# A Way to Reach Moon by Folding a Paper

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Today, I’d like to talk about a famous math problem.

“In order to reach moon, how many times do you need to fold a paper?”

If you never heard this problem, I want you to think before looking at the following answer.

Typical paper thickness is around 0.1 mm, so I will use this value here. A paper thickness which was folded n times is expressed as 0.1 times two to the power of n. Also, the distance between earth and moon is around 384,400 km. Therefore, the answer is forty-two times. When we fold a paper forty-two times, the paper thickness will be 439,804 km. Also, the paper thickness which is folded 15 times is around human height, the paper thickness which is folded 83 times is around a diameter of a galaxy. However, it is said that we can fold a paper no more than 8 times because required force to fold the paper increase while the paper area decrease.