Cosmic Latte: the Average Color of the Universe
Wondering about the color on your fashion-forward, incredible wearable from Inq? Believe it or not, that light beige is officially called “Cosmic Latte,” and it’s the average color of the universe!
In 2002, Johns Hopkins University astronomers used the 2dF Galaxy Redshift Survey to collect detailed measurements of the light from 200,000 galaxies. Given the general average of 100 billion stars per galaxy, we’re talking roughly 20,000,000,000,000,000 stars, so–a whole lotta light (BTW, the Milky Way has around 300 billion stars, but we’re bigger than average). They punched the color data into a computer program to generate a "cosmic spectrum," a graph of all the energy in the visible universe emitted at different wavelengths of light.
Once the astronomers had created the spectrum, they got to wondering– “could we average out those color values”? If so, they could provide an overall measure of the color of the universe; not something you’d actually observe, of course, but at the very least a really cool Technicolor thought experiment made real. Essentially, the result is what somebody would see if they had the universe in a giant box, and saw all the light at once.
So the data got entered, the calculations performed, and amazingly, out came a color! The one! The average color of the universe! It was a sort of light, extra greenish-turquoise. The color was announced, it made the news media, and then the astronomers started thinking, and realized there had been a slight mistake. In a sense, they had forgotten to correct for the proper white balance, so it skewed the final color. If you want to see the effect this has, take out your camera or smartphone, and if you have a white balance control, take two photos of the same subject, with different balance settings; note how vastly different the colors in each photo will appear.
In this case, the important thing the astronomers were trying to take into account is how the universe’s light would look if observed; that is, if a person was seeing it in the theoretical space that was larger than the universe. So they chose a white balance that would reflect a human eye viewing the universe’s light from afar in dark conditions.
When the whites were corrected, the calculations were run again, and we got the calming shade seen on your new shirt. To name the color, an informal poll of Johns Hopkins astronomers was taken with ten choices. Cosmic Latte actually wasn’t the top vote-getter, but it won out in the end because “Latteo" means "Milky" in Italian, Galileo's native tongue. And who can resist a good Galileo homage?
But that’s not the end of the story: when Curiosity Box 400,013 comes out 100,000 years from now, we’ll need to send you another shirt because it turns out the average color of the universe is changing, slowly shifting from blue to red! The change in hue is due to stellar evolution; the process through which stars change color, temperature, and size over time. A typical pattern for a main sequence star like our sun would have it shift over the eons from blue to yellow, and eventually red. So keep us up-to-date on your change of address forms, and we’ll make sure to get that shirt ready for your great-to the 33,000th-generation grandchildren!