Welcome to the alphabetical walkthrough of pioneers and personalities. You're now on letter O. Click through the rest of the alphabet to find out more about the people who've helped shape telecommunication as we know it today.
Hans Oersted discovered that an electric current creates a magnetic field, making electromagnetism the key to modern communication.
Jarkko Oikarinen developed the first Internet chat network, known as Internet relay chat (IRC) in 1988. He was working at the University of Oulu in Finland. This is the forerunner to today’s internet chat movement.
Visit the updated Communicate! galllery at the National Museum of Scotland.
Discover the records behind the history of telecommunications as BT Heritage launches online catalogue.
Last month: History of the internet learning resource
Gallery: From buttons to bytes
Fun activity: BT Tower activity
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