We demonstrate a programmable mobile self-replicator for a non-deterministic, indefinitely scalable computing architecture. We present a 20 day case study that begins by deploying a single diamond-shaped structure, loaded with handwritten “ancestor” code, into a tiled hardware matrix. That diamond moves, grows, and replicates in about an hour, and during the first day the diamond population reaches the carrying capacity of the 76 tile prototype machine. By analyzing captured matrix images, we derive basic vital statistics of the diamond population. This paper presents the new replicator in the context of related work, focusing on the division of labor between ‘physics’ and ‘biology’ in this open-source computational stack. It concludes with a call to focus on paths to technological utility for these robust, scalable, and life-like computational structures.

Computer architectures that presume global hardware determinism are ultimately unscalable, but they are relatively easy to program because each operation is strictly sequenced and has an assured effect. Architectures that forgo global determinism can be indefinitely scalable , but they demand a shift in programming concepts, towards software mechanisms that can perform useful work given only limited, local synchronization and merely best-effort determinism. This paper introduces a parallel computing framework called SPOT— Stage Priority Operation Teams —designed for ulam programmers coding for the 2D grid of the Movable Feast Machine. Spatial threads , a simple but flexible 1D distributed programming paradigm, are introduced as a first use-case for SPOTs, with sample tasks ranging from moving objects to search, quorum sensing, and data reductions. SPOT and spatial threads also make intriguingly literal connections between crass physical concepts—such as space, time, and motion—and computational concepts such as program and data, and suggest a humble but fundamentally sensible meaning for the term ‘object’.

A computer produces outputs from inputs, and to do so reliably, its internal noise and variability must be managed effectively. Traditional computer architecture requires hardware determinism , but such perfect repeatability is increasingly incompatible with large-scale and real-world systems. Natural living systems, without the luxury of deterministic hardware, manage variability across the computational stack—and using such principles, soft artificial life offers a route to much larger and safer manufactured computers. This paper describes the engineering development of C214 , a next-generation self-constructing digital protocell. C214 struggles to survive in a challenging environment that, while not literally malicious, goes well beyond merely non-deterministic to deliberately destructive. Improved self-repair mechanisms, as well as active defenses in depth, give the new cell’s membrane a median survival time more than ten times greater than that of the earlier C211 . A new grid-based cytoplasm is also presented, standing to offer a more stable environment for future layers of the ‘living computation stack’

In spatial computational models such as cellular automata (CA), designing mobile objects larger than the CA neighborhood is challenging when the object properties and dynamics are incompletely specified in advance. This paper introduces C211 , a two-dimensional digital ‘protocell’ with life-like and potentially useful features, designed for the best-effort asynchronous CA called the Movable Feast Machine (MFM). The protocell consists of an amorphous variable-density ‘cytoplasm’ that uses gossiping to coordinate operations such as cell movements, surrounded by an asymmetric ‘bilayer membrane’ providing some environmental isolation while adapting to cytoplasmic dynamics. C211 was engineered in a new ‘little language’ called SPLAT, which adds discrete 2D spatial pattern transforms to the ulam programming language. SPLAT is expressive enough that minimal code was required, for example, to enable membrane topology changes such as cell splitting and fusion. C211 ’s cytoplasm maintains internal state but leaves dozens of bits unused per atom, while its membrane is purely stigmergic and stateless—so vast tracts of pristine CA state space remain available for future cellular dynamics, whether engineered, evolved, or both.

Software-based artficial life will increase the robustness, and enable vastly increased size, of computing systems. To enhance human potential and protect individual liberty in future society-scale systems, the boundary between private and public digital spacesknown in telephone networks as a demarcation point or demarc should be set so that a significant amount of physical computing machinery can be counted as fundamentally personal, for assigning rights and responsibilities. To that end, this note offers a principle called the carried network demarc: The machines that you routinely carry under your own power, and their contents and interactions, should be considered part of your body as a matter of law and social norm. Such machines today may be as prosaic as a watch, pacemaker, or cellphone, but in the future you may regularly carry machines inhabited by multitudes of beneficial alife creaturesakin to the bacterial microbiomes that surround and perfuse our biological bodies that would likewise be considered you and yours in both their physical and computational aspects. The author solicits input from others with expertise bearing on this topic.