Question: to do with weight of world

[asto5]

does the world get heavier everytime someone is born. and obviously vias verse for people dying?! 

[DustMonkey]

No, the world is more or less a constant weight, something in the region of 6x24 kg (that's six with 24 zeroes after it). If you think about it , as a baby undergoes gestation it draws the matter with which to construct its body from the outside world, via it's mother's placenta, and when we die our bodies gradually decompose, with the various vitimans and minerals therein being absorbed back into the earth. The whole thing is all very Buddhist.

[DustMonkey]

appologies, that should be 6x10*24

[Backdrifter]

there will be changes in weight but they are so slight compared to the overall weight, it's negligible. It'd be like a person losing or gaining a bacterium.

 

By the way, shouldn't we be saying "mass" instead of weight? Doesn't weight imply the force a mass exerts on some other body?

[TTFresh]

I should imagine there is a finite number of molucules, atoms etc in the atmosphere and so it is really about the movement of these for a differing purpose - more you think about it the more confusing it weird it gets.  Microbes eaten by tiny fish, eaten by bigger fish, eaten by bigger fish, eaten by seals, eaten by sharks, die and carcass falls to the ocean bed and is eaten by microbes and so on - applies to all things.  Fossil fuels are another good way of reasoning this.  Pretty much what DustMonkey said but obviously in a far less scientific way.

[trilobite]

In all these biological processes, mass is conserved. Being born, dying, eating, growing, do not affect the total mass of the Earth.

Before you are born, you grow by taking mass from your mother.

You grow by eating food from the Earth's surface.

You die and are either shoved back in the ground, putting back your mass into the soil (or contributing to the growth of worms), or you are incinerated and contribute to the mass of the atmosphere.

 

Think about those sealed aquaria things you could get - a plant and a few brine shrimp type-things. A totally enclosed system that continued to live as long as it received light (which has no mass). If you kept it on a balance (scales) you would see that the shrimps dying or hatching would not affect the total mass of the object.

 

Agreed, the Earth is not a closed system, and both gains and loses mass for reasons discussed a few posts ago here;

http://www.theanswerbank.co.uk/Science/Question81814.html

 

But the biological process of being born and dying can not affect the mass of the Earth.

 

[bernardo]

Every time a person eats something, or grows, yes it does take mass from the Earth and add it to the person.  So an unborn baby growing would reduce the mass of the Earth.

[magicdice]

By the way, shouldn't we be saying "mass" instead of weight? Doesn't weight imply the force a mass exerts on some other body?

but the gravitational field acts as uniform within a few thousand feet of the earth's surface,
mass x gravitational field strength = weight
so mass x (constant) = weight, so it makes no difference really

also,

6000000000000000000000000kg = the earth's mass

                                        90kg = generous mass for a person

so yeah, biiiiiiiiiiiiiig difference

[chrisn]

Hmm, i was told that there is a constant amount of matter in the universe.  Matter can neither be created nor destroyed, just converted to different types matter.  Therefore, the earth will always be the same weight (or mass, to be accurate).