The Universe

Do you know the definition of "universe"? According to Access Science, which the library subscribes to, "The universe comprises everything in existence, including all matter and energy, and the enormous volume which contains them. The observable universe currently spans about 2.6 × 1023 km (1.6 × 1023 mi), and contains approximately 2.4 × 1052 kg (5.2 × 1052 lb) of matter, yielding an average density equivalent to a few atoms per cubic meter. Most of the universe, then, is empty space; the matter is distributed thinly throughout, forming objects and structures at a variety of different sizes. The study of this matter and energy, and its distribution, composition, and origin, is what constitutes the sciences of astronomy and cosmology."

Do you want more information on the universe? Like when the Big Bang happened? And what planets are in our universe? Then see Access Science. You can get to that database by starting at the eReference tab of the Science and Technolgy subject page.


(X-ray image: Crab Nebula Courtesy of J. Hester (Arizona State University), NASA/CXC/SAO posted in Access Science.)