Gravity

[STeve555]

Is the earth's gravity less since we shot 3 people into space?

Reverse: does the Earth gain on gravity whenever extraterrestrial mass lands on it?

 

Since gravity is an inverse square law given to distance and all, is the gravitational pull on the moon less when we (all humans) gather in one place facing the moon side, and jump for one second? This all regardless of any space debris falling down on earth, perhaps adding to its mass and gravitational pull.

 

I am asking this because someone on another science forum told me that even if you landed the population of 20 million other civilizations on earth it will not change the gravity that earth exerts. I always thought that humans roaming on earth added to the mass of the earth and thus to the gravitational pull.

 

Much obliged in advance.

Edited October 14, 2012 by STeve555

[zapatos]

Is the earth's gravity less since we shot 3 people into space?

Reverse: does the Earth gain on gravity whenever extraterrestrial mass lands on it?

 

Since gravity is an inverse square law given to distance and all, is the gravitational pull on the moon less when we (all humans) gather in one place facing the moon side, and jump for one second? This all regardless of any space debris falling down on earth, perhaps adding to its mass and gravitational pull.

 

I am asking this because someone on another science forum told me that even if you landed the population of 20 million other civilizations on earth it will not change the gravity that earth exerts.

 

Much obliged in advance.

A lot of this depends on from where you are measuring earth's gravity.

 

If you count people as being part of the earth (and I don't see why you wouldn't) then the earth has lower gravity when people leave it. If however you are measuring the gravity from the moon, and the people are in earth orbit, I don't think you would measure gravity any differently. You would measure earth's gravity as lower if your measurement was done from a position between the earth and the orbiting astronauts.

 

The earth's gravity increases as additional mass is added, whether it is from space debris or millions of civilizations.

 

If we gather on one side of the earth and jump toward the moon, and you are measuring gravity from the moon, there will be no measured change in gravity.

 

You might want to get the person on the other forum to clearly define his terms and premises.

 

When the earth was forming it was once 1/10 the size it is today. Does this person believe that the earth has the same gravity now as it did then?

[Psiddle]

Very well said, Zapatos! I was a bit confused at the time when I was reading steve's query and was amazed what would be its logical answer? But you resolve this matter in quite satisfactory way.

Good work!

[STeve555]

Cheers. I knew I was right. That motofoko!!! on that other forum.

[derek w]

There is a monument in Bernotai Lithuania,that is suppose to be the centre of gravity for Europe,if we all move to Spain we can change it.