as little as possible.
IP Logged
ThudnBlunder
wu::riddles Moderator
Uberpuzzler
*****




The dewdrop slides into the shining Sea

   


Gender: male
Posts: 4489
Re: Golden Ratio or Phi  
« Reply #3 on: Dec 6th, 2006, 7:37am »
Quote Quote Modify Modify

Here is a good source:
 
http://www.mcs.surrey.ac.uk/Personal/R.Knott/Fibonacci/
IP Logged

THE MEEK SHALL INHERIT THE EARTH.....................................................................er, if that's all right with the rest of you.
Mugwump101
Junior Member
**





    KidNovelist
WWW Email

Gender: female
Posts: 61
Re: Golden Ratio or Phi  
« Reply #4 on: Dec 8th, 2006, 3:32am »
Quote Quote Modify Modify

Actually more so, I'm creating a mail merge for an Excel Project and We're trying to send all the people a letter or basically advertisement for an Amusement Park that involves the Golden Ratio. Any ideas for Rides?  
 
I started out with a DNA rollar coaster and a beach with seashells, waves, lanterns, chairs that embody phi.  
 
Do any more brilliant ideas?
IP Logged

"When I examine myself and my methods of thought, I come to the conclusion that the gift of fantasy has meant more to me than my talent for absorbing positive knowledge. "~ Albert Einstein
Whiskey Tango Foxtrot
Uberpuzzler
*****



Sorry Goose, it's time to buzz a tower.

   
Email

Gender: male
Posts: 1672
Re: Golden Ratio or Phi  
« Reply #5 on: Dec 8th, 2006, 7:29am »
Quote Quote Modify Modify

Pretty much anything can implement the golden ratio if you choose it to do so.  Take a ferris wheel as an example.  The dimensions of the cars on a ferris wheel could be determined by the Golden Ratio.  The length and width of the spokes (or whatever they're called) could also do the same.  Even the queue lines to get on the rides could be constructed using the Golden Ratio.  There are an infinite number of applications here.
IP Logged

"I do not feel obliged to believe that the same God who has endowed us with sense, reason, and intellect has intended us to forgo their use." - Galileo Galilei
Aurora
Junior Member
**





   


Gender: female
Posts: 81
Re: Golden Ratio or Phi  
« Reply #6 on: Mar 1st, 2008, 6:58am »
Quote Quote Modify Modify

I found  this website the other day whilst researching Phi for art coursework. There are quite a few examples of where it can be found.
 
http://goldennumber.net/
IP Logged

"In these days, a man who says a thing cannot be done is quite apt to be interrupted by some idiot doing it."- Elbert Green Hubbard
Random Lack of Squiggily Lines
Senior Riddler
****




Everything before 7/1/2008 is now irrelevant.

   


Gender: male
Posts: 460
Re: Golden Ratio or Phi  
« Reply #7 on: Mar 9th, 2008, 5:09pm »
Quote Quote Modify Modify

turns out its 42
IP Logged

You can only believe i what you can prove, and since you have nothing proven to cmpare to, you can believe in nothing.

I have ~50 posts to hack a "R" into a "D". Which one?
Roy42
Senior Riddler
****






    ddhilltop2


Gender: male
Posts: 418
Re: Golden Ratio or Phi  
« Reply #8 on: Mar 18th, 2008, 11:29pm »
Quote Quote Modify Modify

I have a book by Mario Livio about the history of the Golden Ratio, it's origin etc. it's quite good
IP Logged

Regards,

≈Roy42
Benny
Uberpuzzler
*****





   


Gender: male
Posts: 1024
Re: Golden Ratio or Phi  
« Reply #9 on: Jun 5th, 2009, 12:42pm »
Quote Quote Modify Modify

on Dec 6th, 2006, 7:37am, THUDandBLUNDER wrote:
Here is a good source:
 
http://www.mcs.surrey.ac.uk/Personal/R.Knott/Fibonacci/

 
Yes, I like this source. Then I went to another page of the same website:
 
http://www.mcs.surrey.ac.uk/Personal/R.Knott/Fibonacci/phi.html
 
See under "Similar Numbers"
about other numbers that have the Phi property that when you square them their decimal parts remain the same.
 
series of number here is 5, (9), 13, 17, 21, (25), 29, ... which are the numbers that are 1 more than the multiples of 4.  
 
I searched for this series on the "The On-Line Encyclopedia of Integer Sequences" but couldn't find it.
 
Did I miss it?
 
« Last Edit: Jun 5th, 2009, 12:43pm by Benny » IP Logged

If we want to understand our world — or how to change it — we must first understand the rational choices that shape it.
0.999...
Full Member
***





   


Gender: male
Posts: 156
Re: Golden Ratio or Phi  
« Reply #10 on: Jun 17th, 2009, 2:19pm »
Quote Quote Modify Modify

on Mar 18th, 2008, 11:29pm, Roy wrote:
I have a book by Mario Livio about the history of the Golden Ratio, it's origin etc. it's quite good

I have it and agree.
IP Logged
Benny
Uberpuzzler
*****





   


Gender: male
Posts: 1024
Re: Golden Ratio or Phi  
« Reply #11 on: Feb 2nd, 2010, 1:24pm »
Quote Quote Modify Modify

Suppose a Fibonacci sequence starts with (a,b), that is to say:
 
(a, b, a+b, a+2b, 2a+3b, 3a+5b, ..., Fn-2 a + Fn-1 b, ...)
 
with
 
f0 = a,  
f1 = b,  
f2 = a+b,  
f3 = a+2b,  
f4 = 2a+3b,  
f5 = 3a+5b,  
....................................
fi = Fi-2 a + Fi-1 b
 
and the value of fi given, say, 104 = 24 * 54
 
What are the values of f0 and f1 ?
« Last Edit: Feb 2nd, 2010, 1:25pm by Benny » IP Logged

If we want to understand our world — or how to change it — we must first understand the rational choices that shape it.
towr
wu::riddles Moderator
Uberpuzzler
*****



Some people are average, some are just mean.

   


Gender: male
Posts: 13730
Re: Golden Ratio or Phi  
« Reply #12 on: Feb 2nd, 2010, 2:40pm »
Quote Quote Modify Modify

on Feb 2nd, 2010, 1:24pm, BenVitale wrote:
and the value of fi given, say, 104 = 24 * 54
 
What are the values of f0 and f1 ?
There is no way to tell if you're only given one fi
 
For example, if f2=x, then for any a  f0=a, f1x-a works.
And obviously you can work backwards for later i in a similar way.
IP Logged

Wikipedia, Google, Mathworld, Integer sequence DB
Benny
Uberpuzzler
*****





   


Gender: male
Posts: 1024
Re: Golden Ratio or Phi  
« Reply #13 on: Feb 2nd, 2010, 2:58pm »
Quote Quote Modify Modify

on Feb 2nd, 2010, 2:40pm, towr wrote:

There is no way to tell if you're only given one fi

 
Could we use the Index shift rule to determine the first two terms of this sequence?
I thought I could, but I got stuck ... so I posted this problem, here, requesting help.
 
Quote:

For example, if f2=x, then for any a  f0=a, f1x-a works.
And obviously you can work backwards for later i in a similar way.

IP Logged

If we want to understand our world — or how to change it — we must first understand the rational choices that shape it.
rmsgrey
Uberpuzzler
*****





134688278 134688278   rmsgrey   rmsgrey


Gender: male
Posts: 2874
Re: Golden Ratio or Phi  
« Reply #14 on: Feb 2nd, 2010, 5:01pm »
Quote Quote Modify Modify

on Feb 2nd, 2010, 2:58pm, BenVitale wrote:

 
Could we use the Index shift rule to determine the first two terms of this sequence?
I thought I could, but I got stuck ... so I posted this problem, here, requesting help.
 

What towr was trying to convey is that for any given fi, you can choose any value you want for fi-1 and that will give you a different (but still valid) sequence.
 
 
Another way of looking at it is that you have one equation in two unknowns:
fi = Fi-2a + Fi-1b
where everything but a and b is known.
 
Adding in an expression for any other term of the sequence adds another equation and another unknown (that term of the sequence) so doesn't help make the system of equations any more solvable.
IP Logged
Benny
Uberpuzzler
*****





   


Gender: male
Posts: 1024
Re: Golden Ratio or Phi  
« Reply #15 on: Feb 2nd, 2010, 5:49pm »
Quote Quote Modify Modify

Oh, I see. I'm trying to be creative with the Fibonacci series. And, I was trying to figure out a formula to test a number with a Fibo that starts with (a,b)
 
We know that in the Fibo series that starts with (1,1), that is:
 
0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, ...
 
N is a Fibonacci number if and only if 5N2 + 4 or 5N2 – 4 is a square number
 
What would be the formula to test numbers to see if they belong in Fibo (a,b)?
IP Logged

If we want to understand our world — or how to change it — we must first understand the rational choices that shape it.
JohanC
Senior Riddler
****





   


Posts: 460
Re: Golden Ratio or Phi  
« Reply #16 on: Feb 3rd, 2010, 3:22am »
Quote Quote Modify Modify

on Feb 2nd, 2010, 1:24pm, BenVitale wrote:
Suppose a Fibonacci sequence starts with (a,b), that is to say:
 
(a, b, a+b, a+2b, 2a+3b, 3a+5b, ..., Fn-2 a + Fn-1 b, ...)
 
with
 
f0 = a,  
f1 = b,  
f2 = a+b,  
f3 = a+2b,  
f4 = 2a+3b,  
f5 = 3a+5b,  
....................................
fi = Fi-2 a + Fi-1 b
 
and the value of fi given, say, 104 = 24 * 54
 
What are the values of f0 and f1 ?

A more tricky variant on this question would be:
what is the largest i for which the series exists entirely of positive numbers?
IP Logged
pex
Uberpuzzler
*****





   


Gender: male
Posts: 880
Re: Golden Ratio or Phi  
« Reply #17 on: Feb 3rd, 2010, 3:48am »
Quote Quote Modify Modify

on Feb 3rd, 2010, 3:22am, JohanC wrote:
A more tricky variant on this question would be:
what is the largest i for which the series exists entirely of positive numbers?

For fi = 10000, I find i = 13 for (a, b) = (80, 20) by a simple exhaustive search. I don't think it's a coincidence that for these (a, b), fi-1 is approximately 10000 / Phi.
IP Logged
towr
wu::riddles Moderator
Uberpuzzler
*****



Some people are average, some are just mean.

   


Gender: male
Posts: 13730
Re: Golden Ratio or Phi  
« Reply #18 on: Feb 3rd, 2010, 4:23am »
Quote Quote Modify Modify

on Feb 2nd, 2010, 5:49pm, BenVitale wrote:
What would be the formula to test numbers to see if they belong in Fibo (a,b)?

fn ~= (a+b)/sqrt(5) n-2, so if a,b are given it's simple enough.
 
« Last Edit: Feb 3rd, 2010, 4:34am by towr » IP Logged

Wikipedia, Google, Mathworld, Integer sequence DB
Benny
Uberpuzzler
*****





   


Gender: male
Posts: 1024
Re: Golden Ratio or Phi  
« Reply #19 on: Feb 3rd, 2010, 1:18pm »
Quote Quote Modify Modify

Thanks to all of you for the contributions.
 
post deleted
 
Reason: Basically, I asked how was the formula (5N2 + 4 or 5N2 – 4 is a square number) constructed?
 
I found the construction of the formula.
« Last Edit: Feb 3rd, 2010, 1:37pm by Benny » IP Logged

If we want to understand our world — or how to change it — we must first understand the rational choices that shape it.
Benny
Uberpuzzler
*****





   


Gender: male
Posts: 1024
Re: Golden Ratio or Phi  
« Reply #20 on: Feb 20th, 2010, 2:53pm »
Quote Quote Modify Modify

This site suggests that there is a relationship between Fibonacci series and Stock Market prices
 
http://goldennumber.net/stocks.htm
 
What do you think?
IP Logged

If we want to understand our world — or how to change it — we must first understand the rational choices that shape it.
towr
wu::riddles Moderator
Uberpuzzler
*****



Some people are average, some are just mean.

   


Gender: male
Posts: 13730
Re: Golden Ratio or Phi  
« Reply #21 on: Feb 20th, 2010, 3:05pm »
Quote Quote Modify Modify

on Feb 20th, 2010, 2:53pm, BenVitale wrote:
What do you think?
I think they're mad.
IP Logged

Wikipedia, Google, Mathworld, Integer sequence DB
Grimbal
wu::riddles Moderator
Uberpuzzler
*****






   


Gender: male
Posts: 7527
Re: Golden Ratio or Phi  
« Reply #22 on: Feb 23rd, 2010, 2:14am »
Quote Quote Modify Modify

Not mad, just salespeople.
 
The madmen are those who buy from them.
IP Logged
Benny
Uberpuzzler
*****





   


Gender: male
Posts: 1024
Re: Golden Ratio or Phi  
« Reply #23 on: Feb 23rd, 2010, 10:51am »
Quote Quote Modify Modify

Yes, I agree. It is a mad attempt. It is the behavior of a snake oil salesmen.
 
This shows our deep need for control. We are in a deep recession, and we feel out of control. We feel fear.
 
From an evolutionary standpoint, if we are in control of our environment, then we have a far better chance of survival.  
 
The owners of that website are selling a software. Either they believe in their product or are just dishonest. They know that the stock market is driven by fear and greed.
IP Logged

If we want to understand our world — or how to change it — we must first understand the rational choices that shape it.
Benny
Uberpuzzler
*****





   


Gender: male
Posts: 1024
Re: Golden Ratio or Phi  
« Reply #24 on: Sep 3rd, 2011, 2:06pm »
Quote Quote Modify Modify

Mathworld gives the following Golden Ratio Approximations
 
http://mathworld.wolfram.com/GoldenRatioApproximations.html
 
The first two approximations:
(5*pi/6)^.5
http://www.wolframalpha.com/input/?i=%285*pi%2F6%29^.5
or here http://tinyurl.com/4y66rat
 
(7*pi/5*e)
http://www.wolframalpha.com/input/?i=%287*pi%29%2F%285*e%29
 
I found a curious approximation where only the digit 5 is used:
 
 5^.5*.5+.5
 
http://www.wolframalpha.com/input/?i=+5^.5*.5%2B.5  
or here http://tinyurl.com/3as4uau
 
 
 
 
 
« Last Edit: Sep 3rd, 2011, 2:11pm by Benny » IP Logged

If we want to understand our world — or how to change it — we must first understand the rational choices that shape it.
Pages: 1 2  Reply Reply Notify of replies Notify of replies Send Topic Send Topic Print Print

« Previous topic | Next topic »

Powered by YaBB 1 Gold - SP 1.4!
Forum software copyright © 2000-2004 Yet another Bulletin Board