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.
(Photo - NASA)
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
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
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
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
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
This Special English program, EXPLORATIONS, was written by
Paul Thompson. It was produced by Caty Weaver. This is Mary
And this is Steve Ember. Listen again next week to the Voice
of America for the last part of this series about the Information
This V-O-A Explorations Report is published
courtesy of VOAnews.com