Information Age, Part 2
This is Mary Tillotson. And this is Steve Ember with the VOA Special English program EXPLORATIONS. Today we present the second part of our series about communications. We tell how computers are linking many millions of people around the world.
Last week we told about the history of the communication of information. We described how the telegraph was the first important device that could move information quickly from one place to another. And we discussed the beginning of satellite communications.
About six years after the first communications satellite was placed in orbit, the American Department of Defense began developing a new project. It began linking major research universities across the United States. The project began in the early nineteen-seventies.
Professors at many American universities do research work for the United States Government. The Department of Defense wanted to link the universities together to help the professors cooperate in their work. Department of Defense officials decided to try to link these universities by computer. The officials believed the computer would make it easier for researchers to send large amounts of information from research center to research center. They believed they could link computers at these universities by telephone.
They were right. It became very easy to pass information from one university to another. University researchers working on the same project could share large amounts of information very quickly. They no longer had to wait several days for the mail to bring a copy of the research reports.
This is how the system works. The computer is linked to a telephone by a device called a modem. The modem changes computer information into electronic messages that are sounds. These messages pass through the telephone equipment to the modem at the other end of the telephone line. This receiving modem changes the sound messages back into information the computer can use. The first modern electronic communication device, the telegraph, sent only one letter of the alphabet at a time. A computer can send thousands of words in a very few seconds.
The link between universities quickly grew to include most research centers and colleges in the United States. These links became a major network. Two or more computers that are linked together form a small network. They may be linked by a wire from one computer to another, or by telephone. A network can grow to almost any size.
For example, let us start with two computers in the same room at a university. They are linked to each other by a wire. In another part of the university, two other computers also are linked using the same method. Then the four are connected with modems and a telephone line used only by the computers. This represents a small local network of four computers.
Now, suppose this local network is linked by its modem through telephone lines to another university that has four computers. Then you have a network of eight computers. The other university can be anywhere, even thousands of kilometers away. These computers now can send any kind of information that can be received by a computer - messages, reports, drawings, pictures, sound recordings. And, the information is exchanged immediately.
Some experts have said it is easier to understand this network of computers if you think of streets in a city. The streets make it possible to travel from one place in the city to another. Major streets called highways connect cities. They make it possible to travel from one city to another.
Computers communicate information in much the same way. Local networks are like the city streets. And communication links between distant local networks are like the major highways. These highways make communication possible between networks in different areas of the world.
In nineteen-eighty-one this communication system linked only two-hundred-thirteen computers. Only nine years later, it linked more than three-hundred-fifty-thousand computers. Today experts say there are hundreds of millions of computers connected to networks that provide links with computers around the world.
The experts say it is no longer possible to tell how many computers are linked to the information highway. The experts also say the system of computer networks is continuing to grow.
This system of computer networks has had several different names since it began. It is now called the Internet. Almost every major university in the world is part of the Internet. So are smaller colleges and many public and private schools. Magazines, newspapers, libraries, businesses, government agencies, and people in their homes also are part of the Internet.
Computer experts began to greatly expand the Internet system in the last years of the nineteen-eighties. This expansion was called the World Wide Web. It permits computer users to find and exchange written material and pictures much quicker than the older Internet system. How fast is the World Wide Web part of the Internet system? Here is an example. A computer user in London, England is seeking information about the volcanoes in the American state of Hawaii.
She types in the words "Hawaii" and "volcano" in a World Wide Web search program. Within seconds the computer produces a list. She chooses to examine information from the National Park Service's headquarters at the Hawaii Volcanoes National Park. The Park Service computer in Hawaii provides information about the huge volcanoes there, and how they were formed. It also has other useful information.
The researcher in London looks at the information. Then she has her computer print a copy of it. Within seconds she has a paper copy of the National Park information including pictures. It has taken her less than five minutes to complete this research.
The Internet and the World Wide Web have become vehicles for speedy information exchange for most people who can use a computer. Much of the information on the Internet is very valuable. As a research tool, the Internet has no equal.
Suppose you want a copy of this Special English program, EXPLORATIONS. You can find the information by looking for the Voice of America and Special English on the World Wide Web. The electronic address is www dot voa special english dot com. (www.voaspecialenglish.com) You can find written copies of most of our programs and print them for your own use.
Almost any kind of information can be found through the Internet. There are electronic magazines for poetry or children's stories.
There are areas within this electronic world where you can play games or discuss politics or science. You can find valuable medical information, read history, learn about new farming methods or just about anything that interests you. You can look at and collect the beautiful color pictures taken by the Hubble Space Telescope.
You can watch musicians perform their latest songs. You can even join a group that meets electronically to discuss the music of their favorite rock and roll music group.
Who pays for the Internet? That is not easy to explain. Each network, small or large, pays for itself. Networks decide how much their members will pay for their part of the cost of the local service connecting time.
Then all of the large networks decide how much each will pay to be part of the larger network that covers a major area of the country. The area network in turn pays the national network for the service it needs.
Each person who has a computer at home pays a company that lets the computer connect to the Internet. These companies are called Internet service providers. Most charge less than twenty dollars a month for this service.
Next week the EXPLORATIONS program will examine the future of the Internet and the World Wide Web. We will tell about modern technology that lets networks link with telephones that do not need wires.
This Special English program, EXPLORATIONS, was written by Paul Thompson. It was produced by Caty Weaver. This is Mary Tillotson. And this is Steve Ember. Listen again next week to the Voice of America for the last part of this series about the Information Age.