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نام تاپيک: Just Speak In English_Topic: No topic

  1. #71
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    13 Voa 7

    ENVIRONMENT REPORT
    June 21, 2006
    International Whaling Commission

    This is the VOA Special English ENVIRONMENT REPORT.
    Delegations from around the world attended a yearly meeting of the International Whaling Commission last month in Japan. The commission is deeply divided about the issue of whale hunting. Countries including Japan want to lift the ban on whale hunting ordered in nineteen-eighty-six. Countries including the United States support the ban.


    The whaling commission defeated a proposal to permit limited whale hunting for native people in the United States and Russia. These native people depend on whale meat for food.
    The commission voted to continue the worldwide ban on whale hunting. Japan has fought to end the ban on hunting some kinds of whales. Whale hunting is a cultural tradition in Japan.
    Environmental groups are opposed to killing whales. But Japan says whale populations have risen sharply since the ban was established.
    A year after the ban, Japan began hunting hundreds of whales. Japanese officials said these yearly hunts are necessary in order to study how whales feed and move in the oceans.
    Japan is permitted to sell meat collected during these whale hunts. But opponents dispute the value of Japan's research. They say Japan is doing research in order to kill whales. They say whales can be studied without killing them.
    Japan says many kinds of whales have increased quickly and are eating too many fish. It says whales are harming the fishing industry. But American experts at the conference say there is no scientific evidence that whales are causing a decrease of fish in the oceans. They say decreasing fish populations are caused by people, not whales.
    This year, Japan plans to kill seven-hundred whales during hunts in Antarctic waters and the northwestern Pacific Ocean. The hunt includes one kind of whale that the World Conservation Union considers to be endangered.
    The international movement against whale hunting is having an effect in Japan. Some Japanese say they no longer want to eat whale meat because it costs too much and it is no longer a popular food.
    Norway is the only other major whale-hunting nation in the International Whaling Commission. Norway objected to the organization's ban on killing whales and has continued to hunt them.

  2. #72
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    11 Music 3

    The Sound Of A Gun

    I have seen the diamond stylus,
    Cut a groove from north to south,
    Heard them calling from the islands for a better day,
    One by one they tell their story,
    One by one it's just the same,
    "They've taken our leaders,
    And all their believers are paralysed,
    And now we can't turn back - somebody is watching you!
    Don't turn round - yesterday's gone!
    And even the children are waking at midnight in tears,
    Didn't anyone hear? Mother, mother, mother..."

    Hush child go to sleep, it's only the sound of a gun,
    Hush child go to sleep, it's only the sound of a gun;

    Looking out my bedroom window,
    I remember early days,
    When the shot that wounded millions took our breath away,
    But now the shadow of a gunman,
    With his balaclava eyes, is making the news,
    Calling out the warnings on the telephone,
    "You're in the line of fire - wish there was another way!
    Line of fire - anything goes,"
    And who is the winner, and what will the minister say,
    At the end of the day? Never, never, never, never!

    Hush child go to sleep, it's only the sound of a gun,
    Hush child go to sleep, it's only the sound of a gun;

    This is bella soma, this is bella soma...
    Mother, mother, mother...

    Hush child go to sleep, it's only the sound of a gun,
    Hush child go to sleep, it's only the sound of a gun,
    Hush child go to sleep, it's only the sound of a gun,
    Hush child do not weep,
    It's only the sound of a world on the run,
    You're hearing the sound of a gun;

  3. #73
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    hi buddies
    i wanna know after using (can't help) in a sentence how should i use the verb (i mean we should use in base form,infinitive,...what kind?)

  4. #74
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    A galaxy is a system of stars, dust, and gas held together by gravity. Our solar system is in a galaxy called the Milky Way. Scientists estimate that there are more than 100 billion galaxies scattered throughout the visible universe. Astronomers have photographed millions of them through telescopes. The most distant galaxies ever photographed are as far as 10 billion to 13 billion light-years away. A light-year is the distance that light travels in a vacuum in a year -- about 5.88 trillion miles (9.46 trillion kilometers). Galaxies range in diameter from a few thousand to a half-million light-years. Small galaxies have fewer than a billion stars. Large galaxies have more than a trillion.
    The Milky Way has a diameter of about 100,000 light-years. The solar system lies about 25,000 light-years from the center of the galaxy. There are about 100 billion stars in the Milky Way.

    Only three galaxies outside the Milky Way are visible with the unaided eye. People in the Northern Hemisphere can see the Andromeda Galaxy, which is about 2 million light-years away. People in the Southern Hemisphere can see the Large Magellanic Cloud, which is about 160,000 light-years from Earth, and the Small Magellanic Cloud, which is about 180,000 light-years away

  5. #75
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    hi buddies
    today i choose groups & shapes of galaxies from nasa's site i hope its useful
    Groups of galaxies

    Galaxies are distributed unevenly in space. Some have no close neighbor. Others occur in pairs, with each orbiting the other. But most of them are found in groups called clusters. A cluster may contain from a few dozen to several thousand galaxies. It may have a diameter as large as 10 million light-years.

    Clusters of galaxies, in turn, are grouped in larger structures called superclusters. On even larger scales, galaxies are arranged in huge networks. The networks consist of interconnected strings or filaments of galaxies surrounding relatively empty regions known as voids. One of the largest structures ever mapped is a network of galaxies known as the Great Wall. This structure is more than 500 million light-years long and 200 million light-years wide
    Shapes of galaxies
    Astronomers classify most galaxies by shape as either spiral galaxies or elliptical galaxies. A spiral galaxy is shaped like a disk with a bulge in the center. The disk resembles a pinwheel, with bright spiral arms that coil out from the central bulge. The Milky Way is a spiral galaxy. Like pinwheels, all spiral galaxies rotate -- but slowly. The Milky Way, for example, makes a complete revolution once every 250 million years or so.

    New stars are constantly forming out of gas and dust in spiral galaxies. Smaller groups of stars called globular clusters often surround spiral galaxies. A typical globular cluster has about 1 million stars.

    Elliptical galaxies range in shape from almost perfect spheres to flattened globes. The light from an elliptical galaxy is brightest in the center and gradually becomes fainter toward its outer regions. As far as astronomers can determine, elliptical galaxies rotate much more slowly than spiral galaxies or not at all. The stars within them appear to move in random orbits. Elliptical galaxies have much less dust and gas than spiral galaxies have, and few new stars appear to be forming in them.

  6. #76
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    Galaxies of a third kind, irregular galaxies, lack a simple shape. Some consist mostly of blue stars and puffy clouds of gas, but little dust. The Magellanic Clouds are irregular galaxies of this type. Others are made up mostly of bright young stars along with gas and dust.

    Galaxies move relative to one another, and occasionally two galaxies come so close to each other that the gravitational force of each changes the shape of the other. Galaxies can even collide. If two rapidly moving galaxies collide, they may pass right through each other with little or no effect. However, when slow-moving galaxies collide, they can merge into a single galaxy that is bigger than either of the original galaxies. Such mergers can produce spiral filaments of stars that can extend more than 100,000 light-years into space.

  7. #77
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    Emissions from galaxies
    All galaxies emit (give off) energy as waves of visible light and other kinds of electromagnetic radiation. In order of decreasing wavelength (distance between successive wave crests), electromagnetic radiation consists of radio waves, infrared rays, visible light, ultraviolet rays, X rays, and gamma rays. All these forms of radiation together make up the electromagnetic spectrum.

    The energy emitted by galaxies comes from various sources. Much of it is due to the heat of the stars and of clouds of dust and gas called nebulae. A variety of violent events also provide a great deal of the energy. These events include two kinds of stellar explosions: (1) nova explosions, in which one of the two members of a binary star system hurls dust and gas into space; (2) much more violent supernova explosions, in which a star collapses, then throws off most of its matter. One supernova may leave behind a compact, invisible object called a black hole, which has such powerful gravitational force that not even light can escape it. Another supernova may leave behind a neutron star, which consists mostly of tightly packed neutrons, particles that ordinarily occur only in the nuclei of atoms. But some supernovae leave nothing behind.
    The intensity of the radiation emitted by a star at various wavelengths depends on the star's surface temperature. For example, the sun, which has a surface temperature of about 5500 ¡C (10,000 ¡F) emits most of its radiation in the visible part of the electromagnetic spectrum. Radiation of this type, whose intensity depends on temperature as it does for the sun and other normal stars, is called thermal radiation.

    A small percentage of galaxies called active galaxies emit tremendous amounts of energy. This energy results from violent events occurring in objects at their center. The distribution of the wavelengths of the emissions does not resemble that of normal stars, and so the emissions are known as nonthermal radiation. The most powerful such object is a quasar, which emits a huge amount of radio, infrared, ultraviolet, X-ray, and gamma-ray energy. Some quasars emit 1,000 times as much energy as the entire Milky Way, yet look like stars in photographs. Quasar is short for quasi-stellar radio source. The name comes from the fact that the first quasars identified emit mostly radio energy and look much like stars. A radio galaxy is related to, but appears larger than, a quasar.

    A Seyfert galaxy is a spiral galaxy that emits large amounts of infrared rays as well as large amounts of radio waves, X rays, or both radio waves and X rays. Seyfert galaxies get their name from American astronomer Carl K. Seyfert, who in 1943 became the first person to discover one.

    Some active galaxies emit jets and blobs of highly energetic, electrically charged particles. These particles include positively charged protons and positrons and negatively charged electrons. Electrons and protons are forms of ordinary matter, but positrons are antimatter particles. They are the antimatter opposites of electrons -- that is, they have the same mass (amount of matter) as electrons, but they carry the opposite charge. See Antimatter.

    The cause of the intense activity in active galaxies is thought to arise from a colossal black hole at the galactic center. The black hole can be as much as a billion times as massive as the sun. Because the black hole is so massive and compact, its gravitational force is powerful enough to tear apart nearby stars. The resulting dust and gas fall toward the black hole, adding their mass to a disk of matter called an accretion disk that orbits the black hole. At the same time, matter from the inner edge of the disk falls into the black hole. As the matter falls, it loses energy, thereby producing the radiation and jets that shoot out of the galaxy
    The Milky Way is not an active galaxy, but it does have a powerful source of radiation called Sagittarius A* at its center. The cause of this radiation may be a black hole a million times as massive as the sun.

  8. #78
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    Origin of galaxies

    Scientists have proposed two main kinds of theories of the origin of galaxies: (1) bottom-up theories and (2) top-down theories. The starting point for both kinds of theories is the big bang, the explosion with which the universe began 10 billion to 20 billion years ago. Shortly after the big bang, masses of gas began to gather together or collapse. Gravity then slowly compressed these masses into galaxies.

    The two kinds of theories differ concerning how the galaxies evolved. Bottom-up theories state that much smaller objects such as globular clusters formed first. These objects then merged to form galaxies. According to top-down theories, large objects such as galaxies and clusters of galaxies formed first. The smaller groups of stars then formed within them. But all big bang theories of galaxy formation agree that no new galaxies -- or very few -- have formed since the earliest times.

    Astronomers have found evidence of what conditions were like before the galaxies formed. In 1965, American physicists Arno Penzias and Robert Wilson detected faint radio waves throughout the sky. According to the big bang theory, the waves are radiation left over from the initial explosion. The strength of the radio waves appeared to be very nearly the same in every direction. But in 1992, a satellite called the Cosmic Background Explorer (COBE) detected tiny differences in the strength of radio waves coming from different directions. The differences in strength arise from tiny increases in the density of matter in the universe shortly after the big bang. The small regions of increased density had a stronger gravitational force than the surrounding matter. Clumps of matter therefore formed in these regions; and the clumps eventually collapsed into galaxies.

    Most astronomical observations made to date support big bang theories. According to these theories, the universe is still expanding. Two kinds of observations strongly support the idea of an expanding universe. These observations indicate that all galaxies are moving away from one another and that the galaxies farthest from the Milky Way are moving away most rapidly. This relationship between speed and distance is known as the Hubble law of recession (moving backward), or Hubble's law. The law was named after American astronomer Edwin P. Hubble, who reported it in 1929.
    Astronomers estimate the speed at which a galaxy is moving away by measuring the galaxy's redshift. The redshift is an apparent lengthening of electromagnetic waves emitted by an object moving away from the observer. A redshift can be measured when light from a galaxy is broken up and spread out into a band of colors called a spectrum. The spectrum of a galaxy contains bright and dark lines that are determined by the galaxy's temperature, density, and chemical composition. These lines are shifted toward the red end of the spectrum if the galaxy is moving away. The greater the amount of redshift, the more rapid the movement.

    Scientists estimate the distance to galaxies by measuring the galaxies' overall brightness or the brightness of certain kinds of objects within them. These objects include variable stars as well as supernovae

  9. #79
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    hi buddies
    Evolution of spiral galaxies

    Astronomers do not understand clearly how galactic spirals evolved and why they still exist. The mystery arises when one considers how a spiral galaxy rotates. The galaxy spins much like the cream on the surface of a cup of coffee. The inner part of the galaxy rotates somewhat like a solid wheel, and the arms trail behind. Suppose a spiral arm rotated around the center of its galaxy in about 250 million years -- as in the Milky Way. After a few rotations, taking perhaps 2 billion years, the arms would "wind up," producing a fairly continuous mass of stars. But almost all spiral galaxies are much older than 2 billion years.

    According to one proposed solution to the mystery, differences in gravitational force throughout the galaxy push and pull at the stars, dust, and gas. This activity produces waves of compression. A familiar example of waves of compression are ordinary sound waves. Because the galaxy is rotating, the waves seem to travel in a spiral path, leading to the appearance of spiral arms of dense dust and gas. Stars then form in the arms.

  10. #80
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    How do astronomers find the mass of a black hole?


    Black holes often have stars or gas orbiting around them. It is then possible to measure the mass of the black hole, just by measuring the speed of the orbiting material.

    Consider the case in which a star and a black hole orbit around their mutual center of gravity. Although we can't see the black hole, we can see the star. With accurate observations, we can measure the speed of the star as well as the size of the orbit. Once these have been measured, the laws of gravity tell us exactly what the black hole mass is.

    For example, let's assume that a star like our Sun orbits a black hole. Suppose that we measure the speed of the star to be 117 miles per second, and that we measure the diameter of its orbit to be similar to the distance of the planet Mercury from our Sun. This implies that the star orbits the black hole once every 12 days. The laws of gravity then tell us that the black hole must be 10 times more massive than our Sun.

    The supermassive black holes in the centers of galaxies can often be measured using this method. For example, the mass of the black hole in the center of our Milky Way galaxy was calculated by measuring the speeds of individual stars that orbit around it. This showed that the black hole is three million times more massive than our Sun. And the mass of the black hole in the center of the nearby Andromeda galaxy has been calculated by measuring the average speeds of all the stars that orbit around it. This showed that Andromeda's black hole is 30 million times more massive than our Sun

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