Guest: Linda Gordon is Professor Emerita of History at New York University. She is the winner of two Bancroft Prizes for best book in American history, most lately she is the author of Seven Social ...

almost all observed data will fall within three standard deviations (denoted by the Greek letter sigma, or σ) of the mean or average (represented by the Greek letter mu, or µ) of the data.

An ancient stone head has been discovered at a 5th-century Christian church in Rome, Italy, with experts suggesting its craftsmanship, size, and distinct facial expression may indicate it once ...