Why is it that light speeds up again once it has passed through a medium?
919057
It doesn't always speed up. Depends on the material. The less dense the quicker it will be able to go. More dense the slower it will go. The only way it could actually speed up is if it is passing through air directing into a vacuum (near zero particles). http://en.wikipedia.org/wiki/Light#Refraction
263084
The speed of light in a vacuum is constant.\n\nThe speed of light varies in other media.  It varies from medium to medium, such as glass versus copper.  It also varies within a medium depending mainly upon the density of the medium.  For example, the speed of light through air varies with the density of the air.
368951
Same phenomenon happens when you look through a convex lens or at your reflection in a spoon. Something to do with the movement of light. It bends and shows stuff the other way around. Sorry, it's not my expertise. But that's basically how it happens.
41037
actually, none of these answers are correct.\n\nA, B, and C are right out, since i can turn up the power of my radio transmitter which increases the amplitude, and tune my radio transmitter to a different frequency, which is essentially the same thing as varying the wavelength.\n\nD might be what you'd consider the right answer, but it's only true in one special case:  vacuum.  all electromagnetic waves have the same velocity in a vacuum: c, which is around 3x10^8 m/s.\n\nhowever, your question says "in any one material", and vacuum is quite literally the absence of any material.\n\nin a material, things are a little different.  any material has a property associated with it called "dispersion" and basically it means that electromagnetic waves travel at different speeds, depending on their frequency.  dispersion is actually a property of ANY kind of wave in a medium, though it is most familiar in light waves.\n\nfundamentally dispersion is what is responsible for what we call "refraction".  white light splits into a rainbow at the glass-air interface of a prism because the different frequency components move at different speeds in the glass.\n\nso tell your teacher the multiple choice quiz is wrong and explain dispersion and i'll bet ya get some bonus points!\n\nsee the links below for more details about dispersion:\nhttp://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/dispersion.html\nhttp://en.wikipedia.org/wiki/Dispersion_(optics)
681287
OK-Simple and understandable.\nLight is actually small quanta of energy called photons.\nWhen these photons are propagated or travel through a medium, they are only allowed to travel as fast as the medium will allow.\nHydrogen will only let light travel at a certain speed, and that speed is always the same for light travelling through hydrogen.\nLight actually has a different constant for each medium that it is propagated through.\nSo regardless of how fast the light source is travelling, the photons will only propagate at a set speed.\n\nThe closest example would be sound waves. They can only travel at a certain speed as well within a given medium. Once the source of the sound catches up to and passes the sound, it creates a sonic boom.\nSo again, regardless of the speed of the jet, the sound it creates can only go so fast.\n\nThe constancy of the speed of light actually applies to the speed within the medium through which it is being transferred.\n\n\nHope this helps
1166593
The speed of light does depend on the medium in which it travels. See refraction \nRefractive Index = Speed of light in Vacuum / Speed of light in Medium\n\nRefractive index = c / v    where v<c  where c= 299,792.458 kilometer per second or 186,282.397 miles per second. http://en.wikipedia.org/wiki/Speed_of_light\n\nSee http://www.onlinephysicshelp.com/refraction.htm \n\nCURIOUS  is that the speed of light depends only on the medium it travels through. So when it travels in vacuum it is c, when in glass it is v and when it returns to vacuum it is again c.\n\nWhile The Michelson-Morley Experiment), by measuring the speed of a beam of light in the detection and against direction of the Earth's rotation, has demonstrated in 1887 no change in speed of light. That suggested that light wave propagates without a medium. \nhttp://en.wikipedia.org/wiki/Michelson-Morley_experiment  \n\nHowever \nmedium does have effect on its propagation: " The speed of light through a transparent medium (that is, not in vacuum) is less than c; the ratio of c to this speed is called the refractive index of the medium." http://en.wikipedia.org/wiki/Speed_of_light \n\nI hope that helps.
799784
In theory, yes.  Because the light particles that were traveling slower than you would have been slower.  Very good question.  However, speeding past the speed of light would mean the fundamentals of E = Mc^2, would cease to make sense.
11463
The changes propagate at the speed of light, so I guess the time taken is,\n\nt = r/c where c = speed of light
25683
It bounces around and out of the room. Since this happens at the speed of light, you don't notice a gradual fading of light so much as a sharp transition to darkness.
960079
You've lost the point of the equation.  Squaring the speed of light will give you the energy released, not an enhanced speed of light.
1120142
The question is too philisophical. We don't know WHY light travels so quickly, we just observe that it does. We can derive such a speed and we can derive the fact that it always travels at this speed no matter what your reference speed is. We have failed to find a situation where the speed of a single photon has not been the accepted speed of light.\n\nAlso, contrary to a previous post, light travels at a constant speed, independant of its frequency. This opposed to mechanical waves such as sound and water waves..
354651
Well the white light is a mixture of a large number of wavelengths of lights. These different wavelengths of lights travell at different speed in the medium such as glass. In air and vacuum the have alsmost the same speed. But in prism the travell with t&#92;different speeds. So when the pass prism the length of path travelled in the same times is different and hence when the emerge out, the different colrs are at differemt positions resulting in a seperation of colours.\n    This is called the dispersion of light.
955526
Light moves slower through denser media because more particles get in its way. Each time the light bumps into a particle of the medium, the light gets absorbed which causes the particle to vibrate a little and then the light gets re-emitted. This process causes a time delay in the light's movement so the more particles there are (the more dense the medium), then the more the light will be slowed down.\n\nAs the light 'slows' down, it will then bends towards the normal.\n\nthink of a car with 4 wheels getting into a sand area from the road. as the one of the two front wheels hit the sand, it encounters resistance n hence slows down. however, the other three wheels are still moving at the normal speed. this results in the whole car moving forward but turned in the direction of the first wheel that was slowed down by the sand.
224445
The maximum velocity of light is in air (strictly in vacuum).\n\nThe velocity is less in other medium.\n\nThe change in velocity from medium to medium is refraction.\n\nWhen light enters from medium 1 to medium 2, a potion of light is bounced back into the medium 1 and the remaining passes into medium 2 (Refracted). The bouncing back is reflection.\n\nThe proportion of reflection or refraction depends on the angle the \nray makes at the point of incidence on the boundary.\n\nWhen light enters from glass (a medium of less velocity; optically denser medium) into air (a medium of more velocity; optically rarer medium) no portion of light is refracted (do not enter into air) at certain angles of incidences. The whole portion of light is bounced back into glass\n\nThey are TOTALLY AND INTERNALLY reflected.\n\nThere is no change in velocity and therefore total ilnternal reflection is not refraction,
687262
Light doesn't accelerate to that speed, it just propogates at that speed period.  Besides, F = ma says you need a mass to have an acceleration, and light, or photons, have zero mass.
361230
In this imaginary situation, you will still see your headlights working the same way as they normally do. Without going into tricky mathematics, just recall the fundamental postulate of special relativity: \nThe speed of light is CONSTANT in all inertial frames of references (considering the same medium). \nSo, the speed of light will still be the same in the frame of reference attached to your vehical, which is an inertial frame, because it is moving with the (uniform) speed of light!
515706
The atmosphere is made up of several layers,each one with a varying density.Thus,the speed of light differs in different layers of the atmosphere and the light gets refracted(deviated from its path when it travels from one medium to another)when passing from one layer of atmosphere to another.Due to this refraction of light in the different layers of the atrmosphere,stars appear to twinkle