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Not an expert here but what is the relationship between by this and Von Neumann's "Self Replicating Machines"? [0] [0]: https://en.m.wikipedia.org/wiki/Self-re

by max_ 5y ago

Not an expert here but what is the relationship between by this and Von Neumann's "Self Replicating Machines"? [0] [0]: https://en.m.wikipedia.org/wiki/Self-replicating_machine https://en.m.wikipedia.org/wiki/Self-replicating_machine

chriswarbo 5y ago
von Neumann's approach was to define a "universal constructor", with a programmable "arm" for altering cells. He came up with a complicated set of cellular automaton rules which allow such a universal constructor. Then he came up with a "program" for the constructor which, when executed, would create a copy of the universal constructor and of the program. This was all meant to be in analogy to the physical world, where such a constructor could be used to build almost anything, perhaps operating at the atomic-scale. It turns out that we can get much simpler self-replicators if we (a) ignore the "universal constructor" ability, and only focus on self-replication; and (b) choose cellular automaton rules which make self-replication easier, rather than using cells to encode "programs". This approach gives things like Langton's Loops https://en.wikipedia.org/wiki/Langton%27s_loops https://en.wikipedia.org/wiki/Langton%27s_loops The self-replicating property described in the article seems like an extreme form of this approach: the rules are so tailored for replication that they can't do anything else. Of course, making such simplifications sort of defeats von Neumann's original purpose, since such highly-tailored rules are less "realistic", and hence don't particularly help us build physical self-replicators; and even if we could, they wouldn't be particularly useful without the "universal constructor" ability.
- eternalban 5y ago
  Happy to see Chris Langton mentioned. He is often strangely neglected. Here is the transition table for Langton Loops: https://github.com/GollyGang/ruletablerepository/blob/gh-pages/downloads/Langtons-Loops.table https://github.com/GollyGang/ruletablerepository/blob/gh-pag...
- Syzygies 5y ago
  > Of course, making such simplifications sort of defeats von Neumann's original purpose Yes. In von Neumann's last book "Theory of Self-Reproducing Automata", he thought about machines having viable offspring. This was more than a trick with patterns. He had invented the architecture of working computers, and was now moving on. As a math grad student at Harvard around 1980, the wine flowed freely on Friday afternoons. I nevertheless headed over to the biology department, where cannabis-fueled discussions centered on work like von Neumann's.

by max_ 5y ago

chriswarbo 5y ago

von Neumann's approach was to define a "universal constructor", with a programmable "arm" for altering cells. He came up with a complicated set of cellular automaton rules which allow such a universal constructor. Then he came up with a "program" for the constructor which, when executed, would create a copy of the universal constructor and of the program. This was all meant to be in analogy to the physical world, where such a constructor could be used to build almost anything, perhaps operating at the atomic-scale. It turns out that we can get much simpler self-replicators if we (a) ignore the "universal constructor" ability, and only focus on self-replication; and (b) choose cellular automaton rules which make self-replication easier, rather than using cells to encode "programs". This approach gives things like Langton's Loops https://en.wikipedia.org/wiki/Langton%27s_loops https://en.wikipedia.org/wiki/Langton%27s_loops The self-replicating property described in the article seems like an extreme form of this approach: the rules are so tailored for replication that they can't do anything else. Of course, making such simplifications sort of defeats von Neumann's original purpose, since such highly-tailored rules are less "realistic", and hence don't particularly help us build physical self-replicators; and even if we could, they wouldn't be particularly useful without the "universal constructor" ability.

eternalban 5y ago
Happy to see Chris Langton mentioned. He is often strangely neglected. Here is the transition table for Langton Loops: https://github.com/GollyGang/ruletablerepository/blob/gh-pages/downloads/Langtons-Loops.table https://github.com/GollyGang/ruletablerepository/blob/gh-pag...
Syzygies 5y ago
> Of course, making such simplifications sort of defeats von Neumann's original purpose Yes. In von Neumann's last book "Theory of Self-Reproducing Automata", he thought about machines having viable offspring. This was more than a trick with patterns. He had invented the architecture of working computers, and was now moving on. As a math grad student at Harvard around 1980, the wine flowed freely on Friday afternoons. I nevertheless headed over to the biology department, where cannabis-fueled discussions centered on work like von Neumann's.