This idea is based on the metaphor: Line->Paragraph->Book->Bookshelf->Library It is an idea that several small things make up something bigger. From just the metaphor above what could it be used to represent. For me I have: (1) 1D->2D->3D->4D->5D? (2) Visual->measurement->observed results->derived results->??? For (1), 1D is something that can be seen, 2D is something that can be shaped, 3D is something that can be shaped and felt, 4D is something that that can be shaped, felt, and moved. Not sure what 5D can represent (any ideas?). For (2), Visual is something we can see, feel, or touch, Measurement allows us to define an object more clearly, observed results is a collection of measurements, and derived results is what one can derive from a collection of observed results. The next one can be applications (or it could be something else entirely). The above is just a chain that advanced toward a bigger picture or idea from the metaphor mentioned above. What other (meaningful) chain can you think of?