I'm taking an online course from the Iowa Writers Workshop called "How to Create New Idiomatic Expressions." The hope is that, if I can get a PhD in Whimsical Colloquialisms, I might be able to find freelance work inventing quaint clichés to capture recurring experiences in exciting new ways.

This graduate level course has not been easy, though. Unlike most dissertations, where the student's responsibility is to come up with a provocative subject, the IWW folks choose the topic, and it's up to the student to explore the history of that colloquialism and then spin it forward.

My assignment? "The toothpaste is out of the tube." It's a conceptual cousin to "Letting the cat out of the bag," and it's been a toughie. Here's what I've found out:

1. The first "tube" of toothpaste was invented by a New London dentist, Dr. Washington W. Sheffield, in the 1880s. It was properly regarded as not just inspired but also theoretically brilliant. Unfortunately, Sheffield's toothpaste recipe tasted like a charnel pit, and he was lynched by irate and foul-breathed patients.*

2. The "toothpaste out of the tube" expression is meant to convey that, once something has happened, it's too late to undo it. But the analogy is flawed because it presupposes someone would actually want to replace toothpaste in its original casing. In my research thus far, I haven't found even one toothbrusher who squeezed paste onto the cleansing utensil — and then decided, speaking into the mirror: "You know what? I think my breath is fine the way it is. But I don't want to waste the toothpaste already on the brush so I'll just reverse engineer this and put the paste back into the tube ... What the hell? I can't get it back in! What fiend came up with a delivery system for an oral hygiene product but doesn't allow for the possibility of replacing unused paste in the original container?!"

3. I've also been reading research data from physicists who study "fluid mechanics," which concerns properties of liquids in various states and their reaction to forces acting upon them. This applies to my work because the toothpaste — a fluid in gelatinous form — being squeezed from a tube is a force/reaction dynamic. I consulted a friend who's a real-life fluid mechanic about whether one can actually get toothpaste back into the tube. Not by hand, he says, but a device could be consructed that would provide "pressure behind the expelled toothpaste that could get it (back) into the tube." So, thank you to actual fluid mechanic Jaime Duquette, who responded from his vacation on Martha's Vineyard. I hope Jaimie took his cat Murray with him but is extra careful. I'd hate it if Murray accidentally crawled into a piece of luggage thereby requiring Jaimie to let his cat out of the bag.

* Just kidding.