President Trump's long-anticipated infrastructure plan now seems dead on arrival, but few would argue with the need for widespread infrastructure upgrades. Mark Stevenson, author of " An Optimist's Tour of the Future ," and " We Do Things Differently: The Outsiders Rebooting Our World ," says many of our current systems are failing to meet the grand challenges of the 21st century—from climate change, to income inequality, to food production for more than seven billion—and the choice we face is