  Photons excited into ground state modes at finite temperature display
partitioning among photon phases, lifetimes and distances travelled since
creation. These distributions set the distance from an interface a created
photon has some chance of emission. Excited photons at each frequency have a
phase velocity set by each mode propagation index which determines mode density
and internal energy contribution. All photons emitted after striking an
interface obliquely are refracted. Their exit intensities are then irreversible
except when weak internal attenuation occurs. At low temperature attenuation
index is small so reversibility is approximate. As temperature rises refraction
direction varies. Total emission remains reversible after transitioning through
a non equilibrium state with no other heat inputs. In equilibrium the densities
of excitations that create and annihilate photons are in balance with photon
densities while emissivity depends on both indices and internal incident
direction. Modelled exit intensities from pure water and crystalline silica
contain strong resonant intensities and match data accurately. Intrinsic
resonances formed within liquids and compounds are due to photon modes
hybridising with localized excitations, including molecular oscillations and
the anharmonic component of lattice distortions. They explain the many resonant
spectral intensities seen in remote sensing. Each hybrid oscillator is a
photonic virtual bound state whose energy fluctuates between levels separated
by mode energy. Refraction induces solid angle changes and often anomalous
refraction while thermal recycling of internally reflected photons modifies
intensities and internal energy. Enhanced internal heat flux from phonon drag
by photon density gradients under an external temperature gradient is also
predicted.
