What happens if everyone on Earth dances for a while?

Earth has about 7 billion people with a total weight of 363 billion kg. When all people on earth gather and dance together for a while, it creates a small force. So can this force affect the Earth and cause any effect?

When the mass moves into the center of a rotating object, its rotation speed is increased. For example, a figure skater often shortens his hand to help speed up when performing a spin. So, theoretically, you can make the Earth spin faster , which means that one day will pass faster if you apply a force large enough to the surface of the Earth.

Picture 1 of What happens if everyone on Earth dances for a while?

The huge earthquake in Japan in 2011 shifted a large amount of rock to the center of the Earth. In fact, this earthquake made the Earth spin faster, every day on Earth was shorter than 0.0000018 seconds. So can we reproduce the same thing if we gather the power of all people on Earth, through a jump at the same time?

Because humans are widely distributed throughout the Earth, so if we all jump in place, nothing will happen because the forces have been annihilated. So imagine all humans on Earth concentrated in an area of ​​about 1,200 km 2 . At that time, when jumping together, the force will be concentrated at one point compared to the Earth. And this force could make our Earth spin faster.

Picture 2 of What happens if everyone on Earth dances for a while?

Using the laws of kinetic energy and conservation, physicist Rhett Allain of the University of Louisiana tried to figure out what would happen to our Earth in this case. For simplicity, he assumes that each person can jump about 30 cm on average and we all jump exactly at the same time.

Allain concluded that the attempt of 7 billion people on Earth will make its rotation rate increase by about 2.6x10 ^ -13m / s . That means that in a second, the Earth will move about one percent more of the hydrogen atom radius. It means that our day will pass a little faster, but it may be difficult to recognize this difference.

Because the weight of 7 billion people is still too small compared to the huge weight of the Earth, so even if we do it again and again day after day, it can't make a big change The earthquake in Japan has caused, not to mention a significant change.