Gases near a dying star in the Helix Nebula. This nebula is located in the Aquarius constellation. Each knot of gas is several billion miles across. Credit: C. Robert O'Dell and Kerry P. Handron [Rice University], NASA.
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.