In Celtic mythology, Mag Mell ("plain of joy"), also called Tir na n-Og ("land of youth"), was the underworld. Unlike the underworld in most mythologies, Mag Mell was a pleasurable paradise, either an island or at the bottom of the ocean.
... permittivity of vacuum or free space, εr is the dielectric constant or relative permittivity of the insulator used, A is the area of the each of the two plates, and ...