Today is my dad’s birthday and I’m visiting him for the morning — a bit of a brunch party with the New York Times and Verdi in the background. It was and is in this context that I did tai chi this morning, in a room with ceilings that are too low.

The challenge of a low ceiling is that during the rising arm movements like White Crane Spreads Wings, your hands bump against the upper limits. This means changing posture slightly to accommodate the movement, by bending the knees. Which requires straightening the back and spine more carefully. All the interacting systems thus get a more prolonged workout as a result. It’s a lot harder than usual. But it’s also quite worthwhile.