We see the darndest questions on teacher listservs. It seems that, at one school, there was a mystery to be solved. The boys’ urinals were often surrounded by a puddle of “liquid.” Were the urinals weeping water? Or were the boys purposely urinating on the floor (as the janitor believed)? And, most importantly, how can we use our good friend SCIENCE to solve this mystery, the teacher asked?
Is there a powder I can sprinkle on the floor that will turn a particular color?
A UV light to shine on the puddles that will fluoresce?
It turns out that, yes, there is such a device! Specifically created to detect pet urine stains, the Rug Doctor is here to help (and so are a plethora of other products). It’s a blacklight, and it turns out that certain molecules in urine (just like in semen and blood) will fluoresce. They use this at crime scenes too. “Fluorescent” means that a material absorbs light of one color, and then re-emits it in another color. Blacklight is ultraviolet, which is highly energetic light that is “too blue” for us to see. The fluorescent molecules absorb that light, which loses some energy in the process, and re-emit it in as light that’s lower energy (that we can see).
I used to study some fluorescent polymers that fluoresced in room light. They were beautiful. The liquid in the little vial seemed to glow (well, it did glow), this kind of chartreuse. The picture here isn’t from my research, but similar material.
Here are some common materials that glow under blacklight.
Anyway. Back to the problem at hand. We weren’t quite sure how these blacklight devices would work for detecting urine in tile grout (which probably holds all kinds of things). And how would one know if you were detecting backsplatter, or intentional misbehavior?
One teacher helpfully added:
A couple solutions I’ve seen to encourage boys to aim properly- in a bathroom at a truck stop in Alaska, there were the normal plastic filter things over the drain, but they had a little propellor thing labeled “Restroom Roulette” If you directed the stream at it, it would spin around until you stopped and point at various things like “You’re a Winner!” or “Sorry, try again” etc. Most kids would get a kick out of that. I’ve also seen urinals where the realistic image of a fly or a spider is etched/painted onto the urinal at the “sweet spot” where you get the least splashes. Males apparently can’t resist trying to nail the bug to try to wash it down the drain.
“Visualized whirled pees?” responded one.
Other suggestions included:
You could change the school water supply to include small amounts of the super absorbent stuff (sodium acrylate?).
The simple remedy is to issue each boy a pair of vice grips set to clamp to a small circumference. This will restrict flow, encourage returning to class and giving new meaning toclamping down on a problem. (Raleigh McLemore)
I had hoped to avoid stepping into this subject out of fear it may be too deep for me.
Some things are too serious to joke about.
One of our more prolific contributors (Al Sefl) shared:
A classic book has been written about the trajectory of droplets caused by a liquid stream impinging on the urinal receptacle surfaces. I believe The Bathroom by Alexander Kira was the first and most comprehensive study of both male and female urinals with backsplatter patterns. It pointed out that most of the bathroom appliances were poorly designed and kept that way out of some misdirected sense of traditional design. … He came to the conclusion that the clear majority of receptacles were not scientifically designed to minimize splash droplets. Other conclusions included were that the height of male urinals were often above the stream source so the end of the stream, as it peter’s out so to speak, often drops below the lower edge of the urinal. The book was a text used in a course for one of my master’s degrees, Industrial Design. It was very obvious that a complete redesign of the western lavatory in general was needed.
Al Self
Who thinks urinals should have a sign posted over them stating:
MIND THE GAP
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