A Curve, Not a Line

The oldest version of the symbol does not look like the one on the pendant. When a philosopher named Zhou Dunyi drew it about a thousand years ago, the circle of yin and yang was a set of rings inside rings, dark and light in bands. It took five more centuries, and a scholar named Lai Zhide, to simplify it into the figure everyone knows now: two shapes that lock together, meeting along one curve.

That curve is the whole point. The halves do not meet at a straight line, a border, a wall with light on one side and dark on the other. They meet in an S. Each half swells to its widest exactly where the other one is just beginning, and shrinks to nothing exactly where the other one is full. Put your finger on the symbol and turn it, and you can feel what it is a picture of. Not two things. One thing, turning.

Where the dark is widest

People like to say the symbol came from a year of shadows, from marking the length of a stick's shadow at noon every day until the marks drew the figure on their own. No one has found an old book that says so. But a physicist in Zurich recently showed that if you draw the hours of daylight through a year, you do get the shape, near enough. Whether or not the ancients drew it that way, the figure is a fair map of a year.

And here is what the map shows. The dark half is at its widest in midwinter. On the shortest day of the year, the light is a thin sliver. But that is also the exact day the days start getting longer again. The dark is at its fullest at the very moment the turn has already begun, and from inside the dark, you cannot tell.

The fullest dark is where the turn begins.

Now think about your own shortest day

Set the symbol down and think about the lowest point of a hard season you have already come through. Not the one you are in. One that is over.

Maybe it was a night you sat on the kitchen floor. A morning you could not get out of the car in the parking lot at work. The week you stopped answering texts. At the time, it felt like the bottom, and it felt permanent, and if someone had told you that the turn had already started, you would have wanted to throw something at them.

But look back at it now, from here. Was that not, in fact, the turn? The night on the floor was the night before you finally asked for help. The week of silence was the week something in you decided. You could not see it then. Nobody can see it from inside the widest dark. That is not a failure of yours. It is just how the curve works.

We want our seasons to have borders. A date when the grief ends. A morning when the hard job becomes the good one. A line we can stand on and say, that was then, this is now. The curve says there is no such line. The next season does not begin when this one ends. It begins inside this one, as a sliver, while this one is still at its widest. By the time you notice it, it has been growing for a while.

This cuts both ways, and it should. The bright season carries its own thin sliver of coming dark from its first day. That is not a reason for dread. It is just the shape of the thing. Nothing in a life has a straight edge.

There is a yin yang cut as an open spiral in silver that keeps the curve and leaves out the fill, which is the part worth wearing: the turning, with nothing else.

The midwinter rule

A practice for the widest dark. On the day a thing feels most complete, most settled in its gloom, say the midwinter sentence out loud: the days are getting longer. You will not feel it. Say it anyway. The symbol says it is true whether or not you feel it. You are standing on the shortest day, and the shortest day is a turning point by definition.

And inside each half of the figure, there is one more small thing to find: the dot in the dark. This is one of a series of short essays on the yin yang. The rest are gathered here.

Somewhere tonight is the longest night of a year, and the morning after it will be a few seconds longer than the one before.