Colour of the Universe Corrected by Astronomers
From the office of news and information,Johns Hopkins University
"It's our fault for not taking the colour science seriously enough," said an apologetic Karl Glazebrook, an assistant professor of astronomy in the Krieger School of Arts and Sciences at The Johns Hopkins University. "I'm very embarrassed, I don't like being wrong, but once I found out I was, I knew I had to get the word out."
Glazebrook noted that before the colour finding's odd nature led to a widespread public interest, it was originally just a footnote to a comprehensive survey of the spectrum of light emitted by 200,000 galaxies.
He and co-author Ivan baldry, a Hopkins postdoctoral fellow, had set out to simply compile a 'cosmic spectrum' based on data gathered by the Australian 2dF Galaxy Redshift Survey.
The cosmic spectrum initially took the standard scientific form of a graph, but researchers then transformed it into an array of colours, replacing each wavelength with the colour the human eye sees at that wavelength's intensity in the universe.
Glazebrook decided,on a lark, to try and calculate how the spectrum would appear to the human eye, to determine, in essence, what colour the universe would appear to someone 'standing' outside it and seeing all of it's light. The answer was a colour a few percent greener than pale turquoise.
Shortly after the turquoise finding made news, Mark Fairchild contacted the Hopkins astronomers from his post at the Munsell Colour Science Laboratory, a part of the Chester F. Carlson Centre for imaging Science at the Rochester Institute of Technology in Rochester, NY.
Fairchild and his colleagues helped the Hopkins astronomers determine that the freeware computer program they'd used to calculate the colour of the universe had inappropriately set a feature known as 'white point'.
The white point is the point at which light appears white given the environment that the light is viewed in.
"Tungsten lights, for example, can make the white point a bit yellowish," explains Francis Ismai, a senior colour scientist at Munsel. "Some monitors have a bluish white point. Your visual system tries to adapt, so that you assume that colour is white, but it's actually yellowish or bluish."
If you look at all the light in the universe from a room that has a red neon light it may appear turquoise but that's not a standard perspective.
With the white point adjusted to calculate the perceptions of an observer looking at the light in a darkened environment, the colour of the universe came out beige. When the viewing environment was adjusted to daylight, the colour was a faint red; in indoor light, the colour shifted to blue.