"It was a dark evening with only the feeble light of a waning crescent moon." How much basic astronomy is widely understood by those not specifically interested in the subject?

In My Humble Opinion
101

Yeah, the stars aren’t always out, and there’s not always a good view of them (especially not in the city), but given that I was, at the time, whiling away some time by watching them, clearly, at that moment, they were visible. Which the folks who asked me could have determined themselves by just looking up.

I’ve also impressed folks by stepping outside into a light rain (while the sun was shining), and saying “Ah, there ought to be a rainbow right around <step around corner of building and pointing> THERE.” Though that one, I can understand folks not knowing: Rainbows are rare enough that most folks don’t have all that much experience with them (much less experience than seeing the Moon), and many common explanations for how rainbows work are seriously lacking.

Oh, and I’ll say this for the example in the OP: Regardless of whether it works scientifically, it does work poetically. “Things are dark and grim right now, and they’re only going to get darker”, it says.

102

Thanks to Willy Ley’s science books for kids in the 1950s I got an introduction to space and the stuff that fills it up. Thanks to urban light pollution and an inability to recognize any constellation except for the Big Dipper and Orion’s Belt, I soon lost interest in it. I know what waxing and waning and crescent mean, but I have no concept that a waning crescent doesn’t rise until close to dawn.

103

Apparently, the word ‘gibbous’ means ‘humped’.

In another thread we discussed the use of this word by H. P. Lovecraft, and someone wondered if he was confusing it with ‘gibbering’. I’m not so sure; describing an eldritch monster as ‘humped’ seems somewhat apt (depending on just how deformed it is).

104

Just remembered. As a kid I wondered why it was called a quarter moon when obviously half of it was lit. I still remember the epiphany when I realized it meant a quarter of the monthly cycle.

105

I’m not sure it’s all that. I’m a photographer. I understanding lighting much better than the average person. I know where the light source is when I look at the moon. But with the earth rotating, the moon orbiting the earth, and all that, I can’t visualize how that relates as to where in the sky a certain phase of the moon should be at what time. I’d need to see a video to get a better idea, or a demonstration with a physical model.

106

I have no memory of studying this in elementary school nor did we cover it in any of my high school classes. I didn’t take any astronomy classes in college. I know the obvious things that most of the population would know, but I learned more just reading this thread than I ever had taught to me. But ultimately will I remember all the detail? Some, sure, but it’s not especially an interest of mine so I’ll probably forget most. I don’t know that a more than superficial knowledge of astronomy is all that critical.

107

Guess I’ll chime in – I like astronomy and know a fair amount. I could tell you the new moon rises/sets about the same time as the sun (hence can cause solar eclipses) and that a full moon is about opposite of the sun (hence lunar eclipses), but I couldn’t immediately tell you if a waning crescent rises ahead or behind the sun. I could probably figure out that it is soon after/before because it is closer to new, but it would take me a while.(would not be instant)

Brian

108

Just so you know, there’s a whole bunch of people who feel about you and your knowledge the same way that you feel about “car freaks” and their knowledge.

And by the way, there’s a reason why people specialize in things–to wit, there’s a very great deal of knowledge floating around; too much for any one person to learn about. What’s “obvious” to the specialist is anything but to the generalist.

109

I didn’t pay much attention until I built a telescope a few years ago. I look at the moon quite often.

Waxing crescent moon:
Imgur

110

The following is a screen shot from this video which explains the waxing and waning moons really well.

I like this diagram because it better shows what the moon actually looks in relationship to the Sun and Earth.

For a waning crescent moon “A” in the diagram, it could theoretically be seen from Earth anywhere from position “B” to position “C”. IOW, as the Earth rotates, the waning crescent moon comes into view for an observer in B, and remains in view until the Earth rotates past D.

However, because of the sunlight, the moon can’t be seen as the sky gets lighter and lighter. That is shown as “D”.

For an observer in the northern hemisphere, the moon will look at it does in the picture above, with the bright portion to the observer’s left, which is closer to the Sun, but for an observer in the southern hemisphere, it will be reversed and the

It’s easier for me to picture people standing on the poles and looking out, because it’s a horizontal direction.

From the diagram, you can see that waxing moons can never been seen in the morning and waning moons can never been seen in the evening. You would be on the wrong side of the Earth.

Back in the pre-cell phone days, I had a chance to be waiting on a mostly deserted train platform every night for a couple of nights and out of sheer boredom and a minimal amount of curiosity, started to think more and more about the phases of the moons and why they looked that way to me.

From there, it went on to how they would look in other places on Earth, including the poles and the equator, and when you could or couldn’t see particular phases at given times.

I’d never think that much now, because I’d just be glued to my phone now.

111

All these mnemonics! In the northern hemisphere, the moon’s terminator moves from right to left, or west to east.

On a related note, a friend of mine has made it almost to retirement age without knowing the order of the colours on the spectrum. That surprised me.

112

Thank you I will check that out.

113

Let me know if you have any further questions!

114

that should have been:

I had a chance to be waiting on a mostly deserted train platform every night for a couple of months and . . . .

115

Especially since his name was Roy G. Biv.

116

I like to think that I have a good grasp of the geometry of lunar illumination, but there is one effect that blows my mind.
This photo shows the Moon a few moments after sunset, and yet the illuminated face of the Moon points upwards (towards the Sun, which is now below the horizon).
How can this be? Surely the Moon should be pointing downwards?

Hint: it has to do with Great Circles.

117

At first I thought you were referring to the order of the cycle (i.e., the waning moon comes before the waxing moon), which didn’t make much sense to me, since it’s, you know, a cycle. Then I realized you were relating the C and D shapes to the alphabetical order of the words “waning” and “waxing.” D’oh!

The mnemonic I learned for the phases (whence, I know not) is DOC, where O means the full moon. IOW, if the moon looks like a D it is waxing toward full, and if C, waning toward new. (This is for the Northern Hemisphere, of course. The Southern has the more memorable COD.)

As far as literary errors the OP is asking about, in The Wind in the Willows, I believe in the chapter “The Piper at the Gates of Dawn,” the moon rises some time after sunset, but then sets before sunrise. I started wondering about this the last time I read the book, a few years ago, and although I’m still 90% sure it’s impossible, I was wondering whether there might not be some times of year and some places, perhaps in higher lattitudes, where it could happen.

Anyone?

Of course, since this whole chapter has a supernatural dreamlike quality, this “error” could be excused as another indication of that unreal state. Was that intentional on Grahame’s part? Who knows.

118

“King Solomon’s Mines” by H. Rider Haggard has a full moon night and then a total eclipse of the sun the next day. :face_with_raised_eyebrow:

119

This is one of those things that is best shown with a physical model (or somewhat less preferably a good 3D video.) It’s often a lightbulb moment.

120

Also between the tropics too, right? At certain times of year, the midday sun may be to the north of you in the northern hemisphere, for instance.