* Do you remember those hateful black bags behind the silvery wall in Iwaki? In March my only way of measuring them was to approach them at a distance, watching the dosimeter to see whether its displayed accrual would immediately increase. Since its righthand digit represented microsieverts, my local real-time perception of radiation was awfully blunt. Had my total dose display upticked by one within, say, 15 seconds, that would have implied a field of 4 micros a minute . . . 240 micros an hour . . . more than half a sievert per day—far more biological damage than I wished to absorb. And had the numbers in that narrow grey window remained the same—as happened—the radioactivity of the black bags would remain out of my ken.