High Quality Content by WIKIPEDIA articles! The technology relies on strongly coupled electromagnetic resonators, a principle similar to the way a trained singer can shatter a glass using his/her voice.[citation needed] At the receiving resonator's natural frequency, energy is absorbed efficiently, just as a glass absorbs acoustic energy at its natural frequency. At the wall socket, power is put into magnetic fields at a transmitting resonator - basically an antenna. The receiving resonator is tuned to efficiently absorb energy from the magnetic field, whereas nearby objects do not.