Research article of American Journal of Scientific Research and Essays
The Doppler effect of spectral lines and shift of the frequency of light in space
The Doppler effect of spectral lines in space is the change in the frequency of light emitted by an illuminated celestial body, which moves closer or farther away from the Earth in vacuum. A description of the change in light frequency is realized with the assumption that an illuminated celestial body in vacuum moves closer or farther away from the observer in vacuum. In this case, the propagation of light of the moving celestial body toward an observer also occurs in vacuum. Everywhere on Earth and in the surrounding space there is matter, so the choice of vacuum for the Doppler effect and the propagation of light from the moving celestial body toward the observer is not correct. From the observation of space as we know it, such as galaxies and stars, the area between the celestial bodies consists of a vacuum, but in some restricted spaces of the universe there is a transparent mass – gas, that moves at high speed against Earth. These spaces in universe filled by gas were called “intergalactic bubbles of gas” by astronomers. The propagation of light on the trajectory from an illuminated celestial body toward the observer takes place not only in a vacuum, but alternately also in the gases of intergalactic bubbles, respecting the laws of optics. The topic of the propagation of light in the universe is a very broad topic. For further information, please see reference ,  and .