I came across a group called the World Jump Day. Their aim is to reduce the effects of global warming by shifting earth’s axis of rotation. Okay, I buy that. But how do they propose to do this?

Their proposal is to have 600 million people jump at different specified times around the world. Now this, my friends, is ridiculous and impossible due to our old friend called conservation of momentum.

Once we jump up, the earth is actually pushed away by a very tiny amount, and once you land the earth comes to meet you. Momentum is conserved. Another way of saying this is that the total mass x velocity of the system (you and the earth) remains constant. The earth and you go back to where everything began. The only way to really change the momentum is for you to jump high enough to escape earth’s gravity.

Even if we could do this, there would be no way you could get 600 million people organized to do anything worthwhile. The total tally of people signed up is around 60 million, but I suspect this number is inflated.

Filed under Theory. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.