As with all standing waves, the Schumann resonance is also a product of a standing wave whose one end is on the surface of the Earth and the other on the lowest layer of the ionosphere. There are basic (fundamental) waves and so-called harmonics. Sometimes the term “First harmonic” is used for the fundamental wave or frequency. The frequency of the basic wave is 7.83 Hz, but variations are possible depending on atmospheric conditions, solar storms, cosmic radiation, etc. For example, today the frequency of the fundamental wave ranged between 7.46 and 8.11 Hz. The first harmonic, however, had a frequency between 12.60 and 14.90 Hz, the second harmonic in the interval 19.60 – 20.60 Hz, the third in the interval 23.60 – 27.60 Hz, etc. for higher harmonics. Therefore, the basic Schumann frequency does not increase constantly, but can vary by about 5-6% around the value of 7.83 Hz. Of course, if higher harmonics are observed, it is possible to notice higher frequencies, and hence the interpretation that the frequency is constantly increasing appears. However, the basic frequency of 7.83 Hz is the most important and it determines the frequencies of all other harmonics, and has the most important therapeutic role, among other things, because it is the closest to the natural frequency of brain waves that manifest in a person’s awake state. The frequency of each subsequent harmonic is higher than the frequency of the previous harmonic. Lucha T8 device uses red light which already has known therapeutic properties and which flickers at the fundamental Schumann frequency of 7.83 Hz.