I have traveled to the ocean off and on all my life. Whether to Jones Beach while visiting my grandparents on Long Island, or Popham Beach in Maine with my immediate family, later on my own—the beach—the ocean really—has had a call for me. Whenever I visited, I would be in the waves for hours, even when the water was frigid. I would exit with chattering teeth—b-b-b-b-b-ut I’m not cold, Mom.

When I was 11, I started sailing with my father. We took lessons together and practiced on a lake. He kept a boat on the Chesapeake Bay, which was rarely choppy. In my thirties, I joined him on the ocean—home again.

Now I live near the mountains, far enough from the ocean that my friends worry I will miss it. How can you move so far away—from minutes to hours—from the breaking waves? I know a secret. I haven’t. I live in the shadow of ancient waves.

The crust of the earth floats slowly, steadily on the surface of the planet. Mountains are sudden swells where the crust crashes into crust, lifting like three mile high following seas. The break is not here or there—the way you know where and when waves break best along a beach—it rises across hundreds of miles all at once, rapidly—in geological time—and subsiding only when erosion carries the soil and rocks back down the swell—the same way the foam at the crest of a wave slides away to one side or the other of the watery passenger.

How can you tell? Nothing is moving? The earth is solid. It seems that way, yes. Yet in time, over time, over more time than humans can recognize with their eyes and ears and hands built for moments on the savanna—the world is more fluid than solid, and it races. Deep time, geologists call it.

Deep time? Not thousands of years—a blink. Millions begin to register. Billions of years. I once had my students hold one hundred feet of rope, and marked the history of the planet on it. Those who held on to human historical events: Lucy, the Pyramids, the Great Wall of China, the Renaissance, man walking on the moon—could barely wrap a finger around the rope they were crowded so close. Our Western Mountains—the Rockies—and Eastern Mountains—were flung apart, but well after our continent had formed.

Deep time. I stand near the mountain as still as I can be, and wait, my feet apart, on a board as long and wide as a county. Here it comes. I can feel it.