Everyone knows it when they see it. The classic “castle with turrets” periodic table is a beautiful and concise icon that contains a great deal of amazing information, if you only know how to read it. And even if you don’t know anything about the table, it’s still easy to admire and get lost in. Author of The Disappearing Spoon, Sam Kean, talks us through the design of the table that hung in the front of your science class for years, but you probably never really understood.