On October 29, 1969, Leonard Kleinrock sent the first message across the Internet, and it was all of two letters: "lo."

It crashed the entire system. The Internet was born.

Kleinrock, at UCLA, was trying to to communicate with the Stanford Research Institute, and he was trying to write the word "login." The U.S. Department of Defense's Advanced Research Projects Agency had just installed ARPANET, a network of just four computer terminals installed at universities and research institutions in California and Utah.

Unfortunately, the system was quite stable just yet, though the problem wasn't due to the "LO" message, but a memory problem with the receiving computer, Kleinrock told USA Today.

"I actually took part later in the first denial-of-service attack on the Internet as well," he joked. "We sent the first spammer in 1984 so many messages, complaining, that we shut him down."

The ARPANET system later morphed into the Internet we know today, though it took years for the network to move beyond the universities and research houses it had been designed to connect. Not until 1984 was the domain name system established. The first Web browser, NCSA Mosaic, wasn't introduced for another decade.

The Internet has continued to evolve, and a next-generation network is always underway. First there was Internet2, a faster, research- and education-focused network that's been under development since 1996.

Internet2 was built specifically to handle the massive amount of data created by researchers that participate in large scale science projects such as the Large Hadron Collider..

Today's Internet is a mesh of cables and routing equipment, much of which was designed for telephone calls. Internet2 is built with dedicated fiber optic cables, higher capacity routing centers and advanced Internet protocols, meaning there are no outdated components to slow the deluge of data.

But like the original ARPANET, Internet2 is dedicated to universities and research houses. The technology should be integrated with the existing Internet at some point in the future.

If it doesn’t crash, that is.