At the jetty I became entirely irrelevant, and the result was even more exhilarating. Smithson, when searching for a framework with which to explore both limits and limitlessness, found useful the concept of entropy, i.e., the second law of thermodynamics. Entropy proved intriguing to him because, as he understood it, energy was ‘‘more easily lost than obtained’’ and thus, ‘‘in the ultimate future the whole universe will burn out and be transformed into an all-encompassing sameness.’’ I experienced that ultimate future. I experienced what the planet would be like when we were, every one of us, gone. I had, before our visit, worried not only about my crows but also about the loneliness of a planet that might someday have no one to see it, walk through it, feel intense things because of it. That is what made my brain and my heart fold in on themselves. Cities, yes, gone; ice caps, gone; but the beauty of the planet routed through a human consciousness, that’s what I couldn’t comprehend vanishing. This was what, more than my own particular death, I’d despaired at. But on the jetty, I understood what Smithson intuited so long ago in Rome: Beauty did not need us.

‘‘You don’t have to have existence to exist,’’ Smithson said.

If there were a sun, it would have been setting. As the sky grew subtly pinker and purpler, other cars appeared: two families, a lone woman and a couple. Some walked the jetty, but others struck out directly for the invisible horizon and soon became tiny black marks floating in the middle of the same-color distance. The young couple stood on the flats and hugged and kissed. The lone woman neatened the jetty; she found errant rocks and threw them back within the boundaries, redarkening its outline.

Back in the parking lot, as the rain finally started (it had been threatening), we talked to some of these people. All of them were longtime residents in the area. The jetty-neatener said: ‘‘I’ve never been here before. Today just felt like the day.’’

A man told us that in the summer the lake looked like the Arctic, because the sun hardened the salt flats into a pink ‘‘ice’’ crust. Another man told us about the speed races over the salt flats, the time records that had recently been broken because, as already established, time worked differently out here; objects could exist in relation to time differently.

The rain grew heavier. Everyone wished everyone else luck getting home. ‘‘Last week there was snow on all these peaks,’’ one man said, gesturing to the many mountains in the near and far distance. His implication: that snow was water now, and it was heading our way.

At dusk the cows were frisky. By the time we reached the river, its flow had more than doubled in width and intensity. Should we get stuck, no one would have been able to exit the car. A person would have been swept away. In Maine I’d learned to wait: wait until the wind dies or the tide recedes. Hang out until the situation improves. But I had no idea if this situation would improve. Maybe this, right now, was the best the situation would ever be. We took our chances. We entered the water and sank above the bottom of the doors. The current rocked the car. We pushed steadily through the churn and up the eroding bank on the other side.