I had some time to kill in Tampa this afternoon, so I popped into a curiosity shop (more about that later). Though there were innumerable oddities, I only made one small purchase.

I passed over the shrunken heads, buying instead a little novelty item. As you can see, the Fortune Teller Miracle Fish thinks I’m passionate (though I’m not sure I needed a little plastic fish to tell me that).

This curio is definitely misnamed, since it is (purportedly) picking up on my current feelings, and not, in actuality, divining upcoming life events. So, there’s no need to toss out your crystal ball!

The secret to this phenomenon? A thin coating of sodium polyacrylate that reacts to the moisture secreted by sweat glands in our palms. Watch it in action: