Fabian Schmid was born in 1993 in Munich. He studied at the Technical University of Munich, and since 2016, he has been working at the MPQ as a Ph.D. student in the Laser Spectroscopy Division of Professor Theodor Hänsch. Fabians group focuses on precision spectroscopy of hydrogen and hydrogen-like ions. These are the “simplest of atoms” because they only have one proton in the nucleus. These “simplest of atoms” - hydrogen and hydrogen-like ions - allow theoreticians to make very precise calculations of their properties. The calculations are based on the theory of Quantum Electrodynamics (QED) which describes the interaction between light and matter. The aim of Fabians' experiment is to measure the frequency of one particularly narrow spectral line in hydrogen-like helium ions. Spectral lines are the result of the absorption or emission of light by the atoms as well as by molecules. They are kind of like their “fingerprint”.