The Eight Times Rule.

[peter]

In my childhood, there was an old chestnut that used to say that it was impossible to fold any piece of paper, albeit so big, in half more than eight times. Duly, we used to take bits of paper and try it and lo and behold, by the sixth/seventh or at most (at a stretch) eighth time the resultant mass became so clumsy and enwieldy that it resisted further folding just as predicted.

Now why was this true - and is it still so?

Has material science now evolved to such a point that the eight times rule no longer applies? What was it about the topology/thickness relationship of bits of (rectangular) paper back then that made them so rigid in their adherence to the rule ...... was it simply down to the thickness of paper back then (though I seem to recall trying to achieve the feat with the thinnest of tissue paper and failing, but this might be an entirely brain constructed memory - the brain does such things over the long passage of time you know) or is this one of the unwritten laws of the universe akin to (insert an unwritten law of your choice here - suddenly I find I can't think of one), never to be breached until a new universe is formed with a new set of rules.

It's a mystery!

Or is it?

[Hashi Lebwohl]

By the time you have folded the piece of paper in half six times there are now 64 layers of paper to try and fold. The force required to fold that paper again is greater than any amount of force a person would be able to exert; also, by the time that paper has been folded that many times the result of the next fold would make the paper smaller (from a top-down area point of view) smaller than thickness of the paper.

[peter]

Is that latter like a sort of mathematical thing that's always going to happen Hashi? It makes sense that it would be I think?

But the feeling I'm getting is that the eight times rule still ......errrr.....rules - and that maybe it should be renamed (by me perhaps, because I'm not aware that the eight times rule exists as a name anywhere outside my imagination, unless you maths guys have a long complicated name for the same phenomena ) the six times rule instead? Either ways it's rather nice that at least something from my childhood still survives unbroken. I like that!

[Lazy Luke]

[Zarathustra]

It's a myth you can debunk almost as quickly as you can type the question into a search engine. There's even a mathematical formula that tells you the length and thickness of a paper for a given number of possible folds.



L= length
t = thickness
n = number of desired folds

One lady achieved 11. Granted, if you want more folds, your paper must be REALLY long and thin! Having a group of people to help you may also be necessary.

[peter]

Awww Z! As per usual the cold brutality of reality sweeps away the sepia tinted imagery of things as they would be if a bit of whimsy had been scattered into the mix during baking! C'est la vie!