How fast must something travel for it to be rendered invisible to the naked human eye? Is it possible to change eye colour naturally? How many colours can a human eye detect?
Ecotone, Inc is an ecological restoration company that provides full-delivery ecosystem restoration, mitigation, design, construction and consulting solutions throughout the United States.
An ecotone may appear on the ground as a gradual blending of the two communities across a broad area, or it may manifest itself as a sharp boundary line. From Wikipedia