Shadows and Silhouettes in Nature

It wouldn't be "NATURE"!
From Wikipedia (http://en.wikipedia.org/wiki/Nature):

...Within the various uses of the word today, "nature" often refers to geology and wildlife.
Nature may refer to the general realm of various types of living plants and animals, and in some cases to the processes associated with inanimate objects – the way that particular types of things exist and change of their own accord, such as the weather and geology of the Earth, and the matter and energy of which all these things are composed.
It is often taken to mean the "natural environment" or wilderness–wild animals, rocks, forest, beaches, and in general those things that have not been substantially altered by human intervention, or which persist despite human intervention.
For example, manufactured objects and human interaction generally are not considered part of nature, unless qualified as, for example, "human nature" or "the whole of nature"...