Who came up with the idea of middle names?

The expression " middle name" initially showed up in a 1835 Harvard University magazine called Harvardiana, yet the practice goes back much further. 
In extremely old Rome, having many names was a respect, typically given the most imperative individuals - like Gaius Julius Caesar. The brief premium ceased to exist just to lift move down again in Western societies in the 1700s, when rulers/rich and capable individuals began giving their youngsters wonderfully long names to demonstrate their place in (group of individuals/all great individuals on the planet). (in nearly a similar way), long Spanish and Arabic names embrace father-in light of other-based names from past eras to follow the individual's family tree. (In different societies, similar to Chinese, there are as a rule/(previously) no middle names. :)

It may possibly be c i think |-/

Because its reliable.   there is no pollution  the chances of a radiation leak is low