References to these essays must cite them explicitly as unpublished manuscripts. Copies may be circulated if this statement is included on each copy. Physical optics is a branch of modern physics.
Ecological optics is an undeveloped branch of ecology, or ecological physics.
But if the visual perception of terrestrial events depends on changes of steady-state projection in a optic array, not on the propagation of energy from the event to an eye then Einstein's principle need not apply. In the ambient optic array of projections to a point of observation, all terrestrial events are contemporary. In the rays of luminous energy from the night sky to a point of observation, the celestial events are not contemporary. The occlusion of an ordinary object by an edge, a cessation of projection, is not delayed when the edge is distant. But the occlusion of a radiating source by an edge, an interruption of propagation, is delayed when the edge is distant.