Day 51. Outside Ithaca’s Rasa Spa window, the snow moved sideways, fell at a slight slant as it traveled up the Cayuga River inlet and I understood the jet stream. It rushed past on an invisible river current like fog in a flashlight’s beam and dust motes dancing in a sunbeam. The flakes that fell close to the window’s warmth hovered, floated, and did multiple pirouettes, a midair ballerina’s dance.