ABSTRACT
The notion of information bridges the external world of physical events and our perception and understanding, for information of events and things is separate from us in space and time. How to think about and to measure information are still controversial matters, and there are snags, or at least limitations, in all theories and methods. The lead has come from engineers, but until recently at least their concern has been with communication-transmission systems, rather than with brains or minds. With developments in artificial intelligence this is now changing, and we may look for further leads from the engineers who have to grapple with these difficult problems. The issues are technical, and we cannot altogether escape technical detail here.
