Fermilab Discovery Science Resources: Nine Questions
4. Do all the forces become one?
At the most fundamental level, particles and forces may converge, either through hidden principles like grand unification, or through radical physics like superstring. We already know that remarkably similar mathematical laws and principles describe all the known forces except gravity. Perhaps all forces are different manifestations of a single grand unified force, a force that would relate quarks to leptons and predict new ways of converting one kind of particle into another. Such a force might eventually make protons decay, rendering ordinary matter unstable. review.