Great question! This is analogous to asking, “How does life as we know it differ from rust? They both grow..." There is such a thing as trivial replication, t

Great question! This is analogous to asking, “How does life as we know it differ from rust? They both grow..." There is such a thing as trivial replication, the trick is non-trivial replication. I don’t have the background to give you the formal definition, but my layman’s understanding is that non-trivial replication works from a description of a thing and a general-purpose factory that makes things from descriptions. I think the formal definition says something about the information encoded in the thing that is replicating. A fundamental questions mathematicians and computer scientists asked themselves in the first half of the 20th century was whether it was possible for a factory+description to be encoded in the description. 70 years later, we know the answer. but at that moment, it wasn’t obvious how this could be done: If the factory required space F for itself and the description of the factory required space d(F), F+d(F) seemed to be larger than d(F), so the description of a factory plus the description of the description of a factory seems intuitively larger than the description of a factory, call it d(F+d(F)). This seemed to go on ad infinitem, so how could you make a description such that when handed to the factory, the factory would make another factory AND copy the description so you would end up with a new factory plus a new description? Smart people figured out how to do this theoretically with things like the lambda calculus. John von Neumann was interested in self-replciating robots. Stanislaw Ulam had been working with CAs and suggested von Neumann try buildinga self-replicating CA on these lines, and von Neumann showed this could be done with a 29-state CA. This led to John Horton Conway’s radical simplification that we call “Life” today, and it has been both proven and demonstrated that Life is a universal computing machine. You can build self-replciating patterns that have encoded descriptions, universal Turing machines, hexadecimal calculators, and just about everything else. Some of the most amusing oddities actually “output” numbers and letters organized as dots as if printed by a dot matrix printer! Warning: Life is addictive but unremunerative.