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I don't know much about CSS, but Turing completeness is notorious for showing up in systems unintentionally. It doesn't take much to be Turing-complete - if a

I don't know much about CSS, but Turing completeness is notorious for showing up in systems unintentionally. It doesn't take much to be Turing-complete - if a system provides unbounded read/write memory plus branching or conditional recursion you're usually there. As an example, Magic The Gathering (the card game) is Turing-complete: https://arxiv.org/abs/1904.09828 https://arxiv.org/abs/1904.09828 . You can use creature tokens as memory and various game mechanics to do flow control. Was this intentional by the designers? Most likely not...

lproven 8mo ago
> Turing completeness is notorious for showing up in systems unintentionally Greenspun's 10th law. https://wiki.c2.com/?GreenspunsTenthRuleOfProgramming https://wiki.c2.com/?GreenspunsTenthRuleOfProgramming
- Dylan16807 8mo ago
  That's on the opposite end of the complexity spectrum.
  - lproven 8mo ago
    Perhaps so, but ISTM that it encapsulates the same basic point. Try to make something rich and general and you often end up re-implementing a whole computer inside your computer. Which is why these days it's easier in many cases to just embed an Arm core and implement your controller's functionality in software.
    - Dylan16807 8mo ago
      > Try to make something rich and general It's also easy to stumble into Turing completeness when you're just trying to let one setting modify another setting in a basic way.
mycall 8mo ago
* MOV x86: using memory mapped lookup tables, you can simulate logic gates and branching using only MOV. * PowerPoint (Without Macros): using On-Click Animations and Hyperlinks, shapes on slides act as the tape and clicking them triggers animations that move the head or change the state of the slide. * find and mkdir (Linux Commands): find has a -execdir flag executes commands for directories it finds. By using mkdir to create specific folder structures, you can create a feedback loop that functions as a Tag System (aka universal computation). * Soldier Crabs: Researchers showed that swarms of Mictyris guinotae can be funneled through gates to implement Boolean logic. While a full computer hasn't been built with them, the logic gates (AND, OR, NOT) are the building blocks for one. Even water is Turing Complete: * Fluidic Logic Gates: the Coandă effect is the tendency of a fluid jet to stay attached to a convex surface. By using tiny air or water jets to push a main stream from one channel to another, you can create the fluid equivalent of a transistor. * MONIAC (Monetary National Income Analogue Computer) * Navier-Stokes equations describe how fluids move are TC. * In 2015, Stanford researchers developed a computer that operates using the physics of moving water droplets. Tiny iron-infused water droplets moved by magnetic fields through a maze of tracks. The presence or absence of a droplet represents a 1 or a 0. By colliding or diverting each other, the droplets interact perform calculations.

lproven 8mo ago

> Turing completeness is notorious for showing up in systems unintentionally Greenspun's 10th law. https://wiki.c2.com/?GreenspunsTenthRuleOfProgramming https://wiki.c2.com/?GreenspunsTenthRuleOfProgramming

Dylan16807 8mo ago
That's on the opposite end of the complexity spectrum.
- lproven 8mo ago
  Perhaps so, but ISTM that it encapsulates the same basic point. Try to make something rich and general and you often end up re-implementing a whole computer inside your computer. Which is why these days it's easier in many cases to just embed an Arm core and implement your controller's functionality in software.
  - Dylan16807 8mo ago
    > Try to make something rich and general It's also easy to stumble into Turing completeness when you're just trying to let one setting modify another setting in a basic way.

mycall 8mo ago

* MOV x86: using memory mapped lookup tables, you can simulate logic gates and branching using only MOV. * PowerPoint (Without Macros): using On-Click Animations and Hyperlinks, shapes on slides act as the tape and clicking them triggers animations that move the head or change the state of the slide. * find and mkdir (Linux Commands): find has a -execdir flag executes commands for directories it finds. By using mkdir to create specific folder structures, you can create a feedback loop that functions as a Tag System (aka universal computation). * Soldier Crabs: Researchers showed that swarms of Mictyris guinotae can be funneled through gates to implement Boolean logic. While a full computer hasn't been built with them, the logic gates (AND, OR, NOT) are the building blocks for one. Even water is Turing Complete: * Fluidic Logic Gates: the Coandă effect is the tendency of a fluid jet to stay attached to a convex surface. By using tiny air or water jets to push a main stream from one channel to another, you can create the fluid equivalent of a transistor. * MONIAC (Monetary National Income Analogue Computer) * Navier-Stokes equations describe how fluids move are TC. * In 2015, Stanford researchers developed a computer that operates using the physics of moving water droplets. Tiny iron-infused water droplets moved by magnetic fields through a maze of tracks. The presence or absence of a droplet represents a 1 or a 0. By colliding or diverting each other, the droplets interact perform calculations.