Friday, December 4, 2009
Impact of invention on me
What does the telephone do?
How does a Telephone Work?
The telephone operates on simple principles. A telephone mouthpiece contains a thin metallic coating separated from an electrode by a thin barrier (today we use plastic) which connects to a wire carrying an electric current. When a person speaks into the mouthpiece, the acoustic vibrations from her speech push the metallic coating slightly closer to the electrode, resulting in variations in voltage and therefore a speedy conversion from acoustic to electric energy. The electric pulses are conveyed through a wire to the speaker on the other end, where electric pulses are converted into acoustic energy again.
Converting speech to electrical energy before transmission is far more efficient than conveying speech through a mechanical channel, for example a metal pipe, because the walls of mechanical channels absorb so much of the acoustic energy as it travels. Well-insulated wires, however, are effective at protecting electrical energy from dispersing before reaching its destination. Electrical pulses travel at the speed of light, whereas acoustic pulses are limited by the speed of sound. In his 1627 book New Utopia, Francis Bacon referred to the possibility of a long-distance network of tubes to transmit human speech. Many historians consider this the first reference to something like a telephone. Unfortunately, he lacked the scientific knowledge to understand why this would be impractical.
Three critical developments were necessary precursors to the invention of the telephone. First was the understanding that an electrical current can create a magnetic field, and therefore mechanical or acoustic energy. This is credited to Danish physicist Christian Oersted in 1820, who demonstrated that a compass needle can be manipulated by running an electric wire over it. Second was the understanding that the reverse is possible - electrical induction - that is, generating a current by placing a moving magnet next to a wire. This insight is credited to inventor Michael Faraday in the year of 1821. The last necessary development was that of the battery, a chemical device capable of producing a continuous source of electricity. The first very crude battery was the "Leyden jar", a device for storing static electricity invented by two Dutchmen in 1746. Volta and others developed more sophisticated batteries throughout the 18th and 19th centuries.
http://www.wisegeek.com/how-does-a-telephone-work.htmThursday, December 3, 2009
What was the problem this innovation solved?
Wednesday, December 2, 2009
Where Was Phone Invented?
According to wikipidia, the telephone was pattened January 30, 1877 by Alexander Bell; however, the first telephone may have been made in 1849 by Antonio Meucci.
when was the phone invented
Bell accidentally thought about the idea of the telephone while trying to better the function of the telegraph. The telegraph at that time could only send a single message at the time. Bell's in depth knowledge about sound and signals was the key in helping him to figure out a way to transfer multiple messages at one time.
