Dave Davies

Thor Hanson's new book looks at the evolutionary significance of feathers in birds. Hanson tells Fresh Air that he's amazed by birds' magnitude of feathers, how feathers grow and how they're the "most efficient insulation known."

In The Long Road to Antietam, historian Richard Slotkin traces how both Northern and Southern strategies changed in the summer of 1862, when both sides committed to an all-out total war, and Lincoln squared off against Gen. George McClellan.

Jill Tarter works at the SETI Institute, where scientists seek evidence of extraterrestrial lie in the universe by looking for some signatures of its technology. "The amount of searching that we've done in 50 years is equivalent to scooping one 8-ounce glass out of the Earth's ocean," she says.