11. Without an external field there are local anisotropies of different orientations, due to spontaneous magnetization. 12. The external field replaces the interaction of all the other particles to an arbitrary particle. 13. As the external field surpasses the hard material's coercivity, the hard magnet gets fully demagnetized. 14. Thus Rydberg atoms are extremely large with loosely bound ionized by collisions or external fields . 15. The n-body system is replaced by a 1-body problem with a chosen good external field . 16. Electron density shields a nucleus from the external field . 17. The microwave penetration depth is determined by the superfluid density responsible for screening the external field . 18. The amount of this torque is proportional both to the magnetic moment and the external field . 19. These adjustments or reactions to external field changes constituted the absorption of radiation for the particle. 20. But in a ferromagnetic material, all the atomic moments are aligned even without an external field .
