English: Animation of arise Cherenkov's radiation. From the left fly a particle, which polarizes atoms and molecules in surroundings her track. By backward depolarization these atoms and molecules emanate electromagnetic radiation, which from places rise expansive in spherical wave surface. Cover of these wave surface generates conus. In his cut it is possible find rectangular triangle. There is ${\displaystyle \cos \theta =\frac{\frac{ct}{n}}{vt}=\frac{c}{nv}}$. c . t is displacement, which travel Cherenkov's radiation behind time t, v . t is displacement, which travel a particle.