Delusions versus reality in some physics problems: theory and experiment

The important question of the relation between theory and experiment in different physical problems is discussed. A number of examples, both widely and little known, are used to show that some physical theories, considered by many as correct because they corresponded to many experimental facts and to the existing level of science, have been found to be false. One of the important reasons for this is that it is very difficult to distinguish between the causes and consequences of phenomena observed in experiments. The best example is the study of turbulent flows, where the causes and consequences are often erroneously interchanged in relation to the properties and development mechanisms of turbulence. At the same time, some counterexamples are described where phenomena that are impossible from the standpoint of universally accepted theoretical concepts turn out to be reality in special cases.