World Jump Day
From Freepedia
World Jump Day is an event scheduled for July 20 2006 at 11:39.13 GMT, at which time the organization plans to have 600 million people from the western hemisphere jump simultaneously. They claim this will move the Earth out of its current orbit, and into a new one, one that will not cause global warming.
This claim is completely unscientific, however, as it's impossible to permanently change the Earth's orbit using the planet's own mass, which includes the world's population, unless that mass is ejected from the Earth at great velocity. See Newton's third law of motion.
Even suspending some of the known laws of physics, the difference would be negligible: the combined mass of the world's population is too small to cause any significant shift in the planet's orbit; and since Earth's orbit is elliptic, there are already great variations in its distance from the Sun (about 5,000,000 km) with no generally noticeable changes in temperature.
