What should the average person know about science? Because science is so central to life in the 21st century, science educators and other leaders of the scientific community believe that it is essential that everyone understand the basic concepts of the most vital and far-reaching disciplines. Cosmology 101 does exactly that. This accessible volume provides readers - whether students new to the field or just interested members of the lay public - with the essential ideas of evolution using a minimum of jargon and mathematics. Concepts are introduced in a progressive order so that more complicated ideas build on simpler ones, and each is discussed in small, bite-sized segments so that they can be more easily understood. This volume in the Science 101 series provides readers with a solid understanding of how scientist know what they know about the universe.