What is the importance of atomic clocks in the book, The Disappearing Spoon?

Atomic clocks, which run thanks to the element cesium, are a way of measuring time that is more accurate than basing our understandings of time around the movements of our planet and sun, which are inconsequential in the grand scheme of the universe. The idea of measuring time according to the universal qualities of elements, atoms, and electrons is a challenge to our human- and earth-centered ways of looking at and understanding the universe. The contributions of atomic clocks to the science of metrology represent a shift, not only in how we quantify time but also in what we center and give primacy to when measuring the universe.