We parted in our habitual way: he paused on his way past the kitchen table to bend down, cup the back of my head, and kiss me. I set down my tea to grasp his upper arm and kissed him back. The bare skin on his arm was jarringly smooth and firm under the first short-sleeved shirt of the summer. Later, on the bus I remembered the parchment feel of his arm as I turned the pages of the famous scientist's book on physics. In among the undead felines, fruit-based analogies, and quantities named after children's cartoon characters, I read that matter is mostly empty space. The dislike electrons feel when they approach too closely is the only thing that keeps me from falling through the tattered fabric and cracked plastic of the bus seat, through the slush-covered road surface, down past the drifting eggshell continents with their buried treasures and tragedies, to the incandescent roiling iron of Earth's core (briefly I tasted the metallic water we drank from the hand pump at cross country camp), after which the sequence would reverse itself, my falling becoming a drifting ascent barely interrupted by breaching the surface on the other side of the planet, continuing past the increasingly diffuse constituents of the atmosphere and ultimately into the depths of space where I would have no companions save the chorus of ephemeral particles conjured out of the void only long enough to annihilate one another before I can finish introducing myself. Later that night as I slid my hands across his back, I realized that all touch is repulsion and in that moment I felt the first wisps of our relationship unravel and waft away.