DARPA's 'ROCkN' laser-based clocks will know what time it really is, to the sub-picosecond - Breaking Defense Breaking Defense
Optical clocks in labs today "fill out a huge room, a big room with a very complex, very sophisticated apparatus that takes multiple PhDs to run," Tatjana Curcic, who manages DARPA's Robust Optical Clock Network project, told Breaking Defense.
Source: breakingdefense.com