Thursday, April 16, 2009

Volumes in Perspective

I was talking with Paul Kalthoff today about the “biomass” of the human race. I was driving into work and looking over at Pikes Peak (since traffic was running slow on the highway), and thought to myself that we humans really are small compared to that mountain. In fact, I thought to myself, I bet we could throw the whole human race into some imaginary volume hidden behind the peak. Little did I know how much I over estimated, after spending about 10 minutes with Paul doing mental calculations we figured that the whole of the human race would take up only around a cubic kilometer. Here is what I found later that evening:

An accurate estimate of the average volume of a human being was a little hard to come by. However, a rough estimate was proposed in a number of sites found in a Google search that hypothesized the following: the human body is approximately the density of water (1.01kg/l []), the average mass of the human body is around 70kg [], so the average volume of a human comes in around 70.7 liters.

Next is the simple math of translating a human into a cubic meter:
1hu = 70.7l = 0.0707m^3
1m^3 can hold a little more than 14 people (assuming you hit the puree button on the blender):
1m^3 = 14.1443hu

So how many people are on this planet? That you can find all over the internet:
6.790062216E+9 (July 2009 estimate [])

So, again some simple math shows that we human beings, one of the most prolific forms of dry-land life, would take up the massive volume of around:
480E+6m^3 which of course equates to 0.48km^3

That’s right! We add up to less than half a cubic kilometer.

When you read articles that state “The biomass of human bodies now exceeds by a hundred times that of any large animal species that ever existed on land.” []
You are left with comparing that to what: how much we use in resources? How about how much biomass was morphed into coal?

Just for some perspective, comparing the human race to the volume of coal mined on a yearly basis [], I found this interesting article that noted in 2004 approximately 2.1km^3 were mined. So we could pack the mass of the human race into the hole left over from three months of mining coal.

So it would take just a small portion of the top of Pikes Peak (think about a 1km x 1km x 480m box) to hide the whole of the human race.

If you are a visual person, click on the capture of Google Earth where I mapped a 1km line across the Peak.

We are so small.
And yes, I know I’m weird.


1 comment:

SABALE said...

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