> Cosmology & Astrophysics

What is the Big Bang Theory?
One of the most impressive theories of the 20th century, the Big Bang explains the origins of the universe ... at least up to a point. Find out what the theory actually says, what it does not say, and what it may or may not say.

Kepler's Laws of Planetary Motion
Kepler's Laws describe, in three concise rules, the motion of orbital bodies in the solar system.

What is a Black Hole?
A black hole is a curvature of spacetime geometry due to an intense gravitational field. The effects of a black hole are so extreme that even light cannot escape it, thus the name.

Physics Book Review - Endless Universe: Beyond the Big Bang
Steinhardt & Turok present a revolutionary new model of cosmology which removes the need for the inflationary phase in the Big Bang. Using concepts from string theory, they present a new cyclic model in which the laws of physics do not break down at the moment of the universe's creation.

What is Hawking Radiation?
Hawking radiation is an explanation of how radiation can be emitted from a black hole, despite its attractive power, due to quantum effects.

About.com Astronomy & Space Guidesite
For more detailed information on space and astronomy, check out the About.com Astronomy Guide.

Astronomy magazine
The major popular magazine in the space sciences, Astronomy provides excellent information for those interested in the physics of space, or those who just like looking with wonder into the night sky.

Eric Weisstein's World of Astronomy
Eric Weisstein's World of Astronomy is a site full of astronomy information, located on the Wolfram Research website.

Cosmic Journey: A History of Scientific Cosmology
This fantastic website on the history of scientific cosmology is maintained by the American Institute of Physics.

Astronomy Now Online
Astronomy Now is a popular UK-based astronomy magazine, which features a wide range of content and articles in its online publication.

The Astrophysical Journal
This journal of astrophysical research publishes abstracts and full papers online.

Official NASA Website
This is the official website of the National Aeronautics and Space Administration (NASA), which maintains a lot of great information on the space sciences.

NASA's Astronomy Picture of the Day
This Astronomy Picture of the Day is featured on the NASA website, accompanied by a description of the picture with commentary by a professional astronomer.