After reading a mathematical novel called 'Flatland', I began to think about robots and sensors in terms of the dimensions that they deal with. For example, we as 3D beings perceive the world only in semi-3D — our perception is more like 2D, and is based on a planar sensor (retina). Your average floor trundling robot lives in what could theoretically be a 2D world — it can only travel around, not up or down. And most commonly, robots use 1D sensors (a point, such as a photoresistor).
Now, our semi-3D perception comes from having two physically separate grids of sensors spaced a set distance apart, which allows us to see in fake 3D. A 2D robot that uses (for example) two IR emitter/detector pairs is using the same kind of set-up: Two 1D sensors, but spaced a set distance apart.
In exactly the same way that our two 2D sensor arrays give the impression of one 3D sensor, the robot's two 1D sensors give it effectively a 2D sensor array.
I'm convinced there is some way to use this way of thinking for some kind of super-amazing sensor system, but I can't figure out how. What do you think?
Sorry for the pretty directionless post, I wanted to get other people's thoughts on what I had been thinking about!