what causes refraction?i know it's different optical densities,but how does that cause refraction?why bend?
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Refraction occurs when light enters two substances of diferent densities. It bends because the mass of the two substances are different ie, the spacing of particles are different.
746486
I don't know if I exactly understand your question. Indices of refraction are dependent on both the medium and the frequency, so refraction in a car would depend on the frequency of the light, as well as where the light is incident.
166601
Light is not bent. I abruptly changes direction as it passes from one substance with one velocity of light into a second substance with a different velocity of light. The amount of change in direction depends on the wavelength of the light.
273848
There are many types of glass. Different mixures creates different optical densities. These different optical densities will make the refractive index of glass vary. However, in GCSE 'O' Level, the refractive index of glass is usually 1.5. (hope this helps you)
560800
Light is refracted from a single point. Since the light which gets refracted into the same colors is all the same distance from the point source, a circle is formed.\n\n-Wied
55652
light density or intensity? if you're talking about intensity then it depends on distance. that's an inverse square relationship.
1075466
This phenomenon is call total internal reflection.\nThe theory explaining the phenomenon is detailed in most good physics optics textbooks.
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HOW A RAINBOW FORMS:\nWhen light travels from one medium to another, it bends. In other words, it changes direction and moves at different speeds in different mediums. This property of light is called “refraction”. \nWe also know that white light is made up of different colours. Different colors of light have different frequencies. Except in vacuum and air, they travel at different speeds in different mediums.\nIf you were to allow a beam of light to pass through a simple prism, it will bend when it enters the prism, when it leaves the prism it bends again. The different colours of the white light travel with different speeds inside the prism. The slanted surfaces of the prism makes the different colours emerge separately, thus in addition to bending light as a whole, a prism separates white light into its component colors. This splitting of light into its component colours is called dispersion, where prism is a dispersing element.\nThis is exactly what happens when the sun rays hit droplets of water. When the sunlight strikes a raindrop, the light is refracted (bent) because the light is moving from one medium(air) to another( water). Drops of rainwater can disperse light in the same way as a prism.. When the light comes out of the water droplet, the sun's rays (white light)have now been split into their component wavelengths (colors). In this way, each individual raindrop behaves just like a prism, dispersing white sunlight into its seven component colors and a rainbow is formed. \nThe rainbow we see is thus a result of many, many raindrops bending the sun's rays.\n\nWHY U SEE 5 COLORS:\nDont worry much! there are many colors in rainbow but we see only those who are flowing in a great band. i mean which have more thickness! some colors dont have much thickness there, so it becomes tough to see them. we generally see 5 colors where it is said that rainbow have 7 colors. sometimes we see only 3! it depends on rainbow too, and changes from rainbow to another! depends on the sun and the intensity of rain too.\n\nBut to take precautions u can go and see a doctor!
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Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of altitude.\n\nAtmospheric refraction near the ground produces mirages and can make distant objects appear to shimmer or ripple.
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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 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.
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For refractors, the most common problem is chromatic aberration. In this, you get little rainbows around bright objects and a blurrier image around others. This happens because the lenses act like prisms. All refractors are subject to this, but some *very* expensive ones have it less. They fix this by using more than one type of glass.\n\nFor reflectors, the main problem is spherical aberration. This is caused by the mirror not being a perfect paraboloid. It is much easier to grind a sphere than a paraboloid, and most mirrors are first ground to a spherical shape. If the subsequent grinding isn't done right, the resulting images will be blurrier than need be. For decent images, the mirror's shape has to be within 1/4 of a wavelength of light, and for a good image it should be correct to within 1/10 of a wavelength. Considering how small the wavelength of visible light is, you can see how hard that is.
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As mechanical engineer this is out of my normal field but felt you deserved an answer of some sort.\n\n"Because of diffraction effects caused by slits or apertures in optical measurement systems, the radiation energy which is directed towards a particular region on a sample will be spread over a larger area than desirable. By employing an apodizing filter in the radiation path in such system, diffraction tails of the system will be reduced. The apodizing filter preferably has a pattern of alternating high transmittance areas and substantially opaque areas where the locally averaged transmittance function is an apodizing function. In the preferred embodiment, the locally averaged transmittance function varies smoothly and monotonically from the periphery to the center of the filter"\n\nI see the theory here, also found on on using an apodizing mirror to stabalise images in a telescope\n\n"I built and used an apodizing screen for my 6" f/8 scope many years \nago. I made it by layering several layers of window screen, each one \nwith a circular cutout of different diameter. The result was an aperture \nmask with a step-wise approximation to a smooth apodizing function. It \nwas claimed to improve contrast for planetary viewing. Anyway, my \nexperience was that it seemed to make the image more stable but if it \nimproved contrast, I couldn't see it. If you do this on-axis, the \ndownside is that your diagonal mirror will now become more of a factor \nin the contrast equation. The bottom line is I wouldn't recommend it."\n\nAlso "An excellent reference for all sorts of technical techniques is\n>"Procedures in Experimental Physics" (also printed under the title\n>"Physical Laboratory Practice") by John Strong.  I don't recall the\n>publisher, but it came out in the 30's.  The bad news it that it's been\n>out of print for decades (and some SOB stole the copy I got from my\n>father!); the good news is that an outfit called Lindsay is reprinting it\n>in paperback.  (Don't have their name/address here in the office; I'll try\n>to remember to look it up tonight.)\n>\n>                            Dr. Kurt Hillig\n\nEvery ATM should have a copy of this great book. Lots of stuff on\nmirror making, figuring, special laps,making flats, prism ,etc.\nThere is nice modifed Draper machine ( upper disk also powered)\nand a homemade diamond cutting wheel to cut small glass blocks.\n( I would like to build this one someday ) A great section on\nkinematical mechanical construction. Yeah this a mid 30,s book but the \ninfo\nstill can be used. No I don't work for Lindsay Publications,<G>\n\nBob Pfaff\n\n\n This book, in paperback form, can be ordered from\n      http://www.amazon.com, on the Web. It can also be ordered\n      through your local bookstore. Amazon prices it at $23.95, and\n      provides the following information:\n\n      Published by Lindsey Publications\n      Publication date: June 1986\n      ISBN: 0917914562"\n\nSorry couldn't find any really decent expplanations, but at least you've got a starting point.
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Different wavelength (colour) of Light when passed through prism refract (bend) by diferent angles...\nWhen red light is passed .. as it is composed by only on single wavelength, it, as a whole, bends by the same angle..\nSo, there will be a deviation, but no spliiting....\n\nWhite light has many colours super imposed ( made of many wavelength) and hence each component bends by diferent angles ... causing \nwhat is called, Dispersion.of white light
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when a light ray passes from a denser medium to a rarer medium, the refracted ray bends away from the normal and the angle of refraction is greater than the angle of incidence.\nso, when the angle of incidence is continuously increasing the angle of refraction also increases in such a way that agile of refraction is always greater than angle of incidence, till for a particular value of Angle of incidence , the corresponding angle of refraction becomes 90 and the refracted ray grazes along the surface.\nthe angle of incidence in denser medium for which corresponding angle of refraction is 90 in the rarer medium is called the critical angle denoted by C.
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There are two basic kinds, refracting telescopes and refleting telescopes. Refracting telescopes depend on light bending through transparent materials (glass). Have you ever put a pencil in a glass of water? Try it. See how it seems to bend? That's because the light travels at a different (slower) speed through the water, which makes it bend. \n\nA telescope lens is circular, so that all the light rays refract in the same direction, focusing to a point, and the image appears larger (closer.)\n\nThe reflecting telescope works differently. It has a curved mirror to reflect all the light rays to a point. So more light is gathered, across the area of the mirror. You see an image that is larger (closer.)
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It IS the amount of atmosphere, but primarily because of the refraction it causes.\n\nThink of it as looking through a rainbow from the side.  As light travels through dense layers of air, it bends, and the different colors in white light emerge.
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Most commonly observed optical effects (refraction, diffraction, reflection) are linear: if you double the amount of light at the source, the results observed also double. Similarly for decreases in the amount of light. There is a linear relationship between source intensity and observed intensity as the light passes through the optics (lens, mirrors, etc.).\n\nNon-linear optics don't behave that way at all. As the light intensity increases, the medium through which the light propagates (the optics) is stressed by the electrical or magnetic field (or both) of the light wave. This stress changes some physical property of the medium, such as its polarization or its refractive index, as a function of the light intensity. The result is a non-linear response of the material to the electromagnetic field of the light.\n\nThis can have some interesting consequences, such as the generation of harmonics of the original wavelength. It is this non-linear mechanism that allows a strong infrared, or near infrared, laser to be be frequency doubled or frequency tripled to produce coherent light at visible or ultraviolet wavelengths.