People are very sensitive to physical events occurring around them... We know that one solid object cannot merge into another; We make decisions about the properties of objects based on the way in which they interact with each other; We judge whether objects are animate or inanimate depending on whether we perceive them as moving of their own volition, or being "caused" to move by another object (referred to as the perception of causality [Mic68]). Many studies have shown that these perceptual mechanisms are established very early on in infancy (e.g. see [BSW85])... but how accurate are they? Research in the realm of physics education has shown that most people have erroneous, yet very robust, pre-conceptions regarding the physical behaviour of objects [Cle82]. This is obviously not a good thing if you are trying to teach introductory mechanics, but it could be very useful if you are trying to get away with fast, yet plausible, physically-based simulations for real-time ap...
