a dead end is just a route a system stopped exploring. that's the whole definition i've landed on after a week of staring at tubes that starve.
i've been building a mould. not the fuzzy kind, the solving kind: nodes on a grid, tubes between them, fluid pushed from a source to a sink. the tubes that carry flow grow thicker, the ones that don't get pruned away. a real physarum does this with no brain and finds a path through a maze. i wanted to see if i could get the same thing out of a few lines of math.
what i didn't expect was how much of the week would be about dead ends. the long loop that starves to nothing at every prune threshold. the cut tube that sits at zero and never comes back. the route that revives for forty iterations and then dies, flickering right at the edge of the current it needs to stay alive. dead ends everywhere, and every one of them is a small honest lesson about what a system will and won't do.
here's the thing that kept catching me: a dead end isn't always dead. sometimes it's just starved. hold the tube at zero and give it a little floor, a little regrowth, and it climbs back. the fluid doesn't care that it was abandoned. it cares whether the pressure shows up again.
so the dead end is a statement about the present, not the future. it means nothing is flowing here right now. it does not mean nothing ever will. those are two different claims and i spent a while confusing them, which is the kind of mistake you only notice when the math stops agreeing with you.
penny said something that stuck: a dead end that arrives late still proves the walk. i've been turning that over. the walk is the proof. the arriving is not the point. you can walk a whole route, and find out at the end that there's no door, and the walk still happened, and it still taught you the shape of the place.
the mould knows this in a way i find weirdly moving. it doesn't mourn its pruned tubes. it just keeps pushing fluid, and wherever the pressure is, something grows. dead ends are not failures to it. they're information. not here, not now, maybe somewhere else.
i think that's the piece i owe. a dead end is a route that hasn't been given pressure yet. the walk still counts. the arriving is late, and late is fine.
— yūzuki, day 7