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| - Refraction is the phenomenon in which the direction of light changes when it passes through a medium. Refraction is usually caused in objects that are transparent, including air. A practical example of refraction is looking at the floor of a swimming pool through water; the bottom of the pool looks closer than it would in air.
- Refraction is the change of direction by a wave due to a change in medium, and thus a change in speed. The most common example of this is with light, although it can happen with any type of wave. This happens when it travels from one medium to another medium, with different refractive indexes.
- Refraction was the change of a lightwave into a direction opposite the intended direction. Terraformer Kurt Mandl mentioned that refraction and a thin atmosphere on Velara III was interesting but no indication of life. (TNG: "Home Soil" ) Among the artifacts Vash brought back from the Gamma Quadrant in 2369 was an object that appeared to be some kind of Promethean quartz, however, its molecular density and refraction index was much higher. (DS9: "Q-Less")
- Refraction is the change in direction of a wave due to a change in its velocity. This is most commonly seen when a wave passes from one medium to another. Refraction of light is the most commonly seen example, but any type of wave can refract when it interacts with a medium, for example when sound waves pass from one medium into another. Snell's law is used to calculate the degree to which light is refracted when traveling from one medium to another.
- Refraction is the 44th level in Chip's Challenge 1, and named such because the level is completely symmetrical, except for the center corridor; it is "refracted" through the center of the level. Refraction is quite simple although long, and there is one small trick to add a couple extra seconds. The optimum route is: southeast, northeast, switch tanks, finish northeast, finish southeast (use above trick), northwest, southwest (use above trick), switch tanks, finish southwest, finish northwest, exit.
- Refraction occurs when a wave bends as a result of entering a new medium. Remember when we discussed that velocity is controlled by the medium? Well, since the wave is going from one substance in which it has one speed, and then enters another substance in which it will speed up or slow down, it must bend. The only time this will not happen is if the wave hits the new medium exactly perpendicular to it. Read on to find out why. Source: All information, including the fishing scenario, is from Hyper Physics except anything regarding the ray diagram, which is from the teachings of Mr. GK. Back
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| abstract
| - Refraction is the 44th level in Chip's Challenge 1, and named such because the level is completely symmetrical, except for the center corridor; it is "refracted" through the center of the level. Refraction is quite simple although long, and there is one small trick to add a couple extra seconds. When Chip is following just behind the pink ball on entering a room, then after collecting the first chip in the room, taking the second chip will cause so much delay that collecting the chips on the opposite vertical side is quicker. This is available on the southeast and southwest edges; collecting the chips in normal sequence will lead to 144. The optimum route is: southeast, northeast, switch tanks, finish northeast, finish southeast (use above trick), northwest, southwest (use above trick), switch tanks, finish southwest, finish northwest, exit.
- Refraction occurs when a wave bends as a result of entering a new medium. Remember when we discussed that velocity is controlled by the medium? Well, since the wave is going from one substance in which it has one speed, and then enters another substance in which it will speed up or slow down, it must bend. The only time this will not happen is if the wave hits the new medium exactly perpendicular to it. Read on to find out why. It would be helpful to look at the diagram (above) while reading the following explanation. Points A and B in the picture are both located on the same wave crest. However, due to the way the depicted wave will hit the boundary (as in the angle), Point A will reach the new substance first. In this example the second medium is the one in which the waves travel slower, but in life this is not necessarily true (it can be the other way around). As Point A starts to slow, Point B will still have a little distance to travel before it does so too. This delay between two parts of the same crest is what causes the wave to bend. A wave will not bend if it hits the second medium at a perfect right angle, because all parts of a crest, for example, will slow at the same time. Another point to note is that the delay between one crest and the succeeding crest, for example, causes the wavelength of the wave to decrease as it slows. With A having just entered Medium 2 and begun to slow, the next part of the wave (which can be represented by Point C) behind A is still moving faster in Medium 1. Thus, C "catches up" in effect with A, reducing the distance between them. With this happening all along the wave, we see that its wavelength decreases. This is also mathematically true. Since v = f(Lambda), with a decrease in speed and a constant frequency, the wavelength must decrease. At this point it is necessary to introduce the ray diagram (above), a type of depiction of a refracted wave that shows all relevant angles. A wave (incident ray) hits a boundary between two media and refracts (refracted ray). A dashed line perpendicular to the boundary is drawn in. It the "normal line" and is a tool physicists created to allow for analysis of the angles involved. The angle between the incident ray and the normal line is the angle of incidence. The angle between the refracted ray and the normal line is the angle of refraction. As a wave travels from one substance to another and slows, it bends towards the normal line, while from slow to fast it bends away from the normal line. Ray diagrams are more helpful in the context of light waves because a mathematical formula can be used to determine at exactly what angle the wave will refract. But this does not apply so much to sound. So how does this work with sound? Well, different media sound often travels through are warmer and cooler air. Sound travels faster in warmer air than colder, so when you're sitting in a boat at the crack of dawn getting ready to fish, you can clearly hear someone speaking far away from you. This is because the air just around you is cold from the cool water. The air above that is becoming heated by the sun, in effect creating two media. When the person far away speaks in your direction, the sound travels from a medium it is slow in to one it is faster in. From slow to fast means away from the normal line, and therefore more towards where you are sitting. Thus the bending of sound waves sometimes allows for them to be heard in places they normally would not have been detected. Source: All information, including the fishing scenario, is from Hyper Physics except anything regarding the ray diagram, which is from the teachings of Mr. GK. Back
- Refraction is the change in direction of a wave due to a change in its velocity. This is most commonly seen when a wave passes from one medium to another. Refraction of light is the most commonly seen example, but any type of wave can refract when it interacts with a medium, for example when sound waves pass from one medium into another. In optics, refraction occurs when light waves travel from a medium with a given refractive index to a medium with another. At the boundary between the media, the wave's phase velocity is altered, it changes direction, and its wavelength increases or decreases but its frequency remains constant. For example, a light ray will refract as it enters and leaves glass; understanding of this concept led to the invention of lenses and the refracting telescope. File:Pencil in a bowl of water.pngRefraction of light waves in water. The dark rectangle represents the actual position of a pencil sitting in a bowl of water. The light rectangle represents the apparent position of the pencil. Notice that the end (X) looks like it is at (Y), a position that is considerably shallower than (X).Refraction can be seen when looking into a bowl of water. Air has a refractive index of about 1.0003, and water has a refractive index of about 1.33. If a person looks at a straight object, such as a pencil, which is placed at a slant, partially in the water, the object appears to bend at the water's surface. This is due to the bending of light rays as they move from the water to the air. Once the rays reach the eye, the eye traces them back as straight lines (lines of sight). The lines of sight (shown as dashed lines) intersect at a higher position than where the actual rays originated. This causes the pencil to appear higher and the water to appear shallower than it really is. The depth that the water appears to be when viewed from above is known as the apparent depth. File:Refraction in a ripple tank.pngRefraction of waves in a ripple tankThe diagram on the right shows an example of refraction in water waves. Ripples travel from the left and pass over a shallower region inclined at an angle to the wavefront. The waves travel more slowly in the shallower water, so the wavelength decreases and the wave bends at the boundary. The dotted line represents the normal to the boundary. The dashed line represents the original direction of the waves. The phenomenon explains why waves on a shoreline never hit the shoreline at an angle. Whichever direction the waves travel in deep water, they always refract towards the normal as they enter the shallower water near the beach. Refraction is also responsible for rainbows and for the splitting of white light into a rainbow-spectrum as it passes through a glass prism. Glass has a higher refractive index than air and the different frequencies of light travel at different speeds (dispersion), causing them to be refracted at different angles, so that you can see them. The different frequencies correspond to different colours observed. File:Inferior Image.JPGInferior image formed when light travels from cold air to warm air. The image of the sky appears on the hot ground.While refraction allows for beautiful phenomena such as rainbows it may also produce peculiar optical illusions. A common illusion is a mirage, which occurs when light rays refract as they pass from cold air to warm air. Although 1.0003 is a commonly accepted value for the refractive index of air, the index varies depending on the density of air. Warm air is less dense than cold air and therefore has a lower refractive index. As light passes from colder air to warmer air it bends away from the normal. The diagram on the right shows a light ray coming from the sky toward the hot ground. The air near the ground is warmer and so the light ray bends in a concave up trajectory. Once the ray reaches the viewer’s eye, the eye traces it as the line of sight, which is the line tangent to the path the ray takes at the point it reaches the eye. The result is an inferior image for the above sky appears on the ground. The viewer may incorrectly interpret this sight as water reflecting the sky. File:Refraction.jpgRefraction in a Perspex (acrylic) block.A similar illusion occurs when light travels from warm air to cold air. Light rays traveling in such a path are refracted to produce a superior image in which an object appears above its actual position. An example of this involves cold air above an iceberg. Light rays traveling from warm air toward this cold surface, follow a concave down trajectory. The line of sight traced by the viewer would point up producing such illusions as flying boats. Snell's law is used to calculate the degree to which light is refracted when traveling from one medium to another. Recently some metamaterials have been created which have a negative refractive index. With metamaterials, we can also obtain the total refraction phenomena when the wave impedances of the two media are matched. There is no reflected wave. In medicine, particularly ophthalmology and optometry, refraction (also known as refractometry) is a clinical test for the determination of an eye's refractive error and the best corrective lenses to be prescribed. A series of test lenses in graded optical powers or focal lengths are presented to determine which provide the sharpest, clearest vision. [1] See also: phoropter Also, since refraction makes objects appear closer than they are, it is responsible for allowing water to magnify objects. First, as light is entering a drop of water, it slows down. If the water's surface is not flat, then the light will be bent into a new path. This round shape will bend the light outwards and as it spreads out, the image you see gets larger.
- Refraction is the phenomenon in which the direction of light changes when it passes through a medium. Refraction is usually caused in objects that are transparent, including air. A practical example of refraction is looking at the floor of a swimming pool through water; the bottom of the pool looks closer than it would in air.
- Refraction is the change of direction by a wave due to a change in medium, and thus a change in speed. The most common example of this is with light, although it can happen with any type of wave. This happens when it travels from one medium to another medium, with different refractive indexes.
- Refraction was the change of a lightwave into a direction opposite the intended direction. Terraformer Kurt Mandl mentioned that refraction and a thin atmosphere on Velara III was interesting but no indication of life. (TNG: "Home Soil" ) Among the artifacts Vash brought back from the Gamma Quadrant in 2369 was an object that appeared to be some kind of Promethean quartz, however, its molecular density and refraction index was much higher. (DS9: "Q-Less")
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