> the very existence of the Geiger counter or computer may depend on which branch occurred (perhaps there was a bomb on one path?)
At the quantum level, the quantum degrees of freedom in the Geiger counter or the computer still exist even if a bomb goes off. They just have a different relationship in terms of interactions than they would if the bomb didn't go off.
Sure, something has recorded the state. It's just that we like to think of there being fixed, discrete entities that have knowledge, whereas really it's more like that knowledge is an integral part of their identity.
