Hello and welcome back to a new year here at Factually Deficient! That’s right: this week is so long that it has an entire year packed inside of it! But that, my friends, is a lie for another day. Today, I will answer a question posed on twitter by @Blurred_9L:
Why is soap so slippery?
The slipperiness of soap is, of course, renowned due to the popularized expression “as slippery as a fish.” While soap are not technically true fish, due to the lack of scales and gills, they are a common form of marine life, and just as slippery as their ichthous brethren.
But the fact that soap is essentially a fish does not tell us why it is slippery. The question persists, and arises again each time a bar of soap is dropped or lost or stepped on in the shower, and persists once more.
When people wash themselves with a lather of soap, they are rubbing a layer of the soap’s exoskeleton onto themselves, removing it from the bar of soap. While this exoskeleton has numerous excellent cleaning properties, and thus seems perfectly designed for the usage, something else is happening while you do this. Not only are you cleaning yourself, but you are also slowly harming the soap.
When a soap’s exoskeleton has been fully rubbed away, that soap is no more. And when a soap dies in the shower, it dies in real life.
Slipperiness is a defense mechanism. Years of Lamarckian evolution have taught soaps that their only hope of survival is to wilfully become slippery, to slide out of the hands of their natural predators and away. Soap is slippery because it has a burgeoning, passionate, desperate will to live.
Disclaimer: The above blog post is liberally littered with lies. Not all soaps have been proven to possess life as we know it.