Emission spectrum of a ball lightning and annotated emission peaks of silicon, iron, calcium, nitrogen and oxygen. Vertical axis: Intensity (%), horizontal axis: wavelength (nm). Data from Cen, Jianyong; Yuan, Ping; Xue, Simin (17 January 2014). Observation of the Optical and Spectral Characteristics of Ball Lightning, Phys. Rev. Lett. 112,doi:10.1103/PhysRevLett.112.035001
Own work
Olli Niemitalo