Well, that was the fun. The nice people at the Meaning Conference gave me 13 minutes to try to explain what a blockchain technology is, what blockchains might do, and what the implications might be, to an audience of largely creative people. Quite a challenge. Since they were creative types, I thought I ought to frame my explanations with poetry rather than mathematics. I decided to start with the Ur-statement of ordered immutability, the Rubiyaat of Omar Khayyam: “The Moving Finger writes; and, having writ, Moves on: nor all thy Piety nor Wit Shall lure it back to cancel half a Line, Nor all thy Tears wash out a Word of it.” You can see the revised version of the slide deck here (we accidentally sent the wrong version on the day, but it really didn’t matter). It sets out the revised “4x4x4” model of shared ledgers, so that there is context for talking about the blockchain, and then quickly works through how there are different kinds of blockchains (and bitcoin is only one