Why is the night sky dark? How do dolphins sleep without drowning? Why do hangovers occur? Will time travel ever be a reality? What makes a knuckleball appear to flutter? Why are craters always round?

There's only one source to turn to for the answers to the most puzzling and thought-provoking questions about the world of science: Scientific American. Writing in a fun and accessible style, an esteemed team of scientists and educators will lead you on a wild ride from the far reaches of the universe to the natural world right in your own backyard. Along the way, you'll...

From the Scopes Monkey Trial of 1925 to the court ruling against the Dover Area School Board s proposed intelligent design curriculum in 2005, few scientific topics have engendered as much controversy or grabbed as many headlines as evolution. And since the debate shows no signs of abating, there is perhaps no better time to step back and ask: What is evolution? Defined as the gradual process by which something changes into a different and usually more complex and efficient form, evolution explains the formation of the universe, the nature of viruses, and the emergence of humans. A...