Among science's most ambitious goals is seeking to understand the origin and evolution of the entire universe. All the more impressive is that, using precision observations from telescopes both on Earth and in space, science has made great strides toward finding answers to those big questions. Join us in exploring one of the most fundamental properties of our cosmos: its overall shape.

Watch cosmologist and author Lawrence Krauss explain the mysteries of the "fiery echo" of the big bang, and the ways it helps astronomers to measure the shape of the cosmos, at the 2008 World Science Festival, in our section Video: Echoes from the Beginning.

Read about the relationship between the shape of the cosmos and the properties of simple triangles, and the ways of measuring cosmic shape in Shape and Geometry and Measuring Cosmic Shape.

Find out how to track triangles on a sphere, build your own theodolite, understand the expansion of the universe and follow up on the surprising parallels between the early cosmos and the human voice in our section Explorations.

More science? Those intent on digging deeper will find links to further video presentations, recommended websites, and accessible books on the shape of the universe and, more generally, on cosmology in our section Learn more.

Teachers who plan to use material from this section in the classroom will find curriculum tie-ins, lesson plans, background information and ready-for-download material in our section Teacher's Corner.