does the speed of light depend upon the medium in which it is travelling?

Answer 1

The speed of light does depend on the medium in which it travels. See refraction
Refractive Index = Speed of light in Vacuum / Speed of light in Medium

Refractive index = c / v where v
See http://www.onlinephysicshelp.com/refraction.htm

CURIOUS 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.

While 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.
http://en.wikipedia.org/wiki/Michelson-Morley_experiment

However
medium 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

I hope that helps.

Answer 2

The speed of the wavefront of light is 0 when it is absorbed into an atom and increases depending upon the conditions of the forces acting upon it. Emission of a photon in a vacuum will theoretically instantly achieve the maximum speed. But there is no way to measure to see if there is an acceleration to light speed.The theory is that nothing can exceed the speed of light. However, if light is considered a wave then the points ascribed upon the undulating positive and negative tracing of the wave move faster than the wave front itself. Like most "laws" of physics, there are exceptions allowed for the exceptional. Question--- what happens when light is red shifted to such a point that the wave length is flat --- does the altered light move at the speed of light?

Answer 3

The speed depends upon the medium in which it travels.

The refractive index of the medium is defined as the speed of light in vacuum to the speed of light in the medium.

For a given medium the refractive index is different for different frequency of the wave.

Answer 4

Yes, light's speed depends on the medium it travels through. However, the decrease in speed is really quite small. In vaccuum, it travels the fastest, whereas if it were to travel through diamond, it's speed is cut down to about half due to the tight crystal arrangement of diamond. Different media have different effects on the speed of light, however miniscule they may be.

Answer 5

Yes, light travels slower in glass than air. However the wierd thing is: when the light leaves the glass medium it goes back to traveling at the speed it travels in air. It isn't permenantly slowed down by the glass.

Answer 6

The speed at which light propagates through a medium does. indeed, depend upon the medium.

The speed of light in a vacuum is exactly 299,792,458 m/s.
When light enters any other medium, it slows down.
The ration of the speed of light in a vacuum to the speed in a particular medium is called the index of refraction (n).

n = c / v
The index of refraction of a vacuum is exactly 1. Other, more optically dense, substances will have indicies of refraction greater than one...for example, water is said to have a refraction index of about 1.33, whereas a diamond has a very high refractive index of 2.417...meaning light travels 2.417 times faster in a vacuum than it does through a diamond.

Answer 7

Well, your question is a little ambiguous. If you are referring to 'c'- the universal constant equal to the speed of light, then no, there is no adjustment for medium.

If you are talking about propagation of electromagnetic radiation in different mediums, then absolutely. For example, the speed of light in a vacuum does travel faster than electricity through a wire (which may range from .66 to .9 'c').

Answer 8

Sure, it does. The 186,000 miles per second often quoted, which is 2.99 X 10 raised to power 10 cm. per second is the speed in vacuum. In air or in water or in glass it will be less. The ratio of the two speeds is the refractive index of the medium.

Answer 9

In transparent bodies light's speed has different values according their refraction index. The refraction index (n) is the ratio between the speed of light in vacuum (c = 3*10^8 m/s) and speed of light in the media (v).
n = c/v
For water n = 1.33, so the speed of light in water is:
v = c/n = (3*10^8 m/s)/(1.33) = 2.26*10^8 m/s

Because the change of speed of light when travels through transparent media happens phenomenons like refraction, Cerenkov's radiation, etc.

Answer 10

of course it does depend on the medium in which it is traveling, someone actrually made a muck that slow down light enough to see it pass through the much.i double that light is moving at the universal 299000000.