Phi (Golden Ration) Rules

[twistsol]

Just got home and found the book on the shelf. If you have a long plane trip coming up, you can get it on Amazon.

The Golden Ratio, The story of Phi. The world's most astonishing number
by Mario Livio.

With a title like that, how could I not pick it up and read it.

[knotley]

OK, I will hijack my own thread for a comment on my "level vs flat" comment to Loring.

I drive 35 miles one way several times a week. This section of Highway 61 in the MS Delta has almost 30 miles of straight road. No curve for that section period, not even a degree off. And the MS Delta is flat - "a subjective term" for now. On a clear night returning home, there is a night light that I can first spot at 9 miles away, providing the traffic sparse or none. The light is about 12 feet up a pole about 50 feet off the highway. At the 7 mile mark I can see it just above oncoming headlights at a distance. At 5 miles, it is above any cars in the distance, but not trucks. There are a couple depressions in the land for bayous, but once out, the land is still basically flat . . . except it is not flat. It is level - as level is to the curve of the earth. In my case there are no hills or swells or rises etc. The land (highway) is level at most any one point but it certainly is not flat.
Was that confusing?

That was a great explanation. Wonderful.

[leehljp]

I get it. Kinda of like the difference between "level" vs "flat". "Flat" is straight while "level" can be curved.

OK, I will hijack my own thread for a comment on my "level vs flat" comment to Loring.

I drive 35 miles one way several times a week. This section of Highway 61 in the MS Delta has almost 30 miles of straight road. No curve for that section period, not even a degree off. And the MS Delta is flat - "a subjective term" for now. On a clear night returning home, there is a night light that I can first spot at 9 miles away, providing the traffic sparse or none. The light is about 12 feet up a pole about 50 feet off the highway. At the 7 mile mark I can see it just above oncoming headlights at a distance. At 5 miles, it is above any cars in the distance, but not trucks. There are a couple depressions in the land for bayous, but once out, the land is still basically flat . . . except it is not flat. It is level - as level is to the curve of the earth. In my case there are no hills or swells or rises etc. The land (highway) is level at most any one point but it certainly is not flat.
Was that confusing?

[dangre]

I get it. Kinda of like the difference between "level" vs "flat". "Flat" is straight while "level" can be curved.

Good, in that case, my tummy is level.

[leehljp]

Sorry as an scientist/math person I know better but when I mean exact I was thinking like an engineer and I meant you can express it accurately to many decimal places, more than your math resolution...
Pi is 3.1415926 (that's pretty much all an engineer needs for IEEE single precision floating point arthimetic)
Phi is approx 1.6 ... or so.

I get it. Kinda of like the difference between "level" vs "flat". "Flat" is straight while "level" can be curved.

[LCHIEN]

That is news to math nerds everywhere. Pi, e AND Phi are all irrational and therefore not exact.
I have used Phi and the Golden ratio in subwoofer design and cabinets. Sounds good and looks golden.

Sorry as an scientist/math person I know better but when I mean exact I was thinking like an engineer and I meant you can express it accurately to many decimal places, more than your math resolution...
Pi is 3.1415926 (that's pretty much all an engineer needs for IEEE single precision floating point arthimetic)
Phi is approx 1.6 ... or so. It's approximate and if your tried to express it to 6 decimal places and cut it that way I'd laugh at you.

[scmhogg]

I made a caliper that helped me to use the golden ratio.

http://www.bt3central.com/search.php?searchid=6495

Steve

[knotley]

Unlike Pi and e there is not an exact number for Phi. ....

That is news to math nerds everywhere. Pi, e AND Phi are all irrational and therefore not exact.
I have used Phi and the Golden ratio in subwoofer design and cabinets. Sounds good and looks golden.

[graysonh]

I agree Loring, re eyeballing. it's truly amazing how the eye will gravitate toward the golden ratio.

For the record it's "the whole is to the larger part as the larger part is to the smaller part". Ancient Greeks did not really use numbers!

[LCHIEN]

Unlike Pi and e there is not an exact number for Phi. Its an approximation and you can generally eyeball it. An accurate measure is not needed. If you need to know its roughly 1.6.

If you're off a bit no one will notice, as opposed to being off center everyone will notice and the picture will hang crooked.

So seems like a gimmick to me. If you can multiply by 1.6 you don't need the special ruler. Generally I eyeball a pleasing rectangle.

[twistsol]

I bought a book on this years ago, read it, forgot about it, and never used it for any design. I should probably dig it out again sometime and look at it again.

[cwsmith]

Read about them in a couple of my "furniture" books" and basically recall some discussion in that regard to an old high school drafting class; but, I haven't exercised the "golden ratio".

[leehljp]

I just noticed this on LeeValley's site:

http://www.leevalley.com/US/wood/pag...=1,43513,57625

Anyone use these? Kinda remind me of my appreciation of Center Finder Rules. It simplifies my calculations.

There have been several posts in the past on the Golden Ration aspect but I don't remember any suggestions of Phi Rules. Apologies if they have been mentioned.