Alluvium, the silt, clay, sand, and other material transported and deposited by running water. The term excludes lake and ocean deposits and is usually restricted to geologically recent sediments. Alluvium is laid down in many places but occurs most extensively on flood plains (areas along streams that are subjected to flooding); in river deltas; and in alluvial fans, cones, and plains at the base of steep mountains. Some of the world's richest agricultural land consists of alluvial soil. Such regions are also among the most heavily populated on earth. Examples include the Nile River valley and the deltas of eastern and southeastern Asia.
One was a celebrated author, the other a famed physicist. What the two shared was a public exposure of their religious beliefs. Big E had an on-again, off-again relationship with God, while C.S. was an avowed atheist during his early years.
He may have been born in Brooklyn, but Carl Sagan was gunning for the stars as soon as he arrived in this world. Get to know the scientist whose infectious delight in the universe still holds us spellbound.