EDIT it was not youtube, got it from sources. It's here: https://odysee.com/$/embed/Lord-Vetinari_s-Clock/0b5f49b3f88...
My memories of what I've heard over time:
* The grasshopper escapement actually is the demonic insect that sits on the top, "walking" around the serrated ring.
* Although it's backlit electronically it's actually a fully mechanical design - including all of the weird things it does.
* The Chronophage itself blinks its eyes unnervingly.
* It sometimes pauses or ticks slightly backwards, then runs faster to catch up again.
* On certain special dates it does extra weird stuff.
* The "chime" is a metal chain dropping into a box.
There were three made in the series, this was the first one. I've always found it slightly unappealing aesthetically but also compelling - there's no arguing with the fact that there's always a crowd of fascinated observers looking at it.
Adam Savage discussed on Youtube earlier this week[0] the Chinese water torture episode of Myth Busters, and mentioned an email he got some time after, from somebody who had apparently actually used that torture technique in practice, and this person stated that what really made it effective was tuning the drip so the drops were completely unpredictable.
So, with Vetinari's Clock, Pratchett once again managed to, as was his wont, humorously but accurately nail a pretty damn grim bit of real-world trivia.
However, the principle is sound, and the execution is… timely?
Until recently there was one in the wall of a bar in Douglas here on the Isle of Man. Apparently, the inventor of the thing lives here. Another is in his home.
However that bar, the rather rough 1886, is now the Island's first Wetherspoons... :-/
At first sight, it looks like some modern art piece but then you see the plaque that it's not an electronic clock (it has LEDs which made me think it was) and then it's cool!
Where to start, where to start ...
How do I make a mechanical thing happen at a random time with a lava lamp?
The ball on the board with a hole might be something I could figure out …
Use a heat lamp interrupted by the lava globules to activate a wax motor. If you get the angles right you can probably do this with the same light that runs the lamp itself, or you can put another lamp at a 90° angle (but will have to adjust the main lamp to keep the total heat at the level you want).
Or do similar with muscle wire; more temperature needed to trigger the actuator, but you can get them much smaller so the total heat can be smaller, if you run e.g. a collimated infrared laser as your heater across the lamp.
"Daniels claimed that there was little money to be made in watchmaking, but his lifestyle suggested otherwise. In 1982 he moved, for tax reasons, to the Isle of Man, where he bought a substantial Georgian house complete with tradesmen’s entrance and sweeping drive."
https://www.telegraph.co.uk/news/obituaries/8846796/George-D...