I thought it needed atleast the force of a dozen Nuclear missles.... to "knock" the earth out of orbit.....alittle....
or maybe is a excuse to get computer geeks who does nothing but surfs the net to start do jumping jacks...
hmmm
On a SERIOUS note,
wouldn't doesn't Newton's 3rd law rules out their prediction?
(For every action there is an equal and opposite reaction)
I mean, the moument you land back (after you jump..) the earth is exerting the same amount of force onto you...thus, the net force equals zero.... (Fjump = Fg, that would be at the top.... and Fjump1 would equals to Fjump2 so overall, Fnet in system though time = zero...)
(A system in motion(even if its sitting still, as sitting still is still a motion..) stays in motion unless there is a change in Fnet in the system....)
since Fnet = zero... therefore nothing changes in the system..
NOW...unless something is pushing you towards the earth and applying and outside force to the system... that would work...
but I imagine it will take planet-sized Rockets installed on the Earth to move it out of orbit.... the propellant should do the trick...hahaha
lol, I must be bored...and my mind is pacified by Cough Syrup....*hates being sick*
Edit:*note: Nos, I think the number of ppl required is just an arbiturary number... after all, if they REALLY want to do it, they have to Calulcate the MASS of the person as well.... *