Requirements and Horses' Asses

There’s a common joke that makes the rounds of forwarded Internet email that claims the width of the booster rockets on the Space Shuttle) are constrained by the width of an ancient Roman chariot (more colorfully, by “a couple of horses’ asses”). Here’s the linkage:

• Why are the boosters the width they are? So they can fit through train tunnels.
• Why are train tunnels the width they are? Because of the gauge of the track.
• Why do we use that particular track gauge in the US? Because it was built by British engineers who used the British standard.
• Why was that track gauge the British standard? Because it was based on existing horse-pulled mine cars that ran on rails.
• Why was that the width of mine cars? Because it was the standard cart width.
• Why was that the standard cart width? Because it was the spacing of ruts on British roads.
• Who made the ruts? The Romans.
• Why was that the spacing of the ruts? That was the standard width of a Roman chariot.
• Why was that the standard width of a Roman chariot? Because the chariot was pulled by two horses.
• Ergo, the requirements for the Space Shuttle booster rocket width was originally set by a couple of horses’ asses.

The story is exaggerated in its specifics, but it does point out a useful insight: The present is sometimes constrained by the past.

Builder Robert Moses, famously opposed to public transportation, engineered bridges on New York’s Wantagh Parkway with an ulterior motive–he purposely ensured that they were too low for buses, and buses still do not run on his parkway. Similarly, we type on a keyboard with the top row spelling QWERTYUIOP, a jumble of letters designed to slow down our typing so that the keys on our manual typewriter do not jam as they hit the paper.

Why don’t we change to a more efficient system? Too much effort. Legacy costs. Infrastructure limitations. Inertia.

Thousands of business books talk about change resistance as some sort of failure. Your people – or managers – just aren’t flexible enough. Personal agendas undercut corporate improvement. You don’t have the right kind of corporate culture.

We can list numerous reasons, but it all comes down to physics. Inertia is as much a human and organizational concept as it is a law of the physical universe. And why wouldn’t that be true? It would be far more surprising if organizations were exempt from the law that drives everything else in the universe.

If resistance to change is just inertia wearing a clever plastic disguise, what does that teach us? Well, inertia is the tendency of an object at rest to stay at rest, but more importantly, the tendency of a body once in motion to stay in motion, unless acted upon by an outside force. To change the moment of inertia of an object, you apply force over time. But no matter how flexible the management team, you can’t flip the Exxon Valdez around like a speedboat. Massive objects (large companies) are simply harder to move. There’s no point in getting frustrated about it, which is often the reaction. Instead, be realistic about the force you can apply in the time period over which you can apply it in contemplating which changes to pursue.

If inertia applies in the corporate world, what about the other rules of physics? It’s easy to see the everyday effects of friction in human interactions. Why do meetings take so long? Why does it matter so much what the people at work like each other or get along? Well, when moving parts rub up against one another, friction is the result. To overcome friction, you need lubrication. Good manners, kindness, and the spirit of teamwork work wonders as well.

And, of course, there’s entropy, or the tendency of systems to move in the direction of chaos. Things fall apart unless new energy is applied. That great new management initiative will deliver great results just as long as you keep pumping energy into it. Decide you are done, and immediately it begins to unravel.

There are structural limits that reality places on change. Applying these physics concepts of inertia, friction, and entropy allows us to understand more deeply how organizations, systems, societies, and individuals work. They help you identify possible futures, constrain our analysis of alternatives, and point out the paths of least resistance along which history tends to flow.