Frank, Below is a paragraph from "The Origin of Inertia" http://www.calphysics.org/inertia.html . Is this another perspective supporting your speed of phonons? Regards Fran
It is well known that an accelerating observer will experience a bath of radiation resulting from the quantum vacuum which mimics that of a heat bath, the so-called Davies-Unruh effect. This was discovered shortly after, and in connection with, a 1974 paper by Hawking proposing quantum evaporation of very low mass black holes. For an accelerated object moving through the vacuum the zero-point field will yield a non-zero Poynting vector. Scattering of this radiation by the quarks and electrons constituting matter would result in an acceleration-dependent reaction force that would appear to be the origin of inertia of matter (Rueda and Haisch, Physics Letters A, 240, 115, 1998<http://xxx.lanl.gov/abs/physics/9802031>; Foundations of Physics, 28, 1057, 1998<http://xxx.lanl.gov/abs/physics/9802030>). In the subrelativistic case this inertia reaction force is exactly newtonian and in the relativistic case it exactly reproduces the well known relativistic extension of Newton's Law. Both the ordinary, F=ma, and the relativistic form of Newton's equation of motion may be derived from Maxwell's equations as applied to the electromagnetic zero-point field. We expect to be able to extend this analysis in the future to more general versions of the quantum vacuum than just the electromagnetic one. Indeed, it is quite possible that what we have shown is how the electromagnetic ZPF contributes to inertia, but this may not be the whole story. A Resonance Frequency and the de Broglie Wavelength The approach used in the NASA study also suggested that there should be a specific resonance frequency for the particle-ZPF interaction giving rise to inertia. We have found that if, for the case of the electron, the inertia-generating resonance is at the Compton frequency, then such a resonance, driven by the zero-point fluctuations, could simultaneously account for both the inertial mass of the electron and its de Broglie wavelength when in motion as first measured by Davisson and Germer in 1927 (Physics Letters A, 268, 224, 2000<http://xxx.lanl.gov/abs/gr-qc/9906084>, cf. also chapter 12 of de la Pena and Cetto, "The Quantum Dice: An Introduction to Stochastic Electrodynamics, Kluwer Academic Publishers). The de Broglie wavelength of an electron placed in motion appears to be related to Doppler shifts of Compton-frequency oscillations associated with Zitterbewegung. This provides a very suggestive perspective on a connection between electrodynamics and the quantum wave nature of matter, again limited by the validity of SED theory in this domain.
