Elon Musk’s Hyperloop concept has proven extremely polarizing, but not in the right-left manner we’ve come to expect. The practically-minded have pointed out its various structural flaws and impracticalities. Romantics have celebrated the vision and the guts the Hyperloop represents. Timothy Lavin falls somewhere in between, which strikes me as the right place to be. Yes, the Hyperloop will probably never come to pass. But in capturing the public imagination, Musk has issued a challenge to would-innovators that Lavin rightly suggests will be very hard to pass up.