"Atoms, as building blocks of nature, consist of an atomic nucleus and the electron shell. Both systems are governed by similar laws and forces. However, the required energies to create changes in the nucleus or the electron shell differ by many orders of magnitudes. This reflects in largely different tools and methods used for their investigation: atomic physics probes the electron shell mainly by means of lasers. Nuclear physicists create excitations at high energies using particle accelerators such as CERN.The radio isotope 229Thorium is the only atom with the potential to bridge the gap between atomic and nuclear physics. It provides an unnaturally low-energy nuclear excited state, accessible to atomic physics tools, most notably laser excitation. It is the aim of the proposed research project to identify the optical nuclear transition and make it usable for fundamental investigations and applications.Currently, our second is defined as 9.192.631.770 oscillations of a light wave that leads to a specific excitation in the electron shell of the Cesium atom. Using the nuclear excited state of 229Thorium instead would increase the time standard accuracy by many orders of magnitudes, at the same time reducing the experimental complexity considerably. Building such a nuclear clock is the main goal of the research proposal. This will directly lead to improved accuracy in satellite based navigation (GPS) and enhanced bandwidth in communication networks. Furthermore, vomparing a nuclear atomic clock to standard time standards will hence allow addressing one of the most fundamental questions in physics: ""are nature s constants really constant?""."