Recently I’ve been studying process control, one of the last classes in the chemical engineering curriculum. In process control there is a useful and simple concept called process gain. Process gain is defined as the ratio of a process output to a process input, or mathematically:

Process Gain = Output / Input

It’s easy to imagine an example of process gain around the house. Increasing a knob associated with a burner on the stove top from 0 to 10 could increase the temperature of water in a pot on that burner from 70 degrees to 212 degrees F. The process gain would then be:

Gain = (212 – 70) degrees F / (10 – 0) knob units

= 15.2 degrees / knob unit.

A more interesting example applies the idea of process gain outside of the engineering realm. Think about the famous rhyme:

For Want of a Nail

For want of a nail the shoe was lost.

For want of a shoe the horse was lost.

For want of a horse the rider was lost.

For want of a rider the message was lost.

For want of a message the battle was lost.

For want of a battle the kingdom was lost.

And all for the want of a horseshoe nail.

For the lowly input of a nail, the output was the loss of a kingdom, or:

Gain = – kingdom / – nail.

I’ll leave it to the diligent reader to do the unit conversion.

Now to conspiracy theories. It has been said that many people are apt to believe conspiracy theories because it is difficult for them to accept the idea that events so consequential can be perpetrated by people whom are not so. Using the idea of process gain, we can communicate this in a different manner. People expect outputs to be commensurate with inputs, or that process gain should be somehow reasonable.

In other words, if the numerator of the gain equation is the kingdom, the denominator should be something near in value to a kingdom. A numerator as world-altering as 9-11 should have been perpetrated by a denominator with similar weight, like a superpower government. An assassination of someone as powerful as a president should have been committed by a group with similar power, like the mob. Process gain should be on the order of 1, not on the order of 1 billion.

On WDET Detroit today, Craig Fahle featured author Jeff Greenfield talking about his book If Kennedy Lived. The author speculated on that counterfactual: perhaps the conflict in Vietnam would have been wound down, perhaps Lyndon Johnson would not have been able to pass through great-society reforms. He goes on: just before Kennedy was to drive that fateful route in Dallas, it had been raining hard enough that the top needed to be down on his convertible. It of course cleared up slightly thereafter. Who knows how large of a process gain has been obtained by a flicker of a rain cloud with respect to the output of history?