Radio Waves

With wavelengths varying between 0.5 cm to 30,000 m, radio waves have the longest wavelengths in the electromagnetic spectrum and can channel innumerable forms of data through air, usually over millions of miles. Radio waves are not just transmitted from radio stations and onto one’s boom box; but are also emitted by stars. Technologies such as communication, wireless networking , AM and FM broadcasting, GPS, radars, satellite communication and microwaves rely on radio waves to function. Radio waves are a long-wave pattern of radiation that transfers energy through the interaction of electricity and magnetism.

In 1864, Scottish physicist James Clerk Maxwell developed the electromagnetic

theory; a mathematical theory that established that magnetism and electricity were associated. In

the 1888, German physicist Heinrich Hertz proved Maxwell's theory by discovering long-

wavelength radio waves and confirmed it in his book, “Investigations on the Propagation of

Electrical Energy”. In his experiment, an induction coil producing high voltage was connected to

a metal pedestal where a spark produced electromagnetic waves that reached the resonator. Here,

an electric current was produced and formed a spark in the spark gap that helped Hertz detect the

radio waves. Consequently, ...

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theory; a mathematical theory that established that magnetism and electricity were associated. In

the 1888, German physicist Heinrich Hertz proved Maxwell's theory by discovering long-

wavelength radio waves and confirmed it in his book, “Investigations on the Propagation of

Electrical Energy”. In his experiment, an induction coil producing high voltage was connected to

a metal pedestal where a spark produced electromagnetic waves that reached the resonator. Here,

an electric current was produced and formed a spark in the spark gap that helped Hertz detect the

radio waves. Consequently, Hertz’s discovery of the radio waves sparked new inventions and

technologies.

The breakthrough of radio waves led many inventions in its field. Guglielmo Marconi used radio waves to invent the Morse code. Eventually, Marconi’s invention was modified for transmitting voice signals. One of the commercial uses of radio waves is communication. Pilots and taxi cab drivers use radios for communication in order to receive important information. Two-way radios are another use of radio waves that policemen, firemen, and ambulance crew use to report difficulties. Radio waves are also commercially used in transmitting AM, and FM frequencies and television broadcasts to enrich people’s desires. Electronic devices in computers and radio-controlled toys are other commercial aspects that require radio waves. Radio waves have totally changed human society due to their utile properties.

A change in wave amplitude causes a change in speed of a moving electron. This causes charged particles (electrons) to emit electromagnetic radiation and produce radio waves. These movements occur naturally in the outer atmospheric regions of stars. Frequency range for radio waves are transmitted from 3 kilohertz to 300 gigahertz. Some technologies that rely on this frequency range are AM radio band and radars used in maritime communication and aircraft navigation, short waves used in radios, microwaves used for cooking, millimeter waves & telemetry used for local communication, FM radio band where radio waves are transmitted from radio stations and TV’s that receive broadcasts from satellites. Radio waves can be produced naturally or artificially for scientific and commercial purposes.

In general ways, radio waves are considered non ionizing waves and don’t have adequate energy to alter the anatomical structure of atoms in the human body. However, it is theorized that if a person is exposed to mobile phones or base stations, some of the energy will be absorbed by the tissues at the surface of the body and would lead to a brain cancer or tumor. Nevertheless, the risks of getting a cancer or tumor is miniscule since this energy is extremely small for its effects to take place. In conclusion, the discovery of the radio waves by Heinrich Hertz had ushered a new period of communication, networking, and broadcasting and has led to the usage of many technologies, disregarding the ever so small probability of health hazards.

Peer Reviews

Here's what a star student thought of this essay

PicturePerfect

17th of Mar 2012

Quality of writing

Some of the information provided is a little dull, this could be made more lively with added descriptions, and a wider range of vocabulary. In terms of the presentation of the essay, the second paragraph has spaces between lines, which is unnecessary. Iâ€™m assuming this an error, and it can easily be rectified. Also a new paragraph should have been started for the conclusion. Over all the quality of communication in this essay is lower than expected at this level, though in general there is no real issue with spelling or grammar.

Level of analysis

The candidate launches straight into information regarding radio waves. Therefore they fail to provide a proper introduction for this piece of writing. Having an introduction is crucial; it sets the tone for the whole essay and provides a context. For this essay the introduction should include background information, I would suggest classifying radio waves as electromagnetic waves, followed by a description of an electromagnetic wave and a brief description of the properties specific to radio waves. On the positive side the candidate has clearly undergone independent research as they discuss in detail the experiment which led to the discovery of radio waves. This additional knowledge shows the candidate's interest in their subject and makes the essay more enjoyable to read. I feel that this essay is missing important descriptive information such as the fact that radio waves are produced by electrons oscillating in aerials due to an electric field, and the fact that they can be detected by resonance in electric circuits. This basic information shows a true understanding of radio waves and hence showcases your knowledge and ability. In addition, to achieve a high grade it is a good idea to explore beyond the topic, in this case it would be appropriate to discuss polarisation as radio waves are electromagnetic waves and only these types of waves can be polarised. You could also discuss interference, and perhaps how radio waves are transmitted and received. This shows a breadth of knowledge and indicates to the reader that you understand basic physics principles. Finally though the candidate attempts to conclude their writing, it is a little brief and could be improved. A strong conclusion should summarise the key points mentioned in the essay and include a personal note. This is important as it allows you to leave the reader with a good impression.

Response to question

The candidate attempts to discuss various details of radio waves, though they fail to mention basic information. In doing so, they miss the opportunity to fully present their knowledge on the subject. In addition some of the information given is difficult to read, which usually stems from the fact that the candidate hasnâ€™t really understood the information they have provided. Only when you truly understand something can you present it in way that is effortless to read. You should always go back to basics and present information as simply as possible, so that it is clear to the reader, however limited their knowledge of the subject is.

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