تعابير للغة إنجليزية

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Written Expressions
Topic19:

Write a composition on the conception of corruption.
Typical Essay:

There is an old axiom often applied to those with political ambitions: Power corrupts; absolute power corrupts absolutely. In this case, the term corruption means the abuse of a public office for personal gain or other illegal or immoral benefit. Political corruption is a recognized criminal offense, along with bribery, extortion, and embezzlement – three illegal acts often associated with corruption in office. Some forms of corruption may escape legal notice, such as the hiring of relatives for key positions, but they may not escape the scrutiny of voters on Election Day.
Whenever a person accepts a political appointment or wins election to an office, he or she must take an oath to uphold the public trust. While this may sound noble on paper, enforcement of this oath can prove problematic. Very few political candidates successfully reach office without making a few promises along the way. Many of these campaign promises are harmless, such as sponsoring a bill or lobbying for more funding for schools. Other promises, however, may come closer to crossing an ethical line, such as hiring relatives or awarding government contracts to influential contributors.
Political corruption has been a fact of life for thousands of years, beginning with the first attempts at a democratic form of government in ancient Greece and Rome. Almost all of these countries' political representatives were from the wealthier class, which inevitably led to a division between the influential haves and the virtually powerless have-nots. The seeds of political corruption were planted as soon as the senators and other political leaders realized that power and wealth could be equals. Political corruption often begins with favoritism towards those with wealth and influence.
In the modern sense of the term, political corruption is a cancer on the integrity of a governmental body. Very few public officials begin their careers with the intention of becoming corrupt, but some succumb to a sinister form of peer pressure over time. Being placed in a position of significant political power can be overwhelming, and the temptation to bend or break rules for a perceived 'greater good' is always present.
There are a few experienced politicians, however, for whom political corruption is a natural state of being. History is filled with examples of corrupt public officials, such as New York City's Boss Tweed and his political cronies at Tammany Hall during the late 19th century. Charges ranging from bribery and graft to nepotism, racketeering and fraud were all leveled at Tweed's administration, but it was Tweed's skills in political corruption that kept law enforcement at bay for years. A number of judges and law enforcement officers were already on Boss Tweed's secret payroll. Political corruption may always remain a concern for democratic governments, but there are a number of independent checks and balances that can root out corruption before it affects the integrity of the political body as a whole.



Topic20:

Write a composition on embezzlement.

Typical Essay:

Embezzling is the act of taking money that has been placed in your trust but belongs to another person. For instance, someone who works in a bank may secretly steal money that he or she has been entrusted to look after. This money belongs to the bank's customers, and the employee's action can be considered embezzling.
One of the major methods used in embezzling is to falsify records and documents. A recent British case involved a bank manager embezzling 23 million GB pounds (GBP). The bank manager set up many false bank accounts and deposited millions from other bank accounts into them.
Another very successful method of falsifying records is the phantom employee. The manager may create a job role and documents for an employee who does not actually exist. The phantom employee is then paid a salary.
Even charities are threatened by embezzlement. One of the most common methods used in this case is to redirect large amounts of money for administrative purposes. Sadly, many worthwhile charities have been shut down as a result of this type of embezzling.

























Topic21:

Write a composition on bribery.
Typical Essay:

A bribe is a form of corruption which involves the promise of money or a favor to someone in a position of power, with the hope of influencing that person's behavior. Bribery is viewed as a crime in many regions of the world, and people who are caught offering or receiving bribes may face hefty penalties. In other regions, the line between bribing and tipping is sometimes rather blurred, which can make it difficult to prosecute people for bribery, or to understand when one has crossed the line.
There are several reasons why bribery is viewed as a crime. In the first place, accepting a bribe and acting on it is a clear misuse of power, and a dereliction of duty. In egalitarian societies, the thought of greasing the way with bribes is especially distasteful, because it highlights the differences between those who can buy power or favors, and those who cannot. A bribe may also compromise the quality of a transaction. For example, when a construction firm bribes a government official to get a contract, the government official may overlook a company which provides superior or cheaper work, thereby essentially cheating the government.
Bribes can take any number of forms. Historically, bribes to public officials have been extremely common, and in some regions, this continues to be the case. Bribes also play a role in the financial industry, and even in occupations like medicine, where doctors may be bribed by drug companies to prescribe their products. Politics is also rife with bribery in many region, with people bribing politicians to achieve desired ends, and politicians in turn offering bribes to others in the hopes of attaining specific goals, like winning an election.
Drawing the line with bribes is very challenging. For example, many politicians receive healthy campaign contributions from an assortment of companies and industries. These payments could be viewed as bribes in the eyes of some critics, especially when the politicians vote and act in the interests of their biggest contributors. However, it could also be argued that these companies are certainly entitled to support candidates they like, especially when those candidates have political beliefs which align with the interests of the company.
Likewise, the practice of offering a bribe to ministry officials in some countries is so widespread that bribes are viewed almost like set fees. People who attempt to act with integrity may find that the ministry in question never approves a request or a document, thus forcing them to bribe an official to get the job done. In some cases, such bribes are even tax-deductible, with tax agencies recognizing them as a legitimate business expense.







Topic22:

Write a composition on money laundering.
Typical Essay:

Money laundering refers to the process of concealing financial transactions. Various laundering techniques can be employed by individuals, groups, officials and corporations. The goal of a money laundering operation is usually to hide either the source or the destination of money.
Perhaps the best way to understand the concept is to take a look at some common examples. Suppose, for example, that an employee was stealing large sums of cash from her employer without getting caught. If she was to make large deposits into her bank account, some regulator (or computer program) might notice the unusually large deposits, thereby increasing the chances of getting caught. To launder the money, the criminal might simply use the cash to make purchases and then resell the items in a legitimate market. The revenue gained from these sales is 'cleaner' and the criminal is drawing less attention to herself.
The example provided above is a particularly simple example that involves a non-cash step; actual money laundering operations are often complex assortments of various transactions. The term 'money laundering' is typically used to refer to any financial transaction that is not kept transparent. Needless to say, the practice is illegal and large penalties, fines or imprisonment may ensue.
























Topic23:

Write a composition on tax evasion.

Typical Essay:

Tax evasion is usually understood to be an act in which an individual intentionally chooses to not pay income taxes due. This act of not paying taxes may be conducted by simply chooses to not file an income tax return, or choosing to not include information about taxable income on the filed return. In all instances, tax evasion can be considered to be fraud, and usually carries stiff penalties.
While there are some that consider any type of omission from the tax return to constitute tax evasion, it is important to remember that it is possible to omit an item simply because the data was overlooked when filing the return. Thus, the intent of the individual plays a key role in determining if tax evasion has taken place.
However, when it can be demonstrated that the individual willfully attempted to hide information about income that was subject to withholding, the tax agency may choose to impose more than a simple interest fine on the amount omitted. The filer may be subject to stiff fines associated with the deliberate failure to file an accurate tax return, or even possibly face prosecution and some time spent in jail for the intentional negligence.
Tax evasion is considered a crime, and is often classified as fraud. All citizens suffer from tax evasion, as the act prevents the government from collecting funds to use for the operation of essential services to the population. When these funds are not collected, services have to be curtailed and thus result in a lower quality of life for all citizens.
Persons who become aware of an error on calculating taxes on reported income or notice that income was inadvertently left off the tax return for a given period should contact the tax agency and make arrangements to file an amended return as soon as possible. This will help to minimize the chances of being suspected of tax evasion, and allow the matter to be settled before interest charges become significant.















Topic24:

Write a composition on creative accounting.
Typical Essay:

Creative accounting, also called aggressive accounting, is the manipulation of financial numbers, usually within the letter of the law and accounting standards, but very much against their spirit and certainly not providing the "true and fair" view of a company that accounts are supposed to.
A typical aim of creative accounting will be to inflate profit figures. Some companies may also reduce reported profits in good years to smooth results. Assets and liabilities may also be manipulated, either to remain within limits such as debt covenants, or to hide problems.
Typical creative accounting tricks include off balance sheet financing, over-optimistic revenue recognition and the use of exaggerated non-recurring items.
The term "window dressing" has similar meaning when applied to accounts, but is a broader term that can be applied to other areas. In the US it is often used to describe the manipulation of investment portfolio performance numbers. In the context of accounts, "window dressing" is more likely than "creative accounting" to imply illegal or fraudulent practices, but it need to do so.

























Topic25:

Write a composition on currency counterfeiting.

Typical Essay:

Counterfeiting refers to the imitation of something with the intent to deceive. As a general rule, people use the term specifically to refer to people who replicate currency in the hopes of passing it off as legal tender. However, a variety of things can be counterfeited, from designer handbags to legal documents. In terms of counterfeiting money, counterfeiting comes with severe consequences, as it is treated as a very serious crime in most nations around the world.
Most modern counterfeiting is focused on paper money, because paper money has a higher face value. Counterfeiters use a variety of techniques to produce replicas of the desired currency, depending on the security features which a nation uses to protect the integrity of its money and the level of realism desired. For example, a color photocopier can sometimes render a credible replica of legal currency, especially when the currency is run through a washer to age it, but counterfeiters may also use sophisticated printing techniques like those used at a national mint.
Most mints around the world use a number of safety systems to protect their money. For example, many nations print engraved money, meaning that specially engraved plates which are very hard to replicate are used in the production of currency. Many countries also use specialized papers and inks, along with complex designs which are hard to copy, and they may change the look of their currency frequently in an attempt to foil counterfeiters.
Someone who is convicted of counterfeiting will spend at least a decade in prison. He or she may also be forced to pay fines or restitution, and the property used in the counterfeiting process may be seized. Counterfeiting is treated as an extremely serious crime because it devalues a nation's currency, potentially threatening its economic stability and global standi









Topic26:

Write a composition on extortion.
Typical Essay:
Extortion is a crime which involves the illegal acquisition of money, property, or favors through the use of force, or the threat of force. Historically, extortion was defined as an abuse of privilege on the part of a public official who used his or her position to get money or favors, but today, people at all levels of society could potentially commit extortion. Penalties for extortion vary, depending on the specifics of the crime. In some countries, extortion is treated especially seriously because it is linked with organized crime, and sometimes special laws are designed to make it easier to prosecute and punish extortion.
To the casual ear, extortion can sound very similar to blackmail, in which people use a threat to demand payments or favors, and robbery, in which a criminal takes something by force. However, extortion is slightly different from both of these crimes. In blackmail, someone threatens to do something which is entirely legal, such as publishing a set of photographs, with the blackmailee offering payment to avoid exposure and humiliation. Extortion is entirely illegal, as it involves threats of violence or other illegal acts.
In a robbery, the violence is very real, and also very immediate. In extortion, violence may never progress beyond the stage of being a threat, assuming that the person being extorted pays up. For example, if someone is threatened at gunpoint and ordered to surrender all valuables, this is a robbery. If, on the other hand, a criminal strolls into a shop and threatens to shoot the clerk's family unless the criminal receives a share of the store's income each week, this is extortion.
Organized crime is perhaps the most famous user of extortion. For example, members of the Mafia have historically demanded “protection money” from businesses, suggesting that if the businesses don't pay up, they may be robbed or otherwise harassed. Extortion has also been used to keep community groups in fear so that they will not seek prosecution for members of a criminal organization. However, individuals may also commit extortion, as may officials, especially in corrupt agencies or governments.
In order to prove charges of extortion, a prosecutor must be able to prove either that an illegal threat was made, or that goods or services were received in exchange for such a threat. Proving such charges can sometimes be very difficult, as people may be too intimidated to testify.
https://www.wisegeek.com/what-is-extortion.htm










Topic27:

Write a composition on blackmail.
Typical Essay:
Blackmail is the crime of threatening to reveal damaging or embarrassing information in order to coerce money or other goods or forms of cooperation out of the victim. For blackmail to be effective, the blackmailer must, in most cases, have physical proof of the information he or she threatens to reveal, such as photographs or letters. Blackmail is often considered synonymous with extortion, and in this sense it may rely on a threat of action other than exposing the victim's secrets.
Some laws distinguish between blackmail and extortion, while others do not. Blackmail may be defined as extortion attempts in writing. Alternatively, blackmail may refer only to threats of action that is not illegal per se, such as revealing compromising photographs, while extortion relies on more active threats, such as physical harm.
The victim of blackmail is typically threatened with exposure of his or her private life, the consequences of which can range from embarrassing to socially devastating to legally damning. A blackmailer may threaten to expose the victim's extramarital affair, for example. Homosexuals were often blackmailed in the past, though this is less common as alternative sexualities are increasingly more accepted. At its most serious, blackmail may rest on the exposure of a serious crime, which would do infinitely more damage to the victim than complying with the blackmailer. Even secret information that is not of a criminal nature, however, can make the victim of blackmail feel that he or she has no recourse against the crime.
A relatively new form of blackmail, more similar to extortion, is known as commercial blackmail. In this crime, a business is the victim. The blackmailer threatens an action which would be devastating to the company's sales or reputation and typically demands a large payment. The perpetrator may, for example, threaten to interfere with the company's ability to conduct Internet sales. In a recent case of commercial blackmail in Australia, the blackmailer claimed to have poisoned a small random selection of the victim's candy bar products.
https://www.wisegeek.com/what-is-blackmail.htm














Topic28:

Write a composition on child labour.

Typical Essay:

Any child under the age specified by law worldwide works full time, mentally or physically to earn for own survival or adding to family income, that interrupts childs social development and education is called child labour. It is any kind of work children are made to do that harms or exploits them physically, mentally, morally, or by preventing access to education.

However, one must also understand that all work is not bad or exploitive for children. In fact, certain jobs help in enhancing the overall personality of the child. For instance, children delivering newspapers prior to going to school. Or then children taking up light summer jobs that do not interfere with their school timings. When they are given pocket money earning oriented tasks, they understand the value of money, as well as respect it even more.

While this are the positive aspects of tasks and working, the actual universal problem of child labour is the exploitive and dangerous work and working conditions children are put through. For instance, in north India young children, below the age of 14 are made to work in the carpet industry. Their delicate fingers create the world’s finest and most expensive carpets. The children are working twelve to fourteen hours a day. Many lose their fingers. Some are starved. And a number die each year because of the torturous circumstances under which they are made to work.

This is a crime. There have been instances of so-called decent middle class, as well as upper-class people employing young children as domestic helpers. But, they are not working as helpers, but bonded labour. They are made slaves. Frightening stories of how they have been physically tortured are printed in the daily newspapers. And in spite of stringent action being taken against such employers, the problem continues.






























Wriiten Expressions
Topic56:

It was only thanks to the astronomers that the world all around is well-known to us. Discuss.

Typical Essay:
An astronomer is a person who studies, classifies, and describes the phenomena of the heavens. The astronomer has been one of the most important roles in the modern scientific world, with some of the great leaps in methodology coming from the realm of astronomy. In the modern day, there are not many who identify as an astronomer, with the American Astronomical Society having less than 7,000 members, for example. Nonetheless, the concept of astronomer continues to fascinate the public as a romantic figure gazing skyward.
One of the most well-known people to bear the name astronomer was the 16th century astronomer, Nicolaus Copernicus. Copernicus developed a heliocentric model of our solar system, placing the sun at the center and the Earth orbiting it, and in doing so turned most of the predominant world views of the time on their heads. Although a heliocentric model had been put forth by various brilliant minds from the world of Islam, India, and Greece, Copernicus laid his out in the West in such a way that it was impossible for the world to ignore.
Not long after Copernicus, the astronomer Galileo Galilei expanded on Copernicus’ views. He made the telescope substantially more effective than it had been, allowing the astronomer to make much more detailed observations, including viewing craters on the moon, sunspots, and four of the moons of Jupiter. Galileo was a devout Catholic, and in fact traveled to Rome to show the moons of Jupiter to the Jesuit Collegio Romano as evidence of the Copernican heliocentric model. The Church rejected Galileo’s views, and eventually found him highly suspected of heresy and placed under house arrest.
Sir Isaac Newton, in addition to his many other accomplishments, was an influential astronomer. Many of his observations led him to develop some of his grand theories of motion, gravitation, and physical dynamics. Edmond Halley, an 18th century astronomer, conceived of a theory of orbits for comets. He used this theory to predict a comet in 1682, which would eventually be named in his honor, as Halley’s Comet.
One of the fundamental historical distinctions of an astronomer is his or her reliance on observation to come up with theories. It is likely for this reason that the astronomer is such a romantic figure for most people. The heavens at night are awe inspiring for most, and a lifetime spent gazing into them and trying to plumb their mysteries is one that appeals to many. Although the romantic ideal of a wizened old man with his eye to a telescope may no longer truly exist, it has nonetheless inspired generation after generation to become excited about science.
In the modern age, two wonderful things have happened for the field of astronomy: quality has gone up, and price has gone down. This has allowed for a whole new wave of astronomers to crop up, but these are often amateurs. With a relatively small investment now, anyone can be an astronomer. In fact, some important discoveries over the past two decades have been by those who are far from professional astronomers. As technology continues to improve, it is likely that the role the amateur astronomer plays in identification of celestial phenomena with only increase.
Topic57:

Write a composition on the solar system.

Typical Essay:

The Solar System is made up of all the planets that orbit our Sun. In addition to planets, the Solar System also consists of moons, comets, asteroids, minor planets, and dust and gas.
Everything in the Solar System orbits or revolves around the Sun. The Sun contains around 98% of all the material in the Solar System. The larger an object is, the more gravity it has. Because the Sun is so large, its powerful gravity attracts all the other objects in the Solar System towards it. At the same time, these objects, which are moving very rapidly, try to fly away from the Sun, outward into the emptiness of outer space. The result of the planets trying to fly away, at the same time that the Sun is trying to pull them inward is that they become trapped half-way in between. Balanced between flying towards the Sun, and escaping into space, they spend eternity orbiting around their parent star.
How Did The Solar System form?
This is an important question, and one that is difficult for scientists to understand. After all, the creation of our Solar System took place billions of years before there were any people around to witness it. Our own evolution is tied closely to the evolution of the Solar System. Thus, without understanding from where the Solar System came from, it is difficult to comprehend how mankind came to be.
Scientists believe that the Solar System evolved from a giant cloud of dust and gas. They believe that this dust and gas began to collapse under the weight of its own gravity. As it did so, the matter in this could begin moving in a giant circle, much like the water in a drain moves around the center of the drain in a circle.
At the center of this spinning cloud, a small star began to form. This star grew larger and larger, as it collected more of the dust and gas that were collapsing into it.
Further away from the star that was forming in the center were smaller clumps of dust and gas that were also collapsing. The star in the center eventually ignited forming our Sun, while the smaller clumps became the planets, minor planets, moons, comets, and asteroids.










Topic58:

Many theories were formulated about the creation of the world. Choose one and discuss it.
Typical Essay:

In fact, it is difficult for scientists to understand how our world was created. After all, the creation of our world took place billions of years before there were any people around to witness it. Our own evolution is tied closely to the evolution of the Solar System. Thus, without understanding from where the Solar System came from, it is difficult to comprehend how mankind came to be.
Scientists believe that our world evolved from a giant cloud of dust and gas. They believe that this dust and gas began to collapse under the weight of its own gravity. As it did so, the matter in this could begin moving in a giant circle, much like the water in a drain moves around the center of the drain in a circle.
At the center of this spinning cloud, a small star began to form. This star grew larger and larger, as it collected more of the dust and gas that were collapsing into it.
Further away from the star that was forming in the center were smaller clumps of dust and gas that were also collapsing. The star in the center eventually ignited forming our Sun, while the smaller clumps became the planets, minor planets, moons, comets, and asteroids.
https://www.kidsastronomy.com/solar_system.htm























Topic59:

Suppose a comet collided with the earth. Write a composition predicting the consequences of such a collision.

Typical Essay:

For the most part, a comet is an object in the solar system that orbits the sun sometimes has a coma (or atmosphere) and a tail. These characteristics are added mostly because of the effects of solar radiation upon the comet's nucleus (the nucleus is made of rock, dust, ice, etc.).
The interesting thing is that comets' orbits are highly variable. First, they are almost always highly affected by close calls with major planets, sometimes even being moved into orbits that destroy them due to their nearness to the Sun. One of the reasons why comets are so easily moved is because the outgassing that creates their comas and tails propels them in mysterious and unpredictable ways. But if a comet collided with the earth, what would happen then?
If the comet were small enough (and we survived), probably something similar to the situation on the 15th of April 1815, when volcanic eruptions of Mount Tambora ejected immense amounts of volcanic dust into the upper atmosphere, would happen." The year of 1816 (the year after) was often referred to as the Year Without a Summer.

This is because so much dust, from only one volcano, blocked out so much sunlight that several people froze to death and crops around the world died. Prices for food skyrocketed and it caused a major problem in economy.

The meteor that hit the Earth and resulted in the extinction of the dinosaurs probably kicked up 100 times to 1000 times as much dust as this volcano explosion.

So the consequences of such a supposed collision really depend on the size of the comet. The bigger it is, the more devastating its outcomes are.


https://www.secretsofsurvival.com/sur...ith_earth.html















Topic60:

Write a composition on the importance of astronomy.

Typical Essay:
Astronomy is the study of celestial objects, phenomena, and origins. One of the oldest sciences, astronomy has been practiced since prehistoric times. Modern astronomy depends highly on accepted physical theories, such as Newton's Laws of Motion and general relativity. In the past, astronomy was something anyone could do, and many seers and sages made reputations for themselves by using the stars for useful functions, such as telling what time of the year it is, or navigating the seas. Columbus and his contemporaries used the stars to navigate across the Atlantic ocean.
It wasn't until the Renaissance that the theory of heliocentricity in astronomy, the idea that the Earth orbits the Sun rather than vice versa, began to acquire popular currency. Telescopes were invented in 1611 by Galileo Galilei, and he used his to take detailed observations of our Moon, which he revealed was mountainous, and observe Jupiter's four largest moons, now named the Galilean moons in his honor. Newton improved on Galileo's design, inventing the reflecting telescope, which is still used in optical telescopes to this day.
IN 1781, Sir William Herschel discovered the planet Uranus. In 1838, parallax — the slight difference in stellar position due to Earth's ******** in its orbit — was used to precisely determine the distance of stars. Neptune was discovered shortly thereafter. Pluto was discovered only as recently as 1930.
Modern astronomy is very complicated and expensive. Instead of only observing light rays, we observe radar, infrared, x-rays, and even cosmic rays. Orbital observatories such as the Hubble Space Telescope have produced the best images, include extremely high-resolution photographs of other galaxies.
In the mid-20th century, it was discovered that the universe was expanding. This, along with other evidence, led to the theory of the Big Bang, that the entire universe began as a point particle of extreme density. Later observations of the cosmic microwave background confirmed this, and the Big Bang continues as the primary theory of cosmological origins to this day.
The future of astronomy lies in the development of new observational technologies. One of interest is interferometry, sometimes called "hypertelescopes," which use a network of telescopes working cooperatively to resolve images. These could develop to the point where we can observe extrasolar planets with telescopes directly, instead of just detecting








Topic61:

Galileo is often called “the Father of Observational Astronomy”. Discuss.

Typical Essay:
Galileo Galilei was an Italian physicist, mathematician, astronomer and philosopher who has been called “the Father of Modern Science”. Born on 15 February 1564 in Pisa, Italy, Galileo is known for greatly improving the telescope from only 3X magnification to 32X magnification, discovering the moons of Jupiter, observing hills and valleys on the Moon, discovering and analyzing sunspots, popularizing laws of motion for uniformly accelerated objects, making the compound microscope practical, being one of the first to understand sound frequency, and being one of the most ardent advocates of the theory of heliocentrism. Galileo was among the first people in Europe to practice rigorous scientific standards, setting up formal experiments and describing the results using mathematics.
Galileo is probably best known for his advocacy of heliocentrism, the idea that the Earth orbits the Sun rather than vice versa. This was known as the Copernican theory after its inventor, Nicolaus Copernicus. Galileo based his support of Copernicanism after his observations of the satellites of Jupiter – this was the first discovery of celestial bodies that did not supposedly orbit the Earth. If the satellites of Jupiter orbited Jupiter, then could not the Earth orbit the Sun? Unfortunately, this idea was condemned as heresy, and Galileo was put on trial under the Inquisition in 1633. Narrowly avoiding imprisonment, Galileo was put under house arrest until his death in 1642 at age 77.
Galileo is famed for independently creating his own telescope after merely hearing about the concept while visiting Venice in 1608. The basic concept is simple – the combination of a concave and convex lens – but the telescope had only been invented that very year, by Dutch spectacle makers. In March 1610, Galileo published his initial astronomical observations in a short work entitled Sidereus Nuncius (Starry Messenger).
There is a legend that Galileo dropped objects off the Leaning Tower of Pisa as a way of testing the different speeds at which they fell, but this was more likely a thought experiment. In reality, Galileo performed similar experiments with inclined planes that led to the same conclusion. The conclusion, contrary to the Aristotlean wisdom which had held for over a thousand years before, was that objects fall at the same speed regardless of their weight. Heavier objects are just often larger, and therefore slightly more susceptible to air friction. Galileo was not the first modern thinker to realize this, but he played a crucial role in popularizing it.
Because of all his contributions to physics, engineering, and astronomy, Galileo is often called “the Father of Observational Astronomy,” “the Father of Modern Physics,” and other such titles. His basic insights about physics are taught in high schools worldwide.






Topic62:

Long ago, astronomers spotted a galaxy far away and wondered why it was giving birth to so many stars. Discuss.

Typical Essay:


A galaxy is a cluster of stars, nebulae, dark matter, and other astronomical objects. Most galaxies are tens of thousands of light years in diameter, and contain billions of stars. Galaxies come in three primary shapes; spiral galaxies are thin disks, with spiral arms surrounding a central hub; elliptical galaxies are uniform, oval-shaped agglomerations; and irregular galaxies have little or no definite structure.
A spiral galaxy centers around a hub, which is roughly spherical and bulges outward from the disk. The hub is the gravitational center of the galaxy, and usually contains a supermassive black hole. Surrounding the hub are spiral arms, which are bunched-up waves of stars and gas orbiting the center. The spiral arms usually have more gas and dust, and they contain most of the newly formed stars, which make them appear blue in color imagery. A spiral galaxy may have a horizontal bar passing through its hub; our own galaxy, the Milky Way, is believed to contain a bar.
Elliptical galaxies have a large, central hub, but they lack the arms of a spiral galaxy; they usually appear more yellowish in color imagery from old, reddish stars. Irregular galaxies often have no discernible structure, but often they can be recognized as having a distorted spiral or elliptical shape. Elliptical and irregular galaxies often result from collisions, which cause large bursts of star formation and distort the galaxies' structure due to the complex gravitational interactions. Eventually, the two galaxies usually merge to form one large galaxy, which has cast off most of its gas and dust clouds.
There are roughly a hundred billion galaxies in the visible universe; most of them occur in large agglomerations called galaxy superclusters. Between these superclusters are voids with few or no galaxies, often for a hundred million light years or more. By studying the rotation of spiral galaxies, astronomers found that most of the matter in the universe is not stars and gas, but invisible “dark matter” which cannot be seen but still exerts gravity. Dark matter is thought to be responsible for these large clusters, as the gravitational attraction of the dark matter pulled galaxies together.











Topic63:

Unlike the other small bodies in the solar system, comets have been known since antiquity. Discuss.
Typical Essay:
A comet is a small astral body, similar in construction to a planet. A comet may have an unusual orbit, which may at times bring the comet close to the sun and make it visible to the naked eye, or through relatively low strength telescopes. When such a comet can be viewed it is usually noted as having a tail, made of gasses, which early astronomers often mistook for a shooting star.
Most observable comets in our solar system derive from the Oort Cloud, a hypothesized cloud made up of leavings from the sun. These materials form comets, which orbit the sun because are then affected by the gravitational pull of the sun and other planets. While passing by individual planets, the comet may be affected by the gravitational forces of the planets, thus causing an elliptical or oval-type orbit.
Usually, people on earth see a comet when the comet passes in between earth and the sun. It is thought that the comet and its tail, sometimes called the coma and tail, reflect the light of the sun, enhancing visibility. Since comets may orbit the sun in such strange patterns, people may only see the passage of one comet in a lifetime.
In fact, comets are usually classed by the length of time it takes them to orbit the sun. A short period comet takes about 200 years or less to make a full trip around the sun. A long period comet may take far more than 200 years to complete a trip.
For example Halley’s Comet can be viewed on earth about every 75 years. This marks it as a short period comet. Its last sight on earth was in 1986, and it is expected to be seen again in 2061.
A planet may capture a comet and the result can cause significant damage to the comet. Such a gravitational capture may result in the comet breaking into many small pieces, and these smaller pieces can then break off from the comet and hit the capturing planet. Comet Shoemaker-Levy 9, was observed as broken in 1993, and astronomers were able to witness it hitting the atmosphere of Jupiter in 1994.
Most often people looking at the night sky may think that they see “falling stars” which are actually meteors or comets. There are thousands of tiny comets that do not attract much interest. The once in a lifetime comet like Halley’s are often thought of as exciting, since most people will only see them with the naked eye once.







Topic64:

Most people looking at the night sky may think that they see “falling stars” which are actually meteors or comets. Discuss the difference between a meteor and a comet.

Typical Essay:

There are quite a few objects in the universe capable of causing a really, really bad day on planet Earth, including a wayward comet or large asteroid. Most meteors, however, barely rate a 'ho-hum' on an astronomer's scale of scary extraterrestrial events. There are a number of differences between a comet and a meteor, from their general composition to the roles they play in the universe.
A comet is a celestial object believed to be composed primarily of space dust and frozen gases. The birthplace of a comet is thought to be somewhere in the outer parts of the universe, not related to the formation of our solar system at all. A comet follows an orbit that may bring it close to a star, such as our own Sun. As the comet approaches the star, a portion of its ice core may melt and release a trail of dust-sized particles. This cycle can continue for millions of years.
A meteor, on the other hand, does not follow an orbit around the sun. It isn't even called a meteor while it remains floating in outer space – it's called a meteoroid. Only when it enters the Earth's atmosphere is it considered a true meteor.
When the Earth passes through a comet trail or debris field, individual meteoroids hit or skip across the first layers of the atmosphere. Observers on Earth may be fortunate enough to see the last few seconds of a meteor's existence as it streaks across the sky and burns up. Unlike a comet, a meteor will not return a number of years later.
A comet rarely passes within a few million miles of the Earth, while a meteor by its very definition must strike the first layers of the Earth's atmosphere. A comet's arrival can be predicted with some degree of accuracy, but a meteor can enter the Earth's atmosphere at any time of the day or night. A comet can rarely be seen by the naked eye, but during a meteor shower, it is not unusual to see dozens or even hundreds of meteors within a few hours.
A comet also receives an official name for identification, such as Swift-Tuttle, Hale-Bopp or Halley's Comet. A few large asteroids may receive identifying names as well, but meteors do not. Virtually all meteors cease to exist once they've entered the Earth's atmosphere. A rare few make it to the ground, however. Once a meteor has made contact with the Earth's surface, it becomes known as a meteorite. While a comet may be composed of space dust, organic materials and ice, most meteors contain elemental ****ls, such as iron, along with inorganic minerals such as quartz.






Topic65:

Cosmologists and astronomers predicted an expanding universe. Discuss.

Typical Essay:
Ever since Einstein's theory of general relativity was applied to what is known about the universe as a whole, it has been suspected that the universe was expanding. When Edwin Hubble and Milton Humason discovered in the 1920s that practically all galaxies in the sky were moving away from us at great speeds, this boosted suspicions that the universe was expanding at a rapid rate. Yet it was not until 2000 that decisive evidence was finally found in favor of the universe's expansion, in the form of extensive redshift surveys of very distant objects.
The expanding universe is often cited as the most significant finding in modern cosmology. In Einstein's time, the steady-state theory was the predominant one, which stated that the universe remained balanced at the same size. Einstein, whose equations predicted universal expansion or contraction but not stasis, artificially introduced a stabilizing variable into his equations, called the "cosmological constant." After realizing from Hubble's observations that the universe was likely expanding, he later called this his "greatest blunder."
The phenomenon that first led cosmologists and astronomers to predict an expanding universe was Hubble's analysis of redshift. Using the Mount Wilson Observatory, which was the best telescope in the world at the time, Hubble viewed distant galaxies and saw they looked progressively redde. He looked further away in space, and by extension, further back in time as well, as light takes many billions of years to travel from these galaxies to Earth. Because the redness factor correlated so well with increases in distance, Hubble suspected this was a reliable phenomenon with a physical cause.
The cause was determined to be as follows: as the universe expands, the underlying space increases in volume, but the light traveling through it remains the same. The expanding space stretches out the wavelength of the light, making it longer and thereby redder. An analogy sometimes used is dots on the surface of an expanding balloon. Draw a wave pattern on a balloon, and while you blow it up, notice how the wave stretches out and becomes longer. This is the same principle behind the phenomenon of redshift.
In 1998, it was discovered not only that the universe is expanding, but that it is likely expanding at an accelerating rate. The physical reason for this is chalked up to a mysterious "dark energy," so named because we barely know a thing about it.










Topic66:

Satellites facilitated space research. Discuss what a satellite is.

Typical Essay:

A satellite can be defined as any object, either manmade or naturally occurring, that orbits around something else. For example, the moon orbits around Earth and is thus a satellite. The Earth orbits around the sun and is a satellite of the sun. Other examples of naturally occurring satellites include comets, stars, asteroids, and other planets.
Orbit is determined by the gravitational pull of the object around which the satellite circles. The thing around which a satellite circles is called the primary object. However, primary objects are also affected by their satellites, and feel some of their gravitational pull. In some cases, when two objects have a similar size and weight (mass), and a similar gravitational pull, they may be called binary systems, rather than being called a primary object and a satellite. Some argue that Pluto’s moon Charon, and Pluto, represent a binary system instead of a primary object and satellite, since both have similar mass.
Most are more familiar with the term satellite in relationship to the many satellites that circulate the earth. Sputnik was the first artificial satellite, launched in 1957 by the Soviet Union. The launching of Sputnik is almost analogous for the beginning of the Space Race that followed between the US and the USSR. In today’s climate, however, many countries have found that a cooperative effort is more successful in space exploration and studies. The International Space Station, a satellite that orbits earth, is currently the largest manmade satellite in Space, and represents the cooperative effort of numerous countries.
Manmade satellites are classified by types, and there are over ten types. Some of the main types of satellite used today include astronomical satellites, communication satellites, earth observation satellites, weather satellites and space stations. Other types of satellites include those used to monitor earth from a military standpoint, and biosatellites, which may carry animals or other lifeforms for the purpose of research on earth lifeforms in space. Navigational satellites are now popular and form a vital part of the global positioning system (GPS) now available in many cars.
Satellites may also be classified by the height at which they orbit earth or another body. A low earth orbit circles the earth at a height of 0-1240 miles (1995.59 km). High earth orbits can be as far away as 22,240 miles (35,791.81 km). Medium earth orbits represent the distance in between high and low earth orbits. Further distinctions exist to describe the type of orbit a manmade or natural satellite has. For example, Pluto has a slightly elliptical orbit. Also a satellite is often classed by what primary object it orbits. A satellite that circles the Earth has a geocentric orbit, for example. The earth, and the planets in our solar system are classed as having a heliocentric orbit since they circle the sun.
A manmade satellite can serve many purposes. We currently use many different types of satellite systems to track things like weather, to make our cellphones work, to find out how to get somewhere and to gather more information about earth, and about the galaxy. About 5000 manmade satellites currently orbit earth, and on clear dark nights, it’s often possible to see one in the night sky. Of course, viewing a planet, the stars, or comets is also viewing a satellite. We also must remember, we live on a satellite, and are not stationary in the sky.
Topic67:
The National Aeronautics and Space Administration (NASA) contributed much to astronomy. Discuss.
Typical Essay:
The National Aeronautics and Space Administration (NASA) is an American government agency which runs the civilian arm of the space program. The aim of NASA is to increase human understanding of the solar system and the universe that contains it, and to improve American aeronautics ability. Under its charter, NASA is supposed to be a peacetime agency that does not perform military functions, although NASA does cooperate with the military, and many NASA employees have a military background. To achieve this goal, NASA has an annual budget which can be counted in the billions to fund programs and pay tens of thousands of employees.
NASA was founded in 1958, in response to the Soviet launch of Sputnik in 1957. The early years of the organization were driven by Cold War competitiveness, and NASA quickly worked on creating rockets which would allow for manned spaceflight. NASA astronauts Neil Armstrong and Buzz Aldrin were the first humans known to have set foot on the moon in 1969, an action that was considered a major victory for American aeronautics. Riding on this early success, NASA continued development of aeronautic equipment designed to function outside the Earth's atmosphere.
After the moon landing, NASA focused on doing research around the solar system, sending an assortment of manned flights to the moon to collect material for study, and unmanned drones to other planets to collect data. These flights have collected large amounts of data which are constantly being added to and analyzed. Scientific advancement is a large part of NASA's mission. With the assistance of the agency, scientists have been able to conduct experiments in the zero gravity environment of space, and test hypotheses about the universe.
NASA also continues to work on a space shuttle program to make space more accessible. As of 2016, the space shuttle had made 112 flights with astronauts from many nations including the United States, and two of these flights, the Challenger and Columbia, were lost. NASA plans to resume manned flights to the moon by 2020, after safety improvements have been made to the space shuttle.
As part of its mission as a peaceful agency, NASA cooperates with agencies within the United States and international aeronautics agencies. A NASA astronaut can usually be found on board the International Space Station, and astronauts from other nations are invited to participate in NASA events. This fostering of international cooperation will hopefully continue as humans explore space and the possibility of off-Earth human settlements becomes possible.







Topic68:

Cosmologists and astronomers predicted an expanding universe. Discuss.

Typical Essay:
Space travel is a form of travel in which passengers enter space, the vast region outside the protective envelope of the Earth's atmosphere. Space starts 62 miles (100 kilometers) above the Earth's crust, at a point called the Karman Line, and it continues for a distance which appears to be infinite, interrupted periodically by celestial bodies such as stars, planets, and so forth. Humans have long had romantic associations with space travel, with people considering space “the final frontier,” as they famously say on Star Trek.
Humans have been intrigued by the night sky for centuries, tracking the movements of stars, planets, comets, and other features in the sky and pondering the mysteries of the heavens. In the 20th century, the fascination with space took on a whole new level of excitement when humans successfully launched manned spacecraft out of the Earth's atmosphere, putting astronauts in space and on the Moon. With the proof that manned spaceflight was possible, the concept of space travel began to seem less like a pipe dream and more like a reality, and private companies began to enter the field, developing space planes and offering commercial flights.
In the 20th century, space travel was restricted to astronauts who worked for various governments, and it was primarily performed for research purposes. Space travel allowed people to collect samples from the Moon, maintain space telescopes such as the Hubble Telescope, and eventually to perform research on the International Space Station, a structure which orbits the Earth and houses astronauts from several nations at any given time.
While space travel for research is certainly admirable and important, many people are more interested in the potential for space travel as a form of recreation, tourism, or exploration. Civilians began purchasing tickets for tourist flights into space in the early 2000s, sometimes going on brief suborbital flights in which they barely entered space, and sometimes spending several days in space, exploring the International Space Station and enjoying the experience of being in space.
The potential for space travel is infinite, just like the universe, bounded only by human technology. Many people hope that the dreams of science fiction, such as massive ships which can travel between galaxies, will someday be realized. Space travel could be used to explore the rest of the solar system and galaxy, learning more about the nature of the universe and potentially leading to a discovery of life beyond the boundaries of Earth.





Topic69:

We are living in a universe still being discovered. Discuss how big our universe is.

Typical Essay:
The current, observable universe has been determined to have a width of 156 billion light years, with an error of less than 1%, by the latest deep-space telescope WMAP. At first, it might seem impossible that scientists are so sure of this astronomical measurement, but this figure has been narrowed by years of research and determined by several paths of inquiry. Also, the size of the universe is intimately dependent on its shape, age, acceleration, and total mass, so we are very confident in this figure.
In 2003, the Wilkinson Microwave Anisotropy Probe sent back enough data for scientists to publish extremely dependable studies that established two previously unknown facts about the universe. They determined our universe is flat, which means standard Euclidean geometry is valid on the largest scale. This can be understood by saying a straight line more or less stays a straight line for as long as it extends. They also established that the universe is accelerating at an ever-increasing rate, which means that all mass is flying away from each other at faster and faster speeds. The WMAP data measured the temperature, called the cosmic microwave background radiation, of our observable universe with an unprecedented accuracy, to within a 5% error. From these facts, we can deduce figures such as the radius of the universe.
Remember that the size of the universe is not a constant value, nor is it the size of an object as we traditionally understand it. The size of the universe is actually the size of space itself, and as space expands, so does the space between planets, stars, and galaxies. At the beginning of the universe, the Big Bang created space and time as we know them. From that moment, space has been expanding, so we find its size by measuring how far light could have traveled since the Big Bang, along with how much space itself stretched.
We can only possibly look or communicate up to the edge, or "horizon," of where light has traveled since the beginning of the universe. The size of the universe means the space in which we can interact with anything. We will never ever know what is "beyond" this boundary, because there is no way to know anything about it, so it's illogical to consider the realm "outside" of our universe, or to wonder what we are expanding "into."
An independent measure of the size of our universe can be given by studying the oldest stars. The oldest stars we have found are probably somewhere between 11 and 14 billion light years old. If we had stars older than the largest distance light could have traveled, then we'd know there was something wrong with our calculations; there would not be enough time for them to evolve. However, these values are consistent with everything else we know about the universe.




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