Do we want to just use technology or understand its physical principles? Opinions differ on this question. In two physics camps at XLAB, a total of 16 particularly interested students got to grips with these fundamentals - where many find it too complicated. In the laser physics camp, the students worked on the basic principles of energy conversion as well as wave and quantum phenomena using solid-state lasers as an example. Participant Denis (18): "A laser lab was something out of a movie for me, now it's reality." Digital twins of experiments on heat and waves were the subject of the "Physics of Real Systems" camp. Numerical methods made it possible to predict results that would have been very difficult to find by solving the basic equations of physics with paper and pencil. Johanna (18): "I thought it was cool when we did a simulation of a bottle and the heat flow on the computer. We've never done simulations in school before." A big thank you from all participants went to the Wilhelm and Else Heraeus Foundation, which covered the costs of the course, accommodation and shared evening meals.