What if we don't confine ourselves to events in our own galaxy, but look farther afield? Instead of the "hopelessly rare" (in the words of one researcher) supernova in our galaxy, what if we looked for them in a really large arena— the Virgo cluster, which has some 2,500 galaxies, where supernovas ought to be popping from once every few days to once a month or so? That's Catch-222. The Virgo cluster is about 1,000 times farther away than the center of our own galaxy. So a supernova event from the cluster would dispatch gravity waves whose effect on Earth would be some million times weaker (1,000 times 1,000, according to the inverse-square law governing all radiative energy). And that means building a detector a million times more sensitive. "There is no field of science," says Ronald Drever of Caltech and the University of Glasgow, Scotland, "where such enormous increases in sensitivity are needed as they are here, in gravity-wave detection." Trying to detect a supernova in a distant galaxy means having to measure a displacement one-millionth the size of an atomic nucleus.