Do you know what would happen if everyone on Earth would jump up and down at the exact same time? No? Then watch this video to find out!
Not sure the timing, but XKCD did this a bit ago, better :) http://what-if.xkcd.com/8/
Hopefully this guy give XKCD a Hattip somewhere, would be quite lame if not.
no, i dont know, but i do know its far more likely than me ever watching a 7 minute video.
This is why I love science