# Fold a banknote in half 110 times, is the universe really unable to hold it?

Whether it is a piece of money or a piece of paper, it is very thin. After folding them in half, the thickness can be superimposed. On this basis, the more the number of half-folding, the greater the thickness.

The universe is huge, and the observable universe alone has a diameter of 93 billion light-years. Some people say that if you fold a 100-yuan bill in half 110 times, its thickness has already exceeded the diameter of the universe, and the universe can’t fit. First.Not to mention whether it is operable to fold 110 times in half, will this happen in theory?

This kind of origami game has been learned in junior high school. I remember learning it in a math class. At that time, there was such a problem in a math book, that is, a piece of paper is folded 30 times, and its thickness can exceed Mount Everest.?

This problem seems impossible at first glance. A piece of paper is so thin and it is not thick enough to fold it in half. I thought that it would not be possible to fold it in half 30 times to exceed the 8,000-meter Mount Everest. However, after calculation, it was found that it was stillToo young, the exponential growth is indeed powerful.

Assuming that a piece of paper is 0.1 mm thick, each time it is folded in half, its thickness will double. How many times it is folded in half, the thickness of the paper will be doubled by the power of 2, so mathematically it is easy to calculate eachThe thickness after the second fold.

After folding in half once, its thickness will reach 0.2mm;

After folding in half 10 times, its thickness will reach 102.4mm;

After folding in half 20 times, its thickness will reach 104857.6 mm;

After folding in half 30 times, its thickness will reach 107374182.4mm.

Converting the above values shows that after folding 30 times, the theoretical thickness of this piece of paper will exceed 100,000 meters. This height is higher than 10 Mount Everest stacked together. I don’t know, I’m surprised.. It is hard to imagine that after a piece of 0.1 mm paper is folded in half 30 times, the thickness can reach 100,000 meters.

The thickness of the 100 yuan banknote in the fifth set of RMB is also about 0.1 mm, so let's continue to calculate.

After folding in half 100 times, its thickness will reach 1.27×10^29 mm, which is 1270 trillion kilometers;

After folding in half 110 times, its thickness will reach 1.3×10^32 mm, which is 13 billion billion kilometers.

The diameter of the observable universe is 93 billion light-years, about 9.46 trillion kilometers in one light-year, and 93 billion light-years is 8797.8 trillion kilometers.

It can be seen that after 110 times of folding in half, the thickness of this banknote is theoretically far beyond the diameter of the observable universe. In fact, when the banknote is folded in half 103 times, its thickness has reached 100 million billion kilometers., The observable universe can no longer contain it.

However, how big is the universe? Scientists are not sure yet. The universe was born in a big bang and is still accelerating expansion. Counting the part that humans will never observe on the earth, scientists speculate that the diameter of the entire universe is at least nowMore than 24 trillion light-years, it is at least 258 times the diameter of the observable universe. However, if you fold it twice in half on the basis of 110 times, even a universe with a diameter of 24 trillion light-years will not fit this 100-yuan bill..

In the world of mathematics, origami is very simple, but in the real world, after folding a piece of A4 paper in half 7 or 8 times, it is difficult to fold it in half manually unless the paper is very, very thin. If you continue to fold it in half, thisThe sheet of paper may break at the half-fold.

It is reported that the highest record of folding paper in half in the real world is 13. In 2011, a teacher in Texas, USA led students to fold a piece of toilet paper about 4 kilometers in half 13 times.

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