More info at www.worldjumpday.org


This is gonna be one huge fun events, too bad I didn't live in one of those Time Zone range...

No matter how exciting this sounds, its not in accordance with the fundamentals of nature.
well...its pretty simple...when you are jumping you are landing back on earth which means there is no net force to generate enough momentum to displace the earth travelling with an orbital velocity of 29.8km/s within those 1-2 seconds of the jump...unless you have those 600 million ppl jump across the earth's atmospheric boundary with a velocity greater than the terminal velocity, i think.

I want to know what other ppl think?

They gotta have some scientific proven to be able to get this far, I'm pretty sure they can do it... Just a matter of how many people are going to participate in this events... Btw I hate doing science, but I love it... Hmmm am I contradict myself?

I don't know even if it were proven that I'd want to jump to move the earth out of rotation. I like Earth just where it is and I'd rather not stray off course.

Well if it only take us just 1 jump to reduce the global warming, why da hell not? I'm going for it...

It would be fun if the earth goes offcourse, and into the sun (apart from the massive heat). Or maybe colide into another planet. Woo hoo. :bounce: :bounce: :bounce:

Lolz now that is some scary ****... :bounce: :angel:

Ahhh yes this is technically possible using the formula Force = Mass x Acceleration. Lets say one person jumps at a weight of 45kilograms.
Force = 45kg x 9.8m/s (the acceleration due to gravity). So the force that is exerted on you is 441 newtons. Assuming newtons third law is correct. Which states that every action has an equal and opposite reaction. We can say 441 newtons= the mass of the earth x acceleration. or 441 newtons = (5.974 x 10^24 kg) x acceleration. Which means that the acceleration of 441 newtons on the earth is 7.3x 10^-23 m/s. Or 2 protons per second. Multiply this by 600 million and you almost have the earth off course by an entire atom!! Isn't science exciting?

Not posible - not even an atom.

The force exerted in jumping is equal to the force exerted on the earth by landing. As both forces operate in opposite directions, they cancel each other out (don't blame me, blame Newton).

what if D-O-G really spelled C-A-T ?

Hmmmmmmmmmmmm

who would win in a fight a three legged dog with a spear for a tail or a one eyed cat?

ahh, them scientists are full of s***, 6 billion people don't weigh enough to affect the earth.

There must be a thousand other variables. Like for example would all 600 million people have to be standing next to each other in like one big mass? Or 600mil anywhere within a large radius? What about altitute and thus different pressures? What about the material of earth? For example if someone jumps and lands on sand, that would be less force against earth then a person on concrete, where his weight is spread over a larger area.

I'm not very scientific, I don't know any fancy formulas, but picture this okay?

600 million people, all standing next to each other, at 0 altitute, on a hard surface of earth. Everyone jumped the same height and landed at the same time. Now how does an "impact" like that, compare to, say, a meteor hitting? Like what would the diameter be of 600 million people standing in a circle? Picture all those people as like a big hammer against earth.

What is interresting is, when two objects collide with equal force, they cancel each other out. This HAS to be, or else one object would always be pushing the other object to move. Also, if one object is stationary, and able to resist certain forces, it can't be moved. Like if you put both your hands together in front of you and push equally with both arms so that your hands stay still, this is equal force. But then walk up to a block wall and lean on it. If you're leaning 20 pounds against the wall, it is pushing 20 pounds back at you. If you push 150 pounds, it pushes 150 pounds. So until you push more then it can resist, it will stay still and neither of you will move. But if you push 1000 pounds, that wall may push over, and you don't cancel each other out anymore.

So then, what possible difference can ONE person do, jumping? And then multiply that by 600 million. The earth, by far, has enough resistance to cancel such force. Especially if the force is spread over so much space as "western hemisphere".

It is interresting to think about though

A very good point..

when you jump, all of your kinetic energy is transfereed to whetever you're standing on, whether it be sand or concrete. if the material beneath your feet compresses/crushes it can absorb some or all of the hit. sand does not compress.

but whatever you stand on, wherever you are, the answer remains the same.

The total energy exerted on going upwards equals the total energy exerted when going downwards. It's simply newtonian physics.

Yes but what about the impact itself? I mean, if you jump and hit the ground with 400 pounds of force, surely it didn't take 400 pounds of force against the earth to get you up in the air. Or does it?

I does, though it's slightly more complicated if you look at it in fine detail as it will involve a variety of different forms of energy conversion etc, but when it's all added up, it comes out the same, as "every action has an equal and opposite reaction"

Imagine you weigh 200 pounds.

You would have to expend 200 pounds of force simply to stand on the ground. To get off into the air, lets say you require another 200 pounds of force, which would take you far enough into the air to land with 200 pounds of force plus your own weight of 200 pounds, and so it's 400 pounds from jumping to 400 pounds on landing.

Even if you were to climb on something (which would certainly complicate things!!!) the force used to climb is equal to additional force from hitting the floor again.

Of course, it goes into energy conversion from various forms to other various forms, gravitation, etc, etc, but essentially it works out the same due to equal and opposite reactions to whatever you do.

After 20 odd years in the paving business, I can assure you that sand does, indeed, compress. Sand is crushed (or eroded) rock. Using a vibratory compacting device, and with the optimum moisture content (very low %) you can make sand quite stable, especially extremely fine sand (crusher dust). In fact, it can become almost as stable as the rock from whence it came.




witless is bliss

by your logical then the actual jump its self would "expell" enough force to move the planet???? your reasoning is correct but the actual application of it is nonsense... too many variables..
its all complete b*llox IF if if if if..

....if your Aunt had balls she'd be your uncle...no offence like