Various futurist thinkers, and even a few unusually insightful journalists have pointed out that the next generation of threats to humanity are self-replicating technologies.
It’s really too bad that self-replicating technologies are so dangerous, because such technologies would also be most useful for completely realigning the material structure of the world with our collective will.
Self-replication is something that life figured out a long time ago. The DNA in every cell of your body has a replication lineage that can be traced, in an unbroken line, all the way back to the first self-replicating piece of genetic material ever. Every branch on the Tree of Life is a descendant of the first self-replicating organic being.
The problem with this mode of organic self-replication we’re so familiar with is that it’s relatively restricted in what it can build. Water is essential in large quantities for all the processes of life so any terran biological life form must be made up of primarily H2O. This requirement strongly constrains all material properties, including freezing point, boiling point, tensile strength, density, toughness, …