A brand-new phenomenon, and a theory that held.

A metal powder-bed machine started producing a regular dimensional oscillation inside large, densely packed sections of a build: a repeating pattern of oversize and undersize nobody had seen before. It was on no known-issue list, and nobody on site had a theory for it. Genuinely new, with nothing to search for.

Heat build-up in dense regions was understood in general. Small variations across the build area were understood in general. Neither one on its own produced this pattern, and nobody could say why the oscillation lived inside the dense sections specifically, or why some materials showed it far more strongly than others.

Cala proposed a coupling nobody on site had put together: in densely packed regions, the accumulated heat locally changes how much of the delivered energy actually takes effect, and the strength of that coupling differs sharply between materials. That gives you a self-modulating pattern that only shows up where packing is dense, exactly where it was seen, at a strength that depends on the material, exactly as observed.

It didn't stop at the mechanism. It laid out experiments to tell the explanations apart: change the packing without changing the geometry, reorder the build sequence, repeat across materials, each one with a prediction attached.

The experiments ran as designed. The oscillation moved with packing and sequence exactly as predicted, and its strength tracked the material exactly as predicted.

A phenomenon with no name and no write-up went from observation to confirmed mechanism, with a test plan attached. That's the case Cala is built for: not looking up what's known, but reasoning about what isn't.