  Data obtained in the framework of the INTERBALL-Tail Probe (1995-2000) and
RHESSI (from 2002 to the present) projects have revealed variations in the
X-ray intensity of the solar corona in the photon energy range of 2-15 keV
during the period of the quiet Sun. Previously, a hypothesis was proposed that
this phenomenon could be associated with the effect of coronal heating. In the
present study, a new mechanism of coronal plasma heating is proposed on the
basis of the experimental data and the quantum theory of photon pairs that are
produced from vacuum in the course of the Universe's expansion. A similar
mechanism based on the splitting of photon pairs in the interplanetary and
intergalactic space is also proposed to explain the observed microwave
background radiation.
