Previous studies show that city metrics having to do with growth, productivity, and overall energy consumption scale superlinearly, attributing this to the social nature of cities. Superlinear scaling results in crises called “singularities,” where population and energy demand tend to infinity in a finite amount of time, which must be avoided by ever more frequent “resets” or innovations that postpone the system’s collapse. Here, we place the emergence of cities and technological civilizations in the context of major evolutionary transitions. With this perspective, we hypothesize that once a planetary civilization transitions into a state that can be described as one virtually connected global city, it will face an “asymptotic burnout,” an ultimate crisis where the singularity-interval timescale becomes smaller than the timescale of innovation. If a civilization develops the capability to understand its own trajectory, it will have a window of time to affect a fundamental change to prioritize long-term homeostasis and well-being over unyielding growth—a consciously induced trajectory change or “homeostatic awakening.” We propose a new resolution to the Fermi paradox: civilizations either collapse from burnout or redirect themselves to prioritizing homeostasis, a state where cosmic expansion is no longer a goal, making them difficult to detect remotely.

In light of conceptual difficulties with past and current definitions of life, we present a novel characterisation of the living state based on four pillars: thermodynamic dissipation, autocatalysis, homeostasis and learning. We clarify forms of life by introducing the term ‘lyfe’ to describe any system that performs all four fundamental processes, while ‘life' refers only to living systems as we know them on Earth. We note that many non-living structures exhibit subsets of these properties, and we refer to such systems as ‘sublyfe’. Finally, we review exotic lyfeforms that satisfy the four pillars but differ from lifeforms in distinct ways. We suggest a possible form of lyfe that transduces kinetic energy into its metabolism, a so-called mechanotroph.

We present recent results concerning the attractor landscape, memory, hysteresis and computation that can emerge in simple convective obstacle flows. In these systems a single phase fluid is heated from below and cooled from above. Small obstacles (one or two) are placed on the horizontal mid plane of the system and extract some fraction of the fluid’s horizontal or vertical momentum. Horizontal momentum sinks tend to attract convection plumes. Vertical momentum sinks are bistable; the obstacle will either align with a convection cell centre or convection plume depending on initial conditions and the history of the system. The resulting attractor landscape can be exploited to produce a single bit memory or even elementary Boolean logic.

In this paper I present a general modelling framework for coupled fluid dynamics and chemistry problems, and apply it to the simulation of a series of complex, homeostatic reaction diffusion systems. The model can incorporate any number of chemical species and reactions. Those chemical species diffuse, react and are advected by fluid flows. I illustrate some characteristic results from the modelling of the Gray Scott reaction diffusion system with thermally resolved reactions. Extending my previous work on ecological dynamics of nonliving structures, I demonstrate that thermal homeostasis of reaction diffusion spots can occur in systems without the use of the porous wall boundary condition that has traditionally been used for the Gray Scott system. I present an initial analysis of the parameter space of this system as well as detailing the mechanism behind the thermal homeostasis.

We demonstrate the emergence of spontaneous temperature regulation by the combined action of two sets of dissipative structures. Our model system comprised an incompressible, non-isothermal fluid in which two sets of Gray-Scott reaction diffusion systems were embedded. We show that with a temperature dependent rate constant, self-reproducing spot patterns are extremely sensitive to temperature variations. Furthermore, if only one reaction is exothermic or endothermic while the second reaction has zero enthalpy, the system shows either runaway positive feedback, or the patterns inhibit themselves. However, a symbiotic system, in which one of the two reactions is exothermic and the other is endothermic, shows striking resilience to imposed temperature variations. Not only does the system maintain its emergent patterns, but it is seen to effectively regulate its internal temperature, no matter whether the boundary temperature is warmer or cooler than optimal growth conditions. This thermal homeostasis is a completely emergent feature.