What's Your Cosmology

August 21, 2006 5:43 PM

I am looking for sources that give the weight of the earth, volume of all the oceans, total acreage on the planet, total current population and guestimated total weight of said population.

I am doing personal research for a question that came to me last week. I would like to find how much space does the current population of the planet occupy?

posted by goalyeehah to science & nature (11 comments total)

Wikpedia: Earth
- Weight of the earth: 5.9742×10^24 kg
- Acreage of the planet: 148,939,100 km²

Wikpedia: World population
- Total current population: A little over 6.5 million

Wikpedia: Ocean
- Volume of the oceans: 1,340 million cubic kilometers

Wikpedia: Human
- Average weight: 62 kilograms
= 403,000,000,000 kilograms total
posted by cillit bang at 5:53 PM on August 21, 2006

This falls under the google is your friend category...
posted by twiggy at 5:53 PM on August 21, 2006

Population of humans only?

"How much space" is not well-defined. Are you looking for the physical volume of all humans, the surface area covered if all humans were to simultaneously lay down, or perhaps the number of 1 km² segments with at least one human occupant?
posted by Galvatron at 6:07 PM on August 21, 2006

So, you're asking for the world? I'm here all week.
posted by purephase at 6:12 PM on August 21, 2006

When I posted, I was think surface area covered by someone standing.

On re-read, I would also want surface area covered if all humans were to lie down.

And while I am at it.........the volume of the livable atmosphere.
posted by goalyeehah at 6:12 PM on August 21, 2006

Weight of the earth: 5.9742×10^24 kg

Not to be pedantic, but the correct term is mass, not weight.
"weight of the Earth" is essentially a meaningless phrase.
posted by Neiltupper at 6:14 PM on August 21, 2006

To be pedantic, would the weight of the Earth be zero, give or take a bit?
posted by smackfu at 6:36 PM on August 21, 2006

Not to be pedantic, but the correct term is mass, not weight.

Yeah, I know that. I was reusing the poster's headings.

On re-read, I would also want surface area covered if all humans were to lie down.

Ask Metafilter isn't a place where you "want" things. It's a place where you politely ask the community to help you with a problem. I'm shown you how to find the information you want, so your problem should now be solved.
posted by cillit bang at 7:14 PM on August 21, 2006

The poster's most basic questions are easily searched, but the question of surface area covered is actually kind of non-trivial because the world population is not composed of 6.5 billion average humans.

I would start by using 2002 global census data to get a histogram of age distribution. I would then convert this histogram into an approximate weight distribution using a 2002 table of mean weight by age (US data was the best I could find). This diagram suggests that an average adult male has a maximum horizontal cross sectional area of about 170 in², and according to Wikipedia that average person has a weight of 78kg.

Now, assuming humans are geometrically similar (yeah, right...): C = k * W^2/3 where C = cross sectional area and W = weight. You can solve for the constant of proportionality k using the average adult male cross section and weight given above (feel free to use a vertical cross section if you really want the data for humans lying down).

Now apply this formula for every column of the weight histogram to get a distribution of human cross-sectional areas. Sum over 6.5 billion people, and you've got a reasonable estimate. I look forward to reading your results.
posted by Galvatron at 7:46 PM on August 21, 2006

I'm pretty sure that 62 kg the average weight for an adult human. I'm also pretty sure that children make up a considerable portion of the 6.5 billion humans. So the total mass of humanity probably a bit less than 403 billion kilos.
posted by notswedish at 8:49 AM on August 22, 2006

Umm, please insert the word 'is' in its correct places in my preceding comment. Thanks.
posted by notswedish at 8:50 AM on August 22, 2006