Here, applying the Scale-Symmetric Theory (SST), we described the origin of the two intervals of the rotation braking and two plateaus in the curve describing rotation velocity of the main-sequence normal stars as a function of the spectral classes. We did it involving the interactions of the dark-matter (DM) loops with the electron and proton vortices in stars. Calculated here the advection velocity of the proton vortex is about 414 km/s, of the electron vortex is about 10 km/s whereas the mean value is about 212 km/s. The threshold rotational velocities follow from the fact that in hottest stars, near equator, there dominate the light ions, next in colder stars there dominate the neutral light atoms, and next in coldest stars there are created heavier neutral atoms so gravity transfers the angular momentum to the cores of stars. We showed as well that the DM structures are perfectly elastic so it is very difficult to detect them. We answered following question: How should we plan an experiment to detect dark matter?