As part of their ongoing “What If?” series, Randall Munroe of xkcd and Henry Reich of MinutePhysics answered the very common question about what would happen if everyone in the world jumped at once. The short answer, is not much.
It doesn’t really affect the planet. Earth outweighs us by a factor of over ten trillion. On average, we humans can vertically jump maybe half a meter on a good day. Even if the Earth were rigid and responded instantly, it would be pushed down by less than an atom’s width.
A bit more happens when they all land, but the effect is negligible.
Technically this delivers a lot of energy into the Earth, but it’s spread out over a large enough area that it doesn’t do much more than leave footprints in a lot of gardens. A slight pulse of pressure spreads through the North American continental crust and dissipates with little effect. The sound of all those feet hitting the ground creates a loud, drawn-out roar which lasts many seconds.
The only damage is humorously described as being due to human nature.
A cell phone comes out of a pocket. Within seconds, the rest of the world’s five billion phones follow. All of them—even those compatible with the region’s towers—are displaying some version of “NO SIGNAL”. The cell networks have all collapsed under the unprecedented load.
