The case for and against a 5th fundamental force of nature

"Our current best theories are spectacular: quantum field theories that describe the electromagnetic interaction as well as the strong and weak nuclear forces on one hand, and General Relativity describing the effects of gravity on the other hand. Wherever they've been challenged, from subatomic up to cosmic scales, these two classes of theories have always emerged victorious. And yet, they simply cannot represent all that there is."

"We cannot explain why there's more matter than antimatter in the Universe with current physics. Nor do we understand what dark matter's nature is, or whether there's a particle that underlies it. We don't know whether dark energy is anything other than a cosmological constant, or precisely how cosmic inflation occurred (and with what properties) to set up the conditions for the hot Big Bang."

"At a fundamental level, we do not know whether all of the known forces unify under some overarching umbrella in some way, or whether there are additional fundamental forces beyond the known four. We have clues that there's more to the Universe than what we presently know, sure. But is a new, unaccounted-for fundamental force among them?"

Despite quantum field theory and General Relativity's success across all tested scales, significant gaps remain in our understanding of the Universe. Current physics cannot explain why matter outnumbers antimatter, the nature of dark matter and dark energy, or the precise mechanisms of cosmic inflation. Fundamental questions persist about whether known forces unify under a single framework or if additional fundamental forces exist beyond the four currently recognized. These unresolved puzzles indicate substantial discoveries await. Two distinct approaches exist to uncover unknown physics: brute force methods involving more powerful telescopes and particle accelerators, and alternative investigative strategies, though neither approach has yet provided definitive answers.

Read at Big Think