The Physics Potential of Ground-Based Gamma-Ray Astronomy below 50 GeV

Currently three ground-based Air Cherenkov detectors with energy thresholds below 50 GeV are being commissioned (CELESTE and STACEE) or under construction (MAGIC Telescope). Based on the expected performance of the MAGIC Telescope and with an emphasis on those physics questions which are unique to the energy domain below 50 GeV an overview of the scientific prospects of ground-based high energy Gamma-Ray Astronomy in terms of astrophysics, cosmology and particle physics questions is given.