LAUSR

Abstract The phenomenon of circulating ordinary incoherent white light in a thin spherical film of air strongly compressed by this light is the basis for the existence of natural ball lightning. In numerous publications, we have shown that the behavior of circulating light in the earth's atmosphere, which follows from the well-known generally recognized laws of optics and physics, completely coincides with the mysterious and intriguing behavior of natural ball lightning, which is evidenced by eyewitnesses. We can say that natural ball lightning is an experimental confirmation of the existence of circulating light. However, circulating light is not limited to ball lightnings. Over the course of two centuries, numerous attempts have been made to obtain ball lightning in the laboratory. The lack of information about the nature of ball lightning did not allow one to reliably state whether the objects obtained belonged to the same class of phenomena to which natural ball lightning belongs. At the same time, a lot of experimental data has been accumulated on the objects obtained, which properties cannot be explained. In the context of circulating light, we analyze these experimental data related to the spectra radiated by anomalous objects. We show that the spectra are not random, but are radiated by substances whose refractive index is greater than that of air. These substances increase the refractive index of the film, which limits the radiation of the circulating light to free space.