I want to write you a letter about distance. Or maybe it is about the length of a certain distance. The distance to the furthest visible point. That is, the distance to the horizon. So this letter is also about visibility. Distance and visibility.

I recently found an image online known as the Flammarion engraving. Its oldest known publishing is in the 1888 edition of the French astronomer Camille Flammarion's L'atmosphère: météorologie populaire. It depicts a robed figure crouched down on the ground under a solid sky filled with stars. This sky is almost touching the ground. There was a time when people believed the sky was a solid impenetrable substance. The robed figure holds a cane in his left hand. This shows that he is on a journey, that he was walked to where he is. The book's text describes the story of a voyage taken by a missionary of the Middle Ages. This missionary had claimed he had found the horizon, and that he discovered a part where the sky and Earth were not touching, where if you stooped down, you could pass under the sky and see beyond.

But the horizon is not reachable. It always exists away from you at the furthest possible point. It is an impossible place of arrival.

And so this letter is also about that impossibility.

Over the past few weeks in Berlin I went on daily walks each morning. In each walk, always starting from the same location but heading in a different direction, I attempted to walk across the horizon line. This was 4.7 km away, though the actual length of each walk varied since there are no straight lines in the city. I wanted to walk the exact length of visibility from where I started. And, to just slightly cross this point. As if to disappear out of view.

But it is the horizon that seems to have disappeared. In the city the buildings obscure the possibility of looking into distance. Just as light pollution obscures the visibility of the night sky, losing a nightly relationship with the infinite. But it is not just the view of the horizon that is lost. Much of the world we see is through screens only inches away from our eyes. Images stream instantaneously from all over the world. How do you stare into vastness with our attention continuously being invaded? How do you ground yourself? The horizon no longer defines the distance of the visible. It is the remnant of a lost distance.

Did you know that there are three kinds of dusk? Civil dusk, nautical dusk, and astronomical dusk. The second, nautical dusk, marks the moment when the horizon disappears into the darkness of the coming night. It is called nautical because it is the moment when sailors can no longer navigate at sea using the horizon. Have you ever seen this? The disappearance of the horizon? If you stare out at sea after the sun sets, slowly the sea and the sky become indiscernible from each other. It's hard to notice the exact moment it disappears. But at some point you realize it's not there anymore.

I made some photographs for you from my walks. An apple in the sunlight in Volkspark. The stem is sticking up like the gnomon of a sundial (the part that casts the shadow). If you point the stem in the direction of Polaris, the North Star, the shadow will tell you the local time (different from clock time). The redtwig dogwood. In America this is what dreamcatchers were made out of. Some Linden tree seeds found on the ground. The leaf serves as a sail, utilizing the wind for its dispersal (like radio waves flying through the air). The site of murdered sailors in March 1919. The wall was recreated. And some skies, looking straight up, as if distance collapsed in on itself to form a flat surface. A place you can still stare into the vastness of space. A place where our attention can take shelter from brief moment.