An engaging natural and cultural tour of RAIN, from how it helped shape civilization, religion, and art; to the peculiar history of the world's first raincoat, the Mackintosh; to the rain obsessions of our "Founding Forecaster," Thomas Jefferson - all building to the uncharted rains of climate change.  Rain is the source of Earth's water, from the cataclysmic torrents that filled the oceans four billion years ago to miraculous natural cycle that replenishes aquifers, soils, and rivers day after day.   Scientists say changing rainfall patterns are some of the earliest and most-certain tremors of our warming globe. Armed with the computer models looking forward, there is also much to learn from looking back. Too much and not enough, rain is an experience we share. Its history has much to tell us about coming together to adapt in stormy times.