It was June, a summer day like any other, when thousands of green invaders arrived at the Plaice Cove beach in Hampton, New Hampshire. The eerie green globs, which looked and felt like Brillo pads, were everywhere. Marine biologist Ellen Goethel was summoned to explain what they were, but she had never seen anything like them. She wasn't even sure if they were natural or man-made.
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.