Excitation of thorium-229 brings closer the creation of working nuclear clocks

Now let’s take a laser – a concentrated beam of light. If we tune the frequency of this laser to exactly match the energy required to cause this energy jump in a given electron, something very special will happen. The electron absorbs the laser energy and moves to a higher energy level. But this state is unstable, so the electron quickly returns to its original state, emitting a photon, or a small packet of light. It is this phenomenon that is particularly interesting for clocks: the frequency at which photons are emitted is extremely precise and constant. It directly depends on the energy difference between the electronic levels of the atom. By measuring this frequency we can obtain a very precise measurement of time. To put it simply, it is as if each tick of a clock was the result of an electron making a small energy jump in the atom.