Tired light is a class of hypothetical redshift mechanisms that was proposed as an alternative explanation for the redshift-distance relationship. These models have been proposed as alternatives to the metric expansion of space of which the Big Bang and the Steady State cosmologies are the most famous examples. The concept was first proposed in 1929 by Fritz Zwicky, who suggested that if photons lost energy over time through collisions with other particles in a regular way, the more distant objects would appear redder than more nearby ones. Zwicky himself acknowledged that any sort of scattering of light would blur the images of distant objects more than what is seen. Additionally, the surface brightness of galaxies evolving with time, time dilation of cosmological sources, and a thermal spectrum of the cosmic microwave background have been observed — these effects that should not be present if the cosmological redshift was due to any tired light scattering mechanism. Despite periodic re-examination of the concept, tired light has not been supported by observational tests and has lately been consigned to consideration only in the fringes of astrophysics.
Read more about Tired Light: History and Reception, Specific Falsified Models
Famous quotes containing the words tired and/or light:
“We’ve cracked the hemispheres with careless hand!
Now, from the Gates of Hercules we flood
Westward, westward till the barbarous brine
Whelms us to the tired world where tasseling corn,
Fat beans, grapes sweeter than muscadine
Rot on the vine: in the land were we born.”
—Allen Tate (1899–1979)
“What is lawful is not binding only on some and not binding on others. Lawfulness extends everywhere, through the wide-ruling air and the boundless light of the sky.”
—Empedocles 484–424 B.C., Greek philosopher. The Presocratics, p. 142, ed. Philip Wheelwright, The Bobbs-Merrill Co., Inc. (1960)