Figure 1
APS/Alan Stonebraker

Figure 1: Standards keep going up for atomic clocks. A timeline of the fractional uncertainty of the best cesium atomic clocks (blue squares) and the best optical frequency standards (red and green circles.) The red circles correspond to uncertainties determined by referencing the frequency to the cesium clock; the green circles correspond to estimated uncertainties. The white data point represents the new result of Madej et al..