The Cosmic Spectrum and the Color of the Universe
En route to answering big, important, implication-heavy questions on the nature of the Universe, scientists decided to figure out what color it was. Meaning, if you stuck the Universe in a box, and could see all the light at once, and allowed for all variables such as velocity (causing redshift), what color would it be.
The answer seems to be beige.
Previously it was thought to be turquoise, but that turned out to be all wrong.
And it still might be salmon or periwinkle. It kinda depends where you are standing at the time.
But first, the methods:
In a project called the 2dF Galaxy Redshift Survey-a survey of more than 200,000 galaxies and several billion light years-- measured the light from a huge portion of the Universe. With this, scientists constructed "The Cosmic Spectrum" of the optical wavelengths of light. This was then averaged.
The average is expressed with a CIE (x, y) value, specifically 0.345,0.345. This number was "robust and reproducible" in the data set, and was even very similar to earlier values calculated in the Sloan Digital Sky
Survey spectroscopic survey.
The problem now lies in the reference of the value. It doesn't specify brightness. It doesn't tell you what the background should be. And the same value will look quite different depending on if your eyes are adjusted to bright light, dim light, or something in between.
It's like those damn paint chips that you like in the aisles of Home Despot, where they appear bold and distinguished, but despise once you get them home and find that the same paint on your walls looks dull, insipid, and off-white. Or vice versa.
But in average conditions, the color of the Universe is Beige.
Although they couldn't just call it beige, so they named the color "cosmic latte*."
But I dimly remember hearing in the news that the color was turquoise, you think quietly to yourself.
It's true; it was previously published that TCOTU was turquoise. It turns out they got their math wrong before by assuming that white was kinda reddish.
Finally, this isn't the last word on the topic, because the color will continue to change, on a time scale of billions of years. The Universe probably did start out bright blue over 13 billion years ago, and as the billions pass, will become redder and redder until it finally fades into the now starless night.
*Another name considered for the color was "speige"... as in "Speige: the final frontier.
For the real colors, check out: