The ultimate stability of the vacuum of our universe may rest on the masses of two fundamental particles, the Higgs boson — that inhabits all space and time — and the top quark. The latest measurements of those masses reveals that our universe is metastable, meaning that it can persist in its present state essentially forever… or not.
Our universe has not always been the same. In the earliest moments of the Big Bang, when our cosmos was a mere fraction of its current size, the energies and temperatures were enormously high that even the fundamental rules of physics were completely different. Most notably, physicists believe that at one time, all four forces of nature (gravity, electromagnetism, strong nuclear and weak nuclear) were merged into a single, unified force.
The nature of that unified force remains a mystery, but as the universe expanded and cooled from initial state, the forces ...
