Universal Truths: Distant quasars reveal content, age of universe

Using 3,000 recently discovered quasars as searchlights on the distant universe, astronomers have mapped with unprecedented precision the distribution of the diffuse gas between galaxies. By combining these measurements with observations of the faint microwave glow of radiation left over from the Big Bang and other cosmological data, the researchers report that they have pinned down the age of the universe to an accuracy 5 times greater than ever before.