Physical Artifacts have a tangible (i.e. material) part and a temporal extent (i.e. it exists in time). It might or might not also have an intangible part. For example, a particular copy of a book is made of matter, has temporal extent, and also has an intangible part: the information content of the text markings on its pages. Physical artifacts include things as diverse as lenses, folded objects, the back of the hand, a flame, and vapor.