Fermilab

Animation of proton-antiproton collisions (video, 40 seconds)

In the above animation, a proton and an antiproton collide. The moment these two particles interact their total energy (E) creates a flash of pure energy. A fraction of a second later, the energy materializes again, creating particles with a total mass (m).

The outcome of each collision has many possibilities, whose probabilities are described using the quantum theories of the Standard Model. The details of each collision are constrained by the law of energy conservation, one of the fundamental physics laws. Einstein's discovery of the equivalence of energy and mass, E = mc², is confirmed by every single collision. Energy (E) can be converted into mass (m) and vice versa, with the square of the speed of light (c) as the conversion factor. If the initial particles have enough energy, they can create new particles that are much heavier than the particles themselves. As a matter of fact, the proton-antiproton inside the Tevatron regularly produce top quarks, particles that are about 175 times heavier than each of the initial particles.

It's as if two tennis balls collided and a bowling ball flew out…