Why do they say jump on a hard surface? It would matter if you were trying to smash something by jumping on it, but jumping on any surface on Earth will have the same effect (not changing the orbit).
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Originally posted by mwe99
lol didnt they do this before? im sure they did cos i jumped along with my school when a bell sounded at like 11am...
we got a longer break(recess) to jump too haha 
I was going to post this, I saw it on the news. When was it and where?
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Originally posted by damm-o
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Originally posted by CookieRevised
Though, it would be a bit "wrong" if people actually believed they can make the world go into another orbit or believe the stuff about how it would change global warming etc...
Yes, specially at a school.
It was a whole bunch of schools (I think), and it was to make an earthquake (it worked).
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Originally posted by CookieRevised
Also, people are not external forces. If you jump, you actually push into the earth with a (rediculus small) force. And after that it is only a matter of mass which object will attrack the other (human or earth) and will move back towards the other object due to gravity. Thus actually moving back in place as it was before...
For those that didn't understand this; it's like standing on top a panel on timber (example only) and then trying to lift it. No matter how much hard you try, you can't lift the timber because you're on it, and the pull force from your hands is levelled out by the push force of your feet.
If you stand next to the timber, then you can lift it easily because the pull of your hands is on the timber, but the push of your feet is on the ground. That makes you an external force.
If you're standing on the the timber, you and the timber are together, and you can't exert an external force. You might be able to move the panel a bit, you can't lift it. If though somebody else (extremely strong
) can lift you both, being an external force.
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