Pendulums in the Sky with Diamonds

“Leave them alone and they’ll come home, wagging their tails behind them.”
–From the writings of 16th century shepherdess, Little Bo Peep.

This morning, I was about to use the sound of the pendulum’s ticks and tocks, out in the living room, as a focus around which to center my attention, when I realized that the house was silent. I got up and saw that the minute hand was stuck under the more slow-moving hour hand—like a hare trying to pass a tortoise in gym class and getting wedged between the tortoise’s shell and the gymnasium wall—and I immediately knew the reason. This happened about a year ago when the pin fell out of the hub that holds both hands upright on their own trajectories around the clock face. Sure enough the hole for the pin was empty. When I couldn’t see where the pin had fallen, I clipped off the bristle portion of a little brush I use to clean the gaps between my teeth and it fit perfectly. I’ll confess that I felt on top of my game to have solved the issue so smartly.

It was a full moon a few days ago, speaking of that other pendulum, the one that keeps swinging across the sky every day. And this morning, doing some exercises in the sunroom, I noticed the round face of the moon, glancing through the mulberry branches behind our house, now in a different position in the sky than earlier in the week.

An hour later, picking up the newspaper off the driveway, I had a clear view of the moon above the tree tops and, as I stood there with the paper in my hand, I tried to relate its current position to its position earlier that morning and earlier in the week.

It took me a few minutes to sort out the moon’s two drifts in space: one in which the moon, along with all celestial objects, appears to rise over the eastern horizon, cross the heavens toward the west and then fall off the western horizon. That drift is clear enough for anyone living after Copernicus, who gave us the heliocentric view of the solar system, which accounts for how everything visible in the sky—sun, moon, stars—appears to rise in the east and set in the west, as due to the earth spinning on its axis toward the east.

But there is another drift discernable in the moon’s path across the sky. That drift shows up if you observe the moon’s position one day and then its position the next day at the same time. Then it is clear that the moon is moving steadily eastward day by day.

Why is the moon moving in an easterly direction, seemingly against the flow of everything else in the heavens?

Thank you for asking. I was beginning to worry that I was talking to myself.

I first worked this out in my mind a few decades ago, riding in the back of an open truck travelling in the Andes mountains in Peru, where the sky was achingly present in the gaps between the towering peaks that seemed to be raking the very heavens.

The moon moves about an hour each day in an easterly direction across the sky because it is being influenced by the gravitational pull of Earth’s daily rotation. It’s as if gravitational feathers extend 200,000 miles out into space, gently nudging the moon eastward, in the direction those feathers are passing by as Earth rotates beneath.

Somehow those gigantic gravitational feathers have become quite palpable for me, as if I can sense them in the sky. They’re almost as convincing as the images that tell me time is moving in a straight line from past to future; or that space is full of solid objects that exist whether I notice them or not. It’s just another theory to organize experience.

And what about the miniature tooth brush that I inserted to keep the hour and minute hands travelling in their own lanes? Isn’t that clock also a mechanism which measures time–like the metronomes of sun and moon circling the face of days and years–albeit more local and definitely more fallible?

Something occurred to me this morning, which probably has more to do with space than time, although the two are always related in deep, unaccountable ways. It occurred to me that the pin must have fallen inside the closed glass-fronted cabinet in which the pendulum tirelessly swings back and forth for seven days at a stretch, until I wind it again on Wednesdays. And since the two hands had only become tangled in one another’s legs that very morning, at 5:27 to be exact, as the minute hand was trying to pass the hour hand on the inside lane, the pin probably slipped out not long before then, when the glass front would have still been closed. So why hadn’t I seen it?

I think my problem was one of scale. I had looked under the pendulum but then quickly started looking in the area around the clock, as if I thought that the pin might have slipped outside the glass door, even though the clock cabinet had been closed all week.

I realized then that I hadn’t looked for it inside the cabinet as carefully as I could have. So I got a flashlight and began looking in all the little crevices, such as the little ledge beneath the glass pane in the door. But I still didn’t see it. And I was about to close the door when I saw a tiny glint beneath the edge of the key I use to wind the clock, lying on the floor of the clock cabinet. Lifting up the key, there was the pin!

As with Little Bo Peep’s lost sheep, it isn’t enough to race around looking for something that is missing. Sometimes you have to be patiently waiting at home when they appear over the horizon of the neighboring fields. If you are off searching far and wide, you’ll probably miss them when they come back, bleating and baaing. After all–the Big Bang Theory and the expanding universe theory notwithstanding–most wanderers, such as the moon circling the earth, stay close to their own neighborhoods.

It’s relatively rare for anything or anyone to take a long trip without considerable forewarning and planning; although, as with a loved one’s sudden death, it can happen.