Comment on “The Lamb Shift and Ultra High Energy Cosmic Rays” and Comment on “Vacuum Polarization Energy Losses of High Energy Cosmic Rays”

The cosmic ray spectrum has been shown to extend well beyond 10eV. With nearly 20 events observed in the last 40 years, it is now established that particles are accelerated or produced in the universe with energies near or above 10eV. No nearby astrophysical object has been shown to correlate with the arrival directions of the highest energy events, yet the exponential cut-off in the high energy end of the spectrum one expects to see in the case of far sources is not visible. It was recently pointed out that the influence of the vacuum of quantum electrodynamics on particle propagation could explain qualitatively this mystery. This note is a critic to these ideas.