Static electricity has been investigated for more than 2 thousand years1) however, explanations of the physical mechanisms behind the phenomenon are still under dispute.
(The term 'electricity' comes from ἤλεκτρον [ ēlektron ] meaning 'amber' - which was used to generate electrostatic charges by rubbing on cloth.)
“Electrostatics is an exciting area of science, as its most basic scientific questions remain unknown and highly controversial … and yet its consequences are widespread. For example, the identity of the species transferred to generate charge when materials rub is being hotly debated in the leading scientific journals – some researchers argue that it is electrons, others that it is ions, and yet others that it is bits of material.”
Source: Electrostatics Society of America