There’s too much guesswork in cancer surgery. Although a tumor is usually a different color or density than the healthy tissue around it, stray cancer cells near the tumor often blend in, so surgeons carve out an extra fraction of an inch surrounding it. But if post-op tests prove that the extracted tissue has cancer cells on its edge, another round of surgery is required. This happens frequently: About 20 percent of breast-cancer patients need a second surgery because of lingering cancer cells.
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.