When I Google this, I find nothing straight forward. What is "force coupling" and what is "force decoupling"? Here are things I've found online that don't seem to match up. I see that a "force couple" is a way of applying force to a body so as to generate spin without causing translation through space, but here the word "couple" is a noun, where as, in the term "force coupling," "coupling" is a noun, making "couple" a verb. I also understand that "decoupling" is what led to the CMB and the CNB. But this uses the word "decoupling" as a name for a type of event in the history of the universe, and what's more is these events are more specifically called "photon decoupling" and "neutrino decoupling," not "force decoupling." So what exactly are "force coupling" and "force decoupling?"