Are there really black holes, why do galaxies rotate so fast, is it because of dark matter or have we misunderstood something? Is the theory of the big bang really the only conceivable way to build a universe? What is the space and what the time? Can they be bent and curved, or does this idea lead us into a dead end? Physics today is more unchallenged than ever before. It seems to have sovereign answers to every fundamental question of nature. But in fact the decisive questions remain unsolved. Perhaps only a few, but decisive changes are needed to bring movement back into the whole. Here the author takes a critical look at the fundamental theories of physics and seeks ideas and ways to understand the world at large and small.