Eight out of 10 children born in America today will never know a night sky dark enough to see the Milky Way. In our modern world, where nights are getting brighter, most of us no longer experience true darkness. Paul Bogard (James Madison University) is the author of the new book “The End of Night: Searching for Natural Darkness in the Age of Artificial Light.” He believes we now suffer from light pollution and that the lack of darkness at night is affecting our physical, mental, and spiritual health. Plus: When women compare themselves to other people, they actually lose IQ points. Read Montague (Virginia Tech) completed a study that suggests being in groups can have a dumbing-down effect on certain individuals.

Later in the show: Centuries ago, nighttime was a scary and dangerous time. A moonless evening could be filled with both real and imagined perils. In his book, At Day’s Close: Night in Times Past, historian Roger Ekirch (Virginia Tech) sheds light on how pre-Industrial Revolution farmers, tradesmen, and laborers spent their nights. Also featured: Classical guitar music was a constant in the Renaissance and Baroque eras of England, France and Italy. Music professor and guitarist Tim Olbrych (The College of William and Mary) offers a brief history of this instrument and plays selections from his CD, 500 Years of the Spanish Guitar.