SITI ROSMALA
XII IPA 3
Why eiffel tower was built ?
If we talk about the wonders of the world buildings, then we will see eiffel tower as one of them. However many of us do not know the tower’s past history on why it was build. Everything has the reasonable background, especially for the tower which is to be one of the most recognized buildings in the world.
Primarily, the eiffel tower was built for the world exhibition. It was called paris exposition in 1889. The exhibition was organized to celebrate the 100th anniversary of the french revolution. The purpose of building eiffel tower in such structure was to show to the worldfrance’s advancement of technology and beauty. The eiffel tower was designed by gustave eiffel. It seemed that then the name of the tower was derived from the designer’s last name, “eiffel”.
Another reason on why the tower was built was for scientific progress. Although few realized it, the eiffel tower would become the prominent structure in terms of science and technology. Many experiment with temperature, pressure and pendulums were performed atop the unique famous building. Additionally the eiffel tower was used for radio transmission tower. Many experiments were conducted atop the eiffel tower for radio transmission advancement. Once the eiffel tower was proposed to be demolished but it was spared because the tower had the promising future as a radio tower.
SITI ROSMALA
XII IPA 3
How cell phones work ?
A cell phone is a great gadget in this modern world. What is a cell phone? A cell phone is actually a radio in certain way. Like a radio, by a cell phone we can communicate to other people in real time. Million people use cell phone for their communication. Even nowadays, people use cell phones to communicate in voice, written and data. Alexander graham bell is the person who make great change in the way people communicate to each other. He invented a telephone in 1876. While wireless radio was formally known in 18994 presented by guglielmo marconi. By these two technologies, then a cell phone was born. However do you know how actually cell phones work?
This short explanation on how a cell phone work is really wonderful. A cell phone or in long term "cellular telephone' works by transmitting signals of radio to towers of cellular. The towers are networked to a central switching station. The connection usually uses wire, fiber optic-cables, or microwave.
Then the central switching station which handles calls in certain given area is directed connected to the wire-based telephone system. Cellulars are pick up by the towers and relayed to another cellular telephone user or the user of wire-based telephone network.
The towers vary in the capacity and capability to receive signals. Some can receive the signal from short distance and the others can receive more distance. However, there are usually more than one tower in certain given area so that the system can handle the increasing telephone traffic.
