"Definining "nano" in terms of complexity"
"Nanotechnology" and "nanoscience" have been defined in many ways, provoking many arguments. The issue not merely semantic when funding is at stake. I propose that spatial complexity density may be used to formulate a concise, general, technical definition that automatically locates systems with respect to the domains of nanoscience and nanotechnology. I argue that such a definition captures the conventional meaning and usage of these terms. Measures of complexity density include the number of bits required to specify a unit volume of structure, or the spatial spectral bandwidth of the matter distribution. While Shannon's theorem allows us to discount noise from bandwidth, spatial bandwidth and noise form a two-dimensional space within which we can locate crystals, chips, life, etc. Our control of these is separably measurable in the same terms. The objective of nanotechnology is the highest bandwidth and lowest noise in the channel connecting intentions to actual products.