The Moon is a Harsh Mistress

I guess I shouldn’t have been so surprised. After all, it was an experience I had in college that helped fix in my mind the phases of the moon. But I’ll come back to that.

To recap, I wrote:

In a recent National Education Association publication they state,

Not everyone agrees that multiple-choice is the biggest problem. H. D. Hoover, principal author of the Iowa Test of Basic Skills for 40 years (and recently retired), thinks they can be every bit as thought-provoking as open-ended questions.

Case in point:

The full moon rises at midnight…
a. always b. usually c. rarely d. never

That question stumps a lot of adults — and it’s too tough to put on a state test. Figuring it out depends on really understanding why the moon has phases, and then applying that understanding — not bad for a 10-word item.

It amazes me that that is not simply a recollection of fact. And I wondered, do you know the answer to that question? If not, could you figure it out? [No fair looking it up.] I know the answer and I happen to know why as well. But I’m not normal….

First a couple digressions: I remember seeing a really bad werewolf movie on late-night TV several years ago. A group of people were stranded on an island with the creature and were attacked during the full moon… five nights in a row! Now, I can suspend disbelief about the existence of werewolves, but on this planet we will never have a full moon five (or even two) nights in a row. But it was set on a tropical island and there were girls in bikinis so I didn’t turn it off right away….

I have heard that Cat Stevens (now Yusuf Islam) wrote the song Moonshadow after he visited a small town in Spain. He had lived in cities like London where the lights of the city outshined the stars and the moon. He had never seen the moon cast a shadow. [I haven’t found independent verification of that story though, so it’s possible I misunderstood or was misinformed. Still, it’s a good story….] And with that type of light pollution being so pervasive not just in our cities but increasingly in our suburbs, I suppose that most of us never really get to see moon rises on a regular basis or appreciate the brilliance of a full moon. Unless you are a farmer or frequent hunter, fisher, camper, etc. you probably are ignorant of the moon’s regular passage.

One spring break when I was in college a group of us spent the week in Florida. We spent the first few days camping on a small island in the Keys. One night we sat on the beach and watched the sun set over the water. Actually, we did that several nights that week, but on this particular night one of my friends jumped up and said, “It’s a full moon tonight and it’s going to come up right over there,” pointing behind us. And we walked a short distance (it’s a very small island), sat on the beach, and watched the moon rise over the water…. Really cool.

As a result of that and a few other experiences I have no trouble remembering a few simple facts about the phases of the moon. Even if you don’t understand why this happens, it’s not hard to remember what happens very regularly.

  1. The full moon rises at sunset, passes its highest point in the sky in the middle of the night, and sets at sunrise.
  2. There is about one week between each of the four phases.
  3. The moon rises and sets about an hour later each day.
  4. It takes about 29.5 days for it’s cycle to repeat.

The first of those is all one needs to know to answer the question and it is a simple fact, not something one needs to “figure out.” I wonder if anyone fully understands why we see full moons regularly [if we’re looking] (and thus could figure out the answer to the question) without knowing that fact? On the other hand, even without knowing why the moon phases occur, one could use those facts to figure out that:

  1. The new moon rises at sunrise and sets at sunset.
  2. The first quarter moon rises in the middle of the day and sets in the middle of the night.
  3. The third quarter moon rises in the middle of the night and sets in the middle of the day.

All of which are also true. [It’s good to know that my insomnia is good for something.] Although you might not be able to figure out why we call it a quarter moon when we see half of it lit up. And we haven’t even got to what the heck a waning gibbous is yet….


  1. I always had a hard time with multiple choice questions because I could oftentimes rationally explain two or more of the answers, depending on how the question is interpreted/meant.

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