  The paper analyzes a model of optical transmittance of ultra-diluted gas,
considering gas particles' non-locality and the quantum effect of their wave
function spreading derived from solving the Schr\"odinger equation for a free
particle. The analysis does not depend on a particular form of the wave
function, but it assumes the reality of wave function. Among others, we show
conserved mass gas clouds may become significantly more transparent than
predicted by classic transmittance laws. This unexpected phenomenon is possible
because mass conservation is governed by the sum of probabilities, while the
Markov chain's product of probabilities controls the transmittance.
Furthermore, we analytically derive the upper limit the closed system
transmittance may grow and demonstrate a boundless, open gas cloud
transmittance may grow up to 100%. Finally, we show the impact on
interpretations of quantum mechanics. The model is naturally applicable in deep
space conditions, where the environment is sparse. Furthermore, the model
responds to dark matter requirements.
