it travels at c (speed of light in a vacuum)
Light is not refracted when while it passes through a vacuum, or through any uniform material.
It slows from c to c/n where n is the refractive index of water
I have the impression that light is not affected by magnetic fields - at least in a vacuum. If traveling through other substances, the magnetic field can change the light's polarization.
It happens by the refraction of light.
sh@@ happens
The light refracts or bend .
It is redirected as it passes through a medium.
it refracts
It is redirected as it passes through a medium
The velocity of light is greatest when travelling through a vacuum. When travelling through something else, a glass material say, then its velocity is slower. The refractive index is the ratio of the speed of light in a vacuum to the speed of light in that substance. For example light travels in a vacuum about 1.3 times as fast as in water, so we say water has a refractive index of 1.3. And it is likely that the velocity in the glass will be different at different wavelengths of light.
It shows color.
it makes a rainbow!