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Introduction
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Telecommunications |
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History:
The word “telecommunication” stems from the Greek word tele, which means far off. In modern language, telecommunications refers to long-distance communication. In earlier times, telecommunications took the form of smoke signals, drums, light beacons, and other forms of signaling.
Today, long-distance communication is carried out with the aid of electronic equipment such as the radio, telegraph, telephone, television, satellite, fiber optics, sonar, lasers and the Internet. The information that is transmitted can be in the form of voice, symbols, data, pictures, live motion, or in a combination of forms.
Modern telecommunication devices have a foundation in electrical theory which was documented as early as 600 BC with the ancient Greeks who discovered that when amber, a translucent mineral, was rubbed with a piece of fur, it develops the ability to attract small objects such as feathers. The word “electricity” comes from the Greek word for amber, elektron. A breakthrough in the development of electricity occurred in the sixteenth century, when William Gilbert proved that many other substances are electric and that there are two electrical effects, one that attracts, and one that repels. Scientists thought that friction, from rubbing objects was what actually created electricity. “Friction” was their word for charge.
Following the sixteenth century, the theory of electricity really started to evolve. Two famous gentlemen, Benjamin Franklin, in America, and William Watson, in England, independently concluded that all materials possess a single kind of electrical “fluid” that can penetrate all matter freely, and that it can’t be created or destroyed. They determined that rubbing (or friction) was the action that transferred the “fluid” from one body to another, electrifying both. Franklin further defined the fluid as positive, and the lack of fluid as negative, and that the fluid flowed from positive to negative. Today we know that the opposite is true, and that the only difference between a lightning bolt and shock between two people on a dry day is the quantity of electricity.
As the result of the work of numerous scientists world wide over the last 300 years, we have learned a lot about electricity, the backbone of modern telecommunications. Today, telecommunications is supported by hundreds of inventions and electrical devices, which control, store, generate, and switch electricity. These devices are commonly referred to as electronics.
Transition:
Have students identify common electronic devices. This could be an individual writing assignment where students develop a list, or a contest among groups brainstorming a list for the class to review. After reviewing some of the items, ask students if they know how any of the devices work.
Most electronic devices, including telecommunication devices work because of electric circuits, electric motors and electromagnets. We will be building one of each to demonstrate how modern technology has impacted our lives.
State of California State Board of Education Science Content Standards-Grade/4
1. Electricity and Magnetism are related effects that have many useful applications in everyday life. As a basis for understanding this concept, students know:
a. How to design and build simple series and parallel circuits using components such as wires, batteries, and bulbs.b. How to build a simple compass and use it to detect magnetic effects, including earth's magnetic field.c. Electric currents produce magnetic fields and how to build a simple electromagnet,d. The role of electromagnets in the construction of electric motors, electric generators, and simple devices such as doorbells and earphones.e. Electrically charged objects attract or repel each other.f. Magnets have two poles, labeled north and south, and like poles repel each other while unlike poles attract each other.g. Electrical energy can be converted to heat, light and motion
1. Have students identify what kinds of jobs/careers they are aware of where the knowledge of electric circuits, electric motors and electromagnets is important.2. Have students identify the possible secondary and post secondary education options that should be considered in the pursuit of these careers.3. Have the students identify a family member, neighbor, family friend, etc… who may work in an occupation where the concepts of electric circuits, motors and electromagnets are important, and conduct an interview that focuses on their occupation. The interview questions could be developed in class, or given by the teacher. Students could prepare written and/or oral reports.4. Identify career clusters i.e., industrial/technology, communications, health & medical, human services, business & marketing, etc… and have students list the kinds of jobs within each category that might have use of telecommunications technology.
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