Theoretically predicted adatom diffusion mechanism on the fcc surface of some common metals, including Copper, Aluminum, Silver, Gold, Paladium, Platinum, and Nickel. A single atom makes a knight's move across the surface via the illustrated exchange. The primary atoms are colorized for demonstration purposes. All atoms are of the same element. Credit: J.M. Cohen, Los Alamos Nat. Lab, New Mexico Tech, 4Physics.
What is an Atomic Clock?
The watches we wear on our wrists or the clocks we put on our walls are not atomic clocks. There are not all that many true atomic clocks - and they tend to be rather large and expensive. So, unless it looks something like the picture alongside from the National Institute for Standards and Technology [NIST], it is not a state-of-the-art atomic clock.