Before we can understand anything, we must first learn to see. Yet in particle physics, what matters most remains hidden from our eyes. Elementary particles do not reveal themselves directly - they leave only traces, brief signals in complex detectors. This book shows how such traces can be turned into a precise picture of nature. Jurgen Knobloch guides the reader through five decades of experimental physics - from his early work at DESY in Hamburg to the major international experiments at CERN in Geneva. He describes the development of neutrino experiments, the construction of modern detectors, and the precise measurements that have shaped our current understanding of matter. It becomes clear that scientific insight is not a sudden flash of inspiration, but the result of careful experimentation, technical innovation, and close collaboration within international teams. Alongside the physical principles, the book also offers an insight into the practice of research: detectors, data analysis, and the invisible world of complex software. Personal experiences are interwoven with clear explanations to create a vivid account of modern particle physics. The perspective extends beyond the laboratory - to applications in medicine and space exploration, and finally back to the sky, which the author now explores as an amateur astronomer. Optikus is more than a scientific introduction. It is the story of a life spent trying to make visible what lies beyond the reach of our eyes.
