Science: Chemistry: Periodic Table

The periodic table of the chemical elements is a tabular method of displaying the chemical elements. Although precursors to this table exist, its invention is generally credited to Russian chemist Dmitri Mendeleev in 1869. Mendeleev intended the table to illustrate recurring ("periodic") trends in the properties of the elements. The layout of the table has been refined and extended over time, as new elements have been discovered, and new theoretical models have been developed to explain chemical behavior.[1]

The periodic table is now ubiquitous within the academic discipline of chemistry, providing an extremely useful framework to classify, systematize and compare all the many different forms of chemical behavior. The table has also found wide application in physics, biology, engineering, and industry. The current standard table contains 117 elements as of January 27, 2008 (elements 1-116 and element 118).

The layout of the periodic table demonstrates recurring ("periodic") chemical properties. Elements are listed in order of increasing atomic number (i.e. the number of protons in the atomic nucleus). Rows are arranged so that elements with similar properties fall into the same vertical columns ("groups"). According to quantum mechanical theories of electron configuration within atoms, each horizontal row ("period") in the table corresponded to the filling of a quantum shell of electrons. There are progressively longer periods further down the table, grouping the elements into s-, p-, d- and f-blocks to reflect their electron configuration.

In printed tables, each element is usually listed with its element symbol and atomic number; many versions of the table also list the element's atomic mass and other information, such as its abbreviated electron configuration, electronegativity and most common valence numbers.

As of 2006, the table contains 117 chemical elements whose discoveries have been confirmed. Ninety-four are found naturally on Earth, and the rest are synthetic elements that have been produced artificially in particle accelerators. Elements 43 (technetium), 61 (promethium), 93 (neptunium) and 94 (plutonium) have no stable isotopes and were first discovered synthetically; however, they were later discovered in trace amounts on earth as products of natural radioactive decay processes.

In Ancient Greece, the influential Greek philosopher Aristotle proposed that there were four main elements: air, fire, earth and water. All of these elements could be reacted to create another one; e.g., earth and fire combined to form lava. However, this theory was dismissed when the real chemical elements started being discovered. Scientists needed an easily accessible, well organized database with which information about the elements could be recorded and accessed. This was to be known as the periodic table.

The original table was created before the discovery of subatomic particles or the formulation of current quantum mechanical theories of atomic structure. If one orders the elements by atomic mass, and then plots certain other properties against atomic mass, one sees an undulation or periodicity to these properties as a function of atomic mass. The first to recognize these regularities was the German chemist Johann Wolfgang Döbereiner who, in 1829, noticed a number of triads of similar elements:
Some triads Element Molar mass
(g/mol) Density
(g/cm³)
chlorine 35.453 0.0032
bromine 79.904 3.1028
iodine 126.90447 4.933

calcium 40.078 1.55
strontium 87.62 2.54
barium 137.327 3.594

In 1829 Döbereiner proposed the Law of Triads: The middle element in the triad had atomic weight that was the average of the other two members. The densities of some triads followed a similar pattern. Soon other scientists found chemical relationships extended beyond triads. Fluorine was added to Cl/Br/I group; sulfur, oxygen, selenium and tellurium were grouped into a family; nitrogen, phosphorus, arsenic, antimony, and bismuth were classified as another group.
Dmitri Mendeleev, father of the periodic table
Dmitri Mendeleev, father of the periodic table

This was followed by the English chemist John Newlands, who noticed in 1865 that when placed in order of increasing atomic weight, elements of similar physical and chemical properties recurred at intervals of eight, which he likened to the octaves of music, though his law of octaves was ridiculed by his contemporaries.[3] However, while successful for some elements, Newlands' law of octaves failed for two reasons:

1. It was not valid for elements that had atomic masses higher than Ca.
2. When further elements were discovered, such as the noble gases (He, Ne, Ar), they could not be accommodated in his table.

Finally, in 1869 the Russian chemistry professor Dmitri Ivanovich Mendeleev and four months later the German Julius Lothar Meyer independently developed the first periodic table, arranging the elements by mass. However, Mendeleev plotted a few elements out of strict mass sequence in order to make a better match to the properties of their neighbors in the table, corrected mistakes in the values of several atomic masses, and predicted the existence and properties of a few new elements in the empty cells of his table. Mendeleev was later vindicated by the discovery of the electronic structure of the elements in the late 19th and early 20th century.

Earlier attempts to list the elements to show the relationships between them (for example by Newlands) had usually involved putting them in order of atomic mass. Mendeleev's key insight in devising the periodic table was to lay out the elements to illustrate recurring ("periodic") chemical properties (even if this meant some of them were not in mass order), and to leave gaps for "missing" elements. Mendeleev used his table to predict the properties of these "missing elements", and many of them were indeed discovered and fit the predictions well.

With the development of theories of atomic structure (for instance by Henry Moseley) it became apparent that Mendeleev had listed the elements in order of increasing atomic number (i.e. the net amount of positive charge on the atomic nucleus). This sequence is nearly identical to that resulting from ascending atomic mass.

In order to illustrate recurring properties, Mendeleev began new rows in his table so that elements with similar properties fell into the same vertical columns ("groups").

With the development of modern quantum mechanical theories of electron configuration within atoms, it became apparent that each horizontal row ("period") in the table corresponded to the filling of a quantum shell of electrons. In Mendeleev's original table, each period was the same length. Modern tables have progressively longer periods further down the table, and group the elements into s-, p-, d- and f-blocks to reflect our understanding of their electron configuration.

In the 1940s Glenn T. Seaborg identified the transuranic lanthanides and the actinides, which may be placed within the table, or below (as shown above).

Science: Physics: Uses of Optical Fibres

In this section we will show you how optical fibres are used. As you will be able to see when you read further, optical fibres are revolutionising fields like communications and medicine.

Telecommunications Industry

Until the optical fibre network was developed, telephone calls were mainly sent as electrical signals along copper wire cables. As demand for the systems to carry more telephone calls increased, simple copper wires did not have the capacity, known as bandwidth, to carry the amount of information required.

Systems using coaxial cables like TV aerial leads were used but as the need for more bandwidth grew, these systems became more and more expensive especially over long distances when more signal regenerators were needed. As demand increases and higher frequency signals are carried, eventually the electronic circuits in the regenerators just cannot cope.

Optical fibres offer huge communication capacity. A single fibre can carry the conversations of every man, woman and child on the face of this planet, at the same time, twice over. The latest generations of optical transmission systems are beginning to exploit a significant part of this huge capacity, to satisfy the rapidly growing demand for data communications and the Internet.

The main advantages of using optical fibres in the communications industry are:

- A much greater amount of information can be carried on an optical fibre compared to a copper cable.

- In all cables some of the energy is lost as the signal goes along the cable. The signal then needs to be boosted using regenerators. For copper cable systems these are required every 2 to 3km but with optical fibre systems they are only needed every 50km.

- Unlike copper cables, optical fibres do not experience any electrical interference. Neither will they cause sparks so they can be used in explosive environments such as oil refineries or gas pumping stations.

- For equal capacity, optical fibres are cheaper and thinner than copper cables which makes them easier to install and maintain.

Case Study: British Telecom

In the UK at the moment there are three million kilometres of optical fibre cable in the BT network. Most of BT's trunk network now uses optical fibre cables. In a recent trial in Bishop's Stortford optical fibres were actually laid into homes. This allowed customers to receive cable TV and stereo radio as well as phone and information services.

Optical fibres could be put into all homes but currently the cost of the system including lasers and detectors would be too high for simple telephone calls. Some companies have a direct optical fibre link if they need to send large quantities of information by phone, for example between computers at different business centres.

Optical fibre submarine links are in use all around the world. Because of the low loss and high bandwidth of optical fibre systems they are ideal for submarine systems where you want to minimise the amount of complex electronics in regenerators sitting on the sea bed. In fact, the link from the UK to the English Channel Islands is achieved directly without any submerged regenerators.

The world's first international optical fibre submarine cable was laid by BT in 1986 between the UK and Belgium. It is 112Km in length and has only 3 regenerators. BT was a major partner in the first transatlantic optical fibre cable system - TAT 8 (Transatlantic Telecommunications cable no 8) which was capable of carrying 40,000 telephone calls at once, or the equivalent in data, facsimile, or TV pictures.

The second transatlantic cable, TAT 9, which came into service in 1992, has twice that capacity and links five separate landing points in the UK the USA, Canada, France and Spain. The transatlantic optical fibre cable network, completed in 1996, spanned 14,000Km and linked the UK, France and the USA . It could handle up to 320,000 phone calls at one time.

Undersea cables consist of fibres with a copper coated steel conductor which are covered in protective layers of steel and polypropylene. In shallow waters, e.g. the continental shelf, a submersible remote-controlled plough is used to bury the cables one metre below the seabed, to protect them from damage by trawling and ships' anchors.

Medicine Industry

The advent of practicable optical fibres has seen the development of much medical technology. Optical fibres have paved the way for a whole new field of surgery, called laproscopic surgery (or more commonly, keyhole surgery), which is usually used for operations in the stomach area such as appendectomies. Keyhole surgery usually makes use of two or three bundles of optical fibres. A "bundle" can contain thousands of individual fibres". The surgeon makes a number of small incisions in the target area and the area can then be filled with air to provide more room.

One bundle of optical fibres can be used to illuminate the chosen area, and another bundle can be used to bring information back to the surgeon. Moreover, this can be coupled with laser surgery, by using an optical fibre to carry the laser beam to the relevent spot, which would then be able to be used to cut the tissue or affect it in some other way.

Other Uses

- Optical fibres can be used for the purposes of illumination, often carrying light from outside to rooms in the interiors of large buildings.

- Another important application of optical fibres is in sensors. If a fibre is stretched or squeezed, heated or cooled or subjected to some other change of environment, there is usually a small but measurable change in light transmission. Hence, a rather cheap sensor can be made which can be put in a tank of acid, or near an explosion or in a mine and connected back, perhaps through kilometres of fibre, to a central point where the effects can be measured.

An advantage of fibre-optic sensors is that it is possible to measure the data at different points along the fibre and to know to what points the different measurements relate. These are the so-called distributed sensors.

- Fibre optics are also used to carry high power laser beams from fixed installations within factories to the point of use of the laser light for welding, cutting or drilling. The fibre provides a flexible and safe means of distributing high power laser radiation around a factory so that robots or machine tools can be provided with laser machining capability.

- Optical fibres can also be used as simple light guides. At least one fancy modern car has a single high intensity lamp under its bonnet, with optical fibres taking the light to a series of mini-headlamps on the front. Less high tech versions carry light from bulbs to the glove compartment etc.

- A research group at the Clarendon Laboratory, Oxford, is designing a laser installation at the William Hershel Telescope on La Palma to help astronomers make an 'artificial' star in the layer of atomic sodium which exists at a height of 100km above the Earth's surface.

The Earth's atmosphere is a big problem for astronomers. It is a gas that is constantly moving which makes the light traveling through it from distant starts flicker. If astronomers could use a reference 'star' whose brightness they knew, then they could allow for this twinkling.

The telescope will look at how the atmosphere is effecting the artificial star second by second and adjust the telescope's mirror to compensate. This should allow astronomers to capture pictures of astronomical objects of a quality previously only obtainable from the Hubble Space Telescope. The optical fibre in this case is used to pipe the laser power needed to create the artificial star from the lasers to the telescope itself.

- As light is not affected noticeably by electromagnetic fields. It also does not interfere with other instruments that do use electricity. For this reason, fibre-optics are also becoming very important for short-range communication and information transfer in applications situations like aircraft. This application is now being extended into motor cars, and plastic optical fibres will soon (say in 5-8 years time) be very common for transmitting information around the car.



So we can see that optical fibres are not just passive light pipes. Researchers are finding ways in which they can make the fibres become the active elements of the circuit, e.g. amplifiers or filters. This means that the information could remain in light form from one end of a link to the other, removing the limitations of the electronics in circuits and enabling more of the theoretical information carrying capacity to be used.

Engineers of the future can look forward to designing and using telecommunications systems that have no loss, infinite bandwidth and high reliability. New services for customers, such as 3D high definition TV and virtual reality information and entertainment systems, could be more easily provided as well as giving them the benefits of lower costs and greater flexibility - an exciting future.

Eng. Lang./Litera.: Lord of The Flies, Key Facts

full title · Lord of the Flies

author · William Golding

type of work · Novel

genre · Allegory; adventure story; castaway fiction; loss-of-innocence fiction

language · English

time and place written · Early 1950s; Salisbury, England

date of first publication · 1954

publisher · Faber and Faber

narrator · The story is told by an anonymous third-person narrator who conveys the events of the novel without commenting on the action or intruding into the story.

point of view · The narrator speaks in the third person, primarily focusing on Ralph's point of view but following Jack and Simon in certain episodes. The narrator is omniscient and gives us access to the characters' inner thoughts.

tone · Dark; violent; pessimistic; tragic; unsparing

tense · Immediate past

setting (time) · Near future

setting (place) · A deserted tropical island

protagonist · Ralph

major conflict · Free from the rules that adult society formerly imposed on them, the boys marooned on the island struggle with the conflicting human instincts that exist within each of them—the instinct to work toward civilization and order and the instinct to descend into savagery, violence, and chaos.

rising action · The boys assemble on the beach. In the election for leader, Ralph defeats Jack, who is furious when he loses. As the boys explore the island, tension grows between Jack, who is interested only in hunting, and Ralph, who believes most of the boys' efforts should go toward building shelters and maintaining a signal fire. When rumors surface that there is some sort of beast living on the island, the boys grow fearful, and the group begins to divide into two camps supporting Ralph and Jack, respectively. Ultimately, Jack forms a new tribe altogether, fully immersing himself in the savagery of the hunt.

climax · Simon encounters the Lord of the Flies in the forest glade and realizes that the beast is not a physical entity but rather something that exists within each boy on the island. When Simon tries to approach the other boys and convey this message to them, they fall on him and kill him savagely.

falling action · Virtually all the boys on the island abandon Jack and Piggy and descend further into savagery and chaos. When the other boys kill Piggy and destroy the conch shell, Ralph flees from Jack's tribe and encounters the naval officer on the beach.

themes · Civilization vs. savagery; the loss of innocence; innate human evil

motifs · Biblical parallels; natural beauty; the bullying of the weak by the strong; the outward trappings of savagery (face paint, spears, totems, chants)

symbols · The conch shell; Piggy's glasses; the signal fire; the beast; the Lord of the Flies; Ralph, Piggy, Jack, Simon, and Roger

foreshadowing · The rolling of the boulders off the Castle Rock in Chapter 6 foreshadows Piggy's death; the Lord of the Flies's promise to have some “fun” with Simon foreshadows Simon's death

For more information go to http://en.wikipedia.org/wiki/Lord_of_the_flies
AND VISIT http://gayorayo.blogspot.com

Eng. Lang./Litera.: L.O.T.F., Practice Exam Questions

1. What does it mean to say that Lord of the Flies is an allegorical novel? What are its important symbols?

2. Compare and contrast Ralph and Simon. Both seem to be “good” characters. Is there a difference in their goodness?

3. How does Jack use the beast to control the other boys?

ANSWERS AT THE END

Other questions for practice:

1. Of all the characters, it is Piggy who most often has useful ideas and sees the correct way for the boys to organize themselves. Yet the other boys rarely listen to him and frequently abuse him. Why do you think this is the case? In what ways does Golding use Piggy to advance the novel's themes?

2. What, if anything, might the dead parachutist symbolize? Does he symbolize something other than what the beast and the Lord of the Flies symbolize?

3. The sow's head and the conch shell each wield a certain kind of power over the boys. In what ways do these objects' powers differ? In what way is Lord of the Flies a novel about power? About the power of symbols? About the power of a person to use symbols to control a group?

4. What role do the littluns play in the novel? In one respect, they serve as gauges of the older boys' moral positions, for we see whether an older boy is kind or cruel based on how he treats the littluns. But are the littluns important in and of themselves? What might they represent?

ANSWERS TO FIRST 3 QUESTIONS:

1.Lord of the Flies is an allegorical novel in that it contains characters and objects that directly represent the novel's themes and ideas. Golding's central point in the novel is that a conflict between the impulse toward civilization and the impulse toward savagery rages within each human individual. Each of the main characters in the novel represents a certain idea or aspect of this spectrum between civilization and savagery. Ralph, for instance, embodies the civilizing impulse, as he strives from the start to create order among the boys and to build a stable society on the island. Piggy, meanwhile, represents the scientific and intellectual aspects of civilization. At the other end of the spectrum, Jack embodies the impulse toward savagery and the unchecked desire for power and domination. Even more extreme is Roger, who represents the drive for violence and bloodlust in its purest form. Furthermore, just as various characters embody thematic concepts in the novel, a number of objects do as well. The conch shell, which is used to summon the boys to gatherings and as a emblem of the right to speak at those gatherings, represents order, civilization, and political legitimacy. Piggy's glasses, which are used to make fire, represent the power of science and intellectual endeavor. The sow's head in the jungle, meanwhile, embodies the human impulse toward savagery, violence, and barbarism that exists within each person. Throughout Lord of the Flies, Golding uses these characters and objects to represent and emphasize elements of the themes and ideas he explores in the novel.

2.Both Ralph and Simon are motivated toward goodness throughout the novel. Both boys work to establish and maintain order and harmony with the rest of the group and are kind and protective in their interactions with the littluns. However, as the novel progresses, we get the sense that Ralph's and Simon's motivations for doing good stem from different sources. Ralph behaves and acts according to moral guidelines, but this behavior and these guidelines seem learned rather than innate. Ralph seems to have darker instinctual urges beneath: like the other boys, he gets swept up by bloodlust during the hunt and the dance afterward. Simon, on the other hand, displays a goodness and kindness that do not seem to have been forced or imposed upon him by civilization. Instead, Simon's goodness seems to be innate or to flow from his connection to nature. He lives in accordance with the moral regulations of civilization simply because he is temperamentally suited to them: he is kind, thoughtful, and helpful by nature. In the end, though Ralph is capable of leadership, we see that he shares the hidden instinct toward savagery and violence that Jack and his tribe embrace. Although Ralph does prove an effective leaders, it is Simon who recognizes the truth that stands at the core of the novel—that the beast does not exist in tangible form on the island but rather exists as an impulse toward evil within each individual.

3.Jack expertly uses the beast to manipulate the other boys by establishing the beast as his tribe's common enemy, common idol, and common system of beliefs all in one. Jack invokes different aspects of the beast depending on which effects he wants to achieve. He uses the boys' fear of the beast to justify his iron-fisted control of the group and the violence he perpetrates. He sets up the beast as a sort of idol in order to fuel the boys' bloodlust and establish a cultlike view toward the hunt. The boys' belief in the monster gives Lord of the Flies religious undertones, for the boys' various nightmares about monsters eventually take the form of a single monster that they all believe in and fear. By leaving the sow's head in the forest as an offering to the beast, Jack's tribe solidifies its collective belief in the reality of the nightmare. The skull becomes a kind of religious totem with extraordinary psychological power, driving the boys to abandon their desire for civilization and order and give in to their violent and savage impulses.

Eng. Lang./Litera.: Lord of The Flies, Themes

Civilization vs. Savagery

The central concern of Lord of the Flies is the conflict between two competing impulses that exist within all human beings: the instinct to live by rules, act peacefully, follow moral commands, and value the good of the group against the instinct to gratify one's immediate desires, act violently to obtain supremacy over others, and enforce one's will. This conflict might be expressed in a number of ways: civilization vs. savagery, order vs. chaos, reason vs. impulse, law vs. anarchy, or the broader heading of good vs. evil. Throughout the novel, Golding associates the instinct of civilization with good and the instinct of savagery with evil.

The conflict between the two instincts is the driving force of the novel, explored through the dissolution of the young English boys' civilized, moral, disciplined behavior as they accustom themselves to a wild, brutal, barbaric life in the jungle. Lord of the Flies is an allegorical novel, which means that Golding conveys many of his main ideas and themes through symbolic characters and objects. He represents the conflict between civilization and savagery in the conflict between the novel's two main characters: Ralph, the protagonist, who represents order and leadership; and Jack, the antagonist, who represents savagery and the desire for power.

As the novel progresses, Golding shows how different people feel the influences of the instincts of civilization and savagery to different degrees. Piggy, for instance, has no savage feelings, while Roger seems barely capable of comprehending the rules of civilization. Generally, however, Golding implies that the instinct of savagery is far more primal and fundamental to the human psyche than the instinct of civilization. Golding sees moral behavior, in many cases, as something that civilization forces upon the individual rather than a natural expression of human individuality. When left to their own devices, Golding implies, people naturally revert to cruelty, savagery, and barbarism. This idea of innate human evil is central to Lord of the Flies, and finds expression in several important symbols, most notably the beast and the sow's head on the stake. Among all the characters, only Simon seems to possess anything like a natural, innate goodness.

Loss of Innocence

As the boys on the island progress from well-behaved, orderly children longing for rescue to cruel, bloodthirsty hunters who have no desire to return to civilization, they naturally lose the sense of innocence that they possessed at the beginning of the novel. The painted savages in Chapter 12 who have hunted, tortured, and killed animals and human beings are a far cry from the guileless children swimming in the lagoon in Chapter 3. But Golding does not portray this loss of innocence as something that is done to the children; rather, it results naturally from their increasing openness to the innate evil and savagery that has always existed within them. Golding implies that civilization can mitigate but never wipe out the innate evil that exists within all human beings. The forest glade in which Simon sits in Chapter 3 symbolizes this loss of innocence. At first, it is a place of natural beauty and peace, but when Simon returns later in the novel, he discovers the bloody sow's head impaled upon a stake in the middle of the clearing. The bloody offering to the beast has disrupted the paradise that existed before—a powerful symbol of innate human evil disrupting childhood innocence.

Motifs

Motifs are recurring structures, contrasts, or literary devices that can help to develop and inform the text's major themes.
Biblical Parallels

Many critics have characterized Lord of the Flies as a retelling of episodes from the Bible. While that description may be an oversimplification, the novel does echo certain Christian images and themes. Golding does not make any explicit or direct connections to Christian symbolism in Lord of the Flies; instead, these biblical parallels function as a kind of subtle motif in the novel, adding thematic resonance to the main ideas of the story. The island itself, particularly Simon's glade in the forest, recalls the Garden of Eden in its status as an originally pristine place that is corrupted by the introduction of evil. Similarly, we may see the Lord of the Flies as a representation of the devil, for it works to promote evil among humankind. Furthermore, many critics have drawn strong parallels between Simon and Jesus. Among the boys, Simon is the one who arrives at the moral truth of the novel, and the other boys kill him sacrificially as a consequence of having discovered this truth. Simon's conversation with the Lord of the Flies also parallels the confrontation between Jesus and the devil during Jesus' forty days in the wilderness, as told in the Christian Gospels.

However, it is important to remember that the parallels between Simon and Christ are not complete, and that there are limits to reading Lord of the Flies purely as a Christian allegory. Save for Simon's two uncanny predictions of the future, he lacks the supernatural connection to God that Jesus has in Christian tradition. Although Simon is wise in many ways, his death does not bring salvation to the island; rather, his death plunges the island deeper into savagery and moral guilt. Moreover, Simon dies before he is able to tell the boys the truth he has discovered. Jesus, in contrast, was killed while spreading his moral philosophy. In this way, Simon—and Lord of the Flies as a whole—echoes Christian ideas and themes without developing explicit, precise parallels with them. The novel's biblical parallels enhance its moral themes but are not necessarily the primary key to interpreting the story.

Symbols

Symbols are objects, characters, figures, or colors used to represent abstract ideas or concepts.
The Conch Shell

Ralph and Piggy discover the conch shell on the beach at the start of the novel and use it to summon the boys together after the crash separates them. Used in this capacity, the conch shell becomes a powerful symbol of civilization and order in the novel. The shell effectively governs the boys' meetings, for the boy who holds the shell holds the right to speak. In this regard, the shell is more than a symbol—it is an actual vessel of political legitimacy and democratic power. As the island civilization erodes and the boys descend into savagery, the conch shell loses its power and influence among them. Ralph clutches the shell desperately when he talks about his role in murdering Simon. Later, the other boys ignore Ralph and throw stones at him when he attempts to blow the conch in Jack's camp. The boulder that Roger rolls onto Piggy also crushes the conch shell, signifying the demise of the civilized instinct among almost all the boys on the island.

Piggy's Glasses

Piggy is the most intelligent, rational boy in the group, and his glasses represent the power of science and intellectual endeavor in society. This symbolic significance is clear from the start of the novel, when the boys use the lenses from Piggy's glasses to focus the sunlight and start a fire. When Jack's hunters raid Ralph's camp and steal the glasses, the savages effectively take the power to make fire, leaving Ralph's group helpless.

The Signal Fire

The signal fire burns on the mountain, and later on the beach, to attract the notice of passing ships that might be able to rescue the boys. As a result, the signal fire becomes a barometer of the boys' connection to civilization. In the early parts of the novel, the fact that the boys maintain the fire is a sign that they want to be rescued and return to society. When the fire burns low or goes out, we realize that the boys have lost sight of their desire to be rescued and have accepted their savage lives on the island. The signal fire thus functions as a kind of measurement of the strength of the civilized instinct remaining on the island. Ironically, at the end of the novel, a fire finally summons a ship to the island, but not the signal fire. Instead, it is the fire of savagery—the forest fire Jack's gang starts as part of his quest to hunt and kill Ralph.

The Beast

The imaginary beast that frightens all the boys stands for the primal instinct of savagery that exists within all human beings. The boys are afraid of the beast, but only Simon reaches the realization that they fear the beast because it exists within each of them. As the boys grow more savage, their belief in the beast grows stronger. By the end of the novel, the boys are leaving it sacrifices and treating it as a totemic god. The boys' behavior is what brings the beast into existence, so the more savagely the boys act, the more real the beast seems to become.

The Lord of the Flies

The Lord of the Flies is the bloody, severed sow's head that Jack impales on a stake in the forest glade as an offering to the beast. This complicated symbol becomes the most important image in the novel when Simon confronts the sow's head in the glade and it seems to speak to him, telling him that evil lies within every human heart and promising to have some “fun” with him. (This “fun” foreshadows Simon's death in the following chapter.) In this way, the Lord of the Flies becomes both a physical manifestation of the beast, a symbol of the power of evil, and a kind of Satan figure who evokes the beast within each human being. Looking at the novel in the context of biblical parallels, the Lord of the Flies recalls the devil, just as Simon recalls Jesus. In fact, the name “Lord of the Flies” is a literal translation of the name of the biblical name Beelzebub, a powerful demon in hell sometimes thought to be the devil himself.

Ralph, Piggy, Jack, Simon, Roger

Lord of the Flies is an allegorical novel, and many of its characters signify important ideas or themes. Ralph represents order, leadership, and civilization. Piggy represents the scientific and intellectual aspects of civilization. Jack represents unbridled savagery and the desire for power. Simon represents natural human goodness. Roger represents brutality and bloodlust at their most extreme. To the extent that the boys' society resembles a political state, the littluns might be seen as the common people, while the older boys represent the ruling classes and political leaders. The relationships that develop between the older boys and the younger ones emphasize the older boys' connection to either the civilized or the savage instinct: civilized boys like Ralph and Simon use their power to protect the younger boys and advance the good of the group; savage boys like Jack and Roger use their power to gratify their own desires, treating the littler boys as objects for their own amusement.