Another aftershock? Or just an earthquake hangover?

Jishin-yoi means "earthquake drunk"—the feeling that you're experiencing the ground moving beneath you, even when things are still. It might be psychological. It might be a physical balance impairment. Whichever it is, a doctor at the University of Tokyo Hospital estimates that 30% of Japanese living in quake-stricken regions have experienced it. (Via Samuel Rubenfeld)