- Why is the sky blue?
It's one of the most common questions
asked by both kids and adults,
unless you're from ancient Greece.
I know, I know, you'd think the country
that is now ubiquitously known for beautiful blue rooftops,
crystal blue waters, and a blue flag
would have a longer history with the color.
But if you were to read Homer,
uh, not that one,
the famous ancient Greek writer from the 8th century B.C.,
you'd notice that the word blue isn't mentioned once.
Through thousands of pages of "The Iliad" and "The Odyssey,"
black is mentioned 170 times, white 100, red 13 times,
yellow and green each around 10, but blue never appears.
What's weirder is that Homer describes things
that we would normally call blue, like the ocean,
as wine-dark.
He even calls honey green and sheep violet.
For a while, some suggested that maybe
the ancient Greeks just saw colors different than we do,
or maybe they were all color blind.
But we now know that color vision developed
around 30 million years ago so that's not it.
It gets even crazier.
As historians and researchers began looking into
other ancient civilizations, they realized the same thing.
Almost none of them used the word blue.
From Icelandic texts to ancient Indian epics
dating to about four millennia ago,
to ancient Chinese writings,
and even the original Hebrew Bible,
all of them fail to mention blue once,
while all of them mention black, white, and red,
and many, the Bible included, also mention green and yellow.
Again, it's not like they don't talk about things
that we would call blue.
They describe the ocean as wide, stormy, silent,
but never blue.
It wasn't until the mid-1800s
that linguists began to analyze the history of languages
and found something peculiar.
In every culture, black and white are first.
Then the first color to enter the language is always red.
Then yellow follows, then green.
And then blue is the final color to enter language
in every single culture.
Over the years, researchers have found
some minor exceptions with the middle order,
so green and yellow,
but red is always first and blue is always last
in every single language.
So, why this order?
There's two main theories.
First, the evolutionary explanation is simple.
Black and white help distinguish between night and day,
light and dark, and are the most clear and useful,
so every culture has those.
Then red, it's often associated with blood or danger.
Even human faces and communication use red
through the galvanic skin response,
like when you blush or are stressed.
Green and yellow entered language as the need to distinguish
between ripe and unripe foods.
And blue?
There's very few blue things that we actually interact with.
Blue fruits are pretty rare.
Blue animals are rare too.
And when they are blue, it's often not a pigment,
but a sort of light illusion, like in butterflies.
Even the modern European language words for blue
are derived from ancient words for black or green.
The second explanation suggests
that these words don't enter language
until humans could make them.
Red being the easiest and most accessible color,
because you just take a piece of dry clay
and use it as a crayon.
If you think of cave, for example,
there's a lot of black and red in them.
But blue?
It's one of the hardest colors to create.
For thousands because of years,
nobody had it except the Egyptians,
and they had a word for it.
So does this mean that ancient people couldn't see
those colors before they had a word for it?
Not exactly.
Early humans would have considered colors
as simply hues of black, white, or red,
which sounds kind of crazy,
but there's actually modern day evidence for this.
If you look at these 12 colors,
can you spot the one that's different?
We might think clearly it's this one,
but when presented with a similar chart,
the Himba people of Namibia,
who don't have a separate word for blue,
take longer to point out this distinction.
On the contrary, when looking at green colors,
they are more quickly able to note the difference
that we wouldn't catch as quickly, this one.
And this is because they have more words for types of green
than we do in English.
In fact, one of their color categories clumps
some types of blue and green together,
while they have other color categories
for different greens still.
In the 1890s, anthropologists discovered
that indigenous islanders in New Guinea described the sky
as black or dirty like water.
Which, if you think about it, isn't that surprising.
Even if you look at a color picker in Photoshop,
it's clear that a dark or navy blue isn't actually
that far from being black,
and is quite far from other hues
which we would still call blue.
In that sense, black would have been a much broader term
for early and ancient humans.
It's kinda like how these are all shades of red.
We wouldn't call them different colors necessarily.
But this, in English, we call pink.
Even though it's technically just another shade of red,
we've decided to categorize it as separate
and as a result, it's different in our minds.
Of course, even if we didn't name it pink,
we'd still be able to see that it's a different color,
a lighter hue,
but ultimately, we'd consider it a form of red.
Now, you might be thinking this just seems semantic.
So what, they have different names.
There's no functional difference
in the actual color we're seeing.
But neuroscience has found that to be untrue.
It turns out, and this is mind blowing,
that language trains our brain to see colors differently.
What this means is once we have a new word for a color,
there's a feedback loop in the brain
and this exaggerates the differences between those colors,
especially at the border areas between them.
We get used to calling these colors as distinct hues
and as a result, the brain more aptly sees them
as distinct hues.
Without the word, you would still see the color,
but you wouldn't notice or contextualize it in the same way.
If that still feels bizarre, because I know it did for me,
think about learning a new language.
At first, everything just looks or sounds like gibberish.
You can't tell the verbs apart from the nouns,
let alone one word from the next,
because you are just learning.
But slowly over time, your brain starts to pick up
on these categories and patterns
and can recognize minor differences much faster.
It's not like you couldn't tell
the words were different before,
but it all sort of blended together.
Once you become more familiar with it,
you start to see and hear those words much more clearly.
Honestly, it's kinda like when I learn a new English word
and then suddenly I hear it everywhere,
I see it everywhere.
But the truth is I probably came across that word before
but just didn't notice it.
But now that I've surely learned the word,
the feedback loop is there and so I truly notice it.
It's a wild example of how our amazing brains
have allowed us to create language,
but then that language turned back around
and has an impact on brain function.
Not only is our perception of the world an illusion,
our brains are an active part of creating it.
Thank you so much for watching.
I hope you found it as interesting as I genuinely did.
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Peace.