The first "hydrogen" - "thermonuclear" bomb was created and tested in 1952. After that, immediately began work on the creation of controlled "thermonuclear" power reactors - power reactors on light nuclei. Almost seventy years have passed since then, but until now, apart from empty promises of creating an energy paradise on Earth, there are no real hints of success in solving this problem in the thermonuclear problem. The theory of nonlinear oscillations - TNО, after conducting its own investigation, discovered the reason for such long empty promises and real failures in the thermonuclear problem. This reason was formed two hundred years ago, with Ampere's erroneous interpretation of the result of the famous experiment of Oersted (1821). Due to Ampere's mistake, the physics of the microworld thoughtlessly refused to take into account the magnetic interactions between micro-objects. As a result, the reactions of fusion of light nuclei, which provide the release of thermonuclear energy in the Sun and in the "hydrogen" bomb, were misunderstood by physicists. The same reactions were incorporated into the scheme of building controlled "thermonuclear" reactors. A method for solving the "thermonuclear" problem was discovered by TNO when analyzing the causes of equally long failures in the "neutrino" problem [1].