# The Naked Scientists Forum

### Author Topic: If we all jumped would the earth move  (Read 5644 times)

#### iamageek

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##### If we all jumped would the earth move
« on: 17/12/2006 15:41:23 »
if all the people on the earth had to jump would it move?
Anyone with some math formula?
« Last Edit: 17/12/2006 15:57:40 by ukmicky »

#### rosy

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##### Re: If we all jumped would the earth move
« Reply #1 on: 17/12/2006 15:53:48 »
If everyone jumped at the same time on the same side of the earth they'd exert a net force on the earth and move it (tho' not necessarily measurably... I haven't done the maths). However, because there's a gravitational pull between the mass of the people jumping and the mass of the earth which pulls the people back to the earth there's an equal and opposite force pulling the earth back toward the people and so it will only be a temporary wobble.

#### rosy

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##### Re: If we all jumped would the earth move
« Reply #2 on: 17/12/2006 15:55:13 »
Incidentally, I've deleted the identical post in the "general chat" section.

#### Heliotrope

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##### Re: If we all jumped would the earth move
« Reply #3 on: 17/12/2006 16:50:57 »
OK, lets make some broad assumptions.

Population of the planet = 6.6 x10^9
Average person mass = 75 kg
Mass of Earth = 5.9 x 10^24 kg
Total mass of people = 4.9 x 10^11 kg

The Earth masses 12 x 10^12 times the total weight of the current population.
If everyone jumped at once you'd probably get a couple of siesmometers registering it but the effect on the motion of the planet would not even be measurable.
For there to be anything at all you'd have to get everyone in the same place too otherwise any effect would be averaged out over the whole surface of the planet. So nothing would go anywhere.

If, however, the Western world continues to follow the American path of crass consumerism then everyone in America, Europe and Australasia will double their average weight and perhaps have some measurable effect assuming you could get them in a normal plane seat so they could get to wherever it is that you want 3 billion lardarses jumping off your sofa.

#### Karen W.

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##### Re: If we all jumped would the earth move
« Reply #4 on: 17/12/2006 17:02:47 »
OK, lets make some broad assumptions.

Population of the planet = 6.6 x10^9
Average person mass = 75 kg
Mass of Earth = 5.9 x 10^24 kg
Total mass of people = 4.9 x 10^11 kg

The Earth masses 12 x 10^12 times the total weight of the current population.
If everyone jumped at once you'd probably get a couple of siesmometers registering it but the effect on the motion of the planet would not even be measurable.
For there to be anything at all you'd have to get everyone in the same place too otherwise any effect would be averaged out over the whole surface of the planet. So nothing would go anywhere.

If, however, the Western world continues to follow the American path of crass consumerism then everyone in America, Europe and Australasia will double their average weight and perhaps have some measurable effect assuming you could get them in a normal plane seat so they could get to wherever it is that you want 3 billion lardarses jumping off your sofa.

I find your information fine, right up to your last paragraph.  Pardon me , I might be a little sensitive as I have a weight problem as do millions of people all over the world, but I found your comments on The Americans and their weight problems and the terms and ways in which you expressed that paragraph very insulting! Perhaps you were not intentionally trying to do that, but as I read it, that was really how it came across to me!

#### Heliotrope

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##### Re: If we all jumped would the earth move
« Reply #5 on: 17/12/2006 17:48:24 »
Had I intended to target anyone in particular for an insult you may be absolutely assured that there would be no room for any doubt whatsoever regarding for whom it was intended.

Understand that I also included myself as a European hell-bent on crass consumerism judging by the contents of my evening meal tonight which has so far consisted of a large bag of crisps, some chocolate Christmas trees and a large mug of exceptionally expensive coffee.

Do not assume you are being insulted when you are not.
Should I wish to insult someone I will do so.
And I'll do it right to their face so there can be no misunderstandings.

http://en.wikipedia.org/wiki/Caustic_humour

#### Karen W.

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##### Re: If we all jumped would the earth move
« Reply #6 on: 17/12/2006 18:40:39 »
Yes perhaps as I stated, I was sensitive, Seems I have been told that for many years.. LOL I guess It's not really something you choose to do, but it is something one is! I imagine I have been that way for my whole life and will be for the rest of it. I do appreciate your comments and will continue to enjoy the posts!

#### neilep

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##### Re: If we all jumped would the earth move
« Reply #7 on: 17/12/2006 19:20:51 »
Hey  !!..guess what.....someone else asked a very similar question a while ago..here's the link with all the points of view at the time .

http://www.thenakedscientists.com/forum/index.php?topic=1195.0

#### Carolyn

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##### Re: If we all jumped would the earth move
« Reply #8 on: 17/12/2006 19:51:11 »
I thought someone else had asked that highly intelligent question.  Thanks for the link Neil.  Amazing, all those wonderful, bright comments and not one derogatory remark aimed at Americans.

Carolyn

#### Karen W.

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##### Re: If we all jumped would the earth move
« Reply #9 on: 17/12/2006 19:53:04 »
THats funny! Good information!

#### moonfire

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##### Re: If we all jumped would the earth move
« Reply #10 on: 18/12/2006 04:48:06 »
No comment...hehe  I will be good as I have been away...the rebel will be nice tonight... ;-)

#### Heliotrope

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##### Re: If we all jumped would the earth move
« Reply #11 on: 18/12/2006 18:55:28 »
I thought someone else had asked that highly intelligent question.  Thanks for the link Neil.  Amazing, all those wonderful, bright comments and not one derogatory remark aimed at Americans.

Carolyn

You'll find that there was nothing directed solely against Americans.
If you have a problem with my comments I suggest you say so clearly and distincly.

#### neilep

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##### Re: If we all jumped would the earth move
« Reply #12 on: 18/12/2006 20:29:30 »
ought someone else had asked that highly intelligent question.  Thanks for the link Neil.  Amazing, all those wonderful, bright comments and not one derogatory remark aimed at Americans.

Carolyn

You'll find that there was nothing directed solely against Americans.
If you have a problem with my comments I suggest you say so clearly and distincly.

I really don't think Dave (Drummer Supremo !!) intended any uncouth remark towards Americans...and he has said he did not. believe it or not America is the most consumer hungry nation on this planet..It's just a fact that's all....however, I can see how it could have been interpreted as the way it has been..I can see that.....

Perhaps just a big hug all round is needed.....and then it may be worth splitting this thread back to the science.

#### Karen W.

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##### Re: If we all jumped would the earth move
« Reply #13 on: 18/12/2006 20:37:47 »
I have already said my peace, and am steping away...too senstive I guess!
« Last Edit: 19/12/2006 03:44:58 by Karen W. »

#### neilep

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##### Re: If we all jumped would the earth move
« Reply #14 on: 19/12/2006 02:53:25 »

I feel the question has been dealt with and ' iamageek '  (the original poster) has not been back to comment

#### The Naked Scientists Forum

##### Re: If we all jumped would the earth move
« Reply #14 on: 19/12/2006 02:53:25 »