The period of unprecedentedly rapid development of fundamental physics in the XIX – XX centuries is called the golden age of theoretical physics. The theory constructed in that years has led to a revision of concepts that seemed clear and immutable: time, distance, causality and determinism. Today, as a hundred years ago, a fairly complete picture of the world with some quantity of phenomena that are not explained by the existing theory has been formed. However, understanding of the structure of matter and space has not been uniform and rectilinear. On its way, there were unexpected breakthroughs as well as a lot of blind areas and delusions. In the words of Martin Schwarzschild, although the laws that we are committed to open may be perfect, the human mind is far from perfect. Left to itself, it is prone to err, of what we see confirmation among countless examples of the past. We rarely missed an opportunity to be misled. Only new data, hard-won from the nature, take us back to the right way. Often theories built by analogy with already well-proven knowledge turned out eventually to be only approximate and were replaced by others, sometimes very different, which led to unexpected discoveries.