The pulsation principle solves infinite difficulty.(1) All elementary particles convert it in sync. The pulsation model of the elementary particle pulsation principle、 * All elementary particles convert it in sync with a particle trip, a wave trip, a minus number particle trip. * The electromagnetic force works in a wave trip. The electromagnetic force does not work in a particle trip. . The electromagnetic force does not work in a minus number particle trip. * All particles and minus number particles disappear in a wave trip. The conversion synchronizes. The electromagnetic force　of All the photons not work in particle processes and negative particles process. The electromagnetic force works in a wave trip. * The concept of the vacuum of quantum mechanics. Virtual particles (generation, annihilation) model. * The random (generation, annihilation). By it Particles and antiparticles are always infinite pieces exist. * Particles of Infinite number are involved in electromagnetism force. Negative particles of Infinite number are involved in electromagnetism force. By it Renormalization prescriptions are needed. * Photons mediate the electromagnetic force.　　 And Photons are always infinite pieces exist. Equation would be endless.