How do movements spread?

Large movements such as the Rosa Parks Bus Boycott or the Civil Rights Movement always begin with one simple situation and somehow spread to become nation or even worldwide. The power of weak ties is the major force that drives these movements. Charles Duhigg wrote in a chapter of his book From Civil Rights to Megachurches that according to Harvard student, Mark Granovetter, weak ties represent “the links that connect people who have acquaintances in common, who share membership in social networks, but aren’t directly connected by the strong ties of friendship themselves” (91). Strong ties could start the initial movement where a group of friends work towards a common goal  but how it spread is due to weak ties. Proof of weak ties working their magic is through McKibben’s 350.org organization that worked to climate change. He organized a world wide 350 day and found people from countries all over who were willing to work with them. In Bill McKibben’s Do The Math movie, it is acknowledged that “there had been over 5,200 demonstrations in 181 countries. CNN called it the most widespread day of political activity in the planet’s history” (7). If McKibben and his team did not put in the effort to create these weak ties then this day would not of been as successful as it could have been.