Thanks BerserkerCatSplat, Now i have a Q...

[dathrilla]

I just saw the new, rather interesting, Swatch commercial..It shows 7 billion people jumping at the same time(hence the world's population) and arriving on the ground all together... If this were to occur, what would happen? Would it have an earthquake-like affect? any ideas would be appreciated...

[bone]

rumors go that if all chinese people would jump on the same moment, america would get a tsunami

[dathrilla]

wait, u serious?

[FireFox]

http://www.worldjumpday.org

[abhishek2]

sounds like a plan.. would be pretty cool if something really does happen when people jump at the same time..

[dathrilla]

nice!

[fluke667]

sorry to spoil your fun but NOTHING will happen
the mass of all people together is simply too small

[bihus]

Longer days,

If it would happen, we would be in a colder planet too... and planes wouldn't be able to fly (GPS gone crazy).

Basically,

[chaos386]

^Nahhhh, the world jump day thingy wouldn't work since the center of mass of the (planet + people) system can't change without an external force.

[bihus]

I know. Even a meteor would have to be so big that it would kill all living beings.
What I haven't read anything more about of was the fact that the tsunami altered Earth's rotation, slightly afecting GPS systems. HAve you ever read something about it?

[DJ]

It's all about frequency. Match the Earth's frequency by jumping and in enough time one man can split it in half.

[dathrilla]

Yeah, apparently, even if the 6.5 billion ppl jump together, Earth wouldn't move more than the size of an atom.

[andyhui01]

I know. Even a meteor would have to be so big that it would kill all living beings.
What I haven't read anything more about of was the fact that the tsunami altered Earth's rotation, slightly afecting GPS systems. HAve you ever read something about it?

thats what I heard as well... the earthquake that caused the Tsunami actually shooked the earth a tad off its axis

[BerserkerCatSplat]

Interesting question!

Let's assume that each person jumping has an average mass of 70kg, and can jump an average of 0.5m.

The kinetic energy transferred to the earth's crust by each person is Ke=mgh

Ke = (70kg)(9.81m/s^2)(0.5m)

Ke= 343.35 J per person.

Ke(total) = (343.35)(7,000,000,000)

Ke(total) = 2.40345 x 10^12 J total

The crust of the Earth makes up a mere 0.374% of its total mass.
The mass of Earth is 5.9742 × 10^24kg.

Thus, m(crust) = (5.9742 × 10^24)(0.00374)

m(crust) = 2.234 x 10^22 kg


To create earthquake-like effects, we'd have to cause the earth's crust to flex (thus creating the earthquake-like waves). A light earthquake would have a surface wave height of approx. 10cm. Thus, to get earthquake-like results, we have to generate earthquake-like energy. To counteract the crust's potential energy and cause that 0.1m change, we need to calculate the potential energy of the crust.

Kp = [m(crust)](g)(d)

Kp = (2.234 x 10^22 kg)(9.81 m/s^2)(0.1m)

Kp = 2.192 x 10^22 J


Therefore, the energy needed to create surface waves, divided by the energy exerted on the earth's crust by jumping everyone is:

Kp = 21920000000000000000000 J
/ Ke = 2403000000000 J
---------------------------------------------
= 9121930920


We would need 9.12 trillion times more people jumping to cause that effect. Human beings just don't have enough mass, nor can they jump high enough, to cause earthquakes!

[fluke667]

We would need 9.12 trillion times more people jumping to cause that effect. Human beings just don't have enough mass, nor can they jump high enough, to cause earthquakes!

thanks for the maths

[jayjaya29]

Yeah I read the lead post I thought for a second and was like, no way, nothing would happen.

[MixtriX]

since there are ppl all over the earth, wont each persons jump will be canceled out by the person on the other side of the earth?

[jayjaya29]

since there are ppl all over the earth, wont each persons jump will be canceled out by the person on the other side of the earth?

No, the effect of the one person jumping will not be felt by the person on the other side of the earth. The energy of the one person jumping and then coming back down will just dissipate through the ground.

[toma_alimosh]

I like that they put that guy to act as a professor for this website ... it's so damn funny, he even looks pretty convincing, I'd be interested to know how many people have actually signed on for this mission.

Now I keep refreshing that website as I'm reading the new posts in the forums .... and more people are still joining That goes to show that a person is smart, but people are dumb.

[bone]

since there are ppl all over the earth, wont each persons jump will be canceled out by the person on the other side of the earth?

No, the effect of the one person jumping will not be felt by the person on the other side of the earth. The energy of the one person jumping and then coming back down will just dissipate through the ground.

i would more think that the earth would become oval for a moment, and bump back, throwing everyone in the air

that would be cool, you jump, and half a minute later, you get thrown 10m in the air

and i heard about the axis tilted as well, the earth also changed size a little bit (IIRC, a day is 1.254 secs longer since the tsunami)

so shouldn't we be changing our "meter"? caus that 1/40 000th sth of de total distance around the earth