It's easy for us to believe that the universe is a sea of blackness when we look up at night sky. What would the universe's average color look like if all the visible light emanating from the celestial bodies shining down on it was measured?
Let's start by saying that it's not black.
Ivan Baldry, a professor at Liverpool John Moores University Astrophysics Research Institute in U.K., said that "Black isn't a color." "Black is simply the absence of detectable sunlight." He said that color is actually the result of visible light, which is produced throughout the universe by galaxies and stars.
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Baldry and Karl Glazebrook (a respected professor at the Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Australia) co-led a 2002 study that measured light from thousands of galaxies and combined it to create a single spectrum that represented all of the universe.
The pair, along with their colleagues, were able to calculate the average universe color.
The cosmic spectrum
The electromagnetic radiation waves that stars and galaxies emit are divided into groups according to the wavelength of the waves. The groups range from the shortest to the longest wavelength and include gamma, X, X, ultraviolet, visible, radio, microwaves, radio waves, and infrared radiation.
Visible light is a small portion of electromagnetic spectrum, although it has the largest range of wavelengths. The colors we see are simply different wavelengths of visible radiation. Reds and oranges have longer wavelengths while blues and violets have shorter wavelengths.
Baldry stated that the visible spectrum of a star, or a galaxy, is a measurement of the brightness or wavelengths of light that the star, or galaxy emits. This can then be used to determine its average color.
The visible spectra from more than 200,000 galaxies across the universe were captured by Australia's 2dF Galaxy Redshift Survey in 2002. Baldry and Glazebrook created a visible spectrum that accurately represents the whole universe by combining all the spectra from these galaxies. This is known as the cosmic spectrum.
Baldry and Glazebrook created the comic spectrum in an online paper that was not peer-reviewed, based on their discovery. They were able to calculate the average universe color using the cosmic spectrum.
Color conversion
Baldry stated that the researchers used a color matching computer program to convert the cosmic spectra into one color that is visible to humans.
Three types of light-sensitive conuses are present in our eyes. Each cone helps us to perceive different wavelengths of visible light. Baldry and Glazebrook explained in an online paper that there are blind spots that prevent us from correctly registering certain wavelengths. The color we see depends on how we perceive white light. A brightly lit room may have a different color than an object outside on a cloudy day.
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The International Commission on Illumination created the CIE color space in 1931. It compensates for our visual limitations. They assign a color to different wavelength combinations based on what is seen by a standard human observer. This was what the computer models used by the team.
The average universe color is a beige hue that's not too different from white, according to the team. This is a boring result, but it's not surprising, given that white light is the result combining all wavelengths of visible light. The cosmic spectrum also includes a wide variety of wavelengths.
After a poll, the new color was named "cosmic latatte" after the Italian word for milk. Other suggestions were cappuccino cosmico and Big Bang beige, as well primordial clam chowder.
The color "cosmic latte" (Hex triplet = #FFF8E7) (Image credit NASA).
Redefinition
The cosmic spectrum represents the light of our universe, Balrdy & Glazebrook stated in an online paper. It is the light that was emitted throughout all of the universe and not what it appears to us today.
The Doppler effect is a phenomenon that causes light to be stretched over great distances, just like all waves. The Doppler effect is the phenomenon where light's wavelength increases and the color shifts to the red end of its spectrum. Astronomers call this redshift. This means that light we see today is different from the original color it was when it was emitted.
Baldry stated that "we removed the effect redshift from the spectrum of the galaxies." "So, it's the spectra of galaxies that emitted light.
According to Baldry, cosmic latte refers to the color you would see from the heavens if you could see the entire universe from the top and see the light coming from all stars, galaxies, and gas clouds at once.
Original publication on Live Science
