What are Cellular Automata?

Unfortunately I realised while writing this that it is not easy to expain cellular automata (CA) without images or drawings, and I do not want to add too many of those to this blog, so I will do a rough job of explaining what they are, but there may be gaps.

I like wikipedia’s description of what a cellular automata (ca) may be, and so the followng paragraph is largely copied from there:

A cellular automaton consists of a regular grid of cells, each in one of a finite number of states, such as on and off. The grid can be in any finite number of dimensions. For each cell, a set of cells called its neighborhood is defined relative to the specified cell. An initial state (time t = 0) is selected by assigning a state for each cell. A new generation is created (advancing t by 1), according to some fixed rule that determines the new state of each cell in terms of the current state of the cell and the states of the cells in its neighborhood. Typically, the rule for updating the state of cells is the same for each cell and does not change over time, and is applied to the whole grid simultaneously, though there are exceptions.

Life and Cellular Automata

In any given CA, patterns of states in its grid may emerge that have robustness

  • the ability to continue the pattern, when other patterns of states interacts with them. To use an analogy, the human skin is more robust than a piece of cloth since if both were scratched until a small tear apeared, the skin would heal (re-create the pattern that was there) while the cloth would not.

What do I want to say? I want to say that with rules, patterns of states emerge. The patterns that are most robust will evolve. Patterns make us, we want to make patterns.

Life as a CA glider and why programming changes matter: I think of life as emergent patterns of self-replicating or -regulating states of matter in reality, where matter is the smallest element in reality which can have a state. An example that seems to make this definition clear for me and many othes would be the life in the reality of Conway’s game of life (gol). In gol, life emerges in the form of still lifes, oscilators, and spaceships [1]. These patterns can vary greatly in complexity and robustness (the ability to withstand interaction [2] with other patterns of life in reality). As I said earlier it is clear to many that some of the patterns of states in gol seem to exhibit properties of self-replication or self-regulation and look like they exhibit life, hence the name: Game of Life. The same is true in our reality. Certain patterns of states in reality occur in clumps of reality. Patterns that self-replicate are more likely to exist for longer, and so too with patterns that are good at self-regulation i.e. robustness. Evolution by natural selection is the process of patterns interacting with each other and one of the following happens: all interacting patterns cease to replicate; some patterns continue to replicate while others don’t; a new living pattern emerges. Given enough time and space, highly robust patterns might emerge, and they may consist of (or be a part of) living patterns that form a hyper-pattern. This is what we are: a massive number and complicated series of patterns that emerged to make an extremely robust hyper-pattern, the human. I’m a computer scientist who has not studied any of the hard sciences formally, so there will likely be gaps in the following summary, but here are a few layers of pattern formation on the path to a human pattern: quark, atom, molecule, dna, cell, tissue, organ, organism (human). [3]

I’ll continue later.

[1] The wikipedia definitions for these patterns are: still lifes, which do not change from one generation to the next; oscillators, which return to their initial state after a finite number of generations; and spaceships, which translate themselves across the grid [2] Patterns interact when the cells that form them change their state in the next time step, based on the state of cell(s) in the other pattern. [3] This is a bit of a digression but an interesting thing to note is that these patterns did not emerge/arrive in this order. The organism that later became a human came before certain tissues or organs that are now part of the human pattern.

What is the meaning of life?

For me, my purpose is to create the maximally robust and happy pattern.