Steve Ember with EXPLORATIONS in VOA Special English. Today we present the second part of our series about
communications. We tell how computers
are linking people around the world.
week, we told about the early 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 early radio
and television broadcasts and the beginning of satellite communications.
early nineteen seventies, the American Department of Defense began developing a
new project. It began linking major
research universities across the United States.
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.
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 send 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.
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.
first modern electronic communication device, the telegraph, sent only one
letter of the alphabet at a time. A
computer can send thousands of words within seconds.
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.
example, let us start with two computers in the same room at a university. A wire links them to each other. 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 computers. This represents a
small local network of four computers.
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 can
now send any kind of information that can be received by a computer - messages,
reports, drawings, pictures, sound recordings.
And, the information is exchanged immediately.
began, this system of computer networks has had several different names. It is now called the Internet. In nineteen eighty-one, this communication
system linked two hundred thirteen computers.
Only nine years later, it linked more than three hundred fifty thousand
computers. Today, experts say more than
one billion people around the world are linked by computers to the
Internet. And, they say, this number
will continue to grow.
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.
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 easily search for information using software called a
is the World Wide Web part of the Internet system? Here is an example. A
computer user in London, England is seeking information about volcanoes in the
American state of Hawaii. She types in
the words "Hawaii" and "volcano" in a search engine, such as Google.
computer produces a list within seconds.
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.
researcher in London looks at the information on her computer. Then she prints
a copy of it. Within seconds she has a
copy of the National Park information including pictures. It has taken her less than five minutes to
complete this research.
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.
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.
ISP's charge about twenty dollars a month for
a slow dial-up connection to the Internet.
A computer user with a high-speed wireless connection pays at least
forty dollars a month. Wireless
connections generally link computers to the Internet with a special
technological device called a router.
United States used to have the largest number of Internet users in the world.
However, in April, the USA Today newspaper reported that China now has the
largest number of people using the Internet. Estimates from a Chinese research
group said more than two hundred twenty million people in China were using the
Internet as of February. That is about seventeen percent of the Chinese
The newspaper said the United States had two
hundred sixteen million Internet users at the end of last year. That is
seventy-one percent of the population.
The Internet World Statistics Web site notes several other countries
where more than sixty percent of the people use the Internet. They include Japan, Germany, the United
Kingdom, Australia and South Korea.
have shown that people use the Internet for communication and for
research. Much of that research leads
to buying products on the Internet.
More people than ever are now using the computer for e-commerce – to buy
and sell products electronically.
Some governments, private groups and individuals have
criticized the Internet. Some
governments do not trust the Internet because they say it is difficult to
control the information that is placed there.
Some government officials say extremist groups place harmful information
on the Internet. They say dangerous
political information should be banned.
Other groups say it is difficult to protect children from sexual
information and pictures placed on the Internet. They say this kind of information should be banned.
critics say that it is becoming extremely difficult to know if you can trust
the information that is found on the Internet.
They wonder if the information is correct. Still other critics say the Internet is no longer a free exchange
of information and ideas. They say it
has become a big business that sells products, services and information. They want the Internet to be used only for
research and education.
week we will examine some new technologies that have developed with the help of
the Internet. Many of these
technologies are being used in education.
program was written by Paul Thompson.
It was produced by Mario Ritter.
I'm Steve Ember.
Barbara Klein. Our programs are online with
pictures, transcripts and MP3s at voaspecialenglish.com. Join us again next
week for EXPLORATIONS in VOA Special English.