Look at the conclusions of the technical paper https://arxiv.org/abs/1706.09063 Power Area Density in Inverse Spectra ------- Conclusions: 1. The existence of the investigated inverse spectral regions ultra-yellow (UY) and infra-cyan (IC) demonstrates empirically that the inverse spectrum is not merely a visual phenomenon but should be seen as the consequence of radiation energy conservation in spectral experiments.
2. If the data of inverse spectra are evaluated in the same way, then a spectrum with only positive spectral components (ordinary spectrum) as well as an inverse spectrum with equal absolute but negative spectral components are obtained, irrespective of the measured radiometric quantities, the spectral range and the illumination used. 3. In the past, the IR range has been explored through temperature measurements. This has recently led to the question of whether “negative temperatures” can be measured in the inverted IR range (Müller 2015). Since the temperature measurement, like the measurement presented here, is based on power densities, this assumption can be confirmed. If temperature is measured in mutually inverse spectra and the measured values are converted into differences to the temperature of the respective backgrounds, a spectrum with only positive values (ordinary spectrum) and a spectrum with only negative values (inverse spectrum) always results. 4. In the field of classical spectroscopic methods, a spectrum cannot be empirically prioritized in favour of its inverse counterpart: they are spectroscopically equivalent and this equivalence is guaranteed by the energy conservation of the radiation in the spectra pair. -------- Harry On Sat, Oct 31, 2020 at 1:30 PM H LV <hveeder...@gmail.com> wrote: > > > This paper on the same spectral radiance measurements might be more > appealing for some: > > https://arxiv.org/abs/1706.09063 > > Power Area Density in Inverse Spectra > Matthias Rang, Johannes Grebe-Ellis > Abstract > <<In recent years, inverse spectra were investigated with imaging optics > and a quantitative description with radiometric units was suggested (Rang > 2015). It could be shown that inverse spectra complement each other > additively to a constant intensity level. Since optical intensity in > radiometric units is a power area density, it can be expected that energy > densities of inverse spectra also fulfill an inversion equation and > complement each other. In this contribution we report findings on a > measurement of the power area density of inverse spectra for the near > ultraviolet, visible and the infrared spectral range. They show the > existence of corresponding spectral regions ultra-yellow (UY) and > infra-cyan (IC) in the inverted spectrum and thereby present additional > experimental evidence for equivalence of inverse spectra beyond the visible > range.>> >
