Is it really true, that human population growth doesn't affect Earth's weight?

[Roderick_Femm]

@Bozuit

To repeat a popular “fun fact”, if the Earth were reduced to the size of a billiard ball, it would be smoother than one.

But not as round - the oblateness of the earth’s spheroid would be evident even at that size.

This question reminds me of the last scene of an old Tracy-Hepburn comedy called Desk Set. He’s a computer specialist (think Univac) and she’s head librarian for a TV network. He’s installing a new computer to make their work easier. In the last scene, she gets a call asking “what is the weight of the earth?” She types the question into the computer. The computer responds with a question: “With or without people?” She pats the computer console and says “Good girl.”

So that scene was all wrong. Go figure.
Roddy

[dtilque]

@Shagnasty

Y
The distribution of total Earth mass is completely trivial when compared to things like tectonic plate shifting and volcanos. Humans do not and never will have the capability to change the mass distribution on a planetary scale. It is all superficial and barely notable in physical terms.

Some time back, someone did a study and found that humans have changed the distribution of mass on Earth, and not entirely trivially (almost, though). But it wasn’t the mass of humans, but rather the mass of the water impounded behind all the dams. Dams are disproportionately located in the temperate zones which means they are closer to the rotational axis of the Earth than stuff in the tropics. So all this water changed the angular momentum of the Earth enough to cause a very small change in the length of the day. The study didn’t point it out, but I’ll note that this was much less of a change than either the accumulation of ice or subsequent melting during the last Ice Age.

[Mijin]

You want evidence that humans are fatasses?
The city I live in, Shanghai, is actually sinking because we’re such porkers.

Oh, and also because it’s a river delta (soft ground) and the building boom has involved millions of tons of concrete and steel being laid.
I shout at people in the street to eat less tofu, but they don’t listen to me.

[bump]

You could look at it along the lines of moving a penny from the engine compartment to the driver’s seat and then to the trunk of a car.

Does the weight of the car change? No, in every case it’s the weight of the car + 1 penny.

Does the weight distribution change? Technically yes, but we’re talking 2.5 grams in one place or another in a vehicle weighing at least 730 kilograms (Smart ForTwo). It’s just too small.

[WheatCat]

@kunilou

The Earth weighs about 13,170 with 21 zeros behind it pounds.

This would be 1.317 x 10^25lb

@kunilou

All the people on Earth combined weigh 632 with nine zeros behind it pounds.

This would be 6.32 x 10^11lb

So there is about a 2.0 x 10^13 difference (ie 13 orders of magnitude) between the weight of the Earth and the weight of all people on the Earth.

In comparison, say the average person weighs 1.5 x 10^2lb. The weight of all people is only 9 orders of magnitude greater than the weight of the average person. Consider what little difference would register if all the people got on a scale and then one of them got off the scale. Then consider it would make 1,000 times* less* difference to the Earth if all people got off the Earth.

[Lemur866]

@manwithnobrain

That’s what I though.
For example,I’m convinced that a fair share of that pepperoni mass,will be burned, and transformed to heat (not that I’ll go to the gym or something-just by sitting on my couch), which will -ehm-radiate somehow (I hope not all the way into space)

What do you think happens when you burn something? That it turns into pure energy somehow?

No, what happens is that the atoms in the burned substance and atoms in the air are rearranged. So suppose you eat a sugarcube, and digest it and use the energy in the sugarcube. It doesn’t stay in your body forever, but it doesn’t just poof out of existance either.

Sugar consists of Carbon, Hydrogen and Oxygen, forming a carbohydrate. When you burn sugar to power your metabolism the C6H12O6 combines with 6 O2 molecules you get from the air you breathe, and turns into 6 CO2 molecules and 6 H2O molecules. Sugar plus oxygen turns into carbon dioxide and water. You breathe out the carbon dioxide and the water is added to your body’s water budget–some gets exhaled, some sweated out, some peed out, and so on. Nothing gets disintegrated.

And when you burn wood in a campfire the same thing happens. The wood doesn’t vanish, it turns into a bit of ash, and a lot of carbon dioxide and water.

[Really_Not_All_That_Bright]

@Cillasi

Earth, in space as it is, does not have weight. It is weightless. The Earth has mass, and its mass is steadily growing on the order of 40,000 metric tons per year in space debris. On Earth, there is gravity, creating “weight” in its attempt to draw everything to its core. Wouldn’t that balance out?

(I’m not a scientist)

Au contraire. The Earth is actually losing mass, assuming you count the atmosphere.

[ftg]

We’ve brought back 382 kg of Moon rocks via Apollo. There’s a tiny bit more space stuff brought back via the Luna mission and various comet probes and what not.

But that’s small potatoes compared to the mass of the space hardware we’ve sent out and that isn’t coming back.

Thanks to drilling and other work, we’re releasing a lot of Helium into the atmosphere which leaks away faster than the more common gases. Not sure if we’ve significantly added as much Hydrogen to the atmosphere. That’ll be a source of human generated loss.

Presumably global climate change is changing the atmosphere enough to increase the general leakage of gases into space.