Color my world

When you think about it, color vision is kind of strange.  Our eyes -- unless you have a genetic or physical inability to do so -- are able to sort out the frequencies of light, and each range in the visible light spectrum looks different to us.  But why do we have the ability to distinguish between, for example, light with a wavelength of 570 nanometers (which looks yellow) and that with a wavelength of 470 nanometers (which looks blue)?  It's a small shift in wavelength, but triggers a completely different response in our eyes and brain -- so it must be important, right?

Color perception in the natural world seems to serve a fairly small number of functions.  There's sexual signaling -- the (often) brighter colors of male birds, for example, is most likely a cue for females signaling fitness (and thus good genes, worthy of producing young with).  It can be a sign that food is ready to eat, such as fruits changing from the blend-with-the-foliage shades of green to something more eye-catching.  It can also be a danger signal, as with the brilliant warning colorations of coral snakes, the foul-tasting bright orange and black monarch butterfly, and Central and South America's dart poison frogs.

So our ability to sense colors, an ability shared with many other mammals, birds, reptiles, amphibians, fish, and some arthropods, seems to have evolved as a way of distinguishing things that need to stand out from the background, for purposes of reproduction or survival.  There's a reason, for example, that stop signs are red; our dim-light vision is poorest in the red region of the spectrum, so when car headlights catch a bright red stop sign at night, it immediately grabs our attention.  (The flipside of this phenomenon is why snow under moonlight looks blue.  It's not that snow preferentially reflects blue light; it's simply that our eyes are better at picking up the blue region of the spectrum in low light levels, so it's almost as if our eyes are subtracting the red frequencies from the white light reflected from snowbanks, resulting in it appearing blue.)

What this means, of course, is that pigment production has to have evolved in tandem with color perception.  There are undoubtedly exceptions, where colorful chemicals have evolved for other purposes, and their hues are accidental byproducts of their molecular structure; but otherwise, the evolution of bright pigments must have coevolved with the ability to perceive them.  The brilliantly-colored organic compounds produced in the petals of many flowers, for example, are generally for the purpose of attracting pollinators, and the reds, oranges, and yellows of ripe fruit attract animals to consume the fruits and then disperse the seeds.

Scarlet passion flower (Passiflora coccinea) [Image licensed under the Creative Commons gailhampshire from Cradley, Malvern, U.K, Scarlet Passion Flower - Flickr - gailhampshire, CC BY 2.0]

What's curious about this, and why the topic comes up today, are the findings of a study out of the University of Arizona that appeared in the journal Biological Review last week.  It showed that based on genetic studies of distantly-related animal groups, color vision evolved a very long time ago -- on the order of five hundred million years ago, so the middle of the Cambrian Period -- while the first fruits didn't show up for another 150 million years, and the first flowers 150 million years after that.

So the earliest production of functional color (and the ability to perceive it) almost certainly was driven by sexual signaling and warnings.  Then, once animals were able to see in color, it became an evolutionary driver in plants to ride the coattails of that capacity in order to facilitate cross-pollination and seed dispersal.

And once that back-and-forth coevolutionary relationship was in place, it was off to the races.  Give it another couple hundred million years, and we have the rainbow hues of the natural world today.

One thing I still find hard to explain -- from an evolutionary standpoint, at least -- is why we find brightly-colored things beautiful.  Having our attention caught by a bright red apple, or the wild stripes and spots of the venomous lionfish -- sure, those make sense.  But why is it almost universal to find a daffodil or a wild rose beautiful?

Ah, well, maybe it's just one of those accidental things that is a consequence of other, more vital, evolutionarily-derived traits.  Whatever it is, we can certainly still enjoy it, and not let our wondering why it occurs interfere with our appreciation.

But it's still kind of cool that the ability that allows us to have that experience goes back at least five hundred million years.

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Genes, lost and found

There's a famous anecdote about British biologist J. B. S. Haldane.  Haldane was a brilliant geneticist and evolutionary biology but was also notorious for being an outspoken atheist -- something that during his lifetime (1892-1964) was seriously frowned upon.  The result was that religious types frequently showed up at his talks, whether or not the topic was religion, simply to heckle him.

At one such presentation, there was a question-and-answer period at the end, and a woman stood up and asked, "Professor Haldane, I was wondering -- what have your studies of biology told you about the nature of God?"

Without missing a beat, Haldane said, "All I can say, ma'am, is that he must have an inordinate fondness for beetles."

There's some justification for the statement.  Beetles, insects of the order Coleoptera, are the most diverse order in Kingdom Animalia, with over four hundred thousand different species known.  (This accounts for twenty-five percent of known animal species, in a single order of insects.)  The common ancestor of all modern species of beetles was the subject of an extensive genetic study in 2018 by Zhang et al., which found that the first beetles lived in the early Permian Period, on the order of three hundred million years ago.  They survived the catastrophic bottleneck at the end of the Permian and went on to diversify more than any other animal group.

One striking-looking family in Coleoptera is Buprestidae, better known as "jewel beetles" because of their metallic, iridescent colors.  Most of them are wood-borers; a good many dig into dying or dead branches, but a few (like the notorious emerald ash borer, currently ripping its way through forests in the northern United States and Canada) are significant agricultural pests.

A few of them have colors that barely look real:

An Australian jewel beetle, Temognatha alternata [Image licensed under the Creative Commons John Hill at the English-language Wikipedia]

What's curious about this particular color pattern is that beetles apparently had a gene loss some time around the last common ancestor three hundred million years ago that knocked out the ability of the entire group to see in the blue region of the spectrum.  This kind of thing happens all the time; every species studied has pseudogenes, genetic relics left behind as non-functional copies of once-working genes that suffered mutations either to the promoter or coding regions.  However, it's odd that animals would have colors they themselves can't see, given that bright coloration is very often a signal to potential mates.

That's not the only reason for bright coloration, of course; there is also aposematic coloration (also known as warning coloration), in which flashy pigmentation is a signal that an animal is toxic or otherwise dangerous.  There, of course, it's not important to be seen by other members of your own species; all that counts is that you're visible to potential predators.  But jewel beetles aren't toxic, so their bright colors don't appear to be aposematic.

The puzzle was solved in a paper in Molecular Biology and Evolution that came out last week, in which a genetic study of jewel beetles found that unlike other beetles, they can see in the blue region of the spectrum -- and in fact, have unusually good vision in the orange and ultraviolet regions, too.  What appears to have happened is that a gene coding for a UV-sensitive protein in the eye was duplicated a couple of times (another common genetic phenomenon), and those additional copies of the gene were then free to accrue mutations and take off down their own separate evolutionary paths.  One of them gained mutations that altered the peak sensitivity of the protein into the blue region of the spectrum; the other gave their hosts the ability to see light in the orange region.

The result is that jewel beetles became tetrachromats; their eyes have acuity peaks in four different regions of the spectrum.  (Other than a few people --who themselves have an unusual mutation -- humans are trichromats, with peaks in the red, green, and blue regions.) 

What this shows is that lost genes can be recreated.  The gene loss that took out beetles' blue-light sensitivity was replaced by a duplication and subsequent mutation of a pre-existing gene.  It highlights the fundamental misunderstanding inherent in the creationists' mantra that "mutations can't create new information;" if that's not exactly what this is, there's something seriously amiss with their definition of the word "information."  (Of course, I'm sure any creationists in the studio audience -- not that there are likely to be many left -- would vehemently disagree with this.  But since willfully misunderstanding scientific research is kind of their raison d'être, that should come as no surprise to anyone.)

Anyhow, the jewel beetle study is a beautiful and elegant piece of research.  It showcases the deep link between genetics and evolution, and reminds me of the quote from Ukrainian-American biologist Theodosius Dobzhansky, which seems a fitting place to end: "Nothing in biology makes sense except in light of evolution."

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Color my world

Our ability to perceive color is, when you think about it, a peculiar thing.

First, there's the rather hackneyed question of whether we all see color the same way (exclusive, of course, of people who are colorblind).  The way the question is usually phrased goes something like, "How could we tell if when you look at something red, what you see what I call green, but you still call it red because that's what you've learned?"  In other words, if I were to take a look through your eyes and brain, would the colors of objects be the same as what I see?

The answer is: we can't know for sure.  Thus far there's no way for one person to perceive the world through another person's sensory organs and brain.  But the great likelihood is that we all see colors pretty similarly.  All of our visual receptors are put together the same way, as are the visual cortices in our brains.  To assume that even with this structural and functional similarity, each person is still perceiving colors differently, runs counter to Ockham's Razor -- so without any evidence, it seems like a pretty untenable position.

More interesting is the comparison between how we see the world and how other animals do.  Once again, we run up against the issue that we can't see through another's eyes, but at least here we're on more solid ground because we can see that different animals have differently structured eyes.  Dogs, for example, have retinas with a much higher density of rods (the structures that operate in dim light, but only see in shades of gray) and a much lower density of cones (the structures that operate in bright light, and are able to differentiate by wavelength -- i.e., see colors).  Dogs aren't completely colorblind -- their two types of cones peak in sensitivity in the blue and yellow regions of the spectrum -- but they're relatively insensitive to colors outside that.  (This explains why my dog, Guinness, routinely loses his bright orange tennis ball in the bright green lawn -- to me, it stands out from fifty meters away, but he'll walk right past it without seeing it.) 

Then, there are bees and butterflies, which have eyes sensitive not only in the ordinary visible light spectrum but in the infrared and ultraviolet regions, respectively.  There are flowers that look white to our eyes, but to a butterfly they're covered with streaks and spots -- ultraviolet-reflecting markings that advertising nectar to those who can see it. 

A flower of the plant Potentilla reptans, photographed in ultraviolet light.  To the human eye, the flower looks solid yellow -- this is what it might look like to a butterfly.  [Image licensed under the Creative Commons Wiedehopf20, Flower in UV light Potentilla reptans, CC BY-SA 4.0]

But the winner of the wildly complex vision contest is the mantis shrimp, which has sixteen different color receptors (contrasted with our paltry three), rendering them sensitive to gradations of color we aren't, as well as detecting ultraviolet and infrared light, and discerning the polarization angle of polarized light.  How the world looks to them is a matter of conjecture -- but it certainly must be a far brighter and more varied place than what we see.

The reason all this colorful stuff comes up is because of a paper that appeared last week in Proceedings of the National Academy of Sciences, called "What We Talk About When We Talk About Colors," by Colin Twomey, Gareth Roberts, David Brainard, and Joshua Plotkin of the University of Pennsylvania.  The researchers looked at how words describing different colors vary from language to language.  "The color-word problem is a classical one," Plotkin said, in an interview with Science Daily.  "How do you map the infinitude of colors to a discrete number of words?"

And, more central to this research: does everyone do it the same way?  If you showed me a series of gradations from pure blue to pure green, at what point to I switch from saying "this is blue" to saying "this is green" -- or do I call the intermediate shades by a third, discrete name?

What the researchers found was that across 130 different languages, humans tend to group and name colors the same way.  Further, if you give people tiles with varying shades of red and asked them to pick out "the reddest red," the results show remarkable consistency.

Another interesting result of the research was that the sensitivity of our eyes to color variation isn't the same from color to color; we are much better at picking out subtle variations in red, orange, and yellow than we are at seeing differences in (for example) different shades of brown.  The researchers believe this is due to a difference in what they call communicative need; since reds, oranges, and yellows are the colors of ripe fruit, we've evolved eyes that are most sensitive to variations in those colors.  "Fruits are a way for a plant to spread its seeds, hitching a ride with the animals that eat them," Twomey said.  "Fruit-producing plants likely evolved to stand out to these animals.  The relationship with the colors of ripe fruit tells us that communicative needs are likely related to the colors that stand out to us the most...  No one really cares about brownish greens, and pastels aren't super well represented in communicative needs."

So it seems like the great likelihood is that we all see the world pretty much the same way.  Well, all humans, at least.  What the world looks like to a dog, with their better dim-light vision and better motion detection, but far poorer color discrimination, can only be guessed at; and what colors a mantis shrimp sees is beyond the ability of most of us to imagine.

Study lead author Colin Twomey wonders whether the same techniques could be used to study other facets of sensory perception.  "This is something that could be carried to other systems where there is a need to divide up some cognitive space," he said, "whether it's sound, weight, temperature, or something else."

One I wonder about is the sense of taste.  We know that taste differs a great deal between different individuals, not only because everyone likes (and dislikes) particular flavors, and those preferences differ greatly; but there are some people called "supertasters" who are sensitive to minor variations in flavor that the rest of us don't even notice.  (I am most definitely not a supertaster; the joke in my family is that I have two taste buds, "thumbs up" and "thumbs down.")  The daughter of a friend of mine, for example, has amazingly sensitive taste buds, to the point that she can discern whether the coffee was brewed with filtered water or ordinary tap water.

Me, as long as it's brewed with water and not turpentine, I'm fine with it.

But that's all potential future research.  For now, we have a better idea of how each of us colors our world.  And despite our individual differences, the answer appears to be that what you're seeing and what I'm seeing look very much alike.  

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As someone who is both a scientist and a musician, I've been fascinated for many years with how our brains make sense of sounds.

Neuroscientist David Eagleman makes the point that our ears (and other sense organs) are like peripherals, with the brain as the central processing unit; all our brain has access to are the changes in voltage distribution in the neurons that plug into it, and those changes happen because of stimulating some sensory organ.  If that voltage change is blocked, or amplified, or goes to the wrong place, then that is what we experience.  In a very real way, your brain creates your world.

This week's Skeptophilia book-of-the-week looks specifically at how we generate a sonic landscape, from vibrations passing through the sound collecting devices in the ear that stimulate the hair cells in the cochlea, which then produce electrical impulses that are sent to the brain.  From that, we make sense of our acoustic world -- whether it's a symphony orchestra, a distant thunderstorm, a cat meowing, an explosion, or an airplane flying overhead.

In Of Sound Mind: How Our Brain Constructs a Meaningful Sonic World, neuroscientist Nina Kraus considers how this system works, how it produces the soundscape we live in... and what happens when it malfunctions.  This is a must-read for anyone who is a musician or who has a fascination with how our own bodies work -- or both.  Put it on your to-read list; you won't be disappointed.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Color my world

 I'm not absolutely certain about this, but I strongly suspect that every time I taught my biology students about the physiology of color vision, someone asked, "Is it possible that we see colors differently?  Like, what you call red is the color I see as green, but we've both learned to call it red?"

My usual response was, "It's possible, given that I can't see the world through your eyes and interpreted by your brain.  I only have access to my own perceptive apparatus.  However, it's pretty unlikely, given that your eyes and brain are structured pretty much identically to mine, so there's no reason to surmise they see the world in a radically different way.  The most parsimonious explanation is that we all perceive colors alike."

That parsimonious explanation got a boost this week by a paper in Psychological Science called, "Universal Patterns in Color-Emotion Associations Are Further Shaped by Linguistic and Geographic Proximity," by a huge team led by Domicele Jonauskaite of the University of Lausanne.  The researchers asked 4,598 volunteers from different cultures to answer questions about the connections they saw between colors and emotions.  In English, for example, we talk about seeing red, being green with envy, or feeling blue.  Presumably other cultures also associate colors with emotions -- but are the correspondences the same across cultures?

[Image is in the Public Domain]

Interestingly, the answer appears to be yes.  There were a few unusual ones that popped out, such as the association in China of the color white with sadness.  White is traditionally worn at Chinese funerals, thus the link.  The same was found with the color purple in Greece; in Greek Orthodox culture, purple is considered the color of mourning.

But there were far more similarities than differences, including some that when you think about it, are rather odd.  Red is one of the only colors that has connection to two essentially opposite emotions; it is the color both of love and of anger.  This same link turns out to be relatively uniform across cultures.  (The anger part might be because of the association with violence and blood; the connection to love is the stranger one.)  Likewise, brown is the color that has the least emotional impact, regardless what culture you are from.

Unsurprisingly, the closer two cultures were geographically and linguistically, the more similar the correspondences were.  That much you'd expect, because of an overlapping or shared heritage.  But even accounting for that, there were more similarities than differences even between very distantly-related cultures.  "There is a range of possible influencing factors: language, culture, religion, climate, the history of human development, the human perceptual system," said study co-author Daniel Oberfeld of Johannes Gutenberg-Universität Mainz.  "Many fundamental questions about the mechanisms of color-emotion associations have yet to be clarified."

It does, though, settle one thing; we are very likely to all see colors the same way.  Your blue and my blue, for example, are perceived alike, and if we were somehow to switch bodies, we wouldn't suddenly see the world painted in a completely different palette.  If that weren't true, why would yellow be the color of cowardice in both the United States and west Africa?

This doesn't, of course, answer the question of why yellow is for cowards in the first place.  Other than the obvious ones like red=blood, the color-to-emotion correspondences are pretty weird.  But it does seem to support the conjecture that regardless of why we link emotions to colors, my color perception works the same as yours does.

Just as well.  Trying to picture a world where the grass is orange and the sky is yellow is making my head hurt.

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Humans have always looked up to the skies.  Art from millennia ago record the positions of the stars and planets -- and one-off astronomical events like comets, eclipses, and supernovas.

And our livelihoods were once tied to those observations.  Calendars based on star positions gave the ancient Egyptians the knowledge of when to expect the Nile River to flood, allowing them to prepare to utilize every drop of that precious water in a climate where rain was rare indeed.  When to plant, when to harvest, when to start storing food -- all were directed from above.

As Carl Sagan so evocatively put it, "It is no wonder that our ancestors worshiped the stars.  For we are their children."

In her new book The Human Cosmos: Civilization and the Stars, scientist and author Jo Marchant looks at this connection through history, from the time of the Lascaux Cave Paintings to the building of Stonehenge to the medieval attempts to impose a "perfect" mathematics on the movement of heavenly objects to today's cutting edge astronomy and astrophysics.  In a journey through history and prehistory, she tells the very human story of our attempts to comprehend what is happening in the skies over our heads -- and how our mechanized lives today have disconnected us from this deep and fundamental understanding.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Color commentary

The "what colors do you see in this photograph?" thing is back with us, only instead of a dress, this time it's a shoe.

Personally, I see this shoe as gray and a sort of turquoise-greenish-blue, but apparently there are people who see it as pink and white.  What's certain is that once you see it a particular way, you can't somehow see it the other way, as you can with flip-flop illusions like the famous duck and rabbit.

What's different about the claims floating around this time is that supposedly, the fact that I see it as gray and green means I'm a left-brain, logical, sequential, concrete type, and the people who see it as pink and white are right-brain creative, holistic, abstract thinkers.  The problem with this is that a 2017 study at the University of Utah concluded that there is nothing to the right-vs.-left brain dichotomy, at least insofar as personality is concerned.  "It is certainly the case that some people have more methodical, logical cognitive styles, and others more uninhibited, spontaneous style," said Jeffrey Anderson, a neuroscientist who co-authored the study.  "This has nothing to do on any level with the different functions of the [brain's] left and right hemisphere."

It is true that people do tend to have a dominant side of the brain, and this can influence you physically -- for example, what hand you write with and which eye is dominant.  I know on brain-dominance tests I tend to score right in the middle -- left on some tasks, right on others.  When I was in kindergarten I switched which hand I wrote with about a dozen times, till my frustrated teacher told me to simmer down and pick one, for pity's sake, so I ended up right handed.  But I still do a lot of things with my left hand, and probably would be considered mixed-brain dominant.

But the point here is, it has nothing whatsoever to do with my personality, nor with how I perceive color.

The unfortunate part is that this simplistic and inaccurate account of the gray/green vs. pink/white split ignores the fact that we do have a possible explanation for why this happens, and it's actually a good bit more interesting than "you're a right-brained creative type."  The reason seems to be that we evaluate and interpret colors by comparison with their context, not in any sense the "absolute color" of the object (which, as you'll see, is a meaningless concept).  As a rather startling illustration of this, how would you compare the color saturation of the two squares marked A and B in the drawing below?

Nearly everyone is absolutely convinced that A is a lot darker than B, but the fact is, they're exactly the same shade of gray.  The reason your brain made the decision that they're different -- a decision that, even once you know what's going on, is damn near impossible to shake -- is that you interpret B as if it were in a shadow, so in order to appear the shade it is, it must be inherently lighter.  If A and B were observed in the same level of light (your brain says), B would have to be lighter.

Even more striking is the image below:

I'm sure you've already figured out that the band in the middle is all the same shade of gray -- which you can prove to yourself by blocking out the background with a piece of paper.  But as I said, once your brain has made the decision that it's a gradient, it's impossible to compromise.

You do the same thing with colors.  Here's an example -- and once again, A, B, and C are all exactly the same color:

You get the point.  The thing is, you're doing this all the time without being aware of it, and once you have settled on what you're seeing, your brain won't admit it's wrong.  The same is happening with the shoes.  You decide which part of the image to compare the color to, and interpret every other color in the image on the basis of that decision.

We still don't know why some people settle on gray/green and others on pink/white.  But it has nothing to do with which side of the brain is dominant, nor whether you're creative or logical.  It has to do with our faulty method for integrating the data coming from our eyes.  It works well enough most of the time, sure; but when it fails, it fails spectacularly.

So feel free to repost the shoe pic and ask your friends which they see, but kindly don't attribute any differences to your favored side of the brain.  Instead, think about what's really going on here -- which, honestly, is far more interesting.

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I grew up going once a summer with my dad to southern New Mexico and southern Arizona, with the goal of... finding rocks.  It's an odd hobby for a kid to have, but I'd been fascinated by rocks and minerals since I was very young, and it was helped along by the fact that my dad did beautiful lapidary work.  So while he was poking around looking for turquoise and agates and gem-quality jade, I was using my little rock hammer to hack out chunks of sandstone and feldspar and quartzite and wondering how, why, and when they'd gotten there.

Turns out that part of the country has some seriously complicated geology, and I didn't really appreciate just how complicated until I read John McPhee's four-part series called Annals of the Former World.  Composed of Basin and Range, In Suspect Terrain, Rising from the Plains, and Assembling California, it describes a cross-country trip McPhee took on Interstate 80, accompanied along the way with various geologists, with whom he stops at every roadcut and outcrop along the way.  As usual with McPhee's books they concentrate on the personalities of the people he's with as much as the science.  But you'll come away with a good appreciation for Deep Time -- and how drastically our continent has changed during the past billion years.

[Note:  If you order this book using the image/link below, part of the proceeds will go to support Skeptophilia!]

A case of the blues

This post is brought to you by the color blue.

But not to worry: this is not about the damned dress, about which I have heard enough in the past week to last me several lifetimes.  This is about a different viral story, and one that has even less scientific validity than the whole what-color-is-this-dress thing.

I refer to a claim I've seen multiple times in the last few days that claims that because ancient languages had no word for the color blue, that they were unable to see blue.  Or, more accurately, that "blue" didn't exist in their mental and linguistic framework, so they were unable to see the difference between blue and colors that were nearby on the color wheel (especially green).  This, they say, explains Homer's "wine-dark seas," a metaphor I've always thought was as strange as it was evocative.  Kevin Loria, author of the article in question, writes:

In 1858, a scholar named William Gladstone, who later became the Prime Minister of Great Britain, noticed that this wasn't the only strange color description. Though the poet spends page after page describing the intricate details of clothing, armor, weaponry, facial features, animals, and more, his references to color are strange. Iron and sheep are violet, honey is green. 

So Gladstone decided to count the color references in the book. And while black is mentioned almost 200 times and white around 100, other colors are rare. Red is mentioned fewer than 15 times, and yellow and green fewer than 10. Gladstone started looking at other ancient Greek texts, and noticed the same thing — there was never anything described as "blue." The word didn't even exist. 

It seemed the Greeks lived in murky and muddy world, devoid of color, mostly black and white and metallic, with occasional flashes of red or yellow.

Loria goes on to tell us about the studies of a linguist named Lazarus Geiger, who found that there was also no word for blue in ancient Hebrew, Icelandic, Chinese, and Sanskrit.

The conclusion?  Our ability to see blue is a recent innovation -- and has to do with our having a linguistic category to put it in.  Without a linguistic category, we can't discriminate between blue and other colors.

There are two problems, of increasing severity, with this hypothesis.

The first is that this is a specific case of what is called the Strong Sapir-Whorf Hypothesis -- that our experience of the world depends on our having a linguistic framework for it, and without that framework, we are unable to conceptualize categories for things.

The Strong Sapir-Whorf Hypothesis has a difficulty -- which is that it doesn't square with what we know about either physiology or language evolution.  In the case of color discrimination, the fact is that in the absence of a physiological impairment (e.g. colorblindness), most people have similar neural responses to observing colored regions.  There are a small number of people, mostly female, who are tetrachromats -- they have four, instead of three, color-sensing pigments in the retinas of their eyes, and have a much better sense of color discrimination than we trichromats do.  But the physiology would argue that mostly we all experience color the same way.

The Strong Sapir-Whorf Hypothesis, apropos of color discrimination, fails on a second level, however; Brent Berlin and Paul Kay found, back in the 1960s, that languages have a very predictable order in which they add color words to their lexicon.  It goes like this:

1. All languages contain terms for black and white (or "dark" and "light").
2. If a language contains three terms, then it contains a term for red.
3. If a language contains four terms, then it contains a term for either green or yellow (but not both).
4. If a language contains five terms, then it contains terms for both green and yellow.
5. If a language contains six terms, then it contains a term for blue.
6. If a language contains seven terms, then it contains a term for brown.
7. If a language contains eight or more terms, then it contains terms for purple, pink, orange, and/or gray.

This agrees with the way our eyes perceive color, in terms of the peaks of cone sensitivity. It is surmised that the greater the necessity to differentiate between different colors -- for example, in determining the difference between poisonous fruits and edible ones in a rain forest -- the greater the complexity of words for different shades and hues.  In the ancient world, understandably enough, you coined words for things that had survival value, and pretty much ignored everything else.

But what about Loria's claim that many ancient languages didn't have words for blue? This brings us to the second problem with the article -- which is that this is simply an untrue statement.

The ancient Greeks had the word κυανός, which means "dark blue" -- specifically the color of the mineral azurite, which was highly prized for jewelry and statuary.  It's the root of our word "cyan."  And the Greeks weren't the only ones; the Hebrews had the word t'chalet, as in Numbers 15:38:

Speak unto the children of Israel, and bid them that they make them fringes in the borders of their garments throughout their generations, and that they put upon the fringe of the borders a ribband of blue.

Even today, the tallit, or Jewish prayer shawl, is always decorated in blue.  (And it is no coincidence that the Israeli flag is blue and white.)

What about Old Icelandic?  They had the word blár, which meant, you guessed, it, "blue."  It's no new innovation, either; it's used in the 10th century Hrana saga hrings (The Saga Cycle of Hrani), in which we have the line, "Sýndi Hrani, hversu hún hafði rifit af honum klæði, og svo var hann víða blár go marinn," meaning, "Hrani showed that she had torn off his clothes, and he was widely blue and bruised."  (What?  It's an Icelandic saga.  You thought it was going to be about bunnies and rainbows?)

And I don't know any Chinese or Sanskrit, but I'd bet they had words for blue, too.  One of the most prized gemstones in the ancient world was lapis lazuli -- and according to an article posted at the website of the Gemological Institute of America:

Historians believe the link between humans and lapis lazuli stretches back more than 6,500 years. The gem was treasured by the ancient civilizations of Mesopotamia, Egypt, China, Greece, and Rome. They valued it for its vivid, exquisite color, and prized it as much as they prized other blue gems like sapphire and turquoise.

Hard to imagine why our distant ancestors would have done this if they saw blue stones as, in Loria's words, "muddy and murky... mostly black and white and metallic, with occasional flashes of red or yellow."

[image courtesy of photographer Hannes Grobe and the Wikimedia Commons]

So the whole premise is false, and it's based on zero biological evidence.  But that hasn't stopped it from being widely circulated, because as we've seen more than once, a curious and entertaining claim gets passed about even if it's entirely baseless.

I'll end here.  I'm feeling rather blue after all of this debunking business, and not gray or metallic at all.  And I suspect I'd feel that way even if I didn't have a word for it.