The wheel that strikes the grass first slows first, causing the direction to change. Part of the wave strikes the surface first and therefore slows first, causing the direction to change.

Sand Pavement Air Glass 3 x 10 8 m/s 2 x 10 8 m/s v s < v p

Water Air Water Air

Water Air refraction N ww AA The incident and refracted rays lie in the same plane and are reversible.

Index of refraction c v

MediumIndex Vacuum 1.00 Air Water Crown Glass 1.52 Diamond 2.419

v air = c v G = 2 x 10 8 m/s Glass Air For glass: n = 1.50

11 22 n2n2 n1n1 n 1 = n 2 11 22 n2n2 n1n1 n 2 > n 1 11 22 n2n2 n1n1 n 1 > n 2 same speed as the next, it doesn’t bend fast into slow, it will bends in toward normal. slow into fast, it will bends away from normal. click

Examples Object appear higher in water since water has a greater index of refraction than air.

Snell’s Law n1n1 n2n2 11 22

Some Terminology Angles are measured with respect to the line which is perpendicular to the interface, called the normal. The angle the incident (incoming) ray makes with the normal is called the angle of incidence (  1 ). The angle the refracted ray makes with the normal is called the angle of refraction (  2 ).

Fiber Optics- pure glass fibers used for the fastest data transmission through pulses of light that are internally reflected

Dispersion: The process of separating polychromatic light into it’s component wavelengths.

Atmospheric Refraction-the refraction of the sun’s rays through layers of the Earth’s atmosphere, permitting light to be seen even after the sun has set.

Mirages- produced by the bending of light rays in the atmosphere when there are large temperature differences between the ground and the air.

Rainbows

An observer sees red light coming from droplets of water higher in the sky, while droplets of water lower in the sky send violet light to the eye.