Not long ago in Seattle, an astronomical event of sorts happened: Two superstars collided. William Shatner, of "Star Trek" fame, and Neil deGrasse Tyson, America's favorite astrophysicist, took to the stage to explore the nature of exploration. Think of it...

Old books have a distinct smell that many people find comforting and nostalgic. For some, the aroma is so pleasant that it instantly takes them to childhood libraries or cozy reading corners. But what exactly causes this scent, and why do only certain people...