The aim of the study was to obtain a new physical formula for determining the refractive indices of light as a function of wavelength, which can be applied to a wide range of transparent substances. In the process of research on the basis of Einstein's relativistic formula, such a dispersion formula was obtained. Comparison of the obtained indicators with laboratory indicators showed the high accuracy of the new dispersion formula, which was ±10 -7 − 10 -5 in the calculated wavelength ranges of more than 100 nm.
The new dispersion formula is obtained on the basis of the mathematical dependence of the speed of propagation of photons in a transparent substance on the energy density of electron clouds of atoms of the substance. Energy is a universal category, therefore, it is possible to apply the basic version of the new formula (where instead of the wavelength there is the energy density of electron clouds) when conducting research in all areas of light generation, manipulation and detection.
And, finally, the very fact of applying the adapted relativistic Einstein's formula to physical processes occurring at the atomic level allows us to look at the nature of the interaction of light and matter from a new angle.