Japan’s strontium optical lattice clock has been called the…

Japan’s strontium optical lattice clock has been called the “ultimate timepiece.” https://www.nippon.com/en/in-depth/d01235/redefining-the-second-japan%E2%80%99s-staggeringly-precise-optical-lattice-clock-promises-wealth.html Timekeeping is an essential underpinning of daily life and a vital component of our social and technological infrastructure. The Japanese optical lattice clock, a top candidate for redefinition of the second, marks time with such staggering precision that it can measure small differences in elevation using Einstein’s theory of general relativity.