Twenty-three years of my life, I have not understood the meaning of centrifugal. I am not positive but pretty confident that I did understand it for two years (16-18) during high school physics. But now I rely on wikipedia to remind me every time it comes up, every time centripetal and centrifugal swing close enough together that I must verify the difference. I don’t know why I can’t keep them apart. They are companion forces, two aspects of the same thing.  Two sides of the same sheet. I can remember convex and concave.

I had only heard the word until high school. Centrifutal: like when you swing a bucket full of water all the way around you and nothing falls out. It’s not a miracle when you’re a child. Plus, there are other dangerous things like the weight of the bucket and whether an arm can or cannot swing all the way around. I try to get my mom to use the word in conversation so that I can figure out whether I learned centripetal or centrifugal first. It isn’t hard. My mother is rugged and fastidious, a well-spring of knowledge on forces and willing to use the words in sentences. “Centripetal,” she says, “or, is it centrifugal? Are those both words?” During those two years of knowing, I must have destabilized her, too.

I try to remember by attaching them to convex and concave. I picture the inside of a spoon. I picture a spinning propeller. But instead of helping, it just weakens my grip on the two I knew. It’s all funhouse mirrors on merry-go-rounds.

I might not remember what they’re called but I understand how they work. I can draw you diagrams of the forces. I can do small calculations that are useless in my daily life and uninteresting as conversation because I do not have the right names. Formulas are nothing, in stories, without names.

Centrifutal: like when, upon waking to a terrifying noise, you throw your whole body over the person next to you, to protect them, because that’s so deep in you.

The fireworks were over by the time we went up to the roof, in Brooklyn. Smaller, private shows were going off around us in Clinton Hill and Crown Heights.  I felt briefly guilty that we had lured friends over with false promises of pyrotechnics but was secretly relieved at the quiet. Every time someone set off fireworks on Franklin, T would point and call them my cousins.  I don’t have any cousins in Brooklyn. I stayed away from the edge and once in a while tried to count how many people I knew. It was quiet.

KY explained his Silly Bandz to someone else. “This one’s a camel,” he told her, “but I can’t give it away.” He looked up at me, without pulling the day-glo band from around his wrist to demonstrate that it would snap back into the shape of a Bactrian. It was too dark to see any faces. “You can give it away,” I told him, because I had given it to him. I was probably the only sober person up there, but suddenly we were all atop a tottering plate. “I won’t,” he said, because he was going to keep it. The roof shuddered on its axis and dipped violently to the right, flipped all the way over. I was the only one to nearly lose my footing in the imperceptible flip. The rest were left unscathed atop the saucer.

In a tent full of animals at the Nassau County Fair, the camel is swaying. There are goats and sheep and cows, baby buffalo, and steer. They’re all eating or sleeping or pressing their heads through bars to get a little attention. But the camel is shifting dramatically from side to side. Over the P.A. system Katy Perry’s “I kissed a girl” competes with a reminder that the fair will end in thirty minutes. It’s almost the middle of the night on Long Island. The camel shifts its weight as if to settle  in, but then heaves itself upward and over. It rocks around again, nose up, head nearly brushing the roof. It looks like it’s keeping time, but it isn’t dancing.

Weekly, daily, hourly we are flung outward and pull in. We fly off in what seem like lines but turn out to be arcs.  We are kept in motion. We are returned to each other. I’m sure I don’t know how this works– but I do know what to call it.