[Xcelerate]

> then there doesn't seem to be anything to figure out about collapse.

Then why is quantum state evolution seemingly continuous and unitary some of the time, and sharply discontinuous at other times?

[im3w1l]

It seems continuous and unitary when the experimenter takes a lot of care to create a simple and very isolated system. When it's brought into contact with the mess that is the rest of the world it changes character very quickly, and interactions with the rest of the world completely swamp the internal dynamics.