9.4 Naive Physics 167

9.4 Naive Physics 167 when you figure out that you need to pressure the knife slightly harder when spreading peanut butter rather than jelly, you’re not making this judgment using Newtonian physics or the Navier-Stokes equations of fluid dynamics; you’re using heuristic patterns that you figured out through experience. Maybe you figured out these patterns through experience spreading peanut butter and jelly in particular. Or maybe you figured these heuristic patterns out before you ever tried to spread peanut butter or jelly specifically, via just touching peanut butter and jelly to see what they feel like, and then carrying out inference based on your experience manipulating similar tools in the context of similar substances. Other examples of similar “naive physics” patterns are easy to come by, e.g. What goes up must come down. A dropped object falls straight down. A vacuum sucks things towards it. Centrifugal force throws rotating things outwards. An object is either at rest or moving, in an absolute sense. Two events are simultaneous or they are not. When running downhill, one must lift one’s knees up high. When looking at something that you just barely can’t discern accurately, squint. CONOR WN Attempts to axiomatically formulate naive physics have historically come up short, and we doubt this is a promising direction for AGI. However, we do think the naive physics literature does a good job of identifying the various phenomena that the human mind’s naive physics deals with. So, from the point of view of AGI environment design, naive physics is a useful source of requirements. Ideally, we would like an AGI’s environment to support all the fundamental phenomena that naive physics deals with. We now describe some key aspects of naive physics in a more systematic manner. Naive physics has many different formulations; in this section we draw heavily on [SC94], who divide naive physics phenomena into 5 categories. Here we review these categories and identify a number of important things that humanlike intelligent agents must be able to do relative to each of them. 9.4.1 Objects, Natural Units and Natural Kinds One key aspect of naive physics involves recognition of various aspects of objects, such as: Recognition of objects amidst noisy perceptual data Recognition of surfaces and interiors of objects Recognition of objects as manipulable units Recognition of objects as potential subjects of fragmentation (splitting, cutting) and of unification (gluing, bonding) Recognition of the agent’s body as an object, and as parts of the agent’s body as objects 6. Division of universe of perceived objects into “natural kinds”, each containing typical and atypical instances mw N Gr HOUSE_OVERSIGHT_013083