“…The solar input is not constant; climates are subjected to fluctuations; soil is forever being modified; the forests are being destroyed or sometimes planted; factories pour variable amounts of pollution into the air and water; urban areas both expand and decay; populations grow in some areas but decline in othersc apital is moved daily from one place to another, creating new investment opportunities in some regions but less in others. These are but a few general examples of the changes which transform the face of the Earth in an ongoing and even an accelerating manner (Woolmington, 1985). Specific examples of such phenomena are legion.…”