Shamans play an important role in many cultures .… The special treatment of the body and use of stones to keep it in a certain position suggests the woman held a unique position in the community, likely some sort of a shaman, the researchers said.

[T]he shaman guiding the ceremony chants, usually to the birds and the spirits in the sky. Soon the others start to sing, too, their voices overlapping to create a rapturous polyphony. At this point, visions ensue. The shaman is attuned to every participant and monitors what they are feeling, intervening when necessary.

A cellular-automata simulation involves a chessboardlike grid of squares, or cells, each of which is either empty or occupied by one of several possible components. At discrete intervals of time, each cell looks at itself and its neighbors and decides whether to metamorphose into a different component. In making this decision, the cell follows relatively simple rules, which are the same for all cells.

Thanks to irrigation, thanks to the Bureau—an agency few people know—states such as California, Arizona, and Idaho became populous and wealthy; millions settled in regions where nature, left alone, would have countenanced thousands at best; great valleys and hemispherical basins metamorphosed from desert blond to semitropic green.