Changes an electron in the shell of an Atom from one energy state to another, it takes a small amount of energy (E), or gives you. According to Einstein’s famous relationship E=m·c2 (c is the speed of light) changes as a result, the mass (m) of the Atom. It is a tiny amount heavier or lighter, depending on whether the Quantum of energy is absorbed or emitted. Physicists of the Max-Planck-Institute for nuclear physics in Heidelberg, it is now able to measure the minimum change in Mass with precision.

Manfred Lindinger

editor in the Department “nature and science”.

F. A. Z.

As objects of research two highly charged ruthenium were ions, the research team of Klaus Blaum locked in an ion cage. The two particles were, and on the characteristic circular orbits. An Ion was in the ground state, the others were transported to the researchers by the supply of energy in a long-lived excited state. The latter had thus, according to Albert Einstein, also a slightly higher mass.

The mass increase was reflected in the slightly lower frequency of the heavy Ion circled in comparison to its lighter Partner in the ground state on its path. By, the researchers determined the circulation frequencies of the two ruthenium ions in a precise and compared, you could close on the mass difference between the particles in the ground state and the excited state.

This was extremely low. The relative mass increase was roughly the same as an ant that crawls on a full-grown, six-ton elephant around, write the researchers Blaum in the journal “Nature”. In their experiments, the physicists also discovered a hitherto unknown quantum state in the Rutheniumion. He is meta-stable, i.e., it decays only after a certain period of time. Its life span is theoretical calculations, at 130 days. As a result, he could be precise atomic clocks of interest.