What is the riddle about ancient Egyptian home cooling in this radio ad?

July 26, 2023 9:21 PM

There is a radio ad on Tampa-area radio stations that starts with a narrator going "in the opulent homes of ancient Egypt, they used porous clay pots to cool their rooms" (not the exact words, but you get the idea) and then kind of rambles on about the subject. Then, he goes, "there's a tiny mistake; did you catch it?", and it's never explained, just in a generic "we look for the tiny details" kind of thing. It's an ad for an air conditioning repair company. Especially for anyone else who knows what I'm talking about, what's the joke/riddle?
posted by Seeking Direction to Grab Bag (11 answers total)

Porous clay pots full of water?
posted by nouvelle-personne at 9:33 PM on July 26, 2023

Surely we can’t tell you the tiny mistake in the riddle if you don’t actually tell us the riddle? But if I had to guess I would say that the porous clay pots were used to cool the smaller pots inside them, not the rooms they were in.
posted by ejs at 10:06 PM on July 26, 2023

The Evaporative cooler* wiki page mentions the Egyptian qullah.

*AKA Swamp Cooler

Without having heard the ad, I think the joke may be swamp coolers don't work in swamps.
posted by oceano at 10:46 PM on July 26, 2023

the porous clay pots were used to cool the smaller pots inside them

They can be used that way, but swamp coolers are more often used just to cool their surroundings. They'll also cool the water they contain, so when you drink that it'll be below room temperature.
posted by Stoneshop at 11:48 PM on July 26, 2023

Humidity in Cairo right now is a crispy 20%. Humidity in Tampa right now is 83%. As noted above, evaporative coolers don't work where the air is saturated.
posted by late afternoon dreaming hotel at 5:04 AM on July 27, 2023

The error might be that their homes weren't opulent. in reality, the ad got your attentio, so it's very effective.
posted by theora55 at 7:10 AM on July 27, 2023

Humidity in Cairo right now is a crispy 20%. Humidity in Tampa right now is 83%. As noted above, evaporative coolers don't work where the air is saturated.

Cairo's humidity is extremely variable, with dew point going from 59F (dry) to 69F (dangerously humid) over the course of a day. So swamp cooling or evaporative cooling would not work there consistently any better than it would in Tampa, at least in the summer.

Tampa is consistently in the dangerous humidity zone in the summer, along with most of the southern US.
posted by The_Vegetables at 8:04 AM on July 27, 2023

I'm also thinking it's just a borderline nonsensical statement to get you to remember the ad.

An example of this:

30 years ago, my aunt married her older college professor (she was 35ish with a couple kids, so not the usual) who happened to be head of the English department. I met him a couple years earlier, as a 10 year old.

I was prepped that he was the wittiest and funniest person the family had come across, and sometimes his humor was "overwhelming". Our first interaction went like this:

Him: Do you ever hear the one about the salesman who accidentally strangled himself coming through a screen door?

Me: [Hesitantly]...no.

Him: [Frustrated and visibly pained] sigh....damn. [Gets up and walks out of the room].

Fin.

I asked him about it 10 years ago, and while he didn't remember the specific joke, he did say it sounded like the kind of "mean" joke he'd tell a young person.

Reader, I have thought about this for almost 35 years. I won't say I've done it every day, but it's one of those things that just jumps into my head when I'm zoning out. Inception is one of my favorite movies literally because of this. I almost can't help but thinking about it.

Anyway, I hope you don't think about Cairo pots for the rest your life, like I will be doing with salesmen and screen doors.
posted by Back At It Again At Krispy Kreme at 8:58 AM on July 27, 2023

The 2nd law of thermodynamics demands that if you cool an area, part of the device doing the cooling has to be outside of that area. Cooling decreases the entropy of the cooled area, but total entropy must increase, so you have to have some of the device outside, where entropy increases.

An air conditioner inevitably has part of it outside the house, building, or area being cooled. A window AC sticks out of the window. Central AC has an exterior unit. A swamp cooler has a hose or most cloth or something going outside.

A refrigerator has coils on the outside of the unit. This is why you can't cool your home by opening the refrigerator door: the coils on the back inevitably generate more heat than the chilling effect of the refrigerator can counteract.

One caveat: these don't have to happen at the same time. You can chill drinks in a cooler with ice, because the necessary increase in entropy was done when the ice was first made. Then, as they're cooled, the decrease in entropy of the drinks is offset by a greater entropy increase in the warming and eventual melting of the ice.

Note, the reverse is not true: a heating unit can be entirely within the area it heats, because that's an increase in entropy which is perfectly fine on its own by the 2nd law.

I'm not sure that's what the intended solution is, though. I wouldn't call breaking the Second Law of Thermodynamics a "tiny" mistake.
posted by DevilsAdvocate at 9:15 AM on July 27, 2023

It's a local ad. It's probably a minor grammar mistake or a not-quite homonym or something, to get you to listen very closely the next time you hear the ad to try to catch it (and not obvious enough that you're likely to do so). Like Back At It Again At Krispy Kreme said, I doubt it's about the actual technology of ancient Egypt.
posted by lapis at 9:21 AM on July 27, 2023

Update: I recorded (most of) the ad and have it on Vocaroo here.
posted by Seeking Direction at 2:58 PM on August 5, 2023