Coal the heat and pressure of deep burial causes the loss of water, methane and carbon dioxide and an increase in the proportion of carbon. Thus first lignite (also called "brown coal"), then sub-bituminous coal, bituminous coal, and lastly anthracite (also called "hard coal" or "black coal") may be formed. The wide, shallow seas of the Carboniferous Period provided ideal conditions for coal formation, although coal is known from most geological periods. The exception is the coal gap in the Permian–Triassic extinction event, where coal is rare. Coal is known from Precambrian strata, which predate land plants—this coal is presumed to
Eddie Brown (dancer) his dances were filled with syncopated steps and complex patterns. The specific style of tap that he performed and later taught to students was called “scientific rhythm.” Brown explained, “You heard all this music and rhythm but couldn’t see where it was coming from.” Eddie Brown’s natural propensity to hear and create intricate rhythms allowed him to make his mark on the world of tap dance: “A good ear ain’t good or bad, but a good ear is what you need. That’s why tap is scientific.” Eddie Brown (dancer) Eddie Brown, was a dancer born in 1918 in Omaha, Nebraska.