COSMIC WIERDNESS

'Preposterous universe' still perplexes experts

One major sign of the universe's messiness is its makeup. The list of its ingredients turns out to be a recipe for disaster. Only about 3 percent of the total mass-energy mixture is in the form of ordinary matter, the sort that planets and people and stars are made of. About 26 percent is some exotic sort of matter, a species not yet identified (and almost surely a species that has not yet been discovered). And the 70 percent remaining is even more mysterious – it's an unknown form of energy that took command of the universe a few billion years ago, forcing space to expand at an accelerating rate. Hence the disaster – the universe seems to be blowing itself up.