Astronomers measure the randomness in the Cosmic Microwave Background radiation to determine the cause of an anomalously cold spot.
Title: To the Center of Cold Spot with Planck
Authors: V.G. Gurzadyan, A.L. Kashin, H. Khachatryan, E. Poghosian, S. Sargsyan, G. Yegorian
First Author’s Institution: Center for Cosmology and Astrophysics, Alikhanian National Laboratory
The oldest light in the universe is the Cosmic Microwave Background (CMB). It comes from a time when the universe was only about 380,000 years old, at the start of a period in cosmological development known as recombination. This was when the universe had finally cooled enough to allow electrons and protons to bind into hydrogen atoms. Before that time, the universe had been a maelstrom of free electrons and protons, which would constantly absorb light and re-emit it in random directions. Once recombination occurred, light could travel freely as long as it didn’t bump into anything. Some of that light never did, and it is still traveling today; the faint glow of the big bang.
Fig 1. The Cosmic Microwave Background as imaged by WMAP over a period of 9 years. The color scheme in this all-sky map shows the minute variations in temperature of the light. ...