At 21:49:55 on Thu, 29 Nov 2007 Tom Anderson opined:-

Right,

Fanshafting, dialling codes, and now geometry. Melvyn Bragg is currently
talking to me about the Golden Ratio [1]:

http://www.bbc.co.uk/radio4/history/...nourtime.shtml

One of his contributors has cited railway tickets as an everyday object
which is sized according to the Golden Ratio. That ratio is 1:1.618ish;
some quick measurements of tickets give me a ratio of ~1.58, which is
close but not the same. Does anyone have exact numbers from a
specification?

Oh, hang on, it's something called ISO 7810:

http://en.wikipedia.org/wiki/ISO_7810

Which has a side ratio of 1.5857725083364209ish. Right, that's that
sorted. Disregard this.

Where did that size come from? It's not an A-series size.

No idea. I see that the reference states "The proportion of sides is
approximately the golden ratio (1.618:1)."

Not that approximate - about 2% out.
--
Thoss