User:Ssstephen/Reading/Universality in Elementary Cellular Automata

Because a system is universal, some of its properties are undecidable (will it become periodic, will a particular sequence occur)

Because Turing machines are universal, if a compiler exists that can compile any data and program from a turing machine to another computer, then that computer is also universal

Tag systems are universal ACDABBE --> DABBECCDD

Cyclic tag systems can only have a two letter alphabet {Y,N}, but they can emulate tag systems so are also universal.

A glider system from Matthew Cook's paper 'Universality in Elementary Cellular Automata'

A glider system (see image) is a system of moving particles called gliders. In the image you can see diagonal lines which interact with vertical lines (the tape head or data) in the centre, emulating a cyclic tag system. The glider system is running an emulation of the cyclic tag system, which is running an emulation of the tag system. In a way this looks like a vector system to me, of interacting vectors rather than flipping bits.

Lastly you run an emulation of the glider system inside rule 110.

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Fabric version of this could be really interesting. If you got a round loom with 14n pins (a flat loom maybe would be more flexible, to decide different sizes), you could knit a hat or sock program. https://www.youtube.com/watch?v=gOTIAmg0Iow Or does it need to be woven? No idea.

The piece should be a ring so the ends more obviously loop back on themselves. Re: slow computing, computation as labour, This Work of Body / This Body of Work, Meghan Clarke https://www.designacademy.nl/p/study-at-dae/graduation-show/graduation-projects/meghan-clarke Talk to Daniela about double sided knitting, re binary knitting and ternary knitting. So the knitting is the computation; knit the first line of the program then knit further to get the output. A little similar to a quipu, although probably a less efficient system. Are quipus universal?

Programming some A gliders into 110, of increasing width from left to right.

What can you compute on rule 110 (apart from everything)? Can you write a hello world script on a rule 110 computer? Can you add 2+2? https://www.youtube.com/watch?v=QKnSRw_X2w4

First attempts here at coding in the p5.js version of 110 with a few A gliders of increasing widths. Even experimenting on the javascript version of this is so slow, doing this in playing cards or knitting would be incredibly slow. But if it's a statement about computational labour the slowness reveals that.

Stopped at page 13 for now.