Refraction of Light

Refraction

The bending of waves as they obliquely (some angle other than along the normal) enter a new medium.
The bending is caused by one side of the wave changing speed before the other side.   Going from a fast medium into a slower medium will cause the ray of light to bend toward the normal, while going from a slow medium into a faster one will cause the ray to bend away from the normal.

A useful analogy in explaining the refraction of light would be to imagine a marching band as they march from pavement (a fast medium) into mud (a slower medium)  The marchers on the side that runs into the mud first will slow down first.  This causes the whole band to pivot slightly toward the normal (make a smaller angle from the normal) .

Continue to another refraction lesson.

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