Let's turn our attention now to the problem of defining "everyday things". This book will largely assume that everyday things are the objects and materials we encounter in our daily lives. This includes the objects we interact with and the surfaces that support us. Included within our purview therefore will be the things we walk on or otherwise traverse, such as water or grass or dirt, as well as the things we pick up or otherwise manipulate, such as a car's steering wheel or a can of coke.
Things are generally nested within other things. A chair is nested within a dining set, which in turn is nested within our home, which is nested within the wider environment. A car is nested in the context of a road or garage, but a car's parts are nested within the car itself. Those parts in turn nest smaller components, such as wheels, until we reduce down to the smallest components, which likely only our mechanics deal with; literally the nuts and bolts of the vehicle.
How our brains understand the relationships between things nested within other things is a very important topic. But it is not the main focus of this book. Rather, we will speak largely superficially of “things”, in the literal sense; we will focus on surface appearance!
By surface appearance I mean how we perceive the shape, colour, texture, gloss, translucency, etc. of surfaces. What an object is made of will be reflected (somewhat literally) in its surface appearance. What an object is made of is what we call its material properties, and our visual system's seem to be very well adapted to determining, at a glance, material properties based on surface appearance alone, which is quite a remarkable feat.