Zitterbewegung (English: "trembling motion", from German) is a theoretical rapid motion of elementary particles, in particular electrons, that obey the Dirac equation. The existence of such motion was first proposed by Erwin Schrödinger in 1930 as a result of his analysis of the wave packet solutions of the Dirac equation for relativistic electrons in free space, in which an interference between positive and negative energy states produces what appears to be a fluctuation (at the speed of light) of the position of an electron around the median, with a circular frequency of, or approximately 1.6×1021 Hz. Wikipedia, Zitterbewegung
"There is a further important effect verified by observation and experiment: the absorption and emission of these virtual particles also causes the electron's "jitter motion" in a vacuum at absolute zero. As such, this jittering, or Zitterbewegung, as it is officially called, constitutes evidence for the existence of virtual particles and the ZPE of the vacuum." http://www.ldolphin.org/setterfield/redshift.html
See Also
5.8.5 - The complete Contraction Expansion Cycle is as follows Disturbance of Equilibrium DISTURBANCE OF EQUILIBRIUM - Snell Law of Assimilation Laws of Thermodynamics Perpetual Motion Second Law of Thermodynamics Universal Heart Beat ZPE