Science Byte: on the seventh fold

Written by Marie Brown

Questions answers in 250 words or less. Leave any suggestions for more quick questions in the comments.[…]

Can paper be folded in half more than seven times?

It has long been ‘accepted knowledge’ that you can’t fold a sheet of paper in half more than seven times, but is this modern myth, in fact true?

For the most part, yes. If you were to take an everyday sheet of A4 paper, the task would seem impossible. A piece of paper folded just 30 times would be 10km high, making it taller than Mount Everest. Even with the help of a hydraulic press, the paper simply shatters upon the seventh fold; the calcium carbonate becomes so brittle under the extreme pressure that the paper fragments with explosive force.

The art of folding paper was unraveled, however, by a high school student named Britney Gallivan, who theorized that the number of folds that could be achieved by a single sheet of paper could be calculated using the following equation.

L = Πt/6 (2n+4) (2n-1)

Where “n” is the number of folds, “L” is the length of the paper, and “t” is the thickness of the paper.

Gallivan put her theorem to the test, and demonstrated the final proof that the seventh fold was nothing more than an urban myth, by folding an impressive 1200 metres of toilet roll in half 12 times.

So it can be done, but you are going to need a whole lot of paper to do it.

About the author

Marie Brown


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