I looked up at the sky and it was bright and blue and empty, and it was possible, for a moment, to really feel that I was looking up into space, even though it was daytime and the illusion of a great, blue dome was at its full power. There is something dizzying about looking up and realising there is nothing between us and the vast infinitude of the universe except a thin cushion of air held in place by a force we can name but don’t entirely understand, or I don’t anyway. I don’t need to see the stars to know that we are hurtling at incomprehensible speed, heading in an uncertain direction through a medium we cannot conceptualise except as a repetition of something we already know. I cannot feel this motion any more than I can feel my eyes tracking back and forth when I look out of a car or train window, though it is happening all the same. Such is the divergence of knowing and feeling. I was thinking about this and then a plane appeared, and a thin suggestion of cloud. The dome slammed down, the illusion reasserted itself and that cushion of air pressed me back down, safely, into the comfort of my chair.