## The Fifth Force

“Now therefore write ye this song for you, and teach thou it the children of Israel.” Deut. 31:19 The four known fundamental forces are: gravitational force, electromagnetic force, strong (nuclear) force and weak (beta decay) force. Newton first described the gravitational force in his famous universal law of gravity. Today, we use Einstein’s General Theory of Relativity to describe strong gravitation fields. Electromagnetism was described in the 19 c. by Faraday and Maxwell. Strong and week forces were discovered much later, in the second half of the 20 c. Since Albert Einstein started a search for a unified field theory, unsuccessfully trying to unify (describe by a single theory) gravity and electromagnetism, the quest for a unified field theory – the “Theory of Everything” – became the holy grail of theoretical physics. Strong [...]