Geometry of the Universe

摘要

A neat way of measuring the geometry of the Universe offers a new test of the standard cosmological model. It probes, among other things, the elusive dark energy thought to be driving the Universe's expansion.rnTwenty years ago, most cosmologists thought the Universe was dominated by a large amount of dark matter, and the idea of dark energy was no more than a curiosity. Now, as a result of exquisite observations of the radiation left over from the Big Bang, the large-scale structure of galaxies and distant supernovae, all that has changed: we have a generally accepted 'standard cosmological model', in which 23% of the energy density of the Universe is in the form of dark matter, 73% in dark energy, and only 4% in the form of the ordinary matter that we know on Earth.