The story of the Internet begins with military scientists.
The launch of Sputnik in October 1957 by the Soviet Union rocked the USA’s political and military establishments. The event suggested that America was no longer the world’s leader in science and technology.
To get the USA into space, ARPA (the Advanced Research Projects Agency) was created within the US Department of Defence. But when the project to get a man on the moon began in the early 1960s, ARPA’s role was taken over by the National Aeronautics and Space Administration (NASA), and ARPA morphed into a sponsor of advanced research projects, a role it still plays today.
Initial Internet concepts
In the late 1950s the main fear of the US military was that its military communications could be knocked out by a nuclear attack from the USSR. The RAND Corporation was hired by the Pentagon to analyse the vulnerability of these systems and to suggest changes.
RAND came up with two ideas that would later form the basis of how data is transmitted on the Internet: (a) the concept of a distributed network made up of many servers providing files and services, and (b) the breaking of whole messages into packets that are sent separately and rejoined at their destination.
The basic idea was that military messages should be carried over a network that could still be used if an enemy missile destroyed part of the system. To make this easy, each message would be broken into blocks and each block would be sent separately, avoiding any bits of the network that aren’t working.
This is essentially the same method used today to send data on the Internet. It is known as packet-switching. All data – regardless of its content, type, or structure – is grouped into suitably-sized blocks (packets) before being transmitted.
Having many routes by which message packages could go from the sender to the receiver would ‘guarantee’ that the message gets through even if part of the network were damaged. The same concept underpins how data is transmitted in the Internet as we know it today.
The message you sent yesterday from Dublin to Beijing may have gone through Chicago. Tomorrow it could be routed though Pittsburgh. Because the Internet is a network of networks, there are literally thousands of different routes you messages can take to reach the same destination.
The distributed military communications network suggested by RAND was never built. However ARPA put the concept to good use by using it to create links between research establishments.