This topic in depth tackles the complex concept of antimatter. First, Wikipedia (1) provides a simple, concise explanation of antimatter and discusses scientists' successes in producing anti-atoms of hydrogen and anti-deuteron nuclei. This online encyclopedia also offers links to many of the physical terms related to the topic so that novices can easily understand the material presented. The second website (2), created by Space.com, summarizes the findings and mysteries about the natural presence of antimatter. Through this online article, visitors with little knowledge of this phenomenon can learn about the scientific theories, its huge energy potential, and its lifespan. Next, the United Kingdom's Particle Physics and Astronomy Research Council (PPARC) (3) addresses the issue of why, if matter particles and their antimatter partners were created in equal amounts after the Big Bang, they did not eradicate each other. Visitors can learn about experiments taking place at many scientific research centers including CERN, the Stanford Linear Accelerator Center, and Fermilab. The fourth website (4 ), created by Physics Central, educates users about the cloud chamber track of an electron-positron pair. Visitors can learn how matter and antimatter relate to the conservation of momentum and energy. Next, NASA (5) argues that new observations may upset theories about how solar explosions create and destroy antimatter. Users can view the many colorful animations and short movies obtained from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). The Physics Van outreach program at the University of Illinois answers questions about antimatter's uses, effects, and characteristics in the sixth website (6). High school students and educators can benefit from the author's explanation of the similarities and differences between antimatter and matter. Next, Particle Physics in Plain English!, an outreach project for the Lepton Photon 2003 Conference at Fermi National Accelerator Laboratory, (7) discusses how particle physicists are studying antimatter with the hopes of contributing to the current understanding of the universe on all scales, "from revealing the origin of matter shortly after the Big Bang, to uncovering the secrets of elementary particles and their interactions." Students and educators can find clear explanations of the difficult concept of CP violation along with discussions of the BaBar and Belle experiments. Lastly, Argonne National Laboratory discusses (8) the potential for the new MINOS detector at Soudan to prove neutrino oscillation. Visitors can learn how the study could help in the understanding of why we live in a world made up of matter.