6. Fifth Fundamental Force

 

In physics, we have already discussed that there are four observed fundamental forces or interactions that form the basis of all known interactions in nature: gravitational, electromagnetic, strong nuclear and weak nuclear forces. Some speculative theories have proposed a fifth force to explain various anomalous observations that do not fit existing theories. The search for a fifth force has increased in recent decades due to two main discoveries in cosmology which cannot be explained by current theories. 

 

One of the above mentioned two discoveries was the majority of mass of universe is accounted by an unknown form of matter called Dark Matter that was thought to be related to an unknown fundamental force which was later got titled after the second discovery of rapid expansion of universe. The expansion of universe is accelerating that was attributed to a form of energy called Dark Energy. Some physicists speculate that a form of dark energy called Quintessence could be a fifth fundamental force.