Bill Gates has announced the winners of the Reinvent the Toilet Challenge — an effort to develop “next-generation” toilets that will deliver safe and sustainable sanitation to the 2.5 billion people worldwide who don’t have it. The awards recognize researchers from leading universities who are developing innovative ways to manage human waste, which will help improve the health and lives of people around the world. California Institute of Technology in the United States received the $100,000 first prize for designing a solar-powered toilet that generates hydrogen and electricity. Loughborough University in the United Kingdom won the $60,000 second place prize...