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Invention of the Internet


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Professor McAdams's presentation about the origins of the Internet and the WWW

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Invention of the Internet

  1. 1. The Invention of the Internet and the Web Presentation by Mindy McAdams Week 15.1 / MMC 2265
  2. 2. Sputnik and the Cold War <ul><li>When the Soviet Union launched a satellite (1957) before the U.S. was able to do so, it was cause for alarm </li></ul><ul><li>President Dwight D. Eisenhower funded the Advanced Research Projects Agency ( ARPA ) in response </li></ul><ul><li>Originally responsible for the space program, but that moved to NASA in 1958 (pretty quick!) </li></ul>
  3. 3. ARPAnet <ul><li>The seed from which today’s global Internet grew </li></ul><ul><li>Within the U.S. Department of Defense </li></ul><ul><li>Advanced Research Projects Agency Network established as a stand-alone project of ARPA (later called DARPA) </li></ul><ul><li>Responsible for development of the first operational packet-switching network </li></ul>
  4. 4. Primary reason for ARPAnet To allow easier communication (and sharing of research data) among various projects funded by the Defense Department
  5. 5. Packet Switching <ul><li>Digital information is broken apart into small digital “packets” </li></ul><ul><li>Packets are marked with information about sender, receiver, and order </li></ul><ul><li>Packets are transmitted </li></ul><ul><li>Packets are received at the destination and put back together </li></ul><ul><li>See the animated graphic </li></ul>
  6. 6. TCP/IP <ul><li>It is a communication protocol </li></ul><ul><ul><li>That is, a description of rules a digital device must use to communicate (share data) with other digital devices </li></ul></ul><ul><ul><li>The USB protocol, for another example, defines how USB devices communicate with devices that have a USB connector </li></ul></ul><ul><li>TCP/IP includes : </li></ul><ul><ul><li>Internet addresses ( e.g., </li></ul></ul><ul><ul><li>Domain names ( e.g., </li></ul></ul><ul><ul><li>Top-level domains ( e.g., .com, .org, .ca, .mx) </li></ul></ul>
  7. 7. Separated Networks <ul><li>Mid-1970s : Many developed countries were building their own computer networks </li></ul><ul><li>Most were not connected outside their own country </li></ul><ul><li>Exception: Within Europe, where they were just taking the first steps to create the European Union </li></ul>
  8. 8. Metcalfe’s Law <ul><li>The value of a network is proportional to the square of the number of users of the system (n 2 ) </li></ul><ul><li>That is, the value increases exponentially as more people start using it </li></ul><ul><li>A network with very few users: Worthless! </li></ul>
  9. 9. French Minitel <ul><li>Introduced in 1981 </li></ul><ul><li>Basically replaced telephone books </li></ul><ul><li>Some people say Minitel impeded France’s entry into the Information Age in the 1990s </li></ul><ul><li>Comparison to the optical telegraph ? </li></ul>
  10. 10. NSFnet <ul><li>Run by the (U.S.) National Science Foundation (NSF) </li></ul><ul><li>Non-U.S. networks could connect to this, and through NSFnet, to the Internet </li></ul><ul><li>Started in 1988 </li></ul><ul><li>By January 1990 , there were 250 non-U.S. networks connected to NSFnet </li></ul>
  11. 12. This data visualization displays the relative densities of Internet connectivity across the earth. The stronger the contrast, the more connectivity there is. It is immediately obvious, for example, that North America and Europe are considerably more connected than Africa or South America. Source: Chris Harrison
  12. 13. This data visualization displays how the Net is connected. The intensity of edge contrast reflects the number of connections between the two points. No country borders or geographic features are shown. Source: Chris Harrison
  13. 14. Source: Internet World Stats
  14. 15. CERN and the Web <ul><li>World’s largest particle physics research center </li></ul><ul><li>Location: Switzerland </li></ul><ul><li>Supported by 20 European countries </li></ul><ul><li>Produces a very large quantity of scientific research and data </li></ul><ul><li>Full name: European Organization for Nuclear Research (Conseil Européen pour la Recherche Nucléaire) </li></ul>
  15. 16. CERN and the Web (2) <ul><li>Tim Berners-Lee worked at CERN </li></ul><ul><li>In 1989 , he invented the World Wide Web </li></ul><ul><li>Why? Because all that physics research needed to be shared </li></ul><ul><li>Why shared ? </li></ul><ul><ul><li>So scientists could collaborate more efficiently </li></ul></ul><ul><ul><li>So new ideas could be built upon existing ideas </li></ul></ul><ul><li>Berners-Lee invented the HTTP protocol and the first graphical Web browser </li></ul><ul><li>(In 2004, Berners-Lee was knighted by Queen Elizabeth) </li></ul>Details at
  16. 17. The Web Spreads Out <ul><li>1991: More Web servers appeared at other locations in Europe </li></ul><ul><li>December 1991: The first server outside Europe was installed the Stanford Linear Accelerator Center in the U.S. (Stanford University) </li></ul><ul><li>November 1992: Total of 26 Web servers in the world </li></ul><ul><li>February 1993: Mosaic </li></ul><ul><ul><li>The first Web browser software for Windows and Mac personal computers </li></ul></ul><ul><ul><li>Released ( free ) by the National Center for Supercomputing Applications ( NCSA ), in Chicago </li></ul></ul><ul><li>October 1993: At least 200 Web servers </li></ul>
  17. 18. The Web We Know <ul><li>Marc Andreessen (b. 1971) worked on Mosaic at NCSA as a grad student </li></ul><ul><li>After graduation, he moved to California and met Jim Clark, founder of Silicon Graphics (an important technology company in Silicon Valley) </li></ul><ul><li>Together they founded Mosaic Communications (later renamed Netscape) </li></ul><ul><li>November 1994: Netscape beta is released (Andreessen’s age: 23 ) </li></ul><ul><li>July 1995: Internet Explorer 1.0 </li></ul>
  18. 19. Tim Berners-Lee (b. 1955) invented the World Wide Web at CERN in 1990 Marc Andreessen (b. 1971) worked on Mosaic at NCSA and co-founded Netscape in 1994
  19. 20. The Invention of the Internet and the Web Presentation by Mindy McAdams University of Florida