ARPANET
/AR-puh-net/ · noun · Hacker Culture · Origin: 1969
Definitions
Advanced Research Projects Agency Network — the first wide-area packet-switching network and direct precursor to the modern internet. Launched in 1969 connecting four universities, ARPANET pioneered TCP/IP, email, and the fundamental architectural principle that networks should be decentralized and fault-tolerant.
In plain English: The original internet, built by the U.S. military in 1969 to connect university computers — it started with just four machines.
Example: The first ARPANET message in 1969 was supposed to be 'LOGIN' but the system crashed after 'LO' — which, poetically, means 'behold.'
Origin Story
The military network that accidentally invented the internet
The **Advanced Research Projects Agency Network** was funded by the U.S. Department of Defense's ARPA (now DARPA) and went live on October 29, 1969. The first message was sent from UCLA to Stanford Research Institute -- they tried to type "LOGIN" but the system crashed after "LO."
Contrary to popular myth, ARPANET wasn't designed to survive nuclear war. Its primary purpose was to let researchers at different universities share expensive computing resources. The nuclear survivability idea came from Paul Baran's earlier work on packet switching at RAND Corporation.
By 1971, ARPANET connected 15 nodes. Email was invented on it in 1972 by Ray Tomlinson (who chose the @ symbol). The network transitioned to TCP/IP on January 1, 1983 -- "flag day" -- and was officially decommissioned in 1990, having spawned the internet we know today.
Coined by: U.S. Advanced Research Projects Agency (ARPA)
Context: ARPA/DoD, 1969
Fun fact: The first ARPANET message, 'LO', was unintentionally poetic -- it could be read as 'Lo and behold.' The system crashed before 'LOGIN' could be completed. The full message was successfully sent about an hour later.