104 lines
6.7 KiB
Plaintext
104 lines
6.7 KiB
Plaintext
ÜÜÜÜÜÜÜÜÜÜÜÜÜ ÜÜÜ ÜÜÜÜ
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ÜÛÛÛÛÛÛÛÛßÛßßßßßÛÛÜ ÜÜßßßßÜÜÜÜ ÜÛÜ ÜÛÛÛÛÛÛÛÛÜÜÜÜÜÛßß ßÛÛ
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ßÛÛÛÛÛÛÛÛÛÛÛÛÛÛÜ ßÛÛ ÜÛÛÛÜÛÛÜÜÜ ßÛÛÛÛÜ ßÛÛÛÛÛÛÛÜÛÛÜÜÜÛÛÝ Ûß
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ßßßÛÛÛÛÛÛÛÛÛÛÜ ÞÝ ÛÛÛÛÛÛÛÛÛÛÛßßÛÜÞÛÛÛ ÛÛÛÛÛÜ ßßÛÛÛÞß
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Mo.iMP ÜÛÛÜ ßÛÛÛÛÛÛÛÝÛ ÞÛÛÛÛÛÛÛÛÛ ÞÛÛÛÛ ÞÛÛÛÛÛÝ ßÛß
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ÜÛÛÛÛÛÛÛ ÛÛÛÛÛÛÛÛÝ ÞÛÛÛÛÛÛÛÛÝ ÛÛÛ ÛÛÛÛÛÛ
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ÜÛÛÛÛÛÛÛÝ ÞÛÛÛÛÛÛÛÛ ÞÛÛÛÛÛÛÛÛ ß ÞÛÛÛÛÛÛÜ ÜÛ
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ÜÛÛÛÛÛÛÛÝ ÛÛÛÛÛÛÛÛ ÛÛÛÛÛÛÛÛÝ ÞÞÛÛÛÛÛÛÛÛÛß
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ÜÛßÛÛÛÛÛÛ ÜÜ ÛÛÛÛÛÛÛÛÝ ÛÛÞÛÛÛÛÛÝ ÞÛÛÛÛÛÛßß
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ÜÛßÛÛÛÛÛÛÜÛÛÛÛÜÞÛÛÛÛÛÛÛÛ ÞÛ ßÛÛÛÛÛ Ü ÛÝÛÛÛÛÛ Ü
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ÜÛ ÞÛÛÛÛÛÛÛÛÛÛß ÛÛÛÛÛÛÛÛÛ ßÛÜ ßÛÛÛÜÜ ÜÜÛÛÛß ÞÛ ÞÛÛÛÝ ÜÜÛÛ
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ÛÛ ÛÛÛÛÛÛÛÛß ÛÛÛÛÛÛÛÛÛÛÜ ßÛÜ ßßÛÛÛÛÛÛÛÛÛß ÜÜÜß ÛÛÛÛÜÜÜÜÜÜÜÛÛÛÛÛß
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ßÛÜ ÜÛÛÛß ßÛÛÛÛÛÛÛÛÛÛÜ ßßÜÜ ßßÜÛÛßß ßÛÛÜ ßßßÛßÛÛÛÛÛÛÛßß
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ßßßßß ßßÛÛß ßßßßß ßßßßßßßßßßßßß
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ARRoGANT CoURiERS WiTH ESSaYS
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Grade Level: Type of Work Subject/Topic is on:
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[ ]6-8 [ ]Class Notes [Essay on What Light Is ]
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[ ]9-10 [ ]Cliff Notes [ ]
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[x]11-12 [x]Essay/Report [ ]
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[ ]College [ ]Misc [ ]
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Dizzed: 12/94 # of Words:894 School: ? State: ?
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ÄÄÄÄÄÄÄÄÄ>ÄÄÄÄÄÄÄÄÄ>ÄÄÄÄÄÄÄÄÄ>Chop Here>ÄÄÄÄÄÄÄÄÄ>ÄÄÄÄÄÄÄÄÄ>ÄÄÄÄÄÄÄÄÄ>ÄÄÄÄÄÄÄÄÄ
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LIGHT: A FUNDAMENTAL FORCE IN OUR WORLD
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If asked what light is, one could say that it's one of the most basic
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elements of our world and our universe as we perceive it. It is through
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sight that we receive 90% of our information. It is through the use of
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telescopes aiding the naked eye that we are aware of the heavenly bodies
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around us. It is through light that the energy from the sun is transferred
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to us. The sun's energy supports the food chain; plants use it to turn
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water and CO2 into energy usable by other organisms. Solar energy was also
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used, indirectly, to produce all of the fossil fuels that we consume daily.
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Since light is such a basic part of our existence, we should have a basic
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understanding of what it is.
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What we call light, the intangible, powerful force that powers our world,
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is somewhat hard to define in real terms. It shares properties with both
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particles and waves. It follows the same rules as a wave does--it moves in
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a regular fashion, in a perfect sine wave at a certain frequency. It
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travels in a straight line, and is subject to refraction. All of these
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characteristics are found in waves of any type, from radio frequency waves,
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up to Gamma and X- rays. Light, however, also exhibits qualities
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characteristic of particles such as neutrons and protons. A photon, or
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quanta, is the "packet" of energy that is sent in a light wave. Like a
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particle, the photon is believed to have a finite mass, and has the ability
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to affect other matter. As light strikes a photovoltaic solar cell, it
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knocks electrons in the silicon atoms on the surface into a higher state of
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energy. When these return to their normal, or "ground" state, energy is
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produced in the form of electricity. Thus, light is termed a
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"wave-particle," and this property is called the "wave-particle duality of
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nature." Many questions concerning what makes up light still lie
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unanswered, but this much is thought to be true.
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Light can be produced in a variety of ways. Our sun, like other stars,
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uses nuclear fusion to produce energy in the form of light and radiation.
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We can produce light artificially using several methods. If one starts a
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fire, it produces light and heat. (Heat, which is infrared radiation, is
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another type of light energy.) The light and heat are a result of a
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chemical reaction, the combining of oxygen with the carbon in the wood.
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This reaction leaves behind products which have less potential energy than
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they started with. The energy, which left as light and heat, was produced
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when electrons dropped in energy levels during the reaction. The excess
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energy from one atom was given off as a photon, producing light. If one
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examines a fluorescent or incandescent light bulb, one can see that all it
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is doing is having electricity stimulate a metallic or gaseous substrate,
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causing it to give off photons. The principle is the same as it was with
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the fire, only it is more controlled. Still more controlled is the laser,
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which puts out its photons in a single frequency. This is achieved through
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a carefully designed apparatus which stimulates materials in a way that
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allows them to only put out light at a certain wavelength. Laser light is,
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therefore, of all one color. White light, or sunlight, is a broad mixture
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of wavelengths. All methods of producing light, natural and artificial,
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share one common feature: they rely on electrons changing energy levels to
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produce the photons.
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As there are a variety of methods of producing light, so are there a
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multitude of ways it can be applied. The most obvious use of light is in
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supporting our food chain. Without light energy, nothing could live on our
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planet. The plants, which are at the bottom of the food chain, supply
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energy to all other organisms. We as humans are adapted to having sunlight
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around us, and taking in information with our eyes. Aside from keeping us
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alive, light is also employed in highly specialized applications. Laser
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light is being used in surgery. The highly concentrated beam of light is
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far more precise than any surgeon's hand, and much finer than the sharpest
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blade. In the area of communications, light is used in fiber optic networks
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for fast, crystal-clear connections. (Fiber optics allow light to travel in
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a finely directed path with very little distortion.) Optical components in
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computers are starting to see use. Also, lasers are being used to produce
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holographic images, both for industrial and commercial markets. Holographic
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pictures can show an object three dimensionally, and in great detail.
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Finally, new ways of utilizing the sun's energy are being developed that
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will allow light to be more efficiently converted to electricity. Thus,
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light indeed has a wealth of applications.
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It must be remembered that, like most other things around us, light is
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something utilized on a daily basis, yet little understood. With continued
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research, we may someday unravel the mysteries surrounding this unique
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force which is constantly at work in our universe. The applications of
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light in the present are nothing compared with what could be gained if we
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could understand this strange mechanism; it may someday be the key to
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solving our energy problems, or unlocking the secret of the universe.
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