Nope, no click-bait here: Yocto is very much a real word with a real meaning. So if you read no further, at least you can walk away better armed and prepared to score handsomely in your next Scrabble game when that relatively rare, coveted Y-tile (4 points!) lands on your letter rack.

But if you’re still here and reading, it means you are curious. And I will reward that curiosity by getting straight to the point and letting you know (something you can easily google too, of course) that Yocto is the smallest official SI unit, a prefix measuring 10 to the power of -24.

Arguably only useful in measuring infinitesimal quantities, Yocto is thus used to describe stuff like the unit mass of a proton or electron. So don’t be looking for yG values when you go shopping or checking quotes for share prices! But since it is used for quantifying something this miniscule, aside from physicists and their ilk, do us normal people really care ? How much change is change meaningful enough for us to care – honestly?

In the finest traditions of the Socratic method of rhetoric I will answer that question with the following question: have you heard of the ship of Theseus ?

The Ship of Theseus is a Greek myth, and a powerful allegory (sorry, following Socrates, you were not really expecting me to switch historical contexts mid-blog, were you now?). Theseus was the founder-king of Athens who after slaying the mythic Minotaur on Crete sailed back victoriously to the city. His ship was maintained in the harbor of Athens as a memory of said victory, and enthusiastic young Greeks recreated the voyage by sailing the ship annually to Crete to memorialize the triumphant passage. Now as you can imagine, ma Nature started doing her thing, and the ship started corroding and falling apart. No problem – each failing part was replaced one by one until all the boards, oars, sails, planks and rivets were new and no original (=decaying) part of the ship remained, and the Ship of Theseus sailed on year after year in glory, inspiring generations of Athenians.

Staying within the Greek philosophical ouevre, it is now an easy transition to Plutarch, who used the ship of Theseus to posit a fundamental, if existential question: Who am I ? This thought experiment leans on the simplistic question: which is the real ship of Theseus, the physical one that Theseus sailed on, or the one that for a thousand years continued to sail on in commemoration of his victorious voyage ? Similarly: who are you ? Are you the person you were in childhood, are this very minute or will be ten years hence? And are “you” your physical body, your thoughts, or your actions ?? Honestly, there is no static, solid self. Just like the ship of Theseus, throughout our lives our habits, beliefs, and ideas evolve…sometimes beyond recognition. Our physical and social environments change. Heck, even almost all of our biological cells are replaced. Yet we for the most part, remain, to ourselves simply “I”.

The well known Harvard psychologist Dan Gilbert says “Human beings are works in progress that mistakenly think they’re finished.” We are never truly done, until of course we are actually done, by which time it is usually too late to do anything about it. Meanwhile we stumble along, replacing the planks on our personal ship of Theseus, often times taking care to make sure that to the outside world we still appear to be the same person they once knew and loved.

Yet, our lives change every day: sometimes in dramatic and momentous ways, and often times in impossible to spot, almost Yocto-units. Regardless, may we always sail on our own ships of Theseus until that one day when inevitably our ship sails off into the sunset.