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December 10, 2007
Volume 85, Number 50
p. 48

Science Friction with Bob Wolke

Heather Mull
Bob Wolke

It's amazing what one can learn from a pocket calculator. A simple calculation can reveal specific truths that are hiding within aggregate statistics, and as politicians well know, statistics can be used to either spotlight or conceal any specific truth.

These days, virtually all statistics can be had by the click of a mouse on Google. Then with an ordinary calculator, one can manipulate them to yield virtually any desired correlation. As a sometime-statistic myself (the chimerical "average American male"?), I prefer to individualize these clinical numbers. What do they actually mean to me? My calculator lets me find out.

An example: As I write this on Nov. 15, the U.S. national debt stands at $9,113,206,502,561.64, and the estimated U.S. population is 303,217,507. Simple division shows that my single-person share of the nation's indebtedness is $30,055.0143. Now if I could figure out to whom I owe my share, maybe I could pay it off and relieve my guilt. It would be so nice to be able to say, "Don't blame me; I don't owe nobody nothin'!"

(If you are wondering how I handled all those significant digits in the preceding paragraph, I just entered "9,113,206,502,561.64 divided by 303,217,507" into a Google search box and clicked. Unlike my pocket calculator, Google's "calculator in the sky" seems to be able to handle any number of digits.)

On the positive side of the ledger, the total amount of money in circulation in the U.S. is $7.4 trillion, which my calculator tells me comes to about $24,400 per person. So why is there only $27 currently circulating through my wallet?

The most interesting statistic I've come across lately has to do with the so-called obesity epidemic in the U.S. While doing some calculator calisthenics with the published National Institutes of Health obesity estimates, I stumbled upon an unexpected connection to our nation's dependence on foreign petroleum. In fact, I have come up with the ultimate solution to all our energy problems.

I'm not talking about alternative sources such as solar or wind power. Nor do I see anything new in converting corn into ethanol. People in the hills of Tennessee and Kentucky have been doing that for a hundred years; they're called moonshiners. No, I'm talking about a brand-new, untapped source of energy: overweight Americans.

According to federal health statistics, the average adult American male (69.3 inches tall and 190 lb) is 31 lb overweight, and the average adult American female (63.8 inches and 163 lb) is 36 lb overweight. Now the latest census counted 147 million men and 152 million women in the U.S. A simple computation shows that a total of 10 billion lb of surplus flab is being hauled around by Americans. Considering that flab is 85% fat with an energy content of 9.0 kcal/g, I found, after a bit of unit juggling, that the amount of potential energy in this surplus freight is 40 billion KWh. That's enough energy to supply the needs of the entire U.S. for 10 years!

So here's what I propose: We convert all the nation's gasoline stations into liposuction stations—it's just a matter of reversing the pumps. An overweight American drives up, gets out of the car, bellies up to the nozzle, and proceeds to "lose weight" to any desired degree.

The suctioned fat, just like the used deep-frying fat collected from restaurants, is converted into biodiesel fuel, which can be used to run automobiles or generate electricity.

In exchange for his or her donated fat, the customer receives credits for its energy equivalent: 1 gal of diesel fuel or 5 kWh of electricity per pound.

Of course, a few details must be worked out. For one thing, Congress will have to pass an entitlement act to subsidize our disadvantaged skinny citizens.

With this scheme, we can literally live off the fat of the land for 10 years. And then what? Well, let's not kid ourselves. This is clearly a renewable resource.

Readers write: Tom Schmitt of Wyandotte, Mich., informs me that the Roman-numeral calculator I facetiously claimed to have invented in a recent column actually exists (C&EN, Oct. 15, page 56). It was created and christened THROBAC by the late Massachusetts Institute of Technology professor Claude E. Shannon (1916–2001), who is credited as the founder of information theory. THROBAC can be seen at the MIT Museum in Cambridge, Mass.

Bob Wolke can be reached at

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