Just plain wrong, and that’s just okay

I’ve been guilty of my share of blunders. I remember how I used to be convinced that is was better to fill up an ice cube tray with hot water than cold water for the reason that it would freeze faster. I can still remember my mom shaking her head at me and my sister as we lectured her why we steaming hot water in the ice cube tray. The slightest bit of thermodynamics would’ve proved us wrong.

Lucky for my ego, Zambians aren’t any different. There’s a endemic driving error I’ve seen on Zambian roads: minibus highway drivers in Zambia accelerate to high speed, then turn off their engines, coast for a few hundred meters, and do it all over again. The reason?

“I’m saving gas.”

Ok, I’m usually the guy that suspends judgment in a new place, and I’ve only been in Zambia for a month. But this is ridiculous.

Force = mass X acceleration

So when speeding up, a minibus engine has to work hard to provide enough force to accelerate the mass of the vehicle and people. But when maintaining speed, the force needed is only that to overcome wheel friction and air resistance.

Fneeded = Fair resistance + Fwheel friction

This force is scant compared to the force needed for acceleration. That’s why maintaining a constant highway speed is one of the best things you can do for fuel efficiency. These Zambian guys are way, way off the mark. Why? And also, why should I care?

From what I’ve seen, there’s two ways to think about development:

  1. Assume the locals know nothing (less popular, these days), or
  2. Assume the locals are infinitely rational, but that we just aren’t seeing thing the way they are (more popular).

I don’t agree with the first group, and find myself more at home in the second, but there’s the danger: how do you fit in the local stupidity of turning minibus engines off at highway speeds to save gas?

My answer is to remember that we’re all human here, and as many times I’ve fallen prey to misguided logic, superstition, or just plain stupidity, Zambians have done the same. Keeping this in mind I can tell a farmer that burning crop residues is ignorant of soil mechanics, be confident that witch doctor remedies aren’t the way to go, and scold ridiculous minibus drivers while still respecting all of these people.

After all, putting hot water in the ice cube try is no different.


1 Response to “Just plain wrong, and that’s just okay”

  1. 1 Aaron November 13, 2009 at 9:54 am

    Don’t worry, the problem is way over the heads of Zambian mini-bus drivers and you and I. Only 1% of the energy from the bus’s fuel is moving the people, 14% moves the plastic and metal and 85%(!) is being lost as heat. Automobile combustion engine fuel efficiency is a contradiction in terms… or so my mom says.

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Working to include smallholder farmers in agricultural markets, we know there are no easy answers. This blog is a place to ask "What does it take to make it work?" and to share what we're seeing and learning.
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