December 22, 2014 | It's been a roller-coaster year for science. It started with what looked like a remarkable breakthrough in stem cell science, which was soon followed by a stunning announcement by cosmologists: the first detection of gravitational waves, direct evidence for a popular theory of how the universe began. But as the year draws to a close, the first of these discoveries has been thoroughly discredited, and the second appears to be on the ropes. WIRED