Penn State Redefines What "Dark Side of the Moon" Means
55-year old dark side of the moon mystery solved, Penn State
“UNIVERSITY PARK, Pa. — The “man in the moon” appeared when meteoroids struck the Earth-facing side of the moon creating large flat seas of basalt that we see as dark areas called maria. But no “face” exists on farside of the moon and now, Penn State astrophysicists think they know why.”
Keith’s note: This is an odd thing to put in the title i.e. “dark side of the Moon” since this constantly changes – and yet this research focuses on a specific part of the Moon that does not change. So I sent a note to the author, A’ndrea Elyse Messer, Ph.D. Sr. Science & Research Information Officer at Penn State. She replied by email “As it says in the story, the “dark” side of the moon is the side that is always turned away from the Earth. It does not change.”
Baffled by her response, I asked her (again) about this and she followed with really goofy stuff i.e. “yes, the “dark” side of the moon is called that because it is the farside of the moon and was completely unknown until the Russians sent a probe around the back to photograph it. It has absolutely nothing to do with sunlight — as is explained in the story. Dark is used in the same way it used to be used in Darkest Africa. It wasn’t dark in africa, it was unknown.”
“Far” side of the moon is a better term.
Still, one definition of “dark” in Webster’s online dictionary is: “not known or explored because of remoteness, Example: the darkest reaches of the continent.
“Far” is better, and “dark” still enjoys use in terms like “dark matter” and “dark energy”. I think, however, that “dark” no longer applies to the far side of the Moon.
Scientists should be promoting correct terminology. After all, we have a rather sizable issue with scientific literacy in this country, and as such, scientists should be proactive about such things.
Well put. “Dark side of the moon” is an obsolete term. The far side of the moon is no longer an unknown.
But the question of why the hemispheres are different was a major unknown aspect, i.e. a “dark side”, of the Moon. Now let’s try to agree on whether “Moon” warrants a capital when it refers to “the” moon. It is after all a _particular_ person, place, or thing.
i think it is annoying when people who obviously know what it refers to post about this claiming to be “baffled,” come on. we know you’re not. this is making an issue out of nothing. it’s a well known and often used colloquial phrase. there’s no confusion about what the “dark side of the moon” refers to, and to use it in the title of an article is not unusual at all.
Its utterly wrong. And these same astronomers howl in protest when the news media gets something wrong like this.
“it is utterly wrong” is very much a stretch. i’ve already said that the phrase is neither literally nor technically correct. however, the way it was used is simply as a colloquialism. it’s not a new one, at that.
http://www.grammarphobia.co…
i’m surprised you’re making a fuss when half the articles about the moon use this phrase. you’re acting like you’ve never seen it before.
The far side been called the dark side for a coon’s age LoL
As one of the paper’s authors explains ( http://scienceblogs.com/cat… ) the “dark side” refers to the fact that the far side of the Moon receives no reflected sunlight from the Earth, which turns out to be important to its history. The reflected sunlight from the Earth ends up heating the near side of the Moon, and changes it. Thus, the far side of the Moon is always in the “dark” from Earthshine. It’s still probably not a good idea to promote the idea of a “dark side” though, I agree.
Its goofy and it is wrong.
Steven,
No, I’m sorry but you are wrong. NO-ONE refers to the “dark side” because it does not receive reflected Earthlight. The whole article was referring to differences in formation between the Moon’s near and far side because of the differential rate of cooling caused by the near side receiving more of the radiating heat from the earth’s formation and the far side being able to radiate away the heat of its own formation faster. It has nothing to do with reflected sunlight.
I like her answer better than your assumption, Keith – it also makes Pink Floyd seem less ignorant 😉
You can never play too much Pink Floyd.
Especially in planetariums.
I like to think that Pink Floyd’s “dark side” was metaphorical. That allows me to keep them high in my music collection ranking without scientific guilt.
Precision in language is important and it is NOT ‘nothing’. Many, many folks out there incorrectly believe that the far side of the Moon is always dark because it is labeled–incorrectly–as the dark side. This is mixed up with their ignorance regarding the rotation of the Moon as it revolves around the Earth. It takes a bit of effort when I am teaching my middle-school students to unseat this firmly held misunderstanding from more than a few of the students, AND many adults when the subject comes up.
I have NEVER once (in many decades) come across–in my readings, travels with personal discussions on this topic, or teaching experiences-someone who has referred to the “dark” in the Dark Side of the Moon as referring to “unknown”.
This has all the signs of a PR person’s glossing over the pertinent facts with imprecise “common-people” wording. The original authors of the paper use the word “farside”; they certainly know better.
the word “Dark” is often used in this way, though. Dark Matter / Energy. the Dark Ages. the Dark side of the Moon.
yes, in regards to the Moon it’s not literally correct nor technically accurate anymore – in the same way that the Dark Ages are no longer considered Dark and are more correctly referred to now as the Medieval period, or Middle Ages – the far side of the moon is now known to us, and it hasn’t been unknown since Luna 3 flew by and took pictures of it in 1959 – so little wonder nobody in your travels has referred to it as “Dark” in that context.
however, as a colloquial expression, “the Dark side of the Moon” will remain with us, probably as long as Pink Floyd remains well known. so you are very likely stuck with having to explain that the far side of the moon isn’t really in perpetual darkness for some time to come.
Its wrong no matter how you try and excuse it.
since when is a long-standing and still correct definition of a word an excuse? particularly when that word was used correctly?
i will agree that the phrase “the Dark side of the Moon” is neither literally nor technically correct. however, this is true of many colloquial phrases, and this particular phrase has been around for a long time.
http://www.grammarphobia.co…
And language is constantly changing, old terms become disused – particularly when we learn things and correct ourselves.
Why the resistance?
language tends to retain old words, even if their meanings change, the words can still be used with the old meanings. the same goes for phrases. “there’s more than one way to skin a cat” even if very few people skin cats anymore.
in this case, “the Dark side of the Moon” will remain a colloquial phrase for a long time to come, in part because its widespread use thanks to Pink Floyd and that one song from Mulan.
“More than one way to skin a cat” is, by your admission, NOT really used to refer to dealing with cats anymore.
That’s why your analogy fails.
We ARE talking about the moon, here. Not an overrated 70s vinyl disc.
Veterinarians discussing treatments for Fluffy’s dermatitis probably do NOT use “more than one way to skin a cat” in their literature, which would be a more apt analogy.
neither does “the Dark side of the Moon” refer to the far side of the moon being unknown anymore.
however, the phrase “the Dark side of the Moon” is still in use.
i’d say the analogy is dead on.
But, Hug Doug, that is the whole point – this is NOT Pink Floyd and neither is it a colloquial or metaphorical discussion. It is a SCIENTIFIC paper reported in a science journal and the author of this article has failed her responsibility to help clear up this scientific (factual) misconception.
So you’re saying that scholarly papers (or their titles) may never use colloquialisms? that’s absurd. there’s no need to limit the words an author may use. effective communication of ideas is the goal, not the blanket suppression of entire forms of speech.
“the author of this article has failed her responsibility to help clear up this scientific (factual) misconception”
that is not correct. the article makes a very clear statement that the far side is not literally dark: “It was called the dark side because it was unknown, not because sunlight does not reach it.”
OK, so do you use “Sunrise and sunset”? they are also astronomically incorrect but see how many people will look at you funny if you say you are going to watch the sun cross the horizon as the earth rotates…
Pretty much everyone got the memo that the Earth revolves around the Sun, so no widespread myths are being perpetuated by using the terms sunrise and sunset. But a lot of people think that part of the Moon is perpetually dark, a belief promulgated by the continued use of an obsolete terminology.
A similar example for sunrise/sunset is “sound barrier”. The original meaning no longer applies, but the continued use of this phrase in a semantically different context doesn’t seem to perpetuate a myth that supersonic flight is impossible.
JadedObs,
But if more people did that, maybe we could begin to increase the unbelievably low level of scientific literacy and reduce the anti-science bias in this country.
If Pink Floyd is to blame, then all is forgiven.
Just how many angels could dance on the farside again please?
i know you’re being facetious, but that is an interesting question. the surface area of the Moon is 37.9 million square kilometers, and 41% is not visible from Earth. that’s 15.54 million square kilometers – greater than the area of China and India combined. based on their populations, we can say that there could be at least 2.588 billion angels dancing back there.
I would say the answer is presently indeterminate. Angels are metaphysical beings and as such do not have the characteristic of measurable size. However the problem could be solved if we could combine NASA with Pink Floyd.
and combine those two with copious amounts of reefer… i’m sure some conclusion would be reached. 🙂
Using her logic it would be okay to use the term “Dark Continent” in the headline for an article about a recent geological discovery in Africa, as long as somewhere in the article they explain that Africa isn’t really dark.
it’s not logic so much as knowing that the word “Dark” can mean “unknown,” i.e. “Dark Matter”
so assuming the reference is relevant, why not? to use your geology example, the title “New Light Shed on Geographic Formations in the Dark Continent: A Study of East Africa’s Great Rift Valley” sounds pretty poetic to me.
Dark Matter doesn’t interact with photons, so the term means the opposite of light as much or more than it means unknown.
Due to the ongoing confusion in the general public on this topic I think the valid question isn’t why not, but why. Why use the outdated terminology at all. In your example the play on words would at least be a reason to use the antiquated Dark Continent terminology in a headline, unlike the Moon article for which I can find no such reason. Also in my estimation few if any people actually believe that the African continent gets less sunlight than other continents. Whereas we continue to have a large segment of the population who believe that part of the Moon is perpetually dark. The continued use of the out of date phrase is in my opinion the culprit, as I can’t think of anywhere else that people would get such an idea.
Sure the semantics can be argued, that dark doesn’t always refer to the absence of physical light, but that only works when the reader already knows the facts involved. For example if I told a new neighbor that there is a dark street on the far side of our town, they would probably assume that I mean it doesn’t have adequate street lighting, I doubt they would guess that what I really meant was that no one from our neighborhood has been over there yet. So in that case using the term dark is confusing, not enlightening (excuse the pun) and so to get my message across clearly I should probably use different terminology instead of arguing that I am semantically correct.
That being said I am always glad to see articles that do explain the actual facts about sunlight on the Moon, helping to educate the misinformed, and this article does in fact do that, so credit where credit is due. But a lot of people won’t read past the myth perpetuating headline..
you raise some fair points. unfortunately i don’t think that the phrase “the Dark side of the Moon” is going to go away anytime soon, thanks to Pink Floyd (and it occurs to me, that one song from Mulan) but thank you for your comment!
Their research was about the thermal increase in the nearside geology (selenology) due to reflected sunlight from Earth, being the primary cause of the dual-nature of lunar surface features. Hence the farside really is the “dark side”… at least, as Obi Wan would put it… “from a certain point of view”.
Is that why they did it? To play with the idea of that the very-slightly-darker-on-average-side is different from the very-slightly-lighter-on-average-side?
Nope.
Hence the researcher’s idiotic attempt to explain away the stupid headline.
Sounds paternalistic and Euro-centric to me.
this is just an example. you’d want to be careful to not seem that way in a scholarly paper, certainly.
Why not? Because it is UNscientific. it may be “poetic” but in your analogy the article is not in a poetry book. Your example would also be insultingly Eurocentric and should be rejected as a title for any scientific findings related to the rift valley.
does it really matter whether you think it’s “scientific” or not? Since everyone knows it refers to the far side of the Moon, it’s just the author’s choice of phrase. you are taking this way too seriously.
lol, your censure is amusing. my example was just that, an example. i’m not a geology student.
Listen very closely to the end of Pink Floyd’s ” Dark side of the Moon ” album. A strange man’s voice says ” there is no dark side of the Moon. Matter of fact, it’s all dark… “
True. The albedo of moon rocks is only slightly brighter than a lump of coal.
What the dark side of the Moon is to me.
Great music!!!
Can’t you hear it in your head?
http://m.youtube.com/watch?…
Listen
Enjoy!!!!!
24/7/365!
As Carl Sagan noted: “A PhD is not an inoculation against foolishness.”
According to the theory, it was not reflected sunlight which heated the nearside but heat radiated by the earth, still molten, perhaps for centuries, after the massive collision that formed the moon. The differential condensation of aluminum and calcium on the cooler far side is interesting. Then there is the phenomon of impacts punching through the thinner nearside crust but just leaving large craters in the thicker farside crust. In sum, it’s a complex and ingenious theory and I think focusing on the picturesque wording of the headline misses the point. Anyone who reads the article (let alone the paper) will know what it means.
Also when the far side of the Moon is facing the Sun it is almost a half million miles closer to the Sun than the near side is when it is facing the Sun. I would think that this extra direct solar radiation received by the far side would be more than enough to offset the reflected radiation received by the near side.
At least on the moon there aren’t hundreds of millions of people who they’re arrogantly (and bigotedly) considering as not knowing they themselves exist.
All of these continents that were totally barren, unknown and “dark” until Europeans managed to get there – often just about the last to come along, too…
Of course we all know that the good side of the moon faces earth, the center of the known universe and the other side of the moon is evil. That’s why the creator of all things put a smiley face on our side.
Yin and Yang
For the record, the paper itself uses “farside” rather than “dark side.”
http://arxiv.org/abs/1406.2020
Has it been proven that the Earth and Moon were tidally locked when the Earth was still molten and hot enough to heat the Moon? I think this is the main issue here and not the author’s poor choice of words to refer the the far side.
I also emailed her, and revived the same reply, including a dictionary definition of darkest as in darkest Africa! And the assertion that “historically” the usage was normal. I wrote back challenging that, noting that even Cronkite referred to the “far side” during Apollo 8, and asking for actual historical quotes from any scientists or engineers at NASA or elsewhere. No response.
This person apparently has a PhD, but in what? English lit?
well, she’s right. using “Dark” to mean unknown is a correct usage of the word (i.e. Dark Ages, Dark Matter), and even though we’ve known the moon is round (and thus has a far side) since Galileo, and we’ve had images of the far side of the Moon since Luna 3 flew by in 1958, the far side of the moon is still frequently referred to as the Dark side of the Moon, even though it is neither literally nor technically correct. it is a colloquialism that has long been (and still is) in common use.
http://www.grammarphobia.co…
you understood precisely what was meant, and so does the vast majority of everyone who would have read or heard of the paper. there is no reason to harass this woman about her use of a very common phrase.
by the way, going to Google Scholar and typing in “Dark side of the Moon” and constraining the dates to 1957-1975 gets 261 hits, on a range of topics associated with the lunar far side, from crater counts to plasma physics.
Using the Astrophysics Data System (http://www.adsabs.harvard.edu/), you see the earliest usage is on 1822 and refers to the part of the Moon’s face that is dark… not the “far side”. (“On the luminous appearance observed on the dark side of the Moon on February 5, 1821”, pg 157). This practice continues until today (“On the colour of the dark side of the Moon”, Jan 2014) where they still mean the Earth facing part of the Moon that is not illuminated.
Interesting that the phrase may also relate to this study of Earthshine.
however, there are numerous hits that also clearly refer to the Moon’s far side, such as 1967, Diamagnetic Solar-Wind Cavity Discovered behind Moon
Rather a clever play on words. Get a life!
How is it “clever” to use an outdated, confusing expression that was not even used by the scientists involved? Clever might have been to not use it in the title but mention the issue as an aside at the end, or at least put dark in quotes to make it stand out as being a case of special usage.
As is obvious from my other replies, I stand strongly with Keith on this. My point is that Science DOES have rules – you do not get to make things up just because they are “poetic”. Science is not a popularity contest, and authors of articles aimed at a general audience have a responsibility to NOT perpetuate misconception, especially when the term involved (in this case “dark side”) has an agreed SCIENTIFICALLY accepted usage in conflict with the author’s usage. There was nothing to be gained by using the word, especially in the title, and a high risk of confusion. It was thoughtless, and I hope the author will take Keith’s concerns seriously.
1. she didn’t make anything up. “the dark side of the Moon” has referred to the lunar far side for a long time.
http://www.grammarphobia.co…
2. the article does not perpetuate a misconception. the article makes a very clear statement that the far side is not literally dark: “It was called the dark side because it was unknown, not because sunlight does not reach it.”
3. what is this “agreed upon scientifically accepted usage in conflict with the author’s usage” you refer to?
are you sure that it isn’t you who is making things up?
Hug Doug,
1. Not as a scientific term.
2. Then at a minimum it is a waste of space, because if the term was never introduced in the title, it never would have had to be explained.
3. The agreed upon usage is that, when discussing the Moon, “dark side” refers to the (constantly changing) unlit side of the Moon facing away from the sun. The fact that there are lunar days and nights that cause huge temperature changes at the surface is important. There was no need and no gain in knowledge or clarity from this obfuscatory verbage. It was an unnecessary distraction from an otherwise interesting summary of scientific research.
1. so now you say that “Dark side of the Moon” isn’t a scientific term? you claimed it was, earlier.
2. i’m sure that’s debatable. as the title of an article of an article on the internet, i think it’s just fine. the title of the paper itself does not use the phrase.
3. then why is nearly every single use i can find to “Dark side of the Moon” referring to the lunar far side? there are very, very few references which use it when referring to the night side of the moon. perhaps you can link me to some scientific lexicons which use the phrase in this way.
there ARE a few papers that use when referring to the study of Earthshine, in the context you suppose the phrase is meant to be, but they are very few.
also, the only article i’ve found complaining about the use of the phrase is this one, by the way. there are a dozen or so other articles writing about this research, and none have brought this up. i guess everyone else felt the meaning was understood, and not distracting.
you really don’t have a leg to stand on here. the common usage of the phrase is quite clear – it is predominantly used as a reference to the far side of the Moon.
1. You seem to deliberately misrepresent what I said. The clear
meaning was that “dark side” is NOT the scientific term for the far
side. It is the (or one of, or the scientifically defensible) term for
the un-sunlit side of the Moon at any given time. No contradictiction
and no need to add additional contention to the main issue.
2. As you point out, the title of the original paper does NOT use the term, so why would this author? To prove to everyone that she knows the dark side is not really dark? I would applaud what she did if the paper’s authors had used the term and this popularizer also used it in the title, then went the extra mile and clarified what the actual facts are. THAT would have made perfect sense.
3. There are not many cases where “dark side” is strictly needed as other terms such as “lunar night” are used and I would speculate that one possible reason is that people would misinterpret it as Far side so it is avoided. I would contend that “nearly every single use” proves our point. Most mass media don’t care about sloppy terminology. I think all Keith was saying is that we should care a bit more and encourage those with access to a broader audience to think carefully, especially when it comes to headlines or article titles.
1. if “the Dark side of the Moon” is meant to refer to the un-lit portion of the Moon, then why is it rarely used in that context?
2. it’s an internet article. the author decided to use a very well known (and often used) colloquial phrase referring to the lunar far side, because the paper is about the formation of the highlands on the far side of the Moon.
the article did clarify what the facts are. it makes a very clear statement that the far side is not literally dark: “It was called the dark side because it was unknown, not because sunlight does not reach it.”
3. Keith pretended to not understand what “the Dark side of the Moon” meant. i’ve been complaining about that bit of intellectual dishonesty more than anything else.
Spacex delayed another couple days, but the good news is that the launch should now happen in daylight. Maybe they will get some cool close up first stage soft landing video, which will motivate others to do more creative stuff, which will make it possible for some people, to affordability fly around the moon in the near future, enjoying both sides.
“Outdated” was used to counter the contention that “Dark” was being
used in one of its legitimate senses as in unknown. While this usage
may have been acceptable prior to the Space Age, this is no longer the
case, so by analogy if we cannot use “Darkest Africa” to reference
today’s Africa it would be outdated to use “Dark side” to reference
today’s far side. As to the what people knew when about the actual relation of Earth Moon and Sun, I cannot say. But you may be missing my point – the fact that it is (as you say) a contemporary figure of speech is precisely the problem. It should NOT be one based on both the Science >>the far side is not always or preferentially dark<< or in the sense of “unknown” because of technology such as LRO & GRAIL etc and theories precisely like this paper presents that make the far side less “dark” every year.
maybe it shouldn’t be used, but the popularity of the phrase, and its perpetuation thanks to the Pink Floyd album and the song from Mulan, we’re going to be stuck with “the Dark side of the Moon” for a long time.