The problem with all things like this is that they are simple mathematical models being used to argue for highly advanced physics and engineering. I find it ext

The problem with all things like this is that they are simple mathematical models being used to argue for highly advanced physics and engineering. I find it extremely likely that the real world would quickly turn this half a million years into many billions of years once you add in various inefficiencies and limits. After all, life is a self-replicating machine and it has taken slightly longer than that to consume a fraction of the resources on this planet.