The Best and Worst in a Tumultuous Year for Science

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.

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.

That's not to say it was all bad. In October, scientists landed a spacecraft on a comet for the first time ever. And the year saw other interesting breakthroughs in everything from synthetic biology to anthropology. Here are our picks for the best and worst of science in 2014. If nothing else, they remind us that while science often moves in fits and starts, and sometimes stumbles, it keeps pushing forward.