Comment by kazinator

Refraction goes beyond electrical fields. An intuitive feeling for refraction can be obtained from:

- water: when waves go from, say, deeper to shallower water, their speed changes. If they are moving at an angle, refraction is seen. This can be explained by drawing wavefronts. The wavefront doesn't hit the shallower water all at the same time, and so does not slow down all at once, but gradually.

- wheels: when rolling axle with two wheels goes from pavement to grass on an angle, its direction will bend direction, due to the change in speed, which is experienced by one wheel ahead of the other.