Two become one

If supersymmetry exists, then each matter particle has an undiscovered partner that is a force particle, and vice versa. This would mean there is actually only one big family of particles, rather than two.

A lot of scientists think it's important to try and unify matter and forces as much as possible. For many, the ultimate goal is to try and have a single set of equations that will explain everything - a unified theory. They believe nature is 'elegant', and that a single unified theory is the most 'beautiful' explanation of how and why the universe works.