Before programmable metal could become armor or a tool on command, it would need a control stack.
Before programmable metal could become armor or a tool on command, it would need a control stack: sensing, instructions, rearrangement, locking, and heat rejection.
Real systems demonstrate fragments of that stack. Fields can organize particles under controlled laboratory conditions. Some responsive fluids change how they flow or resist deformation. Modular robots and functional voxels can identify neighbors, connect, route signals, and build limited load-bearing structures.
The boundary matters. None of this demonstrates a compact, autonomous material that flows and then becomes an arbitrary weapon or construct.
In The Miracle Metal, programmed nanoparticle rearrangement is established fiction, and Taronite is the fictional bridge. Its detailed sensing, addressing, power, communication, and cooling mechanisms remain unspecified.
The impossible becomes more convincing when the control problem stays visible.