Physicists are as curious as you are. They look for answers to questions that people have pondered since they first began to wonder about the world and their place within it. It often seems that for every answer physicists find, two new questions arise.
Particle physicists try to understand the nature of nature at the smallest scales possible.
Today, we know that atoms do not represent the smallest unit of matter. Particles called quarks and leptons seem to be the fundamental building blocks - but perhaps there is something even smaller. Physicists are still far from understanding why a proton has about 2,000 times more mass than an electron. And on top of it all, scientists suspect a whole new class of undiscovered supersymmetric particles to complete the subatomic family. Empty space, we have discovered, is actually not empty at all.