When we look out of the window, we see lots of things, buildings, trees, cars, people and so on. All these things together form what we call 'reality'. We have been accustomed to view reality as all the things we can see, hear, smell, touch. And that is exactly the way physics treated reality for a long time: reality as the totality of events that actually happen.

Quantum physics has changed our view of reality drastically. Now not only actual events contribute to the evolution of the universe, even all those things, which potentially could, but do not, happen, also influence the future. Reality is no longer just a collection of events, but can be seen more like the totality of possibilities, or the totality of potential events.

Three of the four fundamental forces of nature are very accurately described by quantum theories. Gravity on the other side is described by General relativity. Quantum physics and General relativity stand on very different conceptual grounds and are incompatible to eachother. Many physicists hope, that these problems can be overcome by casting gravity into a quantum theory. Despite enormous efforts such a theory of Quantum gravity has not yet been successfully formulated.

There exist many proposals of solving these problems, String theory and Loop quantum gravity being the most well-known ones. In my doctoral study I will work with an alternative candidate of Quantum gravity, which is called Causal dynamical triangulations. It is a rather conservative approach, which basically performs a path integral over space-times using Monte Carlo simulations.

Besides technical questions I am interested in conceptual issues: what implications does a Quantum gravity theory have on our understanding of reality? Do we need to modify established principles of Quantum physics in order to successfully describe gravity as a Quantum theory? Could our strong (historically grown) bias towards reductionistic thinking be one of the big obstacles which hinders us to make progress?