My friend Maddie and I have been playing with Legos together for three years, ever since we first constructed a miniature Harry Potter world in our attic, which is like an indoor treehouse. With the additions of the Burrow, Diagon Alley, and Platform 9 ¾, it has quickly expanded across the braided rug into a disorganized but wonderful labyrinth. Yesterday, we decided to organize and re-build our Hogwarts Express train track, and challenged ourselves with the goal of engineering a bridge that was high enough to allow the train to pass underneath and strong enough to support its weight. We succeeded! Imagine my delight when Sophie’s World, my assigned summer…