Quarks - Inside the Atom

How do we know what's inside an atom?  How do we know that antimatter exists?  Because experimental physicists perform studies and run tests on huge pieces of equipment known as particle accelerators.  One such place is the Fermilab, near Chicago, where scientists create and study antimatter:

Antimatter is one of the most expensive materials in the world to produce. It requires a particle accelerator that generates six billion electron volts of power and a vacuum storage container, which keeps the antimatter from touching air or other regular matter.

Learn more about what happens at the Fermilab - and what scientists have discovered about quarks and other subatomic particles - in this video clip.