During my second season as a clerk in the Mercantile, the most talked about products we sold were not the Smokey Bear souvenirs or the t-shirts or the plush birds that made authentic calls provided by the Cornell Lab of Ornithology. No, the most talked about products in the Mercantile were the large bags of potato chips.

The bags of chips were purchased in the lowlands with an elevation of only 470 feet. They made the trip up the mountain with The Big Boss Man to our elevation of 6400 feet. According to the AZ  Central article “Nothing Says Fun Like a Bursting Bag of Potato Chips,”

The amount of air in a bag of chips is fixed. If the package was sealed at a lower elevation and carried to a higher elevation the air inside of the bag will swell against the reduced atmospheric pressure.

Kids and adult alike noticed the expanded bags. People often thought the bags were about to explode, but in the time I worked at the Mercantile, I never experienced a bag of chips spontaneously bursting.

Some people thought the bags were full of extra chips. I bet those folks were disappointed when they opened their bags and found them—like most every other bag of chips in the world—only half full of salty, greasy, potato-y goodness.

One man told his family the heat had expanded the bags. I almost started laughing. I’d never seen a bag of chips expand like that in the heat of the desert or the hot humidity of the Deep South. The man spoke with great conviction, even though he was wrong. Actually sir, I said, it’s because of the change in elevation from the valley where the chips are bought to up here.

The fellow looked skeptical, but he didn’t argue with me.

If everybody who talked about the bags of chips actually bought a bag of chips, we wouldn’t have been able to keep the bags on the shelves. Unfortunately, most people were content to talk and not buy.

Late one afternoon while I was working the entire day alone, an elderly man came into the Mercantile. He was a talker, but I was not keen on listening. One of the things I hated about working retail was being a captive audience. Any yahoo who came into the Mercantile could stand in front of me and talk, and I was compelled to listen. It’s amazing how many shirts needed folding when someone decided to talk my ear off on a topic other than giant sequoias or merchandise available for purchase.

The old man said, Those chips expanded because they’re packed at a lower elevation. He said it as if he were telling me something I couldn’t possibly know.

I smiled sweetly and said brightly, That’s right! There’s no potato chip factory on top of this mountain!

Of course they were packed at a lower elevation! Of course the elevation change is what made the bags expand!

We didn’t speak any further about the potato chips and their expanded bags. Perhaps the fellow realized I didn’t need him to school me.