Until relatively recently in human history, the colour blue didn’t exist. It is conspicuously absent from most ancient languages, including Greek, Chinese, Japanese, Hindustani, Icelandic and Hebrew.
It's as if our ancestors were all colour blind, but only when it came to shades of blue. Today I discovered why.
You've probably seen this scientific titbit pop up in your social media feed before. Every few years, a version of the story goes viral as everybody clicks and shares that intriguing headline. In the unlikely event you haven't encountered this theory before, here's a quick recap.
Homer's The Odyssey famously describes the sea as "wine-dark". Even for a poet, that's an odd colour choice - it makes the sea sound more crimson than blue.
It's not just Homer either - the same discrepancy is found in all surviving Ancient Greek texts, with a substitute colour always appearing instead of blue. Curiously, this linguistic blind spot occurs in most other ancient languages too. (The exceptions are the Ancient Egyptians, who had a distinct word for the blue dye they used.)
Obviously, the colour blue, which lies between violet and green on the spectrum of visible light, has always existed. The human eye perceives blue when observing light with a dominant wavelength between approximately 450 and 495 nanometres. So what was going on with our ancestors? Could they really not see the colour blue?
The knowledge site Quora has a pretty good explanation:
It has never been true that human eyes physically lacked the ability to register blue. What you'll often hear is that ancient cultures, and some current ones, don't count “blue” as a separate color, but as a shade of green. Saying those people don't “see” blue is a sensationalist way of saying that they don't have a concept of what “blue” is.
As the post goes on to note, the difference between dark orange and light orange is very similar to the difference between red and pink - yet we only identify the latter as separate colours. To most humans living in ancient times, blue fell into the dark orange/light orange camp: it was considered a different shade of another, dominant colour.
Intriguingly, this inability to "see" blue still exists in some modern cultures. For example, the Himba tribe in Namibia do not have a word for blue. In a recent experiment, members of the tribe had difficulty identifying the blue square in the photo below:
Most of the participants could only see a bunch of green squares. While one was a different "shade", there was nothing particularly unique or different about it. When your language doesn't have a word for a colour, its significance becomes much harder to identify.
As explained on Quora: "Telling [an ancient Greek] that something is “blue” instead of “green” is like someone insisting to you that pumpkins and oranges are completely different colours."
For those interested, the Radiolab podcast Color goes into fascinating detail about humankind's relationship with the colour blue. Click here to have a listen!
Today I Discovered is a daily dose of facts for Lifehacker readers - the weird, wonderful and sometimes worrying. Most of the time, it's just mind-blowing. Let us know if you discovered anything that blew your mind in the comments!
[Via Business Insider]