A more accurate title is "why didn't the Romans invent the optical telegraph". The reason why the optical telegraph didn't become the Internet is very simple: b

A more accurate title is "why didn't the Romans invent the optical telegraph". The reason why the optical telegraph didn't become the Internet is very simple: bandwidth. You need lots of spare bandwidth before you can consider adding extra information to messages so as to create the various protocols that the Internet is built on (Ethernet, TCP, IP, HTML etc.). That's not something you're willing to do with a system that, even when perfected by the French in the 19th century, could only transmit about 1 symbol / minute [1]. [1] http://en.wikipedia.org/wiki/Optical_telegraph#France http://en.wikipedia.org/wiki/Optical_telegraph#France