1174 résultats pour "two"
-
Atom
I
INTRODUCTION
Water Molecule
A water molecule consists of an oxygen atom and two hydrogen atoms, which are attached at an angle of 105°.
spontaneously break apart and change, or decay, into other atoms. Unlike electrons, which are fundamental particles, protons and neutrons are made up of other, smaller particles called quarks. Physicists know of six different quarks.Neutrons and protons are made up of up quarks and down quarks —two of the six different kinds of quarks. The fanciful names of quarks have nothing to do with their properties; the names are simply labels to distinguish one quark from another. Quarks are unique amo...
- ONE TWO, TWO : 122, RUE DE PROVENCE
-
Homer
I
INTRODUCTION
Homer
According to tradition, the Greek poet Homer is believed to be the author of the Iliad and the Odyssey, two great epics of
ancient Greek literature.
The Return of OdysseusAfter the Greek warrior Odysseus returns from the Trojan War to his home in Ithaca, he kills the uninvited and unwantedsuitors of his wife, Penelope, who believed him to be dead. Odysseus’s astonishing skill with the bow convinces Penelopethat he is indeed her long-absent husband. This anonymous engraving is of an unknown date.Corbis The Odyssey narrates the return of the Greek hero Odysseus from the Trojan War. The opening scenes depict the disorder that has arisen in Ody...
- Cyprus is an island divided in two where two communities have opposed each other for more than twenty years.
-
Diego Velázquez (artist)
I
INTRODUCTION
Velázquez and Baroque Theatricality
Spanish painter Diego Velázquez presents two scenes in The Fable of Arachne (about 1656, Museo del Prado, Madrid,
Spain), also known as The Spinners.
search for a position as court painter. In 1623, however, he returned to the capital and, after executing a portrait (1623, Prado) of the king, was named official painterto Philip IV. The portrait was the first among many such sober, direct renditions of the king, the royal family, and members of the court. Indeed, throughout the later1620s, most of Velázquez's efforts were dedicated to portraiture. Mythological subjects would at times occupy his attention, as in Bacchus, also called The Drin...
-
Excerpt from A Tale of Two Cities - anthology.
“Good day, citizeness.” “Good day, citizen.” This mode of address was now prescribed by decree. It had been established voluntarily some time ago, among the more thorough patriots; but, was now law foreverybody. “ Walking here again, citizeness?” “You see me, citizen!” The wood-sawyer, who was a little man with a redundancy of gesture (he had once been a mender of roads), cast a glance at the prison, pointed at the prison, andputting his ten fingers before his face to represe...
-
How does Shakespeare establish the character of Richard in the first two scenes’ of Richard the III?
combined with the skill he has demonstrated in the scene, the audience knows he will achieve his diabolic plans. The question is how. In the next scene, Richard’s ability of being one step in front of people is confirmed. The obstacle he has the overcome in this scene, Anne’s hatred, seems to be hopeless and unachievable. Shakespeare portrays Anne’s animosity towards Richard with the help of actions “she spits at him”, “she looks scornfully at her” but also castigates him as an inhuman, un...
- Beer Street and Gin Lane : Two Aspect of Alcohol
-
-
Homer
I
INTRODUCTION
Homer, the name traditionally assigned to the author of the Iliad and the Odyssey, the two major epics that have survived from Greek antiquity.
Apollo ), and some have argued that portions of the texts, such as the concluding scenes of the Odyssey, were added by another hand. However, they generally believed that Homer was a poet (or at most, a pair of poets) much like the poets they knew from their own experience. They believed that the Iliad and the Odyssey, although based on traditional materials, were independent, original, and largely fictional. In the last 200 years, however, this view has changed radically, following the emer...
- Tom Hanks Tom Hanks, born in 1956, American motion-picture actor, a two-time Academy Award winner who is acclaimed for both his comic and dramatic performances.
-
Excerpt from The Two Gentlemen of Verona - anthology.
JULIA. Is he among these? HOST. Ay; but, peace! Let’s hear 'em. SONG:Who is Silvia? What is she,That all our swains commend her?Holy, fair, and wise is she;The heaven such grace did lend her,That she might admirèd be. Is she kind as she is fair?For beauty lives with kindness.Love doth to her eyes repair,To help him of his blindness;And, being helped, inhabits there. Then to Silvia let us singThat Silvia is excelling;She excels each mortal thingUpon the dull earth dwelling.To her let us garlands...
- Scylla and Charybdis Greek Two mythical characters who inhabited the Straits of Messina, between mainland Italy and the island of Sicily.
- Saddam HusseinSaddam Hussein (1937-2006), former president of Iraq (1979-2003), who led Iraq into two devastating wars.
-
FOOTBALL
a match
two teams playing against each other in a 90-minute game of football
a pitch
the area where footballers play a match
a referee
the person who makes sure that the players follow the rules.
full-time the point of the game when the referee blows the final whistle and the match is over. Normally after 90 minutes and any added injury or stoppage time injury time also called stoppage time, added minutes at the end of the regular playing time at half-time or full-time. Entirely at the referee’s discretion and normally indicated by an official on the sideline (or touchline) extra time if a match has no winner at full-time, 2 x 15 minutes of extra time may be played in some competitions o...
-
Geometry
I
INTRODUCTION
Geometry, branch of mathematics that deals with shapes and sizes.
Conic sections, a commonly studied topic of geometry, are two-dimensional curves created by slicing a plane through a three-dimensional hollow cone. A Euclid’s Postulates Euclid, who lived about 300 BC, realized that only a small number of postulates underlay the various geometric theorems known at the time. He determined that these theorems could be deduced from just five postulates. 1. A straight line may be drawn through any two given points. 2. A straight line may be drawn infinitely or be...
-
Molecule - chemistry.
attracted to the negatively charged electrons between them. The electrons belong to the molecule as a whole. However, each hydrogen atom now has a complete outershell of two electrons. The formula H 2 describes a hydrogen molecule, a discrete unit. When a molecule contains just two atoms, such as the hydrogen molecule does, it is called a diatomic molecule. Some atoms can form covalent bonds with more than one other atom and thus create a larger molecule. Atoms form molecules with covalent bo...
-
-
Hydrogen - chemistry.
Hydrogen gas does not usually react with other chemicals at room temperature. That is, it does not split into two hydrogen atoms to combine with other chemicals. Thebond between the hydrogen atoms is very strong and can only be broken with a large amount of energy. However, when heated with a flame or a spark, hydrogen gaswill react violently with oxygen in the air to produce water in the following reaction: 2H2 + O 2 → 2H 2O This chemical equation shows that two hydrogen molecules (H 2) and o...
-
Genetics - biology.
construct identical buildings. Just as each contractor would require a full copy of the blueprint to construct a complete building, each new cell needs a complete copy ofan organism’s genetic information to function properly. Organisms use two types of cell division to ensure that DNA is passed down from cell to cell during reproduction. Simple one-celled organisms and other organisms thatreproduce asexually—that is, without the joining of cells from two different organisms—reproduce by a proces...
-
Statistics
I
INTRODUCTION
Statistics, branch of mathematics that deals with the collection, organization, and analysis of numerical data and with such problems as experiment design and decision
making.
frequency, column (d), is the ratio of the frequency of an interval to the total count; the relative frequency is multiplied by 100 to obtain the percent relative frequency.The cumulative frequency, column (e), represents the number of students receiving grades equal to or less than the range in each succeeding interval; thus, thenumber of students with grades of 30 or less is obtained by adding the frequencies in column (c) for the first three intervals, which total 53. The cumulative relativef...
-
US Beats USSR in Hockey.
The two sides once again exchanged goals during the first period. Sergei Makarov briefly gave the Soviets a lead when he beat Craig. The goal outraged many in thecrowd who felt that referee Karl Kaisla of Finland missed a holding violation by a USSR player in front of the net. Controversy also played a role in the Americans'game-tying goal at the end of the period. With a few seconds left on the clock, Ken Morrow unleashed an 80-foot slap shot that ricocheted to center Mark Johnson,who deposited...
-
Ice Hockey.
Each period begins with a face-off at the blue dot at center ice. During the face-off one player from each team lines up at the dot with the stick blade on the ice. After the referee drops the puck, the two players attempt to gain possession of it. Quick hands and strength are essential qualities for players participating in the face-off. Once the puck is dropped, it is in play until an official’s whistle stops it, a goal is scored, or time expires. The team on offense tries to move the puck f...
-
Internal-Combustion Engine.
any Otto-cycle engine and in actual engines today is slightly more than 40 percent. Diesels are, in general, slow-speed engines with crankshaft speeds of 100 to 750revolutions per minute (rpm) as compared to 2500 to 5000 rpm for typical Otto-cycle engines. Some types of diesel, however, have speeds up to 2000 rpm. Becausediesels use compression ratios of 14 or more to 1, they are generally more heavily built than Otto-cycle engines, but this disadvantage is counterbalanced by theirgreater effici...
-
Gravitation
I
INTRODUCTION
Gravitation, the force of attraction between all objects that tends to pull them toward one another.
precise observations possible, and Galileo was one of the first to use a telescope to study astronomy. In 1609 Galileo observed that moons orbited the planet Jupiter, afact that could not reasonably fit into an earth-centered model of the heavens. The new heliocentric theory changed scientists' views about the earth's place in the universe and opened the way for new ideas about the forces behind planetarymotion. However, it was not until the late 17th century that Isaac Newton developed a theory...
-
Gravitation - astronomy.
precise observations possible, and Galileo was one of the first to use a telescope to study astronomy. In 1609 Galileo observed that moons orbited the planet Jupiter, afact that could not reasonably fit into an earth-centered model of the heavens. The new heliocentric theory changed scientists' views about the earth's place in the universe and opened the way for new ideas about the forces behind planetarymotion. However, it was not until the late 17th century that Isaac Newton developed a theory...
-
-
Atom - chemistry.
Atoms have several properties that help distinguish one type of atom from another and determine how atoms change under certain conditions. A Atomic Number Each element has a unique number of protons in its atoms. This number is called the atomic number (abbreviated Z). Because atoms are normally electrically neutral,the atomic number also specifies how many electrons an atom will have. The number of electrons, in turn, determines many of the chemical and physical properties ofthe atom. The ligh...
-
Bicycle.
narrow as possible to minimize weight and interference with pedaling. F Specialty Bicycles Many other types of bicycles are designed for special purposes. Although not as common as standard single-rider racing, touring, mountain, or recreational bicycles,they nonetheless have significant niches. Recumbent bicycles are bicycles on which the rider sits upright as if in a chair, with legs and feet stretched out in front. Because they support the rider’s lower back,recumbents allow the rider far mo...
-
John Elway Leads "The Drive".
touchdown against a strong defense. Bedlam reigned inside the stadium. In their two previous possessions the Broncos mustered a total of 15 yards. When Elway entered the huddle, however, he cracked a smile. “I couldn't believe it,”Denver receiver Steve Watson told Sports Illustrated. ”He said, ‘If you work hard, good things are going to happen.’ And then he smiled again.” Elway hit running back Sammy Winder for a short gain. After two more short-yardage plays, Elway shifted into high gear....
-
Johann Sebastian Bach.
from his duties, and even tossed him into jail for “too obstinately requesting his dismissal.” But after several weeks the duke saw it was of no use and let him go. E Köthen: 1717-1723 Bach’s new employer, Leopold, loved and understood music and could play the violin, viola da gamba, and harpsichord as well as sing bass. The prince held Bach in highregard and stood as godfather for his seventh child. Bach, in turn, named the child Leopold August in his employer’s honor. Bach later said that the...
-
The Souls of Black Folk by W.
in amused contempt and pity. One ever feels his two-ness,—an American, a Negro; two souls, two thoughts, two unreconciled strivings; two warring ideals in onedark body, whose dogged strength alone keeps it from being torn asunder. The history of the American Negro is the history of this strife—this longing to attain self-conscious manhood, to merge his double self into a better and truer self. Inthis merging he wishes neither of the older selves to be lost. He would not Africanize America, f...
-
Flower - biology.
insects. The sepals unfurl as the flower opens and often resemble small green leaves at the flower’s base. In some flowers, the sepals are colorful and work with thepetals to attract pollinators. E Variations in Structure Like virtually all forms in nature, flowers display many variations in their structure. Most flowers have all four whorls—pistil, stamens, petals, and sepals. Botanists callthese complete flowers. But some flowers are incomplete, meaning they lack one or more whorls. Incomplet...
-
Rap
I
INTRODUCTION
Jay-Z
Rapper Jay-Z rose to popularity with such albums as Vol.
Run-DMCTypically in rap music, vocalists recite rhyming lyrics in time to a beat that may be sampled from prerecorded music byother groups. Black youths developed rap music on the streets of inner cities in the United States during the 1970s, butthe style has expanded to include a wider variety of performers and audiences. The rap group Run-DMC, shown here, wasa powerful early influence in the genre. The group helped bring rap music into the mainstream when it released “WalkThis Way” (1986), a s...
-
Horse Racing.
interested parties claim the same horse at the same price, lots are drawn to determine the winning offer. Knowledgeable owners and trainers may use claiming races toobtain, at bargain prices, horses whose former owners underestimated the potential of their animals. Two other types of contests are match races and walkovers. A match race pits only two horses, almost always that season’s most successful racers, in a head-to-headduel. A walkover occurs when only one horse has not been scratched (w...
-
-
Inorganic Chemistry - chemistry.
two electrically charged plates (positively charged top plate and negatively charged bottom plate). By measuring the difference in how fast these electron-laden oildrops fell when the metal plates were charged and uncharged, Millikan was able to calculate the total charge on each oil drop. Because each measurement was a wholenumber multiple of -1.60 × 10 -19 coulombs, Millikan concluded this was the charge carried by a single electron. Using Thomson’s electron charge-to-mass ratio, Millikan then...
-
Spider (arthropod) - biology.
The spider’s abdomen is soft and saclike. On the underside of the tip of the abdomen are three pairs of spinnerets. Each spinneret is studded with many fine, hairliketubes called spigots, which produce a variety of silk threads. The spigots lead to several large silk glands inside the abdomen. Silk is formed as a liquid inside theseabdominal glands. As the silk is drawn out through the spigots, protein molecules within the silk line up parallel to one another, causing the silk to harden and form...
-
Relativity
I
INTRODUCTION
Albert Einstein
In 1905 German-born American physicist Albert Einstein published his first paper outlining the theory of relativity.
in calculating very large distances or very large aggregations of matter. As the quantum theory applies to the very small, so the relativity theory applies to the verylarge. Until 1887 no flaw had appeared in the rapidly developing body of classical physics. In that year, the Michelson-Morley experiment, named after the American physicistAlbert Michelson and the American chemist Edward Williams Morley, was performed. It was an attempt to determine the rate of the motion of the earth through t...
-
Nicklaus-Watson Match.
until 1977, primarily because golf officials felt that there weren't enough hotel rooms in the area to attract and accommodate the crowds. But officials finally relented,deciding that the majestic course deserved to stage golf's most noble tournament. The sun shone brightly over this scene for the July event. Nicklaus and Watson were both on the leader board after the first two rounds with identical scores of 68-70-138. Their dramatic play began in the third round, on Friday. Nicklaus jumped...
-
Physics
I
INTRODUCTION
Physics, major science, dealing with the fundamental constituents of the universe, the forces they exert on one another, and the results produced by these forces.
Starting about 1665, at the age of 23, Newton enunciated the principles of mechanics, formulated the law of universal gravitation, separated white light into colors,proposed a theory for the propagation of light, and invented differential and integral calculus. Newton's contributions covered an enormous range of naturalphenomena: He was thus able to show that not only Kepler's laws of planetary motion but also Galileo's discoveries of falling bodies follow a combination of his ownsecond law of m...
-
Reproductive System.
in which the young develop, and a thinner channel, the vagina, which opens exteriorly. V GENITALS In animals that lay their eggs and discharge their sperm into water, the spermatozoa reach the eggs by chemical attraction; the eggs of individuals of a species attractonly the sperm of members of the same species. When eggs and sperm are deposited at great distances from each other, the number of eggs fertilized is small. Manyamphibians and aquatic vertebrates solve this problem by attaching thems...
-
Map - Geography.
Often only southeast slopes are hachured or shaded, giving somewhat the effect of a bird's-eye view of the area illuminated by light from the northwest. Shadings orcarefully drawn hachures, neither of which give elevations, are more easily interpreted than contour lines and are sometimes used in conjunction with them for greaterclarity. IV MAP PROJECTIONS For the representation of the entire surface of the earth without any kind of distortion, a map must have a spherical surface; a map of this...
-
Indo-Pakistani Wars - History.
wrest Jammu and Kashmīr from India through the use of force. This effort failed as India held its ground, and the war ended in a stalemate after almost two months ofarmed conflict. Although the second war over the territory was shorter than the first, the increased firepower of the two nations resulted in a more deadly war, with atotal of about 6,800 battle casualties. A Events Before the War A number of factors precipitated the second conflict over Jammu and Kashm īr. In the wake of a border w...
-
-
Organic Chemistry - chemistry.
B Alkenes and Alkynes Isomeric with the cyclanes, or cycloalkanes as they are sometimes called, is the family of alkenes, also represented by the general formula C nH2n. This family of hydrocarbons is characterized by one or more double bonds between carbon atoms. Propene and cyclopropane, for example, are isomers, as are 1,3-dimethylcyclohexane and 3,4-dimethyl-2-hexene. (The location of the double bond is indicated by the 2-hexene part of the name.) Double bonds may also occur incyclic compou...
-
Chemistry - chemistry.
parts of oxygen by weight, which is a ratio of about 1 to 8, regardless of whether the water came from the Mississippi River or the ice of Antarctica. In other words, acompound has a definite, invariable composition, always containing the same elements in the same proportions by weight; this is the law of definite proportions. Many elements combine in more than one ratio, giving different compounds. In addition to forming water, hydrogen and oxygen also form hydrogen peroxide.Hydrogen peroxide h...
-
United States Senate.
providing for military forces, and declaring war. Article I, Section 8, also gives Congress implied powers—to “make all laws which shall be necessary and proper” forcarrying out the enumerated powers, and to investigate and oversee the executive branch. The Senate also has the power to conduct impeachment trials against thepresident, federal judges, and other officials. The Senate can only impeach someone after the House brings charges, however. A two-thirds majority vote of thesenators in the c...
-
Radioactivity
I
INTRODUCTION
Marie Curie
Working with her husband, Pierre Curie, French physicist Marie Curie discovered the radioactive elements polonium and
radium in 1898.
Rutherford when he allowed an alpha-emitting substance to decay near an evacuated thin-glass vessel. The alpha particles were able to penetrate the glass and werethen trapped in the vessel, and within a few days the presence of elemental helium was demonstrated by use of a spectroscope. Beta particles were subsequentlyshown to be electrons, and gamma rays to consist of electromagnetic radiation of the same nature as X rays but of considerably greater energy. A The Nuclear Hypothesis Rutherford...
-
William Shakespeare
I
INTRODUCTION
William Shakespeare
English playwright and poet William Shakespeare, who lived in the late 1500s and early 1600s, is regarded as the greatest
dramatist in the history of English literature.
Avon, Warwickshire, a prosperous town in the English Midlands. Based on this record and on the fact that children in Shakespeare’s time were usually baptized two orthree days after birth, April 23 has traditionally been accepted as his date of birth. The third of eight children, William Shakespeare was the eldest son of John Shakespeare, a locally prominent glovemaker and wool merchant, and Mary Arden, thedaughter of a well-to-do landowner in the nearby village of Wilmcote. The young Shakespeare...
-
Harry S.
B2 Presiding Judge Political machines, such as the Pendergast organization, were common to both parties in the 1920s. They were based on the spoils system, in which winning politiciansgave government jobs to those loyal party members who had helped them get elected. Using government jobs as rewards, politicians created efficient (and oftenalmost unstoppable) vote-getting “machines,” in which party loyalty was often more important than doing any work. Without local machine support a political ca...
-
Harry S.
B2 Presiding Judge Political machines, such as the Pendergast organization, were common to both parties in the 1920s. They were based on the spoils system, in which winning politiciansgave government jobs to those loyal party members who had helped them get elected. Using government jobs as rewards, politicians created efficient (and oftenalmost unstoppable) vote-getting “machines,” in which party loyalty was often more important than doing any work. Without local machine support a political ca...
-
Northwest Territories - Geography.
million years ago by the severe bending (folding) and faulting (breaking) of sedimentary rock that was once part of the Interior Plains. During the Wisconsin Ice Age,alpine glaciers covered the Cordillera, and the movement of the glaciers created razor-sharp peaks and ridges in these mountains. The moving glaciers also createdbroad U-shaped valleys. To the east of the Interior Plains, the ancient rocks of the Canadian Shield are exposed at the Earth’s surface, resulting in a rough, rolling terra...
-
-
Northwest Territories - Canadian History.
million years ago by the severe bending (folding) and faulting (breaking) of sedimentary rock that was once part of the Interior Plains. During the Wisconsin Ice Age,alpine glaciers covered the Cordillera, and the movement of the glaciers created razor-sharp peaks and ridges in these mountains. The moving glaciers also createdbroad U-shaped valleys. To the east of the Interior Plains, the ancient rocks of the Canadian Shield are exposed at the Earth’s surface, resulting in a rough, rolling terra...
-
Influenza.
days and disappear in seven to ten days. However, coughing and fatigue may persist for two or more weeks. Death from influenza itself is rare. But influenza can aggravate underlying medical conditions, such as heart or lung disease. Invading influenza viruses produceinflammation in the lining of the respiratory tract, damage that increases the risk that secondary infections will develop. Common complications include bronchitis,sinusitis, and bacterial pneumonia, occurring most frequently in olde...