Violins made by the Italian master craftsman Antonio Stradivarius are worth millions of dollars for their unparalleled sound. And that's great, for the handful of musicians who can afford these centuries-old instruments. This month, a new violin made from wood treated with a fungus actually trumped a Stradivarius in a blind listening test, offering hope for violinists who want high tonal quality at an affordable price.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.