Nothing really matters - Proposals for laser experiments on vacuum fluctuations

Abstract Usually the number density of photons in light beams is many orders of magnitude less than the number density of vacuum fluctuations. Therefore, if a vacuum fluctuation interacts with a photon, it almost never interacts with a second photon before the single-photon-excited vacuum fluctuation decays and emits a photon. With developing laser technology, short, intense laser pulses have photon number densities in the focus approaching the high number density required to create a sufficient number density of two-photon-excited vacuum fluctuations that the vacuum permittivity will be increased and the speed of light will be decreased. Particle colliders create high energies and these laser experiments will create high photon number densities as they appeared at the beginning of the big bang. In this publication ideas for laser experiments on vacuum fluctuations will be presented: If two photons in the laser focus create two-photon-excited vacuum fluctuations, they will be delayed relative to single-photon-excited vacuum fluctuation, and this could be measured with a diode, or an auto-correlator, or in interference. Additionally, in a pump-probe geometry this intense laser focus (pump) could be measured with a second laser pulse (probe) in reflection. After passing the intense focus, perhaps even the spectrum and duration of the laser pulse could be influenced, all of which can be measured by standard optical techniques.