Remember the blog entries Quantum computer solves problem... and How to find some bombs... ? Well, they are related, since 'counterfactual computing' is related to 'interaction-free measurement'. The last physics entry then referred to a paper Quantum to Classical Transition... that tries to explain interaction-free measurement based on a RBW point of view. This new paper, The limits of counterfactual computation then relates again to the first link presented. It's all a web of relations...