Self-replicator caught on video

In a previous article, an announcement was made of a complex self-replicating machine (known as the 0E0P metacell) in a simple 2-state cellular automaton. In the interim between then and now, Thomas Cabaret has prepared a most illuminating video* explaining the method with which the machine copies itself:


Note: the video is in French; recently, Dave Greene added an English translation of the subtitles.

* the video is part of Cabaret’s Passe-Science series. You may enjoy some of his other videos, including an explanation of the P vs NP problem and a reduction of Boolean satisfiability to the 3-colourability of planar graphs.

Anachronistic self-propagation

In related news, Michael Simkin recently created a wonderfully anachronistic self-propagator entitled Remini: it uses the same single-channel/slow-salvo construction mechanism as the 0E0P metacell, but it is built from oscillatory components instead of static ones. That is to say, it implements modern ideas using components available in the 1970s.

The project involved slmake together with a suite of additional tools developed by Simkin. There isn’t a video of this machine self-replicating, so you’d need to download a program such as Golly in order to watch it running.

Further reading

For further reading, I recommend (in order):

  • The wiki entry (under construction) for the 0E0P metacell;
  • An article unveiling various simpler examples of self-constructing circuitry;
  • The slmake repository;
  • A tutorial on effective use of slmake;
  • A challenge thread proposing another contraption, that no-one has yet built. This would require the use of slmake followed by some ‘DNA-splicing’ to interleave the construction recipe with extra operations.


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10 Responses to Self-replicator caught on video

  1. Georg von Brzeski says:

    I am a physicist, not a specialist on cellular automation. Growth of anything ( from the physics point of view) assumes an energy exchange process which enables the phenomenon of growth in real physical world. So, where is the energy which sustain self replication process?

    • Thomas Cabaret says:

      In the physical world, our world, conserved quantity like energy comes from continuous symmetries. Energy by example is the conserved quantity we can derived from the continuous translation symmetry through time (see Noether theorem). In cellular automata there is no such a things like the Noether theorem, mainly because we are not dealing with continuous world. Most of the time nothing has to be conserved. But if you want example of cellular automata with some common points with physics, I suggest my other video on cellular automata (same channel), in which I describe “single-rotation” cellular automata, a reversible kind of cellular automata with “matter” conservation and other derived conservation properties. It is also a good illustration of entropy. Regards.

      • Paul Callahan says:

        I think I would answer more succinctly that we’re not dealing with physics here. Conway’s Game of Life (CGOL) does not conserve matter or energy. It is just a deterministic system with a particular set of rules. So “where is the energy” is not a question that applies here.

        CGOL is also irreversible, unlike most of physics. I have wondered what it would take to get self-replication in a reversible system. It should be possible, but it introduces technical challenges. In CGOL, you can make unwanted debris vanish and often do. In a reversible system, all “reaction products” need to persist in some form so they can determine the outcome of reversed steps.

        I spent a little recently on the reversible Margolus rule “Critters” (which has the additional problem that cell count is preserved, so you need both an explicit source of the new matter to organize into copies as well as a way to move debris outside the area of interest. The best I could construct explicitly was a signal fanout with the Critters equivalent of gliders. However, there is no reason that could not be extended to self-replication. We would also have close analogs to energy conservation and entropy (the “heat” consisting of discarded reaction products).

        • Anonymous says:

          I feel , I offended somebody when I mentioned about physics and energy necessary to drive life processes . As a game set by your rules I can agree with you, but remember please that moving your cells on the computer display you inevitably consume electrical power or energy if you wish. So I an still not convinced however impressed by your software skills.

  2. Thomas Cabaret says:

    Great! thx Adam!

  3. Paul Callahan says:

    I’m not sure anyone is offended, or what you are not convinced of. The existence of self-replicating Life patterns is not intended to demonstrate the existence of such structures in physics-like systems with conservation laws (though it may provide some hints to how to make them). Are you at least convinced that it works in Life?

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