Jump!

I have a very odd coincidence to report. I like getting fun questions from folks, the kind that take a little bit of math and physics to explain, but wind up taking you to fun places. A common question like that is, "What would happen if everyone in China jumped all at once?" Would it throw the Earth out of orbit? Would it cause an earthquake? Would it do anything? The answer is, essentially, no. I tackled this a few years back; there was this announcement by a group that wanted to get 600 million people to all jump at once so that the Earth would be pushed farther from the Sun and global warming would be solved. Um, yeah. They called it World Jump Day, and I made quick work of it. Nothing at all would happen, for lots of reasons. Still, it's fun to think about, right? And ...