“Words are the tools with which we work, the material out of which laws are made, out of which the Constitution was written. Everything depends on our understanding of them.” — Felix Frankfurter
One of my favorite things about summer is all the fresh fruits and vegetables. Especially strawberries in June and blackberries in July.
“Well, actually,” my friend said, as he literally pushed his glasses up his nose. “Strawberries and blackberries aren’t really berries.”
What?
“No. Scientifically, a berry is fleshy fruit that has an outer skin, enclosing one or more seeds, without a hard woody pit. Neither strawberries nor blackberries meet that definition.”
A Bad Definition
“Wait. By what definition? According to that definition, bananas and watermelons are berries, which they definitely are not.”
“Yes, they are. And so are oranges and grapefruit, cucumbers and pumpkins, and eggplants and tomatoes.”
“Well, that’s stupid.”
My friend shrugged. “If it makes you feel any better, blueberries and cranberries are berries. But not strawberries, blackberries, raspberries, or mulberries. Scientifically. Or more specifically, botanically.”
“Then botanists are idiots. A definition of ‘berry’ that does not include berries but does include bananas, oranges, and watermelons is a bad definition.”
Defining “Berries”
I checked.
“Berry” is a very old English word. In fact, it comes from Old English, meaning that it dates back to before the year 1150. Along with the word “apple,” it is one of only two English words for fruits that don’t come from other languages. The Old English word means “a small, pulpy fruit without a stone or pit.” So, historically, strawberries, blackberries, raspberries, mulberries, blueberries, and cranberries are all berries. And have been for hundreds of years. Cherries, on the other hand, are not.
The other definition comes from Carl Linnaeus, who included it in Philosophia Botanica, which he wrote in 1751. He screwed up, but botanists have been following his lead ever since.
Process Safety Is Not Immune
Botany is not the only technical field that has adopted definitions that confound ordinary usage. Consider process safety and the word “explosion.” We’ve defined the word to mean “an almost instantaneous expansion of volume of a given amount of matter, usually with the generation of high temperatures and the release of high-pressure gases.”
Yet when someone in the press refers to an “explosion,” I’ve been known to scoff. “That’s no explosion. That’s a vapor cloud fire. Look at the video image. The camera never shakes to show that a shock wave passed by.” I probably even push my glasses up my nose as I’m saying it.
“Explosion,” however, is also an old word. Not as old as “berry,” but it has been around since the 1500s. Originally, it evolved from the Latin word, explodere, which means “driving an actor off the stage by clapping or hissing” (“Ex” for out, “plodere” for clap, as in “applaud.”) In the 1660s, it had come to mean “violent, noisy bursting apart” and not until 1882 was the word used in print to mean “bursting with destructive force.”
So, the press is not wrong. A fire ball, even if it doesn’t generate a shock wave, is certainly “bursting with destructive force.”
Defining “Explosions”
In truth, the word “explosion” is kind of ambiguous. I mentioned shock waves. For an event that is “bursting with destructive force” to generate a shock wave, the flame front must be moving faster than the speed of sound. We have a specific name for supersonic flame fronts: detonation. Detonation is not exactly a new word, either. It comes from the Latin, detonare, meaning “to thunder down or thunder forth,” which at least is consistent with the modern meaning. Etymologists tell us that the first recorded use of the word “detonate” was in 1720.
Some flame fronts don’t travel at supersonic speeds. Sometime between 1881 and 1883, the French chemists, E. Mallard and Henry Louis Le Chatelier, defined the existing word “deflagration,” (originally coined in 1600 and a synonym for “conflagration”) to refer to events with flame fronts travelling at subsonic speeds.
Then there is the word, “bleve.” Originally (and still) an acronym for “Boiling Liquid Expanding Vapor Explosion,” bleve was coined in 1957 by three researchers at Factory Mutual. They very specifically were referring to the phenomenon that occurs when a pressure vessel holding a liquid at a temperature well above its boiling point fails, releasing the liquid, which vaporizes almost instantly. That instant vaporization is the explosion. Any liquid can be involved in a bleve. If the liquid is flammable, the resulting vapor cloud may subsequently ignite and also result in a vapor cloud fire or vapor cloud explosion. They are two separate events, however, and the word “bleve” means exactly what the researchers at FM intended for it to mean.
Why It Matters
To people who do not belong to a particular profession, that profession’s jargon often seems like a barrier designed to keep outsiders out. Worse, when a profession insists that a commonly used word does not mean what people commonly understand it to mean, it just makes the profession seem like—idiots. It undermines our ability to communicate.
In our zeal for precision, we need to be careful not to insist that people are wrong when they are not. Otherwise, they will see us pushing our glasses up our nose, whether we wear glasses or not.
