October 2. While swimming this morning, at a quarter to eight, the sun shone into the hall at such a low angle that a stretch of the pool floor lay in bright light. The wave structure of the surface turned into the pulsating honeycombs of light that everyone knows, but which delighted me and filled me with endless wonder. Who would have thought that waves would become sharply defined webs, with chromatic aberration at the edges, and that their patterns of movement, furiously fast, would not seem like sine functions at all, but like sine functions running against each other and sloshing up briefly. During my eighty laps, the bright stretch grew narrower and narrower as the sun rose higher and higher, and finally disappeared altogether. I often miscounted my laps.