http://fnnews.fnal.gov/collisions.html (World Wide Web Directory, 06/1995)
Fermilab: Research Lab on the Energy Frontier
Answer:"A proton strikes an antiproton head on. They both smash to bits, and pieces fly off in every direction." "Got it?"
"Some of the bits that fly off are heavier than the proton and antiproton combined. For instance, the top quark is more than 100 times as heavy as a proton."
Question:"Hold it. That doesn't make sense. How can the parts be heavier than the whole?"
Answer:"Because of the connection Einstein found between matter and energy. Remember E=mc2? E stands for energy and m stands for mass. The two quantities are tied to each other. Accelerating the proton and the antiproton to almost the speed of light gives them an enormous amount of energy. When they collide, most of that energy can turn into a corresponding amount of mass in the form of the particles that fly out of the collision. It's as if two tennis balls could move so fast that when they collided, a bowling ball flew out."
"That Einstein. What a guy."