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Treebeard's Stumper Answer
8 Nov 96

Take an ordinary piece of notebook paper and fold it in half, then fold it in half again across the first fold, and yet again.... Suppose you did this 50 times in a row. Assume the paper itself is a tenth of a millimeter thick (so 10 pieces are 1 millimeter thick) and ignore creases and air spaces if the paper is not pressed down absolutely tight. How thick would the final bundle be?

How thick would a .1 mm piece of paper be if we could fold it in half 50 times? Not 5 mm! Fold the paper once and you have 2 sheets. Fold it again for 4 sheets. And again for 8 sheets. Each fold doubles the number, so after 50 folds there will be 2x2x2... 50 times, or 2^50 sheets. The actual number is 1,125,899,906,842,624 sheets, a bit over 70 million miles thick, nearly the distance to the sun! Now how big is each of those sheets? And how many times can you really fold a piece of paper?

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Marc Kummel / mkummel@rain.org