# The Naked Scientists Forum

### Author Topic: What would happen if everyone in China jumped at the same time?  (Read 17876 times)

#### Harry

• Guest
##### What would happen if everyone in China jumped at the same time?
« on: 26/04/2010 21:30:02 »

Hello,

What would happen if all the people in China jumped up and down at the same time?

regards

Harry

What do you think?
« Last Edit: 26/04/2010 21:30:02 by _system »

#### LeeE

• Neilep Level Member
• Posts: 3382
##### What would happen if everyone in China jumped at the same time?
« Reply #1 on: 27/04/2010 15:45:23 »
They would slightly compact the ground beneath them slightly, but other than that, not much.

#### daveshorts

• Moderator
• Neilep Level Member
• Posts: 2583
• Physics, Experiments
##### What would happen if everyone in China jumped at the same time?
« Reply #2 on: 28/04/2010 15:50:53 »
They would move the earth slightly, on average. All the people in china weigh about 1 billion * 60kg -> 60 billion kg or 60 million tonnes.

The earth weighs 6 x 1024kg so about 1014 times more. This means that if they all jumped 1m in the air the earth would move about a 1014th of a metre, 19fm or 0.00000000000001m

Far too small for anyone to notice, plus the earth isn't rigid and the force would take many minutes to travel across the earth.

If they were all in the same place, they might be able to make a small earthquake, if all the energy in their jump got transferred into the rock it would have a similar energy to an earthquake of 4-4.5 on the Richter scale.

#### graham.d

• Neilep Level Member
• Posts: 2208
##### What would happen if everyone in China jumped at the same time?
« Reply #3 on: 28/04/2010 15:54:31 »
Shh! This is Britain's idea as a replacement for Trident.

#### LeeE

• Neilep Level Member
• Posts: 3382
##### What would happen if everyone in China jumped at the same time?
« Reply #4 on: 29/04/2010 16:34:01 »
They would move the earth slightly

I think this would only happen if the Earth was perfectly hard and non-deformable.  It's not though, so I still think that you'd only get some local deformation.

#### Geezer

• Neilep Level Member
• Posts: 8328
• "Vive la résistance!"
##### What would happen if everyone in China jumped at the same time?
« Reply #5 on: 29/04/2010 18:23:00 »
Even if the Earth did accelerate away from the "jumpers", it would return to its former position as they accelerated back towards the surface.

#### The Naked Scientists Forum

##### What would happen if everyone in China jumped at the same time?
« Reply #5 on: 29/04/2010 18:23:00 »