In the 670s how was the leadership of Islam determined?

that they needed to invent electrostatic

Answer: The correct answer is : In the year 670 Mu'awiyah was governor of SIria, ill and his son Yazid, who was the son of his favorite spouse, was named as his successor. In 680 Mu'awiyah dies and many people do not agree with his successor, they consider him someone without mercy and for this he had to face many rebellions. Finally Yazid dies in one of these rebellions. He was succeeded by a sick son who also died shortly after.