I’d bet someone has already said this, but I’m not going to dig through the database.
Why can’t I fold the regular sheet of newsprint more than X number of times? (I thought it was 8) Elementary, Watson… add up the number of ply you’re folding after 7 times.
1st fold - 2 ply
2nd fold - 4 ply
3rd fold - 8 ply
4th fold - 16 ply… and so on.
2 ^7 is 128 “pages”
2 ^8 is 256! Can anyone here bend 256 pages against itself? Count out 128 pages of your local phone book, bend them once over themself, and try to bend them again. The outside ones will even tear if you can get the pressure needed.
The thickness, of course, is a factor… and the underlying assumption of the original claim is that you will be using regular, relatively thick paper. Not some space age, ethereal hamburger wrapper only 3 atoms thick.
$0.02 to the good,
Regards,
Jai Pey
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James Parsons
IANBABAIBOTID
“…because the only people for me are the MAD ones…” - J Kerouac
I once doubled and redoubled a piece of tissue paper (like you use for gift wrapping) eight times. There was a trick, even then. After the first several folds, I started using a vise to compress between folds. On the 6th and 7th fold, the paper started to break at the bends and the last fold didn’t resemble a fold so much as a curve, but hey… I won the bet.
I just so happened to recently catch a repeat of Beakman’s World, where Beakman also said you can’t fold regular-thickness paper more than 8 times and he gave the same explanation as you. Instead of “pages”, he used the word “layers”.
Seriously… more than 8 times, you’d be folding a lot of paper. And to compicate matters, there’s an inverse proportion involded with the area of any given layer. Each fold --> layers ^2 : area / 2
So unless you started with an insanely big (and thin) sheet of paper, 8 would be the limit. I remember there being a proviso too, the first time I encountered this … that you use newsprint.
This is obviously not stirring up radical debate.
Jai Pey
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James Parsons
IANBABAIBOTID
“…because the only people for me are the MAD ones…” - J Kerouac
The mechanics are worse than simply inverse. The general rule of thumb is that stiffness goes as the cube of the thickness, so going from the original sheet to the 8th fold, the stiffness has increased about 2 million times. That’s just for the stiffness, which is just getting the stack to bend at all. The actual fold requires compression on the inside and tension on the outside. The exterior tension will generally cause the outer layers to rip and the incompressibility of the inner layers make it increasingly harder to fold.
Not in this case, actually. The stiffness of a solid piece of material increases as the cube of the thickness. However, here we’re talking about a “material” that’s constructed from a series of layers that are allowed to slip past one another, rather than a solid piece. Consider, for example, your phone book. It’s pretty thick, but it will bend in the middle under its own weight: not stiff at all.
Of course, this is complicated by the fact that if you’re folding a piece of paper, you’re probably folding it one way, then cross-ways, then in the first direction, etc. In this case the leaves in the area near the fold are restrained from sliding,
Scientifically testable hypothesis: Seems to me that, rather than folding the paper one way, then cross-ways, and so forth, it ought to be easier to keep folding the paper in the same direction until you can’t any more, then fold it in the other direction. Just tried it, and got eight folds out of a piece of notebook paper (well, OK, the last “fold” was more of a “turn into a semicircle”, but it counts in my book).