What would happen if everyone in the world jumped in the air at exactly same time?

[Tami77]

What would happen if everyone in world jumped in air at exactly same time ?

and

assuming they landed at same rate what would happen when they landed?

[gen2]

Most would land safely, but given the numbers involved, there would bound to be a many with sprained ankles, and quite a few, especially those suffering from osteo-porosis, with broken ankles or hips.  There may even be a few who land stiff legged and transmit the shock up the spine causing spinal injuries or even a fracture at the base of the skull.  It is also possible that a few of these injuries could result in complications leading to the death of the subject.

[Clanad]

I'm assuming that you expect that something would occur because of the transfer of weight or something similar.  However, let's assume there are 6 billion people in the world and that the average weight of all is 170 pounds... this yields about 510,000,000 tons.  The Earth's estimated weight is 5.92 sextillion tons (lotsa zeros).  The weight transfer of all earth;s people is pretty insignificant in comparison.  Additionally, you would have to invoke some mathmatical formula to take into consideration that the "pushing off" of each during their jump would be countered, in lots of cases, by someone on the opposite side of the Earth (antipodes), thereby zeroing out many of the pressures... Short answer... excatly nothing would happen in each case... with the exceptions noted by gen2...

[SteveD]

Surely the impact of 6 billion people all hitting the ground at the same time would have some effect? Visualise the ripples in the coffee cup in the scene from Jurassic Park when T Rex appears for the first time!

[pixi]

hey shall we all do an experiment and see what happens?  we could all jump in the air today at 3.00 GMT i'll do it if everyone else will-do we have to do a little jump or a big jump?

[Gef]

Nothing.

[Tim Baxter]

There have been episodes of organised (thousands simultaneously) school kids trying this.  I can't find enything on Goooooogle but it has been doen.

[Cloned]

Yeah they did this experiment in manchester a long time ago. They got thousand or so students and made them all jump at the same time. It would really move the earth because of newton's third law every action has an opposite and equal reaction. However it did cause i think a very very very small amount of seimic activity. but nothing major. anyway most people can't even clap in time, imagine them all trying to jump at the same time.

[Space]

they would look really stupid.

(especially if they are doing it because of the "world jump day"... )