Learning how Heat Affects Atoms
Though there are many ways to keep time, keeping time as accurately as some researchers need is very difficult. Every method has the same principle at its heart though; counting events that take a regular amount of time. Now researchers at the Joint Quantum Institute and the University of Delaware are working to make the most accurate clocks in the world even better.
In some clocks a pendulum swings back and further at regular intervals, but in atomic clocks it is the motion of an electron from one energy level to another that is counted. The dynamics of this motion are very complex though as any nearby electromagnetic field can affect the atom, as well as heat, which is what the researchers were looking at. The atoms in the clocks are typically held within a special trap to reduce its energy to milli-kelvin and micro-kelvin temperatures, but the chamber that surrounds them can be much warmer and will radiate that heat. Unfortunately that radiation is hard to predict, but by carefully studying a specific electron transition in ytterbium, the researchers hope to push the boundaries of precision.
The results of this study will affect more than just atomic clocks though but all systems that require precise measurements of atoms, such as the search for new physics at ultra-small scales. Also a clock that would only lose a second over the current lifetime of the Universe is just cool.