Study On Shakespeare Richard II Drama Essay

Study On Shakespeare Richard II Drama Essay The opening scene of Richard II is illuminating on several counts. On the one hand, Richard II, as king, appears to be acting out in full, his role as supreme arbiter of the land, by presiding over an appeal for treason. This medieval trial requires the presence of the king as both ruler and immediate dispenser of justice. On the other hand, as the scene unfolds, we gradually learn that what is being undermined is not simply the respective reputations of the rival nobles, Bolingbroke and Mowbray, but the very claims of the king himself to his Divine Right to rule. We learn that what they are fighting about is the murder of Thomas of Woodstock, Richard IIs uncle. Bolingbroke appears to know that Richard had secretly ordered Woodstocks death. Obviously, it is impossible for Bolingbroke to accuse Richard directly of his own crime. Nevertheless, his solution, amounts to a thinly-veiled accusation: he accuses Mowbray of murdering Woodstock while under his custody knowing full well that Mowbray himself was carrying out Richards instructions. Meanwhile, for the same reason, Mowbray cannot publicly name the guilty man and resorts to a perfectly traditional game of returning Bolingbrokes insults and accusations. The otherwise perfectly conventional solution proposed by the king, a joust, is as much deployed in defense of his royal power, as presented as an honorable solution for noblemen. At the very moment when the king appears to be at his most powerful, we can already discern how precarious this hold on power really is and on what it rests: a conflation of political and divinely ordained authority. The implication of the concept of the Divine Rights of Kings is that any challenge to royal power is unthinkable because it is not merely treason, as viewed in other cultures, but also tantamount to blasphemy. This becomes clear in scene 3 when Richard realizes that he may soon lose his crown. Richard refuses to acknowledge that royal power relies on human, rather than divine intervention: Not all the water in the rough rude sea Can wash the balm from an anointed king. The breath of worldly men cannot depose The deputy elected by the Lord. (3.2 50-53) The notion that the ceremonial anointment of the king is divinely ordained and cannot be outdone is acted out in its full pathos when Richard II literally uncrowns himself in Act 4 in a bizarre mirror-ceremony. On the face of it, Henry V as a character could not be more different from Richard II. Unlike Richard who merely ignores his subjects and provokes their rebellion through unwise policies, Henry is much more charismatic and popular, while at the same time, politically much more astute. Through a combination of eloquence and bravery he is able to inspire and unite his kingdom against an external enemy in a way that Richard could only have dreamt of. Henrys political skills are most in evidence in 2.2 when he plays a rather Machiavellian trick on the plotters Cambridge, Grey and Scrope. Henry asks their opinion on whether he should be lenient to traitors. Having received the expected, hypocritical responses, Henry pretends to hand them their written military commissions to be carried out as his faithful subjects. In fact, they are letters informing them that Henry knows of their plot. They are promptly arrested. This is far from being an isolated instance of Henrys cunning side. During a pause in the battle in 4.1, he disguises himself as a common soldier and mixes with his infantry, engaging them in conversation. Their talk centers on the respective roles of king and subject. Henry maintains that despite the apparent gulf, the king is fundamentally the same as the common man: I think the King is but a man, as I am. The violet smells to him as it doth to me; the element shows to him as it doth to meHis ceremonies laid by, in his nakedness he appears but a man, and though his affections are higher mounted than ours, yet when they stoop, they stoop with the like wing. (4.1.99-104) Yet a few lines later, he contradicts himself by countering Williams and Bates (the common soldiers) argument that the king also has greater moral responsibility that comes with power. Henry repudiates his earlier assertion of shared humanity by asserting his special position as king: Twin-born with greatness: subject to the breath Of every fool, whose sense no more can feel But his own wringing. What infinite heartsease Must kings neglect that private men enjoy? (4.1, 216-219) The implication is that because of his divinely ordained kingship, Henrys actions cannot be held to account and scrutinized on the same level as commoners. Henry wants to maintain a problematic and dubious distinction between his own kingly violence and the violence of common men, which is merely criminal. It becomes clear that Henry not only likes power games, but wants to write the rules of the game too. This becomes apparent later, when he pardons Williamss (unintentional) challenge to himself as the king. This scene is then deployed to illustrate royal magnanimity. To these examples can be added Henrys wooing of Catherine in 5.2. Whether or not Catherine is won over is frankly irrelevant because in fact, the French King had already, in scene 3, offered Catherine to Henry before his invasion of France. The wooing scene is thus, strictly, superfluous. Back to: Example Essays Conclusion We have seen how in both plays, the notion of the Divine Rights of Kings is mobilized to defend and extend royal prerogatives. In Richard II, Bolingbrokes rebellion is portrayed as inherently unnatural because it is both treacherous and blasphemous. Yet it is plain how ineffective a monarch Richard is. In Henry V, royal power is likewise portrayed as god-given but as we have seen it deployed we are forced to confront the gulf between virtuous kingship and successful statecraft based on the Machiavellian model. Both plays raise the question that what makes someone an effective king may be very far removed from what makes a morally admirable one. Bibliography: King Henry V Arden Shakespeare, 1995 Richard II Arden Shakespeare, 2002 Hamilton, Donna, The State of Law in Richard II Shakespeare Quarterly 34 (1983): 5-17 Greenblatt, Stephen, Invisible Bullets: Renaissance Authority and its Subversion, Henry IV and Henry V. Political Shakespeare: New Essays in Cultural Materialism. Ed Jonathan Dollimore and Alan Sinfield. Manchester: Manchester University Press, 1985.

The Electromagnetic Waves And Spectrum

The Electromagnetic Waves And Spectrum The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The electromagnetic spectrum of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object. The electromagnetic spectrum is a continuum of all electromagnetic waves arranged according to frequency and wavelength. The electromagnetic spectrum extends from low frequencies used for modern radio to gamma radiation at the short-wavelength end, covering wavelengths from thousands of kilometres down to a fraction of the size of an atom. The long wavelength limit is the size of the universe itself, while it is thought that the short wavelength limit is in the vicinity of the Planck length, although in principle the spectrum is infinite and continuous. The sun, earth, and other bodies radiate electromagnetic energy of varying wavelengths. Electromagnetic energy passes through space at the speed of light in the form of sinusoidal waves. The wavelength is the distance from wave crest to wave crest (see figure below). Light is a particular type of electromagnetic radiation that can be seen and sensed by the human eye, but this energy exists at a wide range of wavelengths. The micron is the basic unit for measuring the wavelength of electromagnetic waves. The spectrum of waves is divided into sections based on wavelength. The shortest waves are gamma rays, which have wavelengths of 10e-6 microns or less. The longest waves are radio waves, which have wavelengths of many kilometres. The range of visible consists of the narrow portion of the spectrum, from 0.4 microns (blue) to 0.7 microns (red). RANGE OF THE SPECTRUM EM waves are typically described by any of the following three physical properties: the frequency f, wavelength ÃŽÂ », or photon energy E. Frequencies range from 2.4ÃÆ'-1023 Hz (1 GeV gamma rays) down to the local plasma frequency of the ionized interstellar medium (~1kHz). Wavelength is inversely proportional to the wave frequency, so gamma rays have very short wavelengths that are fractions of the size of atoms, whereas wavelengths can be as long as the universe. Photon energy is directly proportional to the wave frequency, so gamma rays have the highest energy (around a billion electron volts) and radio waves have very low energy (around femto electron volts). These relations are illustrated by the following equations: Where: c = 299,792,458 m/s is the speed of light in vacuum and h = 6.62606896(33) ÃÆ'-10à ¢Ã‹â€ Ã¢â‚¬â„¢34 J s = 4.13566733(10) ÃÆ'-10à ¢Ã‹â€ Ã¢â‚¬â„¢15 eV s is Plancks constant. Whenever electromagnetic waves exist in a medium with matter, their wavelength is decreased. Wavelengths of electromagnetic radiation, no matter what medium they are travelling through, are usually quoted in terms of the vacuum wavelength, although this is not always explicitly stated. Generally, EM radiation is classified by wavelength into radio wave, microwave, infrared, the visible region we perceive as light, ultraviolet, X-rays and gamma rays. The behaviour of EM radiation depends on its wavelength. When EM radiation interacts with single atoms and molecules, its behaviour also depends on the amount of energy per quantum (photon) it carries. Spectroscopy can detect a much wider region of the EM spectrum than the visible range of 400 nm to 700 nm. A common laboratory spectroscope can detect wavelengths from 2 nm to 2500 nm. Detailed information about the physical properties of objects, gases, or even stars can be obtained from this type of device. Spectroscopes are widely used in astrophysics. For example, many hydrogen atoms emit a radio wave photon which has a wavelength of 21.12 cm. Also, frequencies of 30 Hz and below can be produced by and are important in the study of certain stellar nebulae and frequencies as high as 2.9ÃÆ'-1027 Hz have been detected from astrophysical sources. - The Spectrum of Electromagnetic Waves While the classification scheme is generally accurate, in reality there is often some overlap between neighbouring types of electromagnetic energy. For example, SLF radio waves at 60 Hz may be received and studied by astronomers, or may be ducted along wires as electric power, although the latter is, strictly speaking, not electromagnetic radiation at all (see near and far field) The distinction between X and gamma rays is based on sources: gamma rays are the photons generated from nuclear decay or other nuclear and sub nuclear/particle process, whereas X-rays are generated by electronic transitions involving highly energetic inner atomic electrons. Generally, nuclear transitions are much more energetic than electronic transitions, so usually, gamma-rays are more energetic than X-rays, but exceptions exist. By analogy to electronic transitions, muonic atom transitions are also said to produce X-rays, even though their energy may exceed 6 mega electron volts (0.96 pJ), whereas there a re many (77 known to be less than 10 keV (1.6 fJ)) low-energy nuclear transitions (e.g. the 7.6 eV (1.22 aJ) nuclear transition of thorium-229), and despite being one million-fold less energetic than some muonic X-rays, the emitted photons are still called gamma rays due to their nuclear origin. Also, the region of the spectrum of the particular electromagnetic radiation is reference-frame dependent (on account of the Doppler shift for light) so EM radiation which one observer would say is in one region of the spectrum could appear to an observer moving at a substantial fraction of the speed of light with respect to the first to be in another part of the spectrum. For example, consider the cosmic microwave background. It was produced, when matter and radiation decoupled, by the de-excitation of hydrogen atoms to the ground state. These photons were from Lyman series transitions, putting them in the ultraviolet (UV) part of the electromagnetic spectrum. Now this radiation has undergone enough cosmological red shift to put it into the microwave region of the spectrum for observers moving slowly (compared to the speed of light) with respect to the cosmos. However, for particles moving near the speed of light, this radiation will be blue-shifted in their rest frame. The highest energy cosmic ray protons are moving such that, in their rest frame, this radiation is blueshifted to high energy gamma rays which interact with the proton to produce bound quark-antiquark pairs (pions). This is the source of the GZK limit Radio Waves: whose wavelength range from more than 104 m to about 0.1m, are the results of charges accelerating through conducting wires. They are generated by such electronic devices as LC oscillators and are used in radio and television communication systems. Radio waves generally are utilized by antennas of appropriate size (according to the principle of resonance), with wavelengths ranging from hundreds of meters to about one millimetre. They are used for transmission of data, via modulation. Television, mobile phones, wireless networking and amateur radio all use radio waves. The use of the radio spectrum is regulated by many governments through frequency allocation. Radio waves can be made to carry information by varying a combination of the amplitude, frequency and phase of the wave within a frequency band. When EM radiation impinges upon a conductor, it couples to the conductor, travels along it, and induces an electric current on the surface of that conductor by exciting the electrons of the conducting material. This effect (the skin effect) is used in antennas. EM radiation may also cause certain molecules to absorb energy and thus to heat up, causing thermal effects and sometimes burns. This is exploited in microwave ovens. Microwaves: The super high frequency (SHF) and extremely high frequency (EHF) of microwaves come next up the frequency scale. Microwaves are waves which are typically short enough to employ tubular metal waveguides of reasonable diameter. They have wavelengths ranging from approximately 0.3m to 10-4 m and are also generated by electronic devices. Because of their short wave lengths, they are well suited for radar system and for studying atomic and molecular properties of matter. Microwave ovens are an interesting domestic application of these waves. It has been suggested that the solar energy could be harnessed by beaming microwaves to the earth from a solar collector in space. Microwave energy is produced with klystron and magnetron tubes, and with solid state diodes such as Gunn and IMPATT devices. Microwaves are absorbed by molecules that have a dipole moment in liquids. In a microwave oven, this effect is used to heat food. Low-intensity microwave radiation is used in Wi-Fi, although this is at intensity levels unable to cause thermal heating. Volumetric heating, as used by microwaves, transfer energy through the material electromagnetically, not as a thermal heat flux. The benefit of this is a more uniform heating and reduced heating time; microwaves can heat material in less than 1% of the time of conventional heating methods. When active, the average microwave oven is powerful enough to cause interference at close range with poorly shielded electromagnetic fields such as those found in mobile medical devices and cheap consumer electronics. Infrared Waves: have wavelengths ranging from approximately 10-3m to the longest wavelength of visible light, 710-7m. These waves, produced by molecules and room temperature objects, are readily absorbed by most materials. The infrared energy absorbed by a substance appears as internal energy because the energy agitates objects atoms, increasing their vibrational or translational motion, which results in a temperature increase. Infrared radiation has practical and scientific applications in many areas, including physical therapy, IR photography and vibrational spectroscopy. The infrared part of the electromagnetic spectrum covers the range from roughly 300 GHz (1 mm) to 400 THz (750 nm). It can be divided into three parts: Far-infrared, from 300 GHz (1 mm) to 30 THz (10 ÃŽÂ ¼m). The lower part of this range may also be called microwaves. This radiation is typically absorbed by so-called rotational modes in gas-phase molecules, by molecular motions in liquids, and by phonons in solids. The water in the Earths atmosphere absorbs so strongly in this range that it renders the atmosphere effectively opaque. However, there are certain wavelength ranges (windows) within the opaque range which allow partial transmission, and can be used for astronomy. The wavelength range from approximately 200 ÃŽÂ ¼m up to a few mm is often referred to as sub-millimetre in astronomy, reserving far infrared for wavelengths below 200 ÃŽÂ ¼m. Mid-infrared, from 30 to 120 THz (10 to 2.5 ÃŽÂ ¼m). Hot objects (black-body radiators) can radiate strongly in this range. It is absorbed by molecular vibrations, where the different atoms in a molecule vibrate around their equilibrium positions. This range is sometimes called the fingerprint region since the mid-infrared absorption spectrum of a compound is very specific for that compound. Near-infrared, from 120 to 400 THz (2,500 to 750 nm). Physical processes that are relevant for this range are similar to those for visible light. Visible light: It is the most familiar form of electromagnetic spectrum the human eye can detect. Light is produced by the rearrangement of electrons in atoms and molecules. The various wavelengths of visible light, which correspond to different colours, range from red (ÃŽÂ »=710-7) to violet (ÃŽÂ »=410-7). The sensitivity of the human eye is a function of wavelength, being a maximum of 5.510-7m. This is the range in which the sun and stars similar to it emit most of their radiation. It is probably not a coincidence that the human eye is sensitive to the wavelengths that the sun emits most strongly. Visible light (and near-infrared light) is typically absorbed and emitted by electrons in molecules and atoms that move from one energy level to another. The light we see with our eyes is really a very small portion of the electromagnetic spectrum. A rainbow shows the optical (visible) part of the electromagnetic spectrum; infrared (if you could see it) would be located just beyond the red side of the rainbow with ultraviolet appearing just beyond the violet end. Electromagnetic radiation with a wavelength between 380 nm and 760 nm (790-400 terahertz) is detected by the human eye and perceived as visible light. Other wavelengths, especially near infrared (longer than 760 nm) and ultraviolet (shorter than 380 nm) are also sometimes referred to as light, especially when the visibility to humans is not relevant. If radiation having a frequency in the visible region of the EM spectrum reflects off an object, say, a bowl of fruit, and then strikes our eyes, this results in our visual perception of the scene. Our brains visual system processes the multitude of reflected frequencies into different shades and hues, and through this not-entirely-understood psychophysical phenomenon, most people perceive a bowl of fruit. At most wavelengths, however, the information carried by electromagnetic radiation is not directly detected by human senses. Natural sources produce EM radiation across the spectrum, and our technology can also manipulate a broad range of wavelengths. Optical fiber transmits light which, although not suitable for direct viewing, can carry data that can be translated into sound or an image. The coding used in such data is similar to that used with radio waves. Ultraviolet light: These cover wavelengths ranging from approximately 410-7 to 610-10m. The sun is an important source of ultraviolet (UV) light, which is the main cause of sun burn. Sunscreen lotions are transparent to visible light but absorb most of the ultraviolet light. The higher a sunscreens solar protection factor, or SPF, the greater the percentage of UV light absorbed. Ultraviolet rays have also been implicated in the formation of cataracts, a clouding of lens inside the eye. Most of the UV light from the sun is absorbed by ozone (O3) molecules in the earths upper atmosphere, in a layer called the stratosphere. This ozone shield converts lethal high energy UV energy into IR radiation, which in turn warms the stratosphere. Next in frequency comes ultraviolet (UV). This is radiation whose wavelength is shorter than the violet end of the visible spectrum, and longer than that of an X-ray. Being very energetic, UV can break chemical bonds, making molecules unusually reactive or ionizing them (see photoelectric effect), in general changing their mutual behaviour. Sunburn, for example, is caused by the disruptive effects of UV radiation on skin cells, which is the main cause of skin cancer, if the radiation irreparably damages the complex DNA molecules in the cells (UV radiation is a proven mutagen). The Sun emits a large amount of UV radiation, which could quickly turn Earth into a barren desert. However, most of it is absorbed by the atmospheres ozone layer before reaching the surface. X-rays: They have wavelengths in the range from approximately 10-8m to 10-12m. The most common source of x-rays is the stopping of high-energy electrons upon bombarding a metal target. X-rays are used as a diagnostic tool in medicine (a process known as radiography) and as a treatment for certain forms of cancer as well as for high-energy physics and astronomy.. Because x-rays can damage or destroy living tissues and organisms, care must be taken to avoid unnecessary exposure or over exposure. X-rays are also used in the study of crystal structure because x-ray wavelengths are comparable to the atomic separation distances in solids (about 0.1nm). Hard X-rays have shorter wavelengths than soft X-rays., Neutron stars and accretion disks around black holes emit X-rays, which enable us to study them. X-rays are given off by stars and are strongly emitted by some types of nebulae. Gamma rays: After hard X-rays comes gamma rays, which were discovered by Paul Villard in 1900, these are the most energetic photons, having no defined lower limit to their wavelength. They are electromagnetic waves emitted by radioactive nuclei (such as 60Co and 137Cs) and during certain nuclear reactions. High-energy gamma rays are a component of cosmic rays that enter the earths atmosphere from space. They have wavelength ranging from approximately 10-10m to less than 10-14m. Gamma rays are highly penetrating and produce serious damage when absorbed by living tissues. Consequently those working near such dangerous radiation must be protected with heavily absorbing material such as thick layers of lead. They are useful to astronomers in the study of high energy objects or regions, and find a use with physicists thanks to their penetrative ability and their production from radioisotopes. Gamma rays are also used for the irradiation of food and seed for sterilization, and in medicine they are used in radiation cancer therapy and some kinds of diagnostic imaging such as PET scans. The wavelength of gamma rays can be measured with high accuracy by means of Compton scattering. Note: There are no precisely defined boundaries between the bands of the electromagnetic spectrum. Radiations of some types have a mixture of the properties of those in two regions of the spectrum. For example, red light resembles infrared radiation in that it can resonate some chemical bonds. Application Areas of Electromagnetic Waves Electromagnetic Waves in the modern world have led to evolvement of many advanced communication systems some of them are radio, television, radars, etc. We would now focus on how these electromagnetic waves which carry energy and momentum are used in various applications round the globe. TELEMETRY Telemetry is the process of making measurements from a remote location and transmitting those measurements to receiving equipment. The earliest telemetry systems, developed in the United States during the 1880s, monitored the distribution and use of electricity in a given region, and relayed this information back to power companies using telephone lines. By the end of World War I, electric companies used the power lines themselves as information relays, and though such electrical telemetry systems remain in use in some sectors, most modern telemetry systems apply radio signals. An example of a modern telemetry application is the use of an input device called a transducer to measure information concerning an astronauts vital signs (heartbeat, blood pressure, body temperature, and so on) during a manned space flight. The transducer takes this information and converts it into an electrical impulse, which is then beamed to the space monitoring station on Earth. Because this signal carries information, it must be modulated, but there is little danger of interference with broadcast transmissions on Earth. Typically, signals from spacecraft are sent in a range above 10 10 Hz, far above the frequencies of most microwave transmissions for commercial purposes. RADAR Radio waves can be used to send communication signals, or even to cook food; they can also be used to find and measure things. One of the most obvious applications in this regard is radar, an acronym for RAdio Detection And Ranging. Radio makes it possible for pilots to see through clouds, rain, fog, and all manner of natural phenomena-not least of which is darkness. It can also identify objects, both natural and manmade, thus enabling a peacetime pilot to avoid hitting another craft or the side of a mountain. On the other hand, radar may help a pilot in wartime to detect the presence of an enemy. Nor is radar used only in the skies, or for military purposes, such as guiding missiles: on the ground, it is used to detect the speeds of objects such as automobiles on an interstate highway, as well as to track storms. In the simplest model of radar operation, the unit sends out microwaves toward the target, and the waves bounce back off the target to the unit. Though the speed of light is reduced somewhat, due to the fact that waves are travelling through air rather than through a vacuum, it is, nonetheless, possible to account for this difference. Hence, the distance to the target can be calculated using the simple formula d = vt, where d is distance, v is velocity, and t is time. Typically, a radar system includes the following: a frequency generator and a unit for controlling the timing of signals; a transmitter and, as with broadcast radio, a modulator; a duplexer, which switches back and forth between transmission and reception mode; an antenna; a receiver, which detects and amplifies the signals bounced back to the antenna; signal and data processing units; and data display units. In a monostatic unit-one in which the transmitter and receiver are in the same location-the unit has to be continually switched between sending and receiving modes. Clearly, a bistatic unit-one in which the transmitter and receiver antennas are at different locations-is generally preferable; but on an airplane, for instance, there is no choice but to use a monostatic unit. In order to determine the range to a target-whether that target be a mountain, an enemy aircraft, or a storm-the target itself must first be detected. This can be challenging, because only a small portion of the transmitted pulse comes back to the receiving antenna. At the same time, the antenna receives reflections from a number of other objects, and it can be difficult to determine which signal comes from the target. For an aircraft in a wartime situation, these problems are compounded by the use of enemy countermeasures such as radar jamming. Still another difficulty facing a military flyer is the fact that the use of radar itself-that is the transmission of microwaves-makes the aircraft detectable to opposing forces. MICROWAVE OVENS The same microwaves that transmit FM and television signals-to name only the most obviously applications of microwave for communication-can also be harnessed to cook food. The microwave oven, introduced commercially in 1955, was an outgrowth of military technology developed a decade before. During World War II, the Raytheon Manufacturing Company had experimented with a magnetron, a device for generating extremely short-wavelength radio signals as a means of improving the efficiency of military radar. While working with a magnetron, a technician named Percy Spencer was surprised to discover that a candy bar in his pocket had melted, even though he had not felt any heat. This led him to considering the possibilities of applying the magnetron to peacetime uses, and a decade later, Raytheons radar range hit the market. Those early microwave ovens had none of varied power settings to which modern users of the microwave-found today in two-thirds of all American homes-are accustomed. In the first microwaves, the only settings were on and off, because there were only two possible adjustments: either the magnetron would produce, or not produce, microwaves. Today, it is possible to use a microwave for almost anything that involves the heating of food that contains water-from defrosting a steak to popping popcorn. As noted much earlier, in the general discussion of electromagnetic radiation, there are three basic types of heat transfer: conduction, convection, and radiation. Without going into too much detail here, conduction generally involves heat transfer between molecules in a solid; convection takes place in a fluid (a gas such as air or a liquid such as water); and radiation, of course, requires no medium. A conventional oven cooks through convection, though conduction also carries heat from the outer layers of a solid (for example, a turkey) to the interior. A microwave, on the other hand, uses radiation to heat the outer layers of the food; then conduction, as with a conventional oven, does the rest. The difference is that the microwave heats only the food-or, more specifically, the water, which then transfers heat throughout the item being heated-and not the dish or plate. Thus, many materials, as long as they do not contain water, can be placed in a microwave oven without being melted or burned. Metal, though it contains no water, is unsafe because the microwaves bounce off the metal surfaces, creating a microwave buildup that can produce sparks and damage the oven. In a microwave oven, microwaves emitted by a small antenna are directed into the cooking compartment, and as they enter, they pass a set of turning metal fan blades. This is the stirrer, which disperses the microwaves uniformly over the surface of the food to be heated. As a microwave strikes a water molecule, resonance causes the molecule to align with the direction of the wave. An oscillating magnetron causes the microwaves to oscillate as well, and this, in turn, compels the water molecules to do the same. Thus, the water molecules are shifting in position several million times a second, and this vibration generates energy that heats the water. RADIO COMMUNICATION Among the most familiar parts of the electromagnetic spectrum, in modern life at least, is radio. In most schematic representations of the spectrum, radio waves are shown either at the left end or the bottom, as an indication of the fact that these are the electromagnetic waves with the lowest frequencies, the longest wavelengths, and the smallest levels of photon energy. Included in this broad sub-spectrum, with frequencies up to about 10 7 Hertz are long-wave radio, short-wave radio, and microwaves. The areas of communication affected are many: broadcast radio, television, mobile phones, radar-and even highly specific forms of technology such as baby monitors. Though the work of Maxwell and Hertz was foundational to the harnessing of radio waves for human use, the practical use of radio had its beginnings with Marconi. During the 1890s, he made the first radio transmissions, and, by the end of the century, he had succeeded in transmitting telegraph messages across the Atlantic Ocean-a feat which earned him the Nobel Prize for physics in 1909. Marconis spark transmitters could send only coded messages, and due to the broad, long-wave length signals used, only a few stations could broadcast at the same time. The development of the electron tube in the early years of the twentieth century, however, made it possible to transmit narrower signals on stable frequencies. This, in turn, enabled the development of technology for sending speech and music over the airwaves. THE DEVELOPMENT OF AM AND FM. A radio signal is simply a carrier: the process of adding information-that is, complex sounds such as those of speech or music-is called modulation. The first type of modulation developed was AM, or amplitude modulation, which Canadian-American physicist Reginald Aubrey Fessenden (1866-1932) demonstrated with the first United States radio broadcast in 1906. Amplitude modulation varies the instantaneous amplitude of the radio wave, a function of the radio stations power, as a means of transmitting information. By the end of World War I, radio had emerged as a popular mode of communication: for the first time in history, entire nations could hear the same sounds at the same time. During the 1930s, radio became increasingly important, both for entertainment and information. Families in the era of the Great Depression would gather around large cathedral radios-so named for their size and shape-to hear comedy programs, soap operas, news programs, and speeches by important public figures such as President Franklin D. Roosevelt. Throughout this era-indeed, for more than a half-century from the end of the first World War to the height of the Vietnam Conflict in the mid-1960s-AM held a dominant position in radio. This remained the case despite a number of limitations inherent in amplitude modulation: AM broadcasts flickered with popping noises from lightning, for instance, and cars with AM radios tended to lose their signal when going under a bridge. Yet, another mode of radio transmission was developed in the 1930s, thanks to American inventor and electrical engineer Edwin H. Armstrong (1890-1954). This was FM, or frequency modulation, which varied the radio signals frequency rather than its amplitude. Not only did FM offer a different type of modulation; it was on an entirely different frequency range. Whereas AM is an example of a long-wave radio transmission, FM is on the microwave sector of the electromagnetic spectrum, along with television and radar. Due to its high frequency and form of modulation, FM offered a clean sound as compared with AM. The addition of FM stereo broadcasts in the 1950s offered still further improvements; yet despite the advantages of FM, audiences were slow to change, and FM did not become popular until the mid-to late 1960s. SIGNAL PROPAGATION AM signals have much longer wavelengths, and smaller frequencies, than do FM signals, and this, in turn, affects the means by which AM signals are propagated. There are, of course, much longer radio wavelengths; hence, AM signals are described as intermediate in wavelength. These intermediate-wavelength signals reflect off highly charged layers in the ionosphere between 25 and 200 mi (40-332 km) above Earths surface. Short-wave-length signals, such as those of FM, on the other hand, follow a straight-line path. As a result, AM broadcasts extend much farther than FM, particularly at night. At a low level in the ionosphere is the D layer, created by the Sun when it is high in the sky. The D layer absorbs medium-wavelength signals during the day, and for this reason, AM signals do not travel far during daytime hours. After the Sun goes down, however, the D layer soon fades, and this makes it possible for AM signals to reflect off a much higher layer of the ionosphere known as the F layer. (This is also sometimes known as the Heaviside layer, or the Kennelly-Heaviside layer, after English physicist Oliver Heaviside and British-American electrical engineer Arthur Edwin Kennelly, who independently discovered the ionosphere in 1902.) AM signals bounce off the F layer as though it were a mirror, making it possible for a listener at night to pick up a signal from halfway across the country. The Sun has other effects on long-wave and intermediate-wave radio transmissions. Sunspots, or dark areas that appear on the Sun in cycles of about 11 years, can result in a heavier buildup of the ionosphere than normal, thus impeding radio-signal propagation. In addition, occasional bombardment of Earth by charged particles from the Sun can also disrupt transmissions. Due to the high frequencies of FM signals, these do not reflect off the ionosphere; instead, they are received as direct waves. For this reason, an FM station has a fairly short broadcast range, and this varies little with regard to day or night. The limited range of FM stations as compared to AM means that there is much less interference on the FM dial than for AM. In the United States and most other countries, one cannot simply broadcast at will; the airwaves are regulated, and, in America, the governing authority is the Federal Communications Commission (FCC). The FCC, established in 1934, was an outgrowth of the Federal Radio Commission, founded by Congress seven years earlier. The FCC actually sells air, charging companies a fee to gain rights to a certain frequency. Those companies may in turn sell that air to ot

Women in the Israeli Army Essays -- Military Science, Egalitarianism

Women have always played a very integral role in the Israel Defence Forces (IDF), since its inception in 1948 shortly after the declaration of the State of Israel. The IDF is regarded as one of the most well trained armed forces in the world thanks in part to the progressive changes in the military with regards to equality for women. Historically, at the ground roots of the IDF, women were held back from combat and served mostly in a variety of support duties under the command of Chen (Women’s Army Corps). These support duties were extremely important to the functioning of the IDF, but did not satisfy those women who wanted a more active front line role. The aftermath of the Yom Kippur war in 1973 initiated a great change in military thinking for women in the IDF. The increased need for ground forces allowed women to enter selected operational divisions in the military, but still excluded them from participation in any combat roles. In spite of the new recognition that wo men played in the military after 1973, further equality was slow to come. Finally, in January of 2000 after a Supreme Court battle led by Allice Miller a few years earlier, the Equality amendment to the Military Service Law was implemented. Thus, allowing women the opportunity to volunteer in combat support and light combat roles. The Prime Minister of the State of Israel had a vision to equalize the role of women and men from active combat roles in the IDF. On May 31st, 1948 following the establishment of the State of Israel, the cabinet of Prime Minister David Ben-Gurion officially created the IDF, and declared it as the country’s army. It then became official that women between the ages of 18-24, single or married, without children had to join th... ...//www.idf.il/1283-9679-en/Dover.aspx>. "The Israeli Air Force." The Israeli Air Force. 28 Dec. 2010. Web. 10 Dec. 2011. . "Israeli Army Celebrates First-Ever Female Major General." Israeli Defence Forces, 23 June 2011. Web. 5 Dec. 2011. . "Israeli Women in the Military." Women's Rights. The Israel Project. Web. 5 Dec. 2011. . Izraeli, Dafna Nundi. "Israel Defense Forces." Jewish Women's Archive. 1 Mar. 2009. Web. 11 Dec. 2011. . "Women in the IDF." Krav Maga - Israeli Krav International. Web. 10 Dec. 2011. .

Patriotism and Its Meaning Essay -- Definition Patriot National Essays

Patriotism and Its Meaning In the aftermath of the September 11, 2001 terrorist attacks on the United States we are seeing many forms of Patriotism. I was suprised to find when I researched this word that it had a negative feeling associated with it. I believe that patriotism is actively showing your support for your country, standing up for what you believe in, and fighting for our individual free will and independence. I am proud of my country and I am not ashamed to fly the American Flag. Many men and women have died to give me the freedoms that I take for granted. I applaud their patriotism, and I thank them for giving me my way of life. I will support them in protecting my country. I will try to elect officials who believe in the issues I do, and who work for the better good o...

Racism: White People and South Africa Essay

Compare and contrast between racism in Malaysia and South Africa. â€Å"Racism is man’s gravest threat to man – the maximum of hatred for a minimum of reason†, quoted by Abraham J. Heschel. As we know the history of racism is long and despicable one. The journey to overcome this obstacle that has plagued us for years is just as time consuming and the effort is overwhelming. A recent survey has showed that South Africa is the highest rate of racism among all the country. So now let us analyze the racism between Malaysia and South Africa. The most notable difference between the racism in Malaysia and South Africa is the oppression on women. Till today, men in Africa still hold the traditional perspective that women are like their property and subject to their abuse. The poverty Africa could be one of the main causes why women in Africa are still undergoing such a great deal of oppression unlike women in other areas. They were paid less for a greater amount of work and less benefits too. Sometime, they were dismissed without advance notice or termination pay. Besides, South Africa has the world’s highest level of reported rape – nearly half a million each year. So it is not surprising that South Africa is often called the â€Å"rape capital of the world†. It has shown that women in Africa typically hold lower status and normally weaker than men from physical and mentally. Therefore they are easily to be oppressed and exploited by African men. In Malaysia, the position of women today has greatly improved. The Government’s commitment to promote gender equality is evidenced by several policies, administrative decision and amendments to laws that have attempted to grant equal rights to women and to remove discrimination against them. It should perhaps be acknowledged that most of the changes made were in response to lobbying by women through unions, non-governmental organizations (NGOs) and other women’s groups. For example, in relation to employment rights, women teachers succeeded in getting the Government to adopt the principle of equal pay for equal work in 1967. Yet another difference between the racism in two different countries is discrimination of different race. In South Africa, there is a prohibiting marriage between white people and people of other races. It considers as â€Å"unlawful racial intercourse† and â€Å"any immoral or indecent act† between a white person and an African, Indian or coloured person. Blacks were not allowed to run businesses in those areas designated as â€Å"white South Africa† without a permit. They were supposed to move to their homelands and set up businesses and practices there. Transport and civil facilities were segregated. Black buses stopped at black bus stops and white buses at white ones. Trains, hospitals and ambulances were segregated. Even though black people were not allowed to employ white people in white South Africa. Since Datuk Seri Najib Tun Abdul Razak became the sixth Prime Minister, he introduced a concept of solidarity, which is One Malaysia. 1 Malaysia brought the aspirations to improve race relations to ensure that the people of Malaysia to forge closer unity. The basic thing that needs to be created in the spirit of solidarity is a feeling of respect, sincerity and mutual trust between the races. Therefore, our citizens give priority to the interests of national allegiance and loyalty to the people and solve their own group. For example, one Indian got hit by a reckless car while he was playing outside the house. Some of neighbors (few Chinese but mostly Malays) quickly rushed for help, and they really got angry with the driver and almost smacked him! Although the neighbors are Malays, they stood for an Indian neighbor. Furthermore, the difference of racism between Malaysia and South Africa is the education system. South Africa has a high-cost, low-performance education system that does not compare favorably with education systems in other African countries, or in similar developing economies. There is a multitude of well-publicized problems, including a shortage of teachers, under qualified teachers and poor teacher performance. In the classroom, this results in poor learner standards and results, a lack of classroom discipline and is exacerbated by insufficient resources and inadequate infrastructure. So it is not surprising that many South Africans are low-educated and paid for little salaries. Malaysia’s educational system generally promotes surface and passive learning instead of deep and active learning which are crucial for creating a quality learning environment. The products of our school system are generally ill-prepared either for higher education work or life in general. As we know, our students lack critical and creative thinking skills because our educational system promotes conformity and uniformity. Therefore, a lot of step in transforming our education system are done. For example, one of the crucial steps is begin with the end in our mind. So, Malaysian students and graduates can possess adequate disciplinary knowledge, be self-confident and achievement-oriented persuasive and effective communicators. In conclusion, here are the main three differences between the racism in Africa and Malaysia. Even though racism is wrong, it is still being practiced in this country and in others. The origins are obscure, but it most likely had something to do with the fact that early humankind thought â€Å"black† (because it resembled â€Å"night†) was bad and â€Å"white† (because it resembled â€Å"day†) was good. But our enlightened society has more discernment than this, and we know that a person is neither good nor bad depending on the color of their skin.

Are the Filipinos Ready for K to12? Essay

â€Å"We need to add two years to our basic education. Those who can afford to pay up to fourteen years of schooling before university. Thus, their children are getting into the best universities and the best jobs after graduation. I want at least 12 years for our public school children to give them an even chance at succeeding.† – President Benigno S. Aquino III This is part of President Benigno â€Å"NoyNoy† Aquino III’s Educational Reform Program. The P-Noy Administration firmly believes that adding more years to Basic Education in the Philippines could help solve the problem of unemployment, keep up with global standards, and help Filipino students to have more time to choose the career that best suit their skills. But, are Filipinos ready for it? The enhanced K-12 Education Plan is said to add one more year on both primary and secondary levels excluding kindergarten. The program is proposed to start in school year 2012-2013 for Grade 1 and first year high school students with the target of full implementation by SY 2018-2019. K-12 has been met with criticism from youth and student groups, teachers, parents and the academic community. The DepEd, for its part, appears determined to enact the program with its proposed budget catering mostly to preparing the grounds for its eventual implementation. Critics, however, counteract that the education crisis needs to be addressed more fundamentally and adding more school years would only worsen our condition. As a teacher, I am completely aware of the government’s (through the DepEd) desire to uplift the quality of education here in the Philippines. Each year, the need for highly competitive graduates continues to grow as the demand for high paying jobs spread across the globe. With this proposed K-12 education program, there is a probability that it might help us realize that. Though there are other concerns in the education sector that need more immediate response and attention of the government, we couldn’t defy the fact that we are lagging behind other countries that were once, like us, groping for progress and improvement. Extending the number of years in school will not directly affect nor influence the quality of education because it would only mean adding more budget for more teachers, classrooms, etc. But, we’re aiming for quality and not quantity, right? I believe that introducing something new might make a difference of what we are at present. If we have enough resources, then, why not? We should welcome every opportunity that will assure our place in this rapid changing world. What the youth and country really needs is the improvement and establishment of an education system that will provide the needs of the Filipino youth and the society in general. And this K-12 proposal could be the answer to our problem. Unless we open our minds into these changes, all efforts will remain in vain. And neither 10 nor 12 years would make much of difference.

Early marriage Essay

Early marriages are marriages that happen between people under the age of eighteen. Such marriages are spread all over Palestine. In particular, they occur in Palestinian rural rather than urban areas. These practices take place for several reasons. One very important cause is the religious definition of adulthood which is more related to physical and biological aspects rather than psychological and behavioral. Another essential purpose for this practice is the lack of adequate education. Moreover, sometimes it is caused by the negative social point of view that links between fertility and age for women. However, governments, nowadays, are working to decrease the practice of early marriage as it deprives girls from their major rights and causes many health consequences for them. One effect of the early marriage is that it takes away many of the girls’ major rights. Firstly, it deprives them from the right to continue their education. As an illustration, the majority of girls, especially those who live in rural areas, are forced to get married instead of persisting their education. Furthermore, this deprivation results in lack of knowledge on how to raise the children well. Secondly, being forced to marry at an early age does not allow the girls to choose their lifelong partner. Thus, it makes her more of a follower instead of taking her decisions by herself. Finally, girls who marry at a young age are often isolated from their society and friends. This means, most of the young wives do not have the right to communicate freely with their family and friends since the responsibilities does not allow them to do so. On my point of view, forcing young women to marry before they reach eighteen years old is a violation against basic human rights. Another possible effect of the early marriage is that it leads to some bad health consequences on the woman herself and on her children too. For example, young brides are expected to become pregnant at an early age and there is a strong connection between the age of a mother and affectionate mortality. To be specific, Girls ages l0-14 are five times more likely to die in pregnancy or childbirth than women aged 20-24 and girls aged 15-19 are twice as likely to die .additionally, young mothers live greater risks during their pregnancies and suffer from many complications. For instance, they go through many dangerous conditions such as heavy bleeding, fistula, infection, anemia, and eclampsia which contribute to higher mortality rates  of both mother and child. In addition, early marriages may also lead to vulnerability to HIV/AIDS among young wives. To be particular, in Africa, Being young and female is a major risk factor for infection and young girls are being infected at a considerably disproportional rate to that of boys. Despite the fact that early marriages are sometimes seen by parents as a mechanism for protecting their daughters from HIV/AIDS, future husbands may already be infected from previous sexual encounters; so, it is a risk which is particularly serious for girls with older husbands. The lake of major rights and the physical consequences are some of the effects of early marriage that leads to a poor life to an innocent child. Therefore, there has to be more emphasis on the governments to convince people against it .However, families, nowadays, have recognized that young marriages are not good for children especially for girls. In addition, some concerned groups have actually tried to make new laws in countries so that the legal age of marriage will be raised to eighteen or more in order to save lives and create a better world for females.