I fell yesterday. Caught my toe on the narrow stump of a shrub that had been pruned from the trail. Nature is persistent. You can’t keep a good plant down. I, on the other hand, have a balance point too high to tolerate a disruption so low.

Reflexively, I dove, splayed my arms, tried to get a saving foot down and failed. Left palm on sharp rock. That’s going to bruise. Chest to ground, a small bounce, like sliding head first into second, and then up on all fours as if to bounce back to vertical. No dice. It took me a minute, crouched there, to get things to settle.

Gravity is a force. This much we can say. We can describe what it does. We can even perform it, mid-stride, a small body drawn powerfully to a much larger one. But we don’t know what it is. I didn’t even know that I didn’t know, until I asked myself the question, “What is gravity?”

It’s always like this on the trail, the subtle dance with balance. It doesn’t matter whether I’m running, riding, skiing, or hiking. Gravity is there to make its point. The ups are hard. The downs are managed chaos.

With electromagnetism we can describe the mechanism. Positively charged particles drawing their opposites, combining, moving toward inertia. With gravity we don’t know. What is the interaction? What is the medium, between the Earth and the Moon, between me and the ground? We know there is a call and response, but we don’t know the language.

I’m a humanities man myself. All words and abstractions. But I have a hard crush on science, so I read dilettante-ishly. This guy. And this guy. And this guy, of course. I’m not getting anywhere, except to understand more thoroughly how little I know.

By the end of the day, my left leg had started to ache, one of those deep aches hard to discern between muscle and bone. Gravity precipitated. Under my skin, electromagnetics taking over, blood breaching its capillaries, flooding muscle, occupying spaces it was never meant to. At bed time I pulled back the sheets and rolled in, my left leg suddenly searing my brain with frantic messages.

Don’t. Fucking. Move.

I cried out and swore. The pain subsided, and I wondered at the way the gravitational echo had made it from my morning run to bedtime in this way, all of it inherent in that nano-moment my toe caught the woody stub of a plant climbing, against the grain, toward the sun, defying gravity to stay alive.