Fold a sheet of paper 7 times? No problem if you have a hydraulic press.

Perhaps this is strong if you are!

Have you ever tried to fold a plain sheet of paper? Probably yes. One, two, three times - no problem. Then it's harder. A standard sheet of A4 paper is unlikely anyone will be able to fold more than 7 times without improvised means. All this is due to the presence of a physical phenomenon - repeatedly fold a sheet of paper does not work because of the rapid growth of the exponential function .

As Wikipedia says , the number of paper layers is two to the power n, where n is the number of paper folds. For example: if the paper is folded in half five times, then the number of layers will be two to the power of five, that is, thirty-two. And for plain paper, you can derive the equation.

Equation for plain paper:
')
^,

where W is the width of the square sheet, t is the thickness of the sheet and n is the number of doubles made.
The use of a long strip of paper requires the exact length L :

^,

where L is the minimum possible length of the material, t is the sheet thickness and n is the number of folds made twice. L and t must be expressed in the same units.

If you take not ordinary paper with a density of 90 g / dm3 (or a little more / less), but tracing paper or even gold foil, then such material can be folded a little more than the number of times - from 8 to 12.

Mythbusters somehow decided to check the law by taking a piece of paper the size of a football field (51.8 × 67.1 m). Using such a non-standard sheet, they managed to fold 8 times without special means (11 times using a roller and a loader). According to the fans of the telecast, the tracing paper from the packaging of an offset printing plate of the format 520 × 380 mm with a rather careless folding is effortlessly folded eight times, with the effort nine. In addition, each of the folds should be perpendicular to the previous one. If you bend it from a different angle, you can achieve that the number of bends will be slightly larger (but not always).

Here are a few more attempts:



Well, what if you fold a sheet of paper not with your hands, but take a hydraulic press as your assistant? Let's see what happens then. Please note that the video is in English, with a very strong accent ( Arabic Finnish).