The Invention of the Internet and the Web Presentation by Mindy McAdams Week 15.1 / MMC 2265

Sputnik and the Cold War When the Soviet Union launched a satellite (1957) before the U.S. was able to do so, it was cause for alarm President Dwight D. Eisenhower funded the Advanced Research Projects Agency ( ARPA ) in response Originally responsible for the space program, but that moved to NASA in 1958 (pretty quick!)

When the Soviet Union launched a satellite (1957) before the U.S. was able to do so, it was cause for alarm

President Dwight D. Eisenhower funded the Advanced Research Projects Agency ( ARPA ) in response

Originally responsible for the space program, but that moved to NASA in 1958 (pretty quick!)

ARPAnet The seed from which today’s global Internet grew Within the U.S. Department of Defense Advanced Research Projects Agency Network established as a stand-alone project of ARPA (later called DARPA) Responsible for development of the first operational packet-switching network

The seed from which today’s global Internet grew

Within the U.S. Department of Defense

Advanced Research Projects Agency Network established as a stand-alone project of ARPA (later called DARPA)

Responsible for development of the first operational packet-switching network

Primary reason for ARPAnet To allow easier communication (and sharing of research data) among various projects funded by the Defense Department

Packet Switching Digital information is broken apart into small digital “packets” Packets are marked with information about sender, receiver, and order Packets are transmitted Packets are received at the destination and put back together See the animated graphic

Digital information is broken apart into small digital “packets”

Packets are marked with information about sender, receiver, and order

Packets are transmitted

Packets are received at the destination and put back together

See the animated graphic

TCP/IP It is a communication protocol That is, a description of rules a digital device must use to communicate (share data) with other digital devices The USB protocol, for another example, defines how USB devices communicate with devices that have a USB connector TCP/IP includes : Internet addresses ( e.g., 128.55.0.122) Domain names ( e.g., ufl.edu) Top-level domains ( e.g., .com, .org, .ca, .mx)

It is a communication protocol

That is, a description of rules a digital device must use to communicate (share data) with other digital devices

The USB protocol, for another example, defines how USB devices communicate with devices that have a USB connector

TCP/IP includes :

Internet addresses ( e.g., 128.55.0.122)

Domain names ( e.g., ufl.edu)

Top-level domains ( e.g., .com, .org, .ca, .mx)

Separated Networks Mid-1970s : Many developed countries were building their own computer networks Most were not connected outside their own country Exception: Within Europe, where they were just taking the first steps to create the European Union

Mid-1970s : Many developed countries were building their own computer networks

Most were not connected outside their own country

Exception: Within Europe, where they were just taking the first steps to create the European Union

Metcalfe’s Law The value of a network is proportional to the square of the number of users of the system (n 2 ) That is, the value increases exponentially as more people start using it A network with very few users: Worthless!

The value of a network is proportional to the square of the number of users of the system (n 2 )

That is, the value increases exponentially as more people start using it

A network with very few users: Worthless!

French Minitel Introduced in 1981 Basically replaced telephone books Some people say Minitel impeded France’s entry into the Information Age in the 1990s Comparison to the optical telegraph ?

Introduced in 1981

Basically replaced telephone books

Some people say Minitel impeded France’s entry into the Information Age in the 1990s

Comparison to the optical telegraph ?

NSFnet Run by the (U.S.) National Science Foundation (NSF) Non-U.S. networks could connect to this, and through NSFnet, to the Internet Started in 1988 By January 1990 , there were 250 non-U.S. networks connected to NSFnet

Run by the (U.S.) National Science Foundation (NSF)

Non-U.S. networks could connect to this, and through NSFnet, to the Internet

Started in 1988

By January 1990 , there were 250 non-U.S. networks connected to NSFnet

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

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

Source: Internet World Stats

CERN and the Web World’s largest particle physics research center Location: Switzerland Supported by 20 European countries Produces a very large quantity of scientific research and data Full name: European Organization for Nuclear Research (Conseil Européen pour la Recherche Nucléaire)

World’s largest particle physics research center

Location: Switzerland

Supported by 20 European countries

Produces a very large quantity of scientific research and data

Full name: European Organization for Nuclear Research (Conseil Européen pour la Recherche Nucléaire)

CERN and the Web (2) Tim Berners-Lee worked at CERN In 1989 , he invented the World Wide Web Why? Because all that physics research needed to be shared Why shared ? So scientists could collaborate more efficiently So new ideas could be built upon existing ideas Berners-Lee invented the HTTP protocol and the first graphical Web browser (In 2004, Berners-Lee was knighted by Queen Elizabeth) Details at CERN.ch

Tim Berners-Lee worked at CERN

In 1989 , he invented the World Wide Web

Why? Because all that physics research needed to be shared

Why shared ?

So scientists could collaborate more efficiently

So new ideas could be built upon existing ideas

Berners-Lee invented the HTTP protocol and the first graphical Web browser

(In 2004, Berners-Lee was knighted by Queen Elizabeth)

The Web Spreads Out 1991: More Web servers appeared at other locations in Europe December 1991: The first server outside Europe was installed the Stanford Linear Accelerator Center in the U.S. (Stanford University) November 1992: Total of 26 Web servers in the world February 1993: Mosaic The first Web browser software for Windows and Mac personal computers Released ( free ) by the National Center for Supercomputing Applications ( NCSA ), in Chicago October 1993: At least 200 Web servers

1991: More Web servers appeared at other locations in Europe

December 1991: The first server outside Europe was installed the Stanford Linear Accelerator Center in the U.S. (Stanford University)

November 1992: Total of 26 Web servers in the world

February 1993: Mosaic

The first Web browser software for Windows and Mac personal computers

Released ( free ) by the National Center for Supercomputing Applications ( NCSA ), in Chicago

October 1993: At least 200 Web servers

The Web We Know Marc Andreessen (b. 1971) worked on Mosaic at NCSA as a grad student After graduation, he moved to California and met Jim Clark, founder of Silicon Graphics (an important technology company in Silicon Valley) Together they founded Mosaic Communications (later renamed Netscape) November 1994: Netscape beta is released (Andreessen’s age: 23 ) July 1995: Internet Explorer 1.0

Marc Andreessen (b. 1971) worked on Mosaic at NCSA as a grad student

After graduation, he moved to California and met Jim Clark, founder of Silicon Graphics (an important technology company in Silicon Valley)

Together they founded Mosaic Communications (later renamed Netscape)

November 1994: Netscape beta is released (Andreessen’s age: 23 )

July 1995: Internet Explorer 1.0

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

The Invention of the Internet and the Web Presentation by Mindy McAdams University of Florida