For the first time ever, researchers created time crystals - a previously hypothetical crystal that can potentially stay in perpetual motion without energy, thanks to a fracture in time's symmetry. Imagined in 2002 by the Nobel laureate Frank Wilczek, these structures were deemed "impossible" by most physicists.
The 10 Most Significant Scientific Breakthroughs of 2017. Dec 30, 2017. Bigthink.com