WIRELESS

WIRELESS

Outline:

1.     A wonderful invention.

2.     Marconi; wireless telegraphy and telephony.

3.     How it works.

4.     The good it does.

Wireless has become so common in use now that we cannot imagine life without it. We can tune in our receiving sets and hear music and speeches from Karachi and Dacca, from England and Europe, even from America and all others parts of the world. But if people had been told even fifty years ago that a man’s voice speaking in London could, be heard clearly in Ottawa, Cape town, Sydney, Karachi, and all over the globe, they would have simply laughed at this idea and had taken it as a fairy tale. Wireless or radio is a wonderful invention.

The inventor of wireless was an Italian, Guglielmo Marconic. He was born in 1874. He knew, of course of the telegraph and the telephone and he knew of the electric waves in the ether discovered by the German scientists, Hertiz, Marconi asked himself if massages can be sent by means of electric waves along a conducting wire, why can’t messages be not sent by the electric waves.

How is it so? the idea is this Like light, sound also moves waves; but through the air, and very slowly as compared with light or electricity. When you speak into the transmitter the sound waves of your voice are changed into electric waves. These fly off at a tremendous speed (186.000 miles a second!) until they reach a receiving set. The receiver changes the electric waves back again into sound waves, which enter the ears of the person at the receiver as words. As the electric waves travel as fast as light, they are heard as sounds even thousands of miles away at practically the same time as they leave the transmitter. 

But the knowledge of how it is done can never underrate the wonder of wireless. How marvelous to hear at 10-30 p.m in Karachi Big Ben striking five O’clock in London seven thousand miles away! Wireless has made the world smaller. It has shortened time and contracted space. We are so much used to it that we can’t even think of that life is possible without it. 

Ether without using any wires? Years of experimenting brought about the invention of wireless telegraphy, by which a message was sent from England to Newfoundland in 1901. Wireless telegraphy led later to wireless telephony or “broadcasting”. In wireless telegraphy messages are tapped out in the Morse Code; but in wireless telephony, the human voice is carried to the listener. So now we can “listen in” and hear the singing, playing and speaking of people thousands of miles away.