What Early Discovery had the most Impact on the Development of Mass Communications?

   In a modern society, information goes faster than people. To get to know what's going on in this world, all you need is either a computer or a smartphone or any electric device that access to the internet. We are now living in a world with well-developed mass communication. But if we go back to thousands of years ago, before we had the great high technology, how did people communicate then?

     But first, what is Mass Communication? According to Wikipedia, "Mass communication is the study of how individuals and entities relay information through mass media to large segments of the population at the same time." But the first media I can think of, is book. Which lead to my answer to the topic, I think paper is the early discovery had the most impact on the development of mass communication. 

    The invention of paper was call on of the " Four Great Invention of China". Before the paper was invented by Tsai Lun, people used to write on shell,stone, skin of the animal, bamboo and silk. Those materials are either too heavy or expensive for everyone to have, which make it impossible for people to own a book. Ever since the paper was invented, there were more books been handing down, more people get educated, and people started to write letters. This great invention changed people's life. 

   Without his invention, we wouldn't be able to have books, newspapers and magazines. If we do they might be dead heavy but expensive. As these are the important steps of the development of modern mass communication, paper is the most important discovery.