We show that the mysterious and intriguing behavior of ball lightning, observed by many eyewitnesses, is explained on the assumption that ball lightning consists only of light and compressed air. In contrast to a soap bubble, the spherical shell of a ball lightning consists of highly compressed air, in which ordinary white light rotates in all possible directions. Light compresses the air due to optical electrostrictive pressure. In turn, the shell of compressed air is a two-dimensional lightguide that prevents the propagation of light in free space. Thus, ball lightning is a self-confined light in a nonlinear optical medium in the form of the conventional air atmosphere. The light fell into the trap he made for himself. The intensity of the rotating light is more than a billion times greater than that of the light propagating in a straight line. In this case, the optically induced forces, which in normal conditions are extremely small, manifest themselves completely. It is these forces that determine the mysterious behavior of ball lightning in the atmosphere. In numerous publications, we have shown that the behavior of a light bubble and ball lightning are the same, and there are no mysteries in the behavior of ball lightning. The question of the nature of ball lightning resolved. In this article, we analyze the physical processes inside the light bubble and determine the parameters of compressed air, the intensity of light and a magnitude of the electrostriction pressure.