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
Society for Scientific Exploration Society for Scientific Exploration The Society for Scientific Exploration, or SSE, is a group committed to studying fringe science. The opinions of the organization in regard to what are the proper limits of scientific exploration are often at odds with those of mainstream science. Critics argue that the SSE is devoted to disreputable ideas far outside the scientific mainstream. The Society was founded in 1982. Its first meeting took place at the University of Maryland, College Park in 1982. Of the SSE and its journal, journalist Michael D.. Lemonick writes, "Pretty much anything that might have shown up on The