[Aardwolf]

Here's something I wonder:

Imagine you're stuck on an island or in a forest, and you're stuck with what you find in nature only, or perhaps you get very primitive technology (e.g. basic metal working only):

What's the simplest way you could build some (mechanical) logic gates to do some form of useful computation?

I've seen some from lego or 3D printed ones, but they all look very complicated, e.g. requiring rubber bands or springs but not looking practical to combine many together in a useful circuit

[kwhitefoot]

If you have basic metal working facilities you aren't far from being able draw wire and then you can make relays. It might take a while to replicate Konrad Zuse's machines but I think that it might be simpler to do that than go for purely mechanical computers, see https://en.wikipedia.org/wiki/Z3_(computer)

But if you only want a calculator the there are plenty of examples from Blaise Pascal onwards: https://en.wikipedia.org/wiki/Pascal's_calculator.

A friend of mine in high school had a calculator like this one: https://www.computinghistory.org.uk/det/4584/Magic-Brain-Cal... that could be made quite easily.

And of course the serious calculator enthusiast would have a Curta. Needs a bit more than basic metal working I suspect: https://en.wikipedia.org/wiki/Curta

[jacobr1]

Not quite what your are asking: but you could probably easily build a slide-rule, once you bootstrap the basic tools needed.

[gdprrrr]

Water and dominos are possibilities https://www.youtube.com/watch?v=IxXaizglscw

[kickofline]

relevant xkcd: https://xkcd.com/505/

[zero__one]

There are several issues with that comic:

1. In finite time, it is not possible for a human to create an infinite row of rocks.

2. The academic paper for Rule 110 describes it as "weakly universal" rather than Turing-complete because it depends on an infinite pattern.

3. The rocks act as RAM, not the CPU. The human is applying the rules. The human is the CPU.

In the Tetris paper, the agent is just a TAS recording while Tetris acts as RAM and the CPU.

[DesiLurker]

isn't this the core idea behind Wolfram Hypergraph thing?

ref: https://writings.stephenwolfram.com/2020/04/finally-we-may-h...