The universe is big – mind-bogglingly so. On its largest scales of billions of lightyears, it has a filamentous, labyrinthine structure that many have noticed bears a resemblance to biological structures, such as the network of neurons in an animal brain – see figure 1 below.
This is more than idle speculation, peer reviewed scientific publications such as Vazza and Feletti 2020 have examined this relationship and looked at the underlying pattern forming processes:
The discussion of early cosmic inflation, at the excellent “History of the Universe” channel:
made me realise that the expanding universe might represent a Turing reaction-diffusion system. Turing conceived his reaction-diffusion model to explain biological complex structure, theoretically by interaction between a long range inhibitor exerting negative feedback and a short range promotor exerting positive feedback, as discussed by Kondo and Miura, 2010:
Basically two agents with different distance scales and opposite effects. The result is emergent pattern like the dots and stripes on fish and land animals.
In the expanding universe dark vacuum energy drives expansion over vast scales while gravity attracts object together over shorter distance. This looks analagous to the two opposing forces in a Turing reaction-diffusion system – the long range negative feedback (dark energy pushing apart) and the closer range positive feedback (gravity pulling together). So the expanding universe will inevitably be a Turing reaction between these two opposing and differently scaled forces, causing complex labyrinthine emergent pattern – this is what happens with the universe’s filamentous structure.
Forgetting chaos theory is always a mistake when attempting to explain nature. With emergent pattern it is no longer necessary for everything to be fine tuned at the outset for structure to evolve in a linear manner thereafter. Even the apparent Minkowski flatness of the universe could be emergent, not fine tuned at the outset. In the same way that thermal homeostasis is emergent in complex dissipative thermodynamic systems, like living organisms or the climate.
Could Turing-like reaction-diffusion emergent pattern avoid the need for early fine tuning?