However, an alternative explanation, the "tired-light" hypothesis, claimed that galaxies' light reddens because it loses energy as it passes through space.
A team of astronomers used the powerful 10-meter Keck telescope at Mauna Kea, Hawaii, to search for faint galaxies in the immediate surroundings of quasars at high redshifts (a measure of distance based on the degree to which their light is reddened by the expansion of the universe).
To evaluate the influence of light on the leaf reddening process, canopy openness was measured over 28 S. hirsuta plants at the time of leaf fall of beeches (the main tree species of the study site) on 19 November 2012.
That takes a little more blue light "away", which reddens the sunsets even more.
Up to the 1930s, dust particles were widely considered as idle materials that dim the light of stars, redden their colors, and interfere with studies of stars themselves.
Whereas SN Ia observed at optical wavelengths have been shown to be excellent standardizeable candles, using empirical correlations between luminosity, light curve shape, and color, the CfAIR2 data set strengthens the evidence that SN Ia at NIR wavelengths are essentially standard candles, even without correction for light-curve shape or for reddening.
You might see that bread again at the end of the meal, with the very good regional cheeses, or as an appetizer beneath poached oysters and a light oyster cream sauce reddened with lobster coral, a suave and untricky dish that would almost be at home in New Orleans.
While such phenomena are sometimes referred to as "redshifts" and "blueshifts", in astrophysics light-matter interactions that result in energy shifts in the radiation field are generally referred to as "reddening" rather than "redshifting" which, as a term, is normally reserved for the effects discussed above.
Visibly reddening, he blurted, "What?
Shelgel spun around, his fair face reddening.
He's reddening by the word.
