"There was a lot of technological change with the Industrial Revolution," McManus said. "It seems glacial in the context of our time. But in the context of their time, it was cutting-edge that the average person could read and transmit ideas."
In turn, the French Revolution inspired revolt in Haiti, where slaves used the ideas of the French to justify their rebellion.
A more recent revolutionary wave occurred in the early 2000s against corrupt governments, beginning in Georgia, Ukraine and Kyrgyzstan, among other countries. Called the Color Revolutions, protests then spread to Kuwait, Iran, China and beyond.
One reason that revolutions are so ripe for contagion is that they are based on big ideas.
"If you don't have ideas, you're not doing a revolution and we call it something else, like a coup or power-grab," Beck said. "Ideas have a universal component that people can use to derive inspiration from elsewhere."
Revolutionary waves have always been fueled by the latest communication technologies, from the printing press to the telegraph to Twitter, Beck said. Because communication can happen so much more rapidly now than it used to, waves seem to be spreading more quickly, too.