How heavy or how big can an object be before losing its quantum properties and obeying to the laws of classical physics? This question drives many research groups all around the globe. Answers still remain to be given as currently there are no systems which allow observing the expected tiny signatures of quantum effects in macroscopic objects. The novel system developed in the MPG Junior Research Group “Laboratory of Photonics” led by Dr. Tobias Kippenberg could resolve this problem.