27 August 2011

Bloody maths

Ladies and gentlemen—a view of Canobie Lake in Southern New Hampshire, if it were filled with blood instead of water:

I tinted the clouds red because I figured they'd reflect the lake a bit,
not because I was trying to make the scene even more sinister. :P (original image)
You may be assuming I'm a bit of a creep for creating that image (and I am), but lemme explain:

I was listening to the song "3rd Planet" by Modest Mouse the other day, when I was inspired to take one of the lines far too literally. Dozens of browser tabs, piles of conversions, and way more hours than I'd planned later, and we get the image above and this post.

The line goes, "When it occurred to me that the animals are swimming around in the water in the oceans in our bodies; and another had been found, another ocean on the planet, given that our blood is just like the Atlantic."

It's lovely imagery, but it got me wondering: how does the volume of blood inside all living human beings compare to the volume of large bodies of water like the Atlantic Ocean?

I did some quick Googling to try to figure out how much blood is in the average human body. The links I clicked seemed to suggest 6 or 7 quarts of blood, leaning a bit toward six. The CIA World Factbook informed me that most living human beings are adults, with about a quarter of the population being under 14 years. Thus, I deigned to reduce the value of volume of blood per body to 5.5 quarts, in a blatantly arbitrary attempt to account for the smaller contributions of the world's children. 5.5 quarts comes out to about 5.2 liters, which I then multiplied by the Factbook's estimated world population of 6,928,198,253. That got me 38,105,090,391.5 L.

38 billion liters (about 10 billion gallons) is certainly an impressive amount, but then there's the matter of the volume of the Atlantic Ocean. Wikipedia informed me that it is 354,700,000 cubic kilometers. 1 L is 0.001 m³, and 1.0 × 10-12 km³. Thus, the total volume of human blood on Earth is about 0.0381 km³, compared to the 350 million km³ of the Atlantic. So ya, barely a drop (about 0.00000001%).

Turns out oceans are pretty big. (image source)
How about Lake Superior? That's about 12,000 km³, so the total volume of human blood (shall we abbreviate it? How about TVHB?) is about 0.0003% of its volume. A little better, but perhaps still not the impressive (nor easily visualized) proportion we humans would like.

What about Lake Winnipesaukee, the largest lake in my home state of New Hampshire? That's 625 billion gallons, which comes out to 2.37 km³. That means TVHB is 1.61% the volume of Lake Winnipesaukee. At least our percentage values are greater than one now, which is somewhat more impressive, I suppose.

Lake Winnipesaukee (photo source)
Okay, so going any smaller with lakes is going to lose us even more of the usefulness in comparison, since fewer and fewer people will be able to use the particular lake for reference. But let's go with another fairly well-known lake in the area, Canobie Lake, which is home to one of the major amusement parks in the New England region. I'm totally unqualified in saying so, but I'd guess that it's a pretty typical local lake, at least for New England. The internet tells me it's 375 acres (I'm going to go ahead and assume that's only the surface area of the water) and has an average depth of 28 feet. A few (hopefully correct) conversions later, and we find that the volume of the lake is somewhere around 3.4 billion gallons. Now we're talking: the total volume of blood flowing through living human beings could fill Canobie Lake about three times.

Lovely, eh? (original image)
For a small amount of people, that's a very useful image. But I suppose I should try to accommodate as many folks as possible, and for that I think I'll have to resort to that most hackneyed of volume comparisons, the Olympic-sized swimming pool. The minimum volume for such a pool is 660,000 gallons, meaning the TVHB could fill more than 15,000 of them. Have fun imagining that; you're welcome.

Now all of this math was done in the middle of the night through bleary eyes, so it's entirely possible that something is off somewhere. But in my sleep-deprived wisdom, I'm going to go ahead and say, "nah, probably not," because I spent a lot of time doing all this that should have been spent sleeping, and I'd hate for it all to be a waste. 

I wish I could conclude this post with some sort of profound point but sadly the numbers of mild interest are pretty much all the content I have for you, aside from the song that got this all started:

No comments:

Post a Comment