I do admire Neil deGrasse Tyson for his work in science communication, particularly for bringing some much needed diversity to a profession which still sorely needs it. However, he does have… shall we say, a certain proclivity for pedantry.
This afternoon, I stumbled across this on twitter:
It’s true. Neil has a strange fixation with this phrase and seems to pin all of the blame on Pink Floyd.
It’s certainly become something of a running joke at this point, that Tyson likes to “well, actually” things like this. But he isn’t always right, even on little crusades which he’s evidently spent years championing.
The “dark side of the moon” thing seems to be a popular little phrase to argue about among people on the internet with too much time on their hands too, no matter how inconsequential it may be. At least one article I’ve written before ended up with a few “well, actually” comments being made.
Honestly, I dislike being needlessly pedantic, but sometimes you just need to fight meticulosity with meticulosity⭐. Fine. Let’s look at this.
Not That Kind of Dark
The term “dark side of the moon” is older than you might realise and, in a good many old phrases, the exact meanings of the words may not be a perfect match with the modern usage with which you may be familiar📚. Languages are messy like that. In many cases though, older meanings still do exist in any given language and are perfectly valid in modern usage.
In this case, the word dark refers to the unseen or the mysterious. For instance, the Merriam-Webster dictionary defines one meaning of the word to be “not known or explored because of remoteness.” Originally, the word derives from an Anglo-Saxon word deorc, which in turn relates to an Old High German word terchennen (also pronounced/written derchennen), which means to hide.
So generally, this meaning of the word dark refers to things which are hidden, secret, or obscure🔮🍫, and have since at least Shakespearian times. A bit like, oh, I don’t know, a side of the Moon which we can never see from the surface of Earth.
We still only rarely see the dark side of the Moon. Not many spacecraft have been there, and not all took any photographs. It wasn’t until 1959 when the Soviet Luna 3 probe send us the first images of the Moon’s outward facing surface.
Older Than You Think
So I mentioned it’s an old phrase. How old exactly? Well, it’s definitely older than Pink Floyd’s 1973 psychedelic prog rock album, that’s for sure.
There are various references to the term here and there in literature. An instance which some purport to be the first appearance in print comes from the Rural Visitor, a newspaper from New Jersey in the USA, published in 1810, stating:
“[People] may be found possessing great professional knowledge, much integrity, and yet be as utterly unnoticed as though they tenanted the dark side of the moon.”
The casual usage of the phrase here heavily implies that this was already a widely used phrase in the US back in 1810. Google ngram seems to agree on this.
The first use in literature is from the early 1700s, and there’s no way of saying how much the phrase may have been used prior to this. So slightly predating Pink Floyd, then.
Evidently, the two terms “dark side of the moon” and “far side of the moon” may be synonymous, but the former term is older and has always been more frequently used. It should be borne in mind though, that this may be swayed by this term having two meanings, refering both to the Moon’s far side and the side which is in shadow (the literal dark side).
More generally, the phrase “dark side” in English literature apparently dates back to at least the 17th century.
All Sides Get Sunlight
Something which gets said a lot, and for convenience I’m going to just overlook the fact that a sphere only has one single curved side.
The thing is, yes, we know this. We have known this for a long time. Leonardo Da Vinci studied the way shadows fell on spheres back in the 15th century, and while he may have been a particularly prominent (and rather interesting) individual, I doubt he was the first to do so.
From there, it doesn’t take a huge leap in logic to figure out that when the Moon appears dark from Earth, its far side must be bathed in sunlight. But the term in English is never used to refer to the side of the Moon which faces Earth.
And honestly, I’ve never understood why some people get their panties in such a bunch over this.
The phrase “dark side of the moon” is one which the overwhelming majority of native English speakers know. It also has a certain poetic charm about it, which is probably why Pink Floyd ended up popularising it. Ulimately, I’ve no problem with the evolution of language and time will tell which phrase ends up being the more popular of the two.
I suspect that once the Moon’s usually non-visible side becomes more well known to us, perhaps when we finally start sending astronauts back there, the term “dark side” will truly cease to have any meaning beyond in poetry. Then maybe we’ll see some more images like this gorgeous photo from Apollo 16 in 1972, where the camera was being held by an actual human as it was being used.
Until then, I see no particular reason to stop using it. Telling people that they’re wrong isn’t really good science communication, especially when you’re not actually correct. If you want to go on a crusade against common English words and phrases, fighting against the ones which are discriminatory would be a better place to choose your fights.
I really doubt anyone’s “busy” with this, and I know I never have been. Using a common phrase is not damage. It was in use long before Pink Floyd. A sphere only has one side. The term refers to the metaphorical dark as opposed to literal darkness.
I’m just going to let Luke Skywalker sum up my feelings on Tyson’s tweet:
⭐ Yes this is a real word. “Meticulousness” sounds cumbersome.
📚 The changing meanings of words is all part of what makes a living language so vibrant, as certain words fall in and out of favour with the general population. This is why I make a point of not using words like “colony” or “settlement” due to unfortunate connotations which remain as a hangover from colonialism – and despite what some might believe, connotations are an important part of a word’s meaning which often lie outside the dictionary definitions. Where there’s a word to use without negative historical connotations, it seems far more logical to use that. But that’s a post for another time…
🔮 As an aside, the fact that dark has also come to mean sinister in English is probably responsible for all kinds of unfortunate associations. For instance, “the dark arts” is a term any fans of Harry Potter will know. It’s actually older than the term “dark magic” which has come to be synonymous with it. I suspect it’s quite likely that “dark arts” originally meant something more like “unseen arts” because people believed in folklore to use magic would presumably do so away from public view.
🍫 As a second aside, dark also has a dictionary-defined meaning of “posessing depth or richness” which I rather like. It’s quite evocative of things like dark chocolate, black coffee, and other complex flavours. Merriam-Webster’s lovely example of “a dark voice” makes me feel like we should use this meaning more in common English.