So I recently mentioned that there isn't a dark side of the moon and that Neil DeGrasse Tyson has spent a good amount of wasted time explaining this whereupon I received the following email from a listener by the name of "Matt":
"That's twice now that I've heard you attempt to fool your listeners by saying that there is no such thing as the dark side of the moon. As such, I can no longer bite my tongue on this one.Do you think the Earth is flat or something?If there is no dark side of the Moon, then please, let the listeners know what the side of the moon that faces away from the sun is called. Also, please explain what that big black part of the moon that we see in front of the sun that we see during a solar eclipse is called.I guess you've never heard of the equivalent thing that happens on Earth called, "night" - a time when the dark side of the Earth is experienced?Other than this, my son (16) and I always enjoy your show. Keep up the good work!"
I responded to Matt with the following video and asked him to please watch it.
(please click the "READ MORE" button after the intrusive ad.)
I then followed up with another email that read:
"Do you have a dark side of you? All sides of you receive light with the exception of when you cast a shadow. All sides of the moon receive light from the sun which is why there are different phases, a shadow is being cast upon it. There is no dark side."
Mr. Matt responded with the following diatribe:
I think you are confusing those who think that the opposite side of the Moon from the one that faces the Earth is somehow perpetually dark with those of us who understand that there is a difference between the "dark side of the Moon" and the "opposite side of the Moon".
I've listened to that whole album. Hundreds of times. Front to back. Back to front (yes... looking for backwards masking). Sober. Not sober. Altered. With the Wizard of Oz. You name it... Just like certainly most every kid I went to school with at the time, I know every word, ever chord, and every drum beat to that whole album. I've even seen every color that one could possibly imagine (and several that one cannot fathom) emanate from my speakers playing that album. Never did I hear Pink Floyd try to make us believe that the dark side of the Moon was always the same side of the moon, or that it was the side of the moon we cannot see from the Earth.
There are indeed people who think the opposite side of the moon is perpetually dark. Those people are just as incorrect as those who think there is no dark side of the Moon, and that the Earth is flat.Do I have a dark side to me? Yes. For instance, right now, the soles of my feet are certainly "dark". My armpits too. And my legpits (legpits are a real thing, right?) and a few other places that I will not bother mentioning. But to keep it more congruent with our discussion, I will, by very definition, have a "dark side" to me when I'm not fully illuminated on all sides. But I can be in a situation where I do not have a dark side as well. This is possible because unlike the Moon, I am an Earthly body, not limited to only that lighting which comes from the Sun. As such, I can put four or more lights all around me arranged as in the points or surfaces of a three-sided pyramid. Why four? Less than four point-source-lights will by very definition cause there to be shadows, however minuscule, where the light is at an angle greater than 90 degrees from my surface. Imagining that I have no hidden crevasses or cavities such as what I mentioned, and being lit on every side, I will have no "dark side" to me. Without at least three humongous flashlights strategically arranged and magically hanging out in space, the Moon cannot be lit in this manner. For the sake of discussion, we're discounting "Earth shine"; the same thing as "Moon shine" except on the Moon instead of the Earth.Now, if we're talking about a "dark side" to me in a metaphorical sense, then I have no comment ;)Again, yes there is a, "dark side of the Moon." If there were no "dark side" then there would be no phases of the Moon, because by very definition, if there is no "dark side" then all sides would be "light", making Earth's moon appear perpetually "full". As I wrote before, that dark side is always going to be the side which is facing away from the Sun. Just like the dark side of the Earth; the side which is facing away from the Sun, causing what we refer to as, "night". Just like the dark side of every single other planet, asteroid, comet, or otherwise three-dimensional object that is in this solar system. In fact, the Moon has the special ability of (during a total lunar eclipse) having all sides being the "dark" side by very definition. During this time (most commonly referred to as a blood Moon) no part of the Moon will be in direct sunlight; the Moon only being lit indirectly by the Earth's Umbra or shadow.
That being said, the term "dark" is very much a relative term. There is always at least starlight shining on the Moon's dark side, even when the Moon is on the exact opposite side of the Earth. But we're not discussing such minutia. We're discussing the fact that every object in the solar system is mainly lit by what can be considered a "point source" of light coming from one direction; the Sun. As such, by very definition, any three-dimensional object will have a sun-illuminated (light) side and a not-sun-illuminated (dark) side at any given moment. That side might not always be at the same point (there is no tidally-locked planetoid in our solar system to the sun) but it is certainly still a "side", and it is certainly still "dark". Interestingly enough, other solar systems in our galaxy (and most certainly the universe) do indeed have a planet that is tidally locked to it's star, and not only is it's "dark side" dark, but it is always the exact same side of that planet. Even more interesting, scientists think that a tidally locked planet could be an ideal destination to seek if we ever have to "abandon ship" so to speak.But then again, I'm only an amateur astronomer of 40 years' experience. And this DeGrasse guy is only an entertainer who probably has some degree to some college; proof that just because one has a degree doesn't mean one knows what one is talking about. For instance, Stephen Hawking's claims that global warming is man-made and that the surface of the Earth will be just like Venus in a couple of years is a case in point, but (God bless his soul) I digress... If DeGrasse is trying to say that there is no dark side of the moon, when one only has to look up into the sky and see it on any day (or night) that the moon is not full (Oh, lookie there... the Sun is at an angle to the Moon from our vantage point, and it's lighting up the side of the Moon that is facing the Sun, while the side that is not being exposed to the Sun is indeed dark!), then he's just as full of it as those flat Earthers. As such, thanks, but I'm not going to waste my time watching that video; he probably even believes the Earth is flat. Sorry.
Hope this helps, and thanks for the "conversation!" I always enjoy doing public outreach when it comes to astronomy :)
I responded with:
"If you are willing to ignore an astrophysicist on this subject that you choose to argue, I am not willing to entertain your misguided mind in any further way. I am not going to argue a fact that I know because you have a philosophical stance on the subject. Saying the earth if flat does not make it so anymore than saying that there is a dark side of the moon makes it a fact. You might find Grimm Fairytales to be quite entertaining."
And Matt responded with:
By very definition, there is no arguing a "fact", so I'm not sure where you got the idea that I'm doing that. It is not my "philosophy". And if you so chose to ignore that fact, then neither I as an amateur scientist, nor even anyone else as a professional scientist will be able to help you understand. Just try not to forget what the true difference between an amateur and a professional is. That being said, if my amateur illustration doesn't make it clear that there is a light and dark side of the moon, far be it from me to help you stop making a fool of yourself on the radio. In fact, it was quite a popular discussion at the last Raleigh Astronomy Club meeting. We certainly appreciated the entertainment and the topic of discussion. It led to a couple of fun anecdotal stories that some of the members had about things they heard grade-schoolers say at outreach programs.
Saying that there is no "dark side of the moon" when clearly anyone with sight can see with their own eyes that there is, but instead saying that just because an astrophysicist mistakenly thinks there is no "dark side of the moon" makes it so clearly proves from where you think, and proves that indeed, as you say, there is no use for further discussion.As far as "professional" goes, good luck with your employer's bankruptcy proceedings. I know lots of good people are on edge due to it, but of course, a professional can never be wrong about something, so it will all be okay. Right?"
WOW! Ah, I see what you did there Matt, when all else fails, attempt to insult the person's job. Neil DeGrasse Tyson wouldn't need to do such a thing to impose his authority on this subject matter as he is an authority through his education and time in the field. By your own admission your are an amateur. I find it very hard to believe that in Raleigh there is a group of people who are entertained by Tyson's findings and laugh about them. What world did I wake up to? Google "Is there a Dark Side of the Moon" and you will see countless articles about how there isn't one, and I'm supposed to believe a stranger who listens to me on the radio who I don't know from Adam? Really? *sigh* I think I'll stick with the professionals.