Type an address into your phone, and up will pop a step-by-step route from where you are to where you want to be. This is, in its way, magic -- magic that has, at this point, been rubbed and polished into a simple fact of life. The ease with which we machine-carrying humans make our way through the world, though, is quite new. And it's the product of a long, painstaking history: of people plotting a course, getting lost, and finally finding their way.

The newest exhibit at the Smithsonian's Air and Space museum, "Time and Navigation: The Untold Story of Getting from Here to There," opened this weekend, shares the story of human route-charting -- in the seas, in the sky, on the street, and in space. And it's largely a story of failure. The first spaceships we sent to the moon either missed their destination completely or crashed into it. Amelia Earhart was very likely lost due to poor navigation. Columbus and his ships were, famously, misdirected.

But the story of navigation is also one of gradual knowledge and readjustment, of looking to the constant objects of the physical world -- the sun, the moon, the stars -- and using them to understand, ever more precisely, how to find our way in the world. "Dead reckoning" (positioning oneself using time, direction, and speed) has now given way to global positioning using satellites. And that, in turn, is giving way to atomic clocks that can keep time within three billionths of a second -- clocks that may soon make it to our phones. So it's easy to imagine that, given our tools, we have made getting lost obsolete. But that's to take the luxury of location-based living for granted. "Navigation was the great scientific challenge of our time," an animated 19th-century British "admiral" notes in a video tour of navigation's history. And it was the challenge on which many more challenges hinged. As explorers ventured off into distant, unknown lands, they needed above all to know where they were going -- to be, as they say, on the right path. Navigation was in many ways a leap of faith. It's just that the faith in question concerned calculations.