Fiber Optics
Fiber optics is a cable that is quickly replacing out-dated copper wires. Fiber optics is based on a concept known as total internal reflection. It can transmit video, sound, or data in either analog or digital form . Compared to copper wires it can transmit thousands of times more data. Some of its general uses are telecommunications, computing, and medicine.
The very first “fiber” was made in 1870 by the British physicist John Tyndal. In this experiment that he showed to the Royal Society he placed a powerful waterproof lamp inside a tank of water, which had closed pipes coming out the sides. When he opened up the pipes so water could flow, to the amazement of the crowd, the light totally internally reflected inside the beam of water as it fell to the ground.
One of the very first forms of optical communication was done Paul Revere in his famous Paul Revere’s ride. Here he used the well-known signal “one if by land, two if by sea.” Although primitive, this was still optical communication and we must give him credit for it. Another contender was Alexander Gram Bell and his photophone. With this device, one person would speak into a microphone causing a mirror to vibrate. Then sunlight would reflect off the vibrating mirror and hit another mirror 200 meters away. This mirror would then cause a selenium crystal to vibrate and sound would come out the other end. This seems interesting, but unfortunately this did not work very well at night, in the rain, or when someone simply walked in front of it.
In the summer of 1970, scientists at the Corning Glass Works developed a single mode fiber with a loss of 20 dB/km. This corresponds to over a 99% loss over 1 km, which may seem useless, but at the time it was a spectacular breakthrough. On October 30, 1986, a fiber across the English Channel became operational. In December 1988, the TAT-8, the first transatlantic fiber cable became fully functional. Currently, the standard losses of fiber are within 0.5 – 0.25 dB/km with a data transfer rate of 1 trillion bits per second.
The basic setup for a fiber optical system is that first, a transmitter receives an electrical signal, usually from a copper wire. The transmitter drives a current on a light source and the light source launches the optical signal into the fiber. Inside the cable, repeaters often amplify the signal due to slight lo...
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... two fiber cables together, you need some pretty fancy equipment and some well trained people. Because of this difficulty in connecting cable, if something happens to your network, and a line breaks, you’re in trouble.
Since fiber is much better than copper, its beginning to have many applications. Telephone and cable television companies are both begging to use fiber. Lines connecting central offices in companies are often using fiber. Power companies use it for communication because of its lack of electrical interference. Computing is one of the other main uses. LAN’s usually have their backbones made of fiber. For example, here at Texas A&M we have a fiber optic ring going around campus which connects some of the main buildings such as Blocker, Heldenfels, and the Student Computing Center. Individual computers do not yet have fiber lines going directly into them, but they are probably soon to come.
In conclusion, fiber optics is extremely important in today’s world of technology. It is vastly superior to copper mainly due to its incredible bandwidth. It is used in telephone systems to computer systems. Only time will tell just how important fiber will be in the future.
fiber-optic cables that run from a major city to another major city. So if you
rapid development of polymer chemistry after World War II a host of new synthetic fibers
However, the inhalation of some kinds of asbestos fibres is now thought to cause various illnesses, including cancer, and thus most uses of asbestos are banned in many countries. Fibre glass has been found to be a suitable substitute for thermal insulation and woven ceramic fibre performs as well or better as an insulator of high-temperature electrical conductors. Most respirable asbestos fibres are invisible to the unaided human eye because their size is about 3.0-20.0 µm in length and can be as thin as 0.01 µm. Fibres ultimately form because when these minerals originally cooled and crystallized, they formed by the polymeric molecules lining up parallel with each other and forming oriented ... ... middle of paper ... ...
It started with the British, with the arc lamp in 1835. For years after people around the world experimented on an incandescent lamp. They tried things like filling the bulb with gas but they did not last very long and they were very expensive. Finally in 1879, Thomas Edison made a bamboo filament (the part of the bulb that actually makes the light) that was able to last 1,200 hours. Lighting has changed over the years but some of the new inventions still were made in the 1800’s. Glassblower Heinrich Geissler and physician Julius Plücker discovered that they could make light by removing almost all of the air from a long glass tube and by passing an electrical current through it. They called it the Geissler tube. In the early 1900’s Peter Cooper Hewitt made the fluorescent lamp. While the Cooper Hewitt lamps were more efficient than incandescent bulbs, no one really used them because of the blue green color of the light. European researchers made neon tubes coated with phosphors (that made the light white). In the mid and late 1930s the U.S. was showing the fluorescent lights to the navy and at the 1939 New York World’s Fair. These lights lasted longer and were about three times more efficient than incandescent bulbs. In 1976, Edward Hammer at General Electric figured out how to bend the fluorescent tube into a spiral shape, creating the first compact fluorescent light
Being a government research project, the concept was introduced to the public, and companies were encouraged to compete for the right to develop the fibre. The in fact that multiple companies were competing for the development rights not only meant that it was cheap for the government to fund, but also that the final product would be high quality. Corning Ultimately won the developmental rights, and developed fibre optic cable into what we use today. The development of Fiber Optics has given us many benefits such as:
The ‘B’ form fibre photograph from the X-ray diffraction picture also known as ‘Photograph 51’, is now famous in identifying the structure of
Although telescopes has been around for several hundreds of years, there has been great discrepancy as to who invented it first. Here is one authors opinion. Lippershey was a Dutch spectacle marker during the early 17th century (approximately 1600). He was one of the first who created the "looker" (now called telescope) by placing two pieces of lenses together. The discovery that placing lenses together can magnify images were made by children who took Lippershey's spectacles and looked at a distant church tower.
The new technology expanded words per minute. The words transferred per minute were up to a 1,000. It usually ranged to 25-40. Even when Thomas Edison was improving the telegraph he made new ones. People during the wars used the telegraph. This telegraph changed the world for people with hearing problems because he had them. He tried to work around his disadvantage. When trying to make the telegraph better, he managed to make another based on his perforated pen, that needed no one to tap out the message at the receiving end. Thomas Edison helped a lot of people. During World War 2 people used telegraphs to send messages to each other. Overall, Thomas Edison made the world more advanced and better for people who had disadvantages with
Carbon fibers were discovered in the late 1800s by Thomas Edison. The early lightbulbs Edison created used the carbon fibers as filaments. These carbon fibers used to create the early lightbulbs had a substantial tolerance to heat, but they lacked the tensile strength of modern carbon fibers. Edison used cellulose-based materials, such as cotton or bamboo, to make his carbon fibers. He used a method called “pyrolysis” to cook the bamboo at high temperatures in a controlled atmosphere to carbonize bamboo filaments, making them fire-resistant and capable of enduring intense heat needed for luminescence.
The Telephone System The telephone is one of the most creative and prized inventions in the world. It has advanced from its humble beginnings to its wireless communication technology today and for the future. The inhabitants of the earth have long communicated over a distance, which has been done by shouting from one hilltop or tower to another. The word "telephone" originated from a combination of two Greek words: "tele", meaning far off, and "phone", meaning voice or sound, and became the known term for "far- speaking." A basic telephone usually contains a transmitter, that transfers the caller's voice, and a receiver, that amplifies sound from an In the transmitter there are two common kinds of transmitters: the carbon transmitter, and the electric transmitter.
Cell phones have immensely changed the way people communicate today. A cell phone can be all a person need for interaction. From a cell phone, a person can make calls, send text messages, emails, and send and also receive directions, buy things online, do online banking, listen to music and much more. Since someone can do everything with one device, there is no longer a need to go around with multiple devices about. Greek hydraulic semaphore systems were used as early as the 4th century. The hydraulic semaphores, which functioned with water filled containers and visual signals, functioned as optical telegraphs. However, they could only apply a very limited range of pre-determined messages, and as with all such visual telegraphs could only be deployed during good visibility conditions. Experiments on communication using electricity was carried out in 1729 but was not successful. The experiment was proposed by William Fothergill Cooke. In 1837, William invented a practical electric telegraph which entered commercial use in 1838 (J. B. Calvert, May 2004). The first telephone was invented in 1878 by Alexander Graham Bell. He experimented with a ‘phonautograph’, it is a machine shaped like a pen that can draw shapes of sound waves on smoked glass by tracing vibrations.
The index of refraction is defined as the speed of light in vacuum divided by the speed of light in the medium. In this experiment, the index of refraction for the perspex is 1.50. Snell's Law relates the indices of refraction of the two media to the directions of propagation in terms of the angles to the normal. It refers to the relationship between the different angles of light as it passes from one transparent medium to another. When light passes from one transparent medium to another, it bends according to Snell's law which states: [IMAGE] where: n1 is the refractive index of the medium the light is leaving, n2 is the refractive index of the medium the light is entering, sin 2 is the is the incident angle between the light ray and the normal to the medium to medium interface, sin 1 is the refractive angle between the light ray and the normal to the medium to medium interface.
In 1879, after spending $40,000, and performing 1,200 experiments, he succeeded. He made a light bulb using carbonized filaments from cotton thread. Carbonized thread is ordinary cotton sewing thread that has been burned to an ash. The light bulb burned for two days. The electric light took the greatest amount of time and required the most complicated experiments of all his experiments.
Light bulb is one of the most influential inventions in the word. It makes us work more productive at night and helps us enjoy more activities at night. It significantly change people lives all over the world. The born of light bulb also helped us by making more inventions that related to light, such as phones, televisions, and computes. By using light bulb, we actually reduced the probability of having fire accidents because if we don’t have light bulb, we will use candles instead which can cause fire easily. There are a lot more benefits we get from light bulb, and all of these are credited to Thomas Alva Edison.
Internet as part of the history is the most important invention around the world which connects people thru phones, satellites and cables. People all over the world have access to it as it is everyday usage, and internet becomes globally real and in demand. To mention here, the usage for permits technically for travelling or getting tickets are electronically through internet, paying bills, shopping thru nets without going out (just browsing), playing games, and mostly the merit of possibly downloading music and movies in no time (just a click).